BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Tomas Roubicek (Math. Inst. Charles University) DTSTART:20201012T134000Z DTEND:20201012T151000Z DTSTAMP:20260405T094550Z UID:NSCM/1 DESCRIPTION:Title: The old Stefan problem in a new mechanical context\nby Tomas Roubicek (Ma th. Inst. Charles University) as part of Nečas Seminar on Continuum Mecha nics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Martin Doskar (Czech Technical University) DTSTART:20201019T134000Z DTEND:20201019T151000Z DTSTAMP:20260405T094550Z UID:NSCM/2 DESCRIPTION:Title: Mic romorphic model for mechanical metamaterials\nby Martin Doskar (Czech Technical University) as part of Nečas Seminar on Continuum Mechanics\n\n \nAbstract\nMetamaterials\, with their internal composition carefully desi gned to feature exotic and often counterintuitive properties such as cloak ing or band gaps\, are the prime example of a pronounced influence of mate rial’s microstructure on its macroscopic response. Regarding mechanical responses\, metamaterials have already delivered high stiffness-to-weight ratio\, negative compressibility\, and tunable auxetic behaviour. These me chanical metamaterials often rely on internal instability mechanisms that trigger transformation of their periodic microstructure into predefined pa tterns\, which introduces strong kinematic coupling among adjacent periodi c metamaterial cells and leads to significant size and boundary effects. A s a result\, the standard first-order computational homogenization fails t o provide an effective model of such metamaterials.\n\nThis talk presents a micromorphic computational homogenization scheme that has been recently developed specifically for the instability-driven mechanical metamaterials . The scheme introduces characteristic deformation patterns at microscale\ , whose magnitudes are communicated across adjacent macroscopic material p oints by scalar modulation fields\, which are added to the standard contin uum formulation at the macroscale and for which an additional micromorphic -like conservation law emerges at macroscale. Consequently\, the presented scheme captures the above-mentioned size effect and boundary layers and a ccounts for with spatial mixing of multiple patterns. Combined with the bi furcation analysis\, the scheme also correctly predicts local to global (i .e. micro vs. macro) buckling transitions.\n LOCATION:https://researchseminars.org/talk/NSCM/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Edoardo Mainini (University of Genoa) DTSTART:20201026T144000Z DTEND:20201026T161000Z DTSTAMP:20260405T094550Z UID:NSCM/3 DESCRIPTION:Title: Lin earization of finite elasticity\nby Edoardo Mainini (University of Gen oa) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nWe sho w some new results about the linearization of finite elasticity by means o f Gamma-convergence\, including the incompressible case and pure traction problems.\n LOCATION:https://researchseminars.org/talk/NSCM/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Marco Bresciani (TU Vienna) DTSTART:20201102T144000Z DTEND:20201102T161000Z DTSTAMP:20260405T094550Z UID:NSCM/4 DESCRIPTION:Title: Lin earized von Kármán theory for incompressible magnetoelastic plates\n by Marco Bresciani (TU Vienna) as part of Nečas Seminar on Continuum Mech anics\n\n\nAbstract\nWe study the asymptotic behavior\, in the sense of Ga mma-convergence\, of a thin incompressible magnetoelastic plate\, as its t hickness goes to zero. We focus on the linearized von Kármán regime. The model features a mixed Eulerian-Lagrangian formulation\, as magnetization s are defined on the deformed configuration.\n LOCATION:https://researchseminars.org/talk/NSCM/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Daya Reddy (University of Cape Town) DTSTART:20201221T144000Z DTEND:20201221T161000Z DTSTAMP:20260405T094550Z UID:NSCM/5 DESCRIPTION:Title: Som e mathematical aspects of models of strain-gradient plasticity\nby Day a Reddy (University of Cape Town) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nStrain-gradient plasticity has become well establ ished as an approach to modelling seize-dependent phenomena at the meso- a nd microscales. This presentation is concerned with a class of models of s train-gradient plasticity\, which mathematically are formulated as variati onal inequalities. Conditions for well-posedness are reviewed\, following which attention is given to some aspects of what is referred to as the dis sipative model. Though in a sense a natural extension of conventional plas ticity\, this model possesses some distinctive features\, most particularl y that the plastic flow relations take a global form. The consequences of this feature are discussed\, for example\, in relation to determining the stage at which incipient plastic behaviour takes place. The presentation a lso treats issues relevant to approximations\, such as the convergence of predictor-corrector algorithms\, and approximations under conditions of mi nimal regularity.\n LOCATION:https://researchseminars.org/talk/NSCM/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Marco Bravin (BCAM Bilbao) DTSTART:20201109T144000Z DTEND:20201109T161000Z DTSTAMP:20260405T094550Z UID:NSCM/6 DESCRIPTION:Title: On some properties for an incompressible\, non-viscous in-out flow in a 2D do main\nby Marco Bravin (BCAM Bilbao) as part of Nečas Seminar on Conti nuum Mechanics\n\n\nAbstract\nIn this talk I will present some recent resu lts on some properties of an in-out flow\nassociated with a perfect two di mensional fluid. In particular I present existence of\nsolutions in differ ent classes of regularity and I will conclude with the study of the\nasymp totic limit of some shrinking sources and sinks. This work is motivated by a\nquestion left open by Judovic in [2].\nThe system consists of an Euler type system in a bounded domain with some holes\nwhere non-homogeneous bo undary conditions are prescribed. I will present how to extend some classi cal existence results in this setting and then I will consider the case\nw hen the holes shrink to points. The boundary conditions lead to the creati on of some\npoint sources and sinks associated with some vortex points in the limit. Similar type of\nsystems have been already study by Chemetov an d Starovoitov in [1]\, where a different\napproximation approach was consi dered.\n\nReferences\n\n[1] Chemetov\, N. V.\, Starovoitov\, V. N. (2002). On a Motion of a Perfect Fluid in a Domain with Sources and Sinks. Journa l of Mathematical Fluid Mechanics\, 4(2)\, 128–144.\n\n[2] Judovic\, V. I. (1964). A two-dimensional non-stationary problem on the flow of an\nide al incompressible fluid through a given region. (Russian) Mat. Sb. (N.S.) 64 (106)\n562–588\n LOCATION:https://researchseminars.org/talk/NSCM/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Jacopo Ciambella (Sapienza Università di Roma) DTSTART:20201116T144000Z DTEND:20201116T161000Z DTSTAMP:20260405T094550Z UID:NSCM/7 DESCRIPTION:Title: Fib re re-orientation in anisotropic viscoelastic materials\nby Jacopo Cia mbella (Sapienza Università di Roma) as part of Nečas Seminar on Continu um Mechanics\n\n\nAbstract\nIn this talk\, we will derive a nonlinear visc oelastic model for fibre-reinforced materials based on the kinematic assum ption that the deformation gradient can be multiplicatively decomposed int o viscous and elastic components\, i.e.\, F=Fe Fv. The model is thermodyna mically consistent and the evolution equation of the viscous deformation w ill be derived by combining suitable constitutive prescriptions with balan ce equations. We will show that\, when external sources are absent\, an Es helbian-like torque drives the passive reorientation of the fibres. During the talk\, some issues underlying the definition of anisotropic and inela stic models will be discussed\, including the evolution of the symmetry gr oup of the material response due to the inelastic relaxation. Finally\, so me prototype boundary value problems will be presented with the intent of highlighting the best experimental procedure to evaluate the constitutive coefficients of such a model.\n LOCATION:https://researchseminars.org/talk/NSCM/7/ END:VEVENT BEGIN:VEVENT SUMMARY:‪Giuseppe Tomassetti‬ (Università Roma Tre) DTSTART:20201130T144000Z DTEND:20201130T161000Z DTSTAMP:20260405T094550Z UID:NSCM/8 DESCRIPTION:Title: Sha pe programming of a magnetic elastica\nby ‪Giuseppe Tomassetti‬ (U niversità Roma Tre) as part of Nečas Seminar on Continuum Mechanics\n\n \nAbstract\nWe consider a cantilever beam which possesses a possibly non-u niform permanent magnetization\, and whose shape is controlled by an appli ed magnetic field. We model the beam as a plane elastic curve and we suppo se that the magnetic field acts upon the beam by means of a distributed co uple that pulls the magnetization towards its direction. Given a list of t arget shapes\, we look for a design of the magnetization profile and for a list of controls such that the shapes assumed by the beam when acted upon by the controls are as close as possible to the targets\, in an averaged sense. To this effect\, we formulate and solve an optimal design and contr ol problem leading to the minimization of a functional which we study by b oth direct and indirect methods. In particular\, we prove that minimizers exist\, solve the associated Lagrange-multiplier formulation (besides non- generic cases)\, and are unique at least for sufficiently low intensities of the controlling magnetic fields. To achieve the latter result\, we use two nested fixed-point arguments relying on the Lagrange-multiplier formul ation of the problem\, a method which also suggests a numerical scheme. Va rious relevant open question are also discussed.\n LOCATION:https://researchseminars.org/talk/NSCM/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Charlotte Perrin (CNRS Marseille) DTSTART:20201123T144000Z DTEND:20201123T161000Z DTSTAMP:20260405T094550Z UID:NSCM/9 DESCRIPTION:Title: Com pressible Euler equations under a maximal density constraint\nby Charl otte Perrin (CNRS Marseille) as part of Nečas Seminar on Continuum Mechan ics\n\n\nAbstract\nIn this talk\, I will present recent results on solutio ns to a one-dimensional Euler system coupling compressible and incompressi ble phases. With this original fluid system we intend to model congestion (or saturation) phenomena in heterogeneous flows (mixtures\, wave-structur e interactions\, collective motion\, etc.). Here the compressible-incompre ssible model will be seen as the limit of a fully compressible Euler syste m endowed with a singular pressure law. The goal of the talk is to present theoretical results concerning this singular limit. This is a joint work with Roberta Bianchini.\n LOCATION:https://researchseminars.org/talk/NSCM/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Tai-Peng Tsai (University of British Columbia) DTSTART:20201214T153000Z DTEND:20201214T170000Z DTSTAMP:20260405T094550Z UID:NSCM/10 DESCRIPTION:Title: Th e Green tensor of the nonstationary Stokes system in the half space\nb y Tai-Peng Tsai (University of British Columbia) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nWe prove the first-ever pointwise e stimates of the (unrestricted) Green tensor and\nthe associated pressure t ensor of the nonstationary Stokes system in the half-space\, for\nevery sp ace dimension greater than one. The force field is not necessarily assumed to\nbe solenoidal. The key is to find a suitable Green tensor formula tha t maximizes the\ntangential decay\, showing in particular the integrabilit y of Green tensor derivatives.\nWith its pointwise estimates\, we show the symmetry of the Green tensor\, which in\nturn improves pointwise estimate s. We also study how the solutions converge to the\ninitial data\, and the (infinitely many) restricted Green tensors acting on solenoidal\nvector f ields. As applications\, we give new proofs of the existence of mild solut ions of the\nNavier-Stokes equations in Lq\, pointwise decay\, and uniform ly local Lq spaces in the\nhalf-space.\nThis talk is based on arXiv:2011.0 0134\, a joint work with Kyungkeun Kang\, Baishun\nLai and Chen-Chih Lai.\ n\nThis seminar session will exceptionally start at 16:30.\n LOCATION:https://researchseminars.org/talk/NSCM/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Arnab Roy (Math. Inst. Czech Academy of Sciences) DTSTART:20201207T144000Z DTEND:20201207T161000Z DTSTAMP:20260405T094550Z UID:NSCM/11 DESCRIPTION:Title: Ex istence of strong solutions for a system of interaction between a compress ible viscous fluid and a wave equation\nby Arnab Roy (Math. Inst. Czec h Academy of Sciences) as part of Nečas Seminar on Continuum Mechanics\n\ n\nAbstract\nIn this talk\, we consider a fluid-structure interaction syst em\nwhere the fluid is viscous and compressible and where the structure i s\na part of the boundary of the fluid domain and is deformable. The flui d\nis governed by the barotropic compressible Navier-Stokes system whereas \nthe structure displacement is described by a wave equation. The\nreferen ce configuration for the fluid domain is a rectangular cuboid\nwith the el astic structure being the top face. We use a modified\nLagrangian change o f variables to transform the moving fluid domain into\nthe rectangular cub oid and then analyze the corresponding linear system\ncoupling a transport equation (for the density)\, a heat-type equation\nand a wave equation. T he corresponding results for this linear system\nand estimations of the co efficients coming from the change of variables\nallow us to perform a fixe d point argument and to prove the existence\nand uniqueness of strong solu tions for the nonlinear system\, locally in\ntime.\n LOCATION:https://researchseminars.org/talk/NSCM/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Karoline Disser (Universitaet Kassel) DTSTART:20210104T144000Z DTEND:20210104T161000Z DTSTAMP:20260405T094550Z UID:NSCM/12 DESCRIPTION:Title: Gl obal existence and stability for dissipative processes coupled acro ss volume and surface\nby Karoline Disser (Universitaet Kassel) as pa rt of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nThe modelling o f technological and biological processes and devices is\noften characteriz ed by non-smoothness: material edges and corners\,\nabruptly changing mate rial properties and a large scope of relevant\ntemporal and spatial scales . From a PDE point-of-view\, we need to deal\nwith domains of low boundary regularity\, mixed and dynamic boundary\nconditions\, degeneracy and disc ontinuity of parameters\, and\, possibly\nafter rescaling\, with the coupl ing of dynamics across voulme and\nlower-dimensional interfaces or surface s.\n\nIn this talk\, I want to consider models of non-linear\nreaction-dri ft-diffusion type in non-smooth and/or volume-surface\nsettings and discus s their analysis based on the choice of specific\nfunctional analytic sett ings. The aim is to discuss some aspects of the\ninteraction of thermodyna mically consistent modelling and the analysis\nof the PDE and to establish strategies for simultaneously dealing with\nnon-linearity and non-smoothn ess.\n LOCATION:https://researchseminars.org/talk/NSCM/12/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20210111T144000Z DTEND:20210111T161000Z DTSTAMP:20260405T094550Z UID:NSCM/13 DESCRIPTION:Title: No lecture\nby semester break as part of Nečas Seminar on Continuum Mec hanics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/13/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20210118T144000Z DTEND:20210118T161000Z DTSTAMP:20260405T094550Z UID:NSCM/14 DESCRIPTION:Title: No lecture\nby semester break as part of Nečas Seminar on Continuum Mec hanics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/14/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20210125T144000Z DTEND:20210125T161000Z DTSTAMP:20260405T094550Z UID:NSCM/15 DESCRIPTION:Title: No lecture\nby semester break as part of Nečas Seminar on Continuum Mec hanics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/15/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20210201T144000Z DTEND:20210201T161000Z DTSTAMP:20260405T094550Z UID:NSCM/16 DESCRIPTION:Title: No lecture\nby semester break as part of Nečas Seminar on Continuum Mec hanics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/16/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20210208T144000Z DTEND:20210208T161000Z DTSTAMP:20260405T094550Z UID:NSCM/17 DESCRIPTION:Title: No lecture\nby semester break as part of Nečas Seminar on Continuum Mec hanics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/17/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20210215T144000Z DTEND:20210215T161000Z DTSTAMP:20260405T094550Z UID:NSCM/18 DESCRIPTION:Title: No lecture\nby semester break as part of Nečas Seminar on Continuum Mec hanics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/18/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20210222T144000Z DTEND:20210222T161000Z DTSTAMP:20260405T094550Z UID:NSCM/19 DESCRIPTION:Title: No lecture\nby semester break as part of Nečas Seminar on Continuum Mec hanics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/19/ END:VEVENT BEGIN:VEVENT SUMMARY:Easter Monday DTSTART:20210405T134000Z DTEND:20210405T151000Z DTSTAMP:20260405T094550Z UID:NSCM/20 DESCRIPTION:Title: No lecture\nby Easter Monday as part of Nečas Seminar on Continuum Mech anics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/20/ END:VEVENT BEGIN:VEVENT SUMMARY:Jiří Outrata (ÚTIA\, Czech Acad. Sci.) DTSTART:20210301T144000Z DTEND:20210301T161000Z DTSTAMP:20260405T094550Z UID:NSCM/21 DESCRIPTION:Title: On the solution of static contact problems with Coulomb friction via the sem ismooth* Newton method\nby Jiří Outrata (ÚTIA\, Czech Acad. Sci.) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nThe lectur e deals with application of a new Newton-type method to the numerical solu tion of discrete 3D contact problems\nwith Coulomb friction. This method s uits well to the solution of inclusions and the resulting conceptual algor ithm exhibits\,\nunder appropriate conditions\, the local superlinear conv ergence. After a description of the method a new (primal) model\nfor the c onsidered contact problem\, amenable to the application of the new method\ , will be presented. The second part of\nthe talk is then devoted to an ef ficient implementation of the general algorithm and to numerical tests. Th roughout the whole\nlecture\, various tools of modern variational analysis will be employed.\n LOCATION:https://researchseminars.org/talk/NSCM/21/ END:VEVENT BEGIN:VEVENT SUMMARY:Malte Kampschulte (Charles University) DTSTART:20210322T144000Z DTEND:20210322T161000Z DTSTAMP:20260405T094550Z UID:NSCM/22 DESCRIPTION:Title: Mi nimizing movements and a two-scale method for nonconvex problems involving inertia\nby Malte Kampschulte (Charles University) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nWhen dealing with fully nonl inear\, nonconvex\, quasistatic (i.e. inertialess) problems in continuum m echanics\, de Giorgi's method of minimizing movements has long been a stap le for existence proofs. However by its very nature\, it has always been r estricted to purely dissipative\, gradient flow-type systems. The aim of t his talk is to present a new two-scale method\, developed jointly with B. Benešová and S. Schwarzacher\, which allows to add inertial\, conservati ve effects by using the minimizing movements method as a stepping stone to solve an approximative time-delayed problem in the same nonlinear\, nonco nvex state space. Using a flow-map approach\, this method is not only able to cope with problems in Lagrangian\, but also with those in Eulerian and even mixed formulations. While the method itself is quite general\, we wi ll illustrate its application at several examples involving solids\, fluid s and their interaction.\n LOCATION:https://researchseminars.org/talk/NSCM/22/ END:VEVENT BEGIN:VEVENT SUMMARY:Eitan Tadmor (University of Maryland\, College Park) DTSTART:20210329T134000Z DTEND:20210329T151000Z DTSTAMP:20260405T094550Z UID:NSCM/23 DESCRIPTION:Title: Em ergent behavior in swarming hydrodynamics\nby Eitan Tadmor (University of Maryland\, College Park) as part of Nečas Seminar on Continuum Mechan ics\n\n\nAbstract\nI will discuss recent developments in our study of swar ming \ndynamics.\nA main question of interest is the emergent behavior whi ch we \ncharacterize by\nspectral analysis\, covering different classes of long-range and \nshort-range communication kernels.\nThese include examp les of metric-based and topologically-based kernels\, \nand kernels derive d from a unified paradigm of anticipation.\nIn the canonical case of metri c-based short-range kernels\, we derive \nlower-bounds on the spectral gap \,\nindependent of thermal equilibrium (no closure for the pressure)\, whi ch \nyield an emergent behavior of non-vacuous smooth solutions.\nThe latt er are known to exist in one- and two space dimensions and we \nsettle th e question of existence for arbitrary dimension.\n LOCATION:https://researchseminars.org/talk/NSCM/23/ END:VEVENT BEGIN:VEVENT SUMMARY:Antonio J. Gil (University of Swansea\, UK) DTSTART:20210308T144000Z DTEND:20210308T161000Z DTSTAMP:20260405T094550Z UID:NSCM/24 DESCRIPTION:Title: On the use of mixed formulations for computational polyconvexity and multi -variable convexity\nby Antonio J. Gil (University of Swansea\, UK) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nThe computat ional modelling of large strain multi-physics problems is nowadays an area of intensive research by numerous scientists. Among problems of this kind \, two pressing applications underpin the motivation behind this presentat ion. On the one hand\, the in-silico design of highly flexible dielectric elastomers for soft robotics applications and\, on the other hand\, the re alistic simulation of the electromechanical interactions of the cardiac mu scle from the physiological and pathological standpoints. In both applicat ions\, the requirement for extremely accurate and stable results at\, poss ibly\, large values of the field variables (i.e. strains and electric/card iac potential) proves very challenging from the computational point of vie w.\nThe presentation starts by revisiting the now well-accepted requiremen t of polyconvexity (a sufficient condition for rank-one convexity) in the case of reversible hyperelasticity\, where the strain energy functional is described by a convex combination of the minors of the deformation gradie nt tensor. We then extend this concept to the case of energies which depen d on non-strain based variables\, for instance\, other physical measures s uch as the electric displacement\, leading to the introduction of a new co mputational paradigm\, Multi-Variable Convexity. Crucially\, this new defi nition of the internal energy enables ellipticity to be extended to the en tire range of deformations and electric fields and\, thus\, spurious numer ical instabilities can then effectively be removed from the model whilst m aintaining real physical instabilities.\nThe polyconvexity of the energy f unctional with respect to its set of arguments guarantees the definition o f well-posed counterpart work conjugates\, where a one to one (invertible) relationship can be established. This ensures the existence of alternativ e energy potentials via the use of partial or total Legendre transforms an d opens up the possibility for new extended Hu–Washizu-type variational principles in terms of using various interpolation spaces for the differen t unknown fields\, leading to enhanced type of formulations. A series of e xamples will be presented demonstrating the potential of this new paradigm when coupled with the use of Finite Element type discretisation technique s.\n LOCATION:https://researchseminars.org/talk/NSCM/24/ END:VEVENT BEGIN:VEVENT SUMMARY:Adrian Muntean (Karlstadt University) DTSTART:20210426T134000Z DTEND:20210426T151000Z DTSTAMP:20260405T094550Z UID:NSCM/25 DESCRIPTION:Title: Do es vesicle micro-dynamics enhance the signaling among plants macro-transpo rt? Multiscale discussions around a model problem\nby Adrian Muntean ( Karlstadt University) as part of Nečas Seminar on Continuum Mechanics\n\n \nAbstract\nWe study a transport problem for signaling among plants in the context of measure-valued equations. We report on preliminary results con cerning the modeling and mathematical analysis of a reaction-diffusion sce nario involving the macroscopic diffusion of signaling molecules enhanced by the presence of a finite number of microscopic vesicles - pockets with own dynamics able to capture and release signals as a relay system. The c oupling between the macroscopic and microscopic spatial scales relies on t he use of a two-scale transmission condition and benefits of the posing of the problem in terms of measures. Mild solutions to our problem will turn to exist and will also be positive weak solutions. A couple of open quest ions at the modeling\, mathematical analysis\, and simulation levels will be pointed out. This is a joint work with Sander Hille (Leiden\, NL) and i s supported financially by the KVA’s G. S. Magnussonsfond.\n LOCATION:https://researchseminars.org/talk/NSCM/25/ END:VEVENT BEGIN:VEVENT SUMMARY:Valerio Pagliari (TU Vienna) DTSTART:20210412T134000Z DTEND:20210412T151000Z DTSTAMP:20260405T094550Z UID:NSCM/26 DESCRIPTION:Title: Co nvergence of nonlocal geometric flows to anisotropic mean curvature motion \nby Valerio Pagliari (TU Vienna) as part of Nečas Seminar on Continu um Mechanics\n\n\nAbstract\nWe consider the Cauchy problem for motions by nonlocal curvature\, whose \nwell-posedness may be established in the fram ework of viscosity solutions.\nWe show that a suitable rescaling of the no nlocal curvature induces a \nlocalisation effect\, that is\, as the scalin g parameter tends to 0\,\nwe retrieve an anisotropic mean curvature functi onal. From this fact\, \nthanks to the theory of geometric barriers by De Giorgi\,\nwe prove that the solutions to the rescaled nonlocal motions loc ally \nuniformly converge to the solution of the local flow.\nThe talk is based on joint work with A. Cesaroni (Padova).\n LOCATION:https://researchseminars.org/talk/NSCM/26/ END:VEVENT BEGIN:VEVENT SUMMARY:‪Denis Bonheure (Université Libre de Bruxelles) DTSTART:20210510T134000Z DTEND:20210510T151000Z DTSTAMP:20260405T094550Z UID:NSCM/27 DESCRIPTION:Title: Eq uilibrium configuration of a rectangular obstacle immersed in a channel fl ow\nby ‪Denis Bonheure (Université Libre de Bruxelles) as part of N ečas Seminar on Continuum Mechanics\n\n\nAbstract\nFluid flows around an obstacle generate vortices which\, in turn\, generate lift forces on the o bstacle. Therefore\, even in a perfectly symmetric framework equilibrium p ositions may be asymmetric. We show that this is not the case for a Poiseu ille flow in an unbounded 2D channel\, at least for small Reynolds number and flow rate. We consider both the cases of vertically moving obstacles a nd obstacles rotating around a fixed pin.\nJoint work with P.G. Galdi and F. Gazzola\n LOCATION:https://researchseminars.org/talk/NSCM/27/ END:VEVENT BEGIN:VEVENT SUMMARY:Maria Neuss-Radu (University of Erlangen-Nuremberg) DTSTART:20210524T134000Z DTEND:20210524T151000Z DTSTAMP:20260405T094550Z UID:NSCM/28 DESCRIPTION:Title: Ho mogenization of a reaction-diffusion-advection problem in an evolving mic ro-domain and including nonlinear boundary conditions\nby Maria Neuss- Radu (University of Erlangen-Nuremberg) as part of Nečas Seminar on Conti nuum Mechanics\n\n\nAbstract\nWe consider a reaction-diffusion-advection p roblem in a \nperforated medium\, with nonlinear reactions in the bulk and at the \nmicroscopic boundary\, and slow diffusion scaling. The microstru cture \nchanges in time\; the microstructural evolution is known a priori. The \naim of the paper is the rigorous derivation of a homogenized model. We \nuse appropriately scaled function spaces\, which allow us to show \n compactness results\, especially regarding the time-derivative and we \npr ove strong two-scale compactness results of Kolmogorov-Simon-type\, \nwhic h allow to pass to the limit in the nonlinear terms. The derived \nmacrosc opic model depends on the micro- and the macro-variable\, and the \nevolut ion of the underlying microstructure is approximated by time- and \nspace- dependent reference elements. This is a joint work with Markus \nGahn (Uni versity of Heidelberg) and Iuliu Sorin Pop (Hasselt \nUniversity).\n LOCATION:https://researchseminars.org/talk/NSCM/28/ END:VEVENT BEGIN:VEVENT SUMMARY:Patrick Dondl (University of Freiburg) DTSTART:20210315T144000Z DTEND:20210315T161000Z DTSTAMP:20260405T094550Z UID:NSCM/29 DESCRIPTION:Title: En ergetic bounds for paperboard delamination under bending\nby Patrick D ondl (University of Freiburg) as part of Nečas Seminar on Continuum Mecha nics\n\n\nAbstract\nPaperboard is an engineering material consisting of a number of separate sheets of paper\, that have been bonded together. Exper imental evidence shows that paperboard undergoing bending develops phenome nologically plastic hinges. We consider a nonlinearly elastic mathematical model for paperboard\, allowing debonding of the sheets at a given cost p er unit area. Analysis of our model predicts a number of different regimes \, including somewhere bending is concentrated in delaminated hinges\, whe re the mid-plane of each individual layer may deform isometrically. This i s joint work with Sergio Conti (Bonn) and Julia Orlik (Kaiserslautern).\n LOCATION:https://researchseminars.org/talk/NSCM/29/ END:VEVENT BEGIN:VEVENT SUMMARY:Summer break DTSTART:20210607T134000Z DTEND:20210607T151000Z DTSTAMP:20260405T094550Z UID:NSCM/30 DESCRIPTION:Title: We 'll meet again in October 2021\nby Summer break as part of Nečas Semi nar on Continuum Mechanics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/30/ END:VEVENT BEGIN:VEVENT SUMMARY:Jan Březina (TU Liberec) DTSTART:20210503T134000Z DTEND:20210503T151000Z DTSTAMP:20260405T094550Z UID:NSCM/31 DESCRIPTION:Title: Co ntinuum-fracture approach to modelling crystalline rock\nby Jan Březi na (TU Liberec) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbst ract\nWe start with a statistical description of the fracture networks in real (crystalline) rocks and related heterogeneous material properties. Ne xt\, we shall present continuum-fracture (CF) approach to the description of the processes in real rock. CF description has been consistently applie d in the Flow123d simulator of THMC proceses. We will summarize simulated processes\, numerical schemes\, and software tools. Finally\, we present p articular applications in the safety of deep nuclear waste repositories an d the efficiency of enhanced geothermal systems.\n LOCATION:https://researchseminars.org/talk/NSCM/31/ END:VEVENT BEGIN:VEVENT SUMMARY:Jan Stebel (TU Liberec) DTSTART:20210517T134000Z DTEND:20210517T151000Z DTSTAMP:20260405T094550Z UID:NSCM/32 DESCRIPTION:Title: Co ntinuum-fracture models of porous media processes: derivation and analysis \nby Jan Stebel (TU Liberec) as part of Nečas Seminar on Continuum Me chanics\n\n\nAbstract\nMathematical modelling of heterogeneous materials s uch as granitic rocks requires special treatment of fractures. We present the derivation of the so-called continuum-fracture model for two types of problems: advection-diffusion process (e.g. transport of contaminants or h eat) and hydro-mechanical coupling based on Biot’s theory. For the hydro -mechanical problem we distinguish the linear case and the case of contact and shear-dilation conditions at fractures. Existence of weak solutions is established. The problem is discretized by the finite element method an d solved using the so-called fixed-stress iterative splitting whose conver gence is analyzed.\n LOCATION:https://researchseminars.org/talk/NSCM/32/ END:VEVENT BEGIN:VEVENT SUMMARY:Milan Pokorný (Mathematical Institute\, Charles Universiy) DTSTART:20210531T134000Z DTEND:20210531T151000Z DTSTAMP:20260405T094550Z UID:NSCM/33 DESCRIPTION:Title: Ho mogenization of Navier--Stokes--Fourier system in domains with tiny holes< /a>\nby Milan Pokorný (Mathematical Institute\, Charles Universiy) as par t of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nWe consider the compressible Navier--Stokes--Fourier system in a domain with large number of holes. Under the assumption that the holes are sufficiently small\, tog ether with certain standard assumptions on the adiabatic exponent and the behaviour of the heat conductivity\, we show that if passing simultaneousl y with the number of holes to infinity and their size to zero\, in the lim it we obtain again solution to the compressible Navier--Stokes--Fourier sy stem in the domain without holes. The result holds both for the steady and evolutionary problem. It is a joint work with Yong Lu (Nanjing University ) and Emil Skříšovský (Charles University\, Prague).\n LOCATION:https://researchseminars.org/talk/NSCM/33/ END:VEVENT BEGIN:VEVENT SUMMARY:Manuel Friedrich (University of Muenster) DTSTART:20210419T134000Z DTEND:20210419T151000Z DTSTAMP:20260405T094550Z UID:NSCM/34 DESCRIPTION:Title: Em ergence of rigid polycrystals from atomistic systems\nby Manuel Friedr ich (University of Muenster) as part of Nečas Seminar on Continuum Mechan ics\n\n\nAbstract\nWe investigate the emergence of rigid polycrystalline s tructures from atomistic particle systems. The atomic interaction is gover ned by a suitably normalized pair interaction energy\, where the `sticky d isk’ interaction potential models the atoms as hard spheres that interac t when they are tangential. The discrete energy is frame invariant and no underlying reference lattice on the atomistic configurations is assumed. B y means of Gamma-convergence\, we characterize the asymptotic behavior of configurations with finite surface energy scaling in the infinite particle limit. The effective continuum theory is described in terms of a piecewis e constant field delineating the local orientation and micro-translation o f the configuration. The limiting energy is local and concentrated on the grain boundaries\, i.e.\, on the boundaries of the zones where the underly ing microscopic configuration has constant parameters. The corresponding s urface energy density depends on the relative orientation of the two grain s\, their microscopic translation misfit\, and the normal to the interface . Joint work with Leonard Kreutz (Münster) and Bernd Schmidt (Augsburg).\ n LOCATION:https://researchseminars.org/talk/NSCM/34/ END:VEVENT BEGIN:VEVENT SUMMARY:Jan Zeman (Faculty of Civil Engineering\, Czech Tech. Uni.) DTSTART:20211004T134000Z DTEND:20211004T151000Z DTSTAMP:20260405T094550Z UID:NSCM/35 DESCRIPTION:Title: De signing optimal reinforcement for high-performance composite tubes with se midefinite programming\nby Jan Zeman (Faculty of Civil Engineering\, C zech Tech. Uni.) as part of Nečas Seminar on Continuum Mechanics\n\nLectu re held in K3 Karlin.\n\nAbstract\nFueled by their excellent stiffness-to- weight ratio and the availability of mature manufacturing technologies\, f ilament wound carbon fiber reinforced polymers represent ideal materials f or thin-walled laminate structures. However\, their strong anisotropy redu ces structural resistance to wall instabilities under shear and buckling. Increasing laminate thickness degrades weight and structural efficiencies and the application of a dense internal core is often uneconomical and lab or-intensive. In this contribution\, we introduce a convex linear semidefi nite programming formulation for truss topology optimization to design an efficient non-uniform lattice-like internal structure. The internal struct ure not only reduces the effect of wall instabilities\, mirrored in the in crease of the fundamental free-vibration eigenfrequency\, but also keeps w eight low\, secures manufacturability using conventional three-dimensional printers\, and withstands the loads induced during the production process . We showcase a fully automatic procedure in detail for the design\, proto type manufacturing\, and verification of a simply-supported composite mach ine tool component\, including validation with roving hammer tests. The re sults confirm that the 3D-printed optimized internal structure almost doub les the fundamental free-vibration eigenfrequency\, allowing to increase t he working frequency of the machine tool\, even though the ratio between e lastic properties of the carbon composite and the ABS polymer used for 3D printing exceeds two orders of magnitude.\n LOCATION:https://researchseminars.org/talk/NSCM/35/ END:VEVENT BEGIN:VEVENT SUMMARY:Hanuš Seiner (Inst. of Thermomechanics\, CAS) DTSTART:20211018T134000Z DTEND:20211018T151000Z DTSTAMP:20260405T094550Z UID:NSCM/36 DESCRIPTION:Title: La ndau-energy landscape reconstruction for a Ni-Fe-Ga(Co) Shape Memory Alloy \nby Hanuš Seiner (Inst. of Thermomechanics\, CAS) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nIn the framework of continuu m mechanics\, the thermo-mechanical behavior of shape memory alloys is oft en described using the Landau-theory approach\, where the multi-well free energy density of the crystal is approximated by a polynomial with the req uired number of minima and energy barriers. Here we show how the energy la ndscape (in the strain-temperature space) can be reconstructed from experi ments\, and how accurately this energy is approximated by the Landau-theor y ansatz. Elastic behavior of single crystals of Ni-Fe-Ga(Co) ferromagneti c shape memory alloys is studied in a broad temperature range. Using tensi le stress-strain measurements and ultrasonic characterization\, we prove t hat austenite and martensite phases of the given alloy exhibit strongly no n-linear elastic responses\, and we utilize the non-linear stress-strain d ata for constructing an energy function describing the observed behavior i n the context of the Landau theory. We discuss the implications of the con structed model\, focusing in particular to the so-called critical point in the energy landscape\, where the austenite-martensite transition becomes weakly second-order.\n LOCATION:https://researchseminars.org/talk/NSCM/36/ END:VEVENT BEGIN:VEVENT SUMMARY:Katharina Brazda (University of Vienna) DTSTART:20211025T134000Z DTEND:20211025T151000Z DTSTAMP:20260405T094550Z UID:NSCM/37 DESCRIPTION:Title: Mu ltiphase biological membranes\nby Katharina Brazda (University of Vien na) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in K3 Karlin\, Sokolovska 83\, Praha 8.\n\nAbstract\nBiological membranes are t hin layers of lipid molecules. Mechanically\,\nthey can be described as in compressible viscous fluid surfaces with\nbending elasticity. The equilibr ium shapes of homogeneous membranes\nminimize the Canham-Helfrich energy u nder area and enclosed volume\nconstraints. In particular\, this variation al model explains the typical\nbiconcave shape of human red blood cells. C onfigurations of\nheterogeneous biomembranes also feature an intriguing co upling effect\nbetween composition and geometry\, which originates from th eir inherent\nfluidity. In this talk\, we introduce these models and prese nt an\nexistence result for multiphase membranes with sharp phase interfac es\,\nobtained in the framework of oriented curvature varifolds.\n LOCATION:https://researchseminars.org/talk/NSCM/37/ END:VEVENT BEGIN:VEVENT SUMMARY:Filippo Riva (University of Pavia) DTSTART:20211011T134000Z DTEND:20211011T151000Z DTSTAMP:20260405T094550Z UID:NSCM/38 DESCRIPTION:Title: In ertial Balanced Viscosity solutions to rate-independent systems\nby Fi lippo Riva (University of Pavia) as part of Nečas Seminar on Continuum Me chanics\n\n\nAbstract\nRate-independent evolutions frequently occur in mec hanics when \nthe problem\nunder consideration presents such small rate-de pendent effects\, as \ninertia or viscosity\, that can be neglected. If th e driving potential \nenergy is nonconvex any (reasonable) solution necess arily exhibits \ntime-discontinuities. To describe the behaviour of the ju mps\, in the \nlast decades the notions of Energetic and Balanced Viscosit y solutions \nhave been developed\, the latter as a refinement of the form er. While for \nEnergetic solutions the cost at jumps is described only in terms of the \nrate-independent dissipation potential\, in the case of Ba lanced \nViscosity solutions it arises from a suitable coupling between th is \ndissipation potential and a smaller and smaller viscosity potential\, \nwhich is reminiscent of an original presence of viscous damping.\nIn th is talk we present a novel notion of solution to rate-independent \nsystem s\, named Inertial Balanced Viscosity (IBV) solution\, which in \naddition takes into account small inertial effects. Differently from the \npreviou s cases\, now the jump cost turns out to be rate-dependent. In \nfinite di mension\, we show how IBV solutions can be obtained as a \nvanishing inert ia and viscosity limit of dynamic evolutions\, and we \nintroduce a multis cale Minimizing Movements algorithm which can be used \nto build such solu tions.\nThis is a joint work with G. Scilla and F. Solombrino.\n LOCATION:https://researchseminars.org/talk/NSCM/38/ END:VEVENT BEGIN:VEVENT SUMMARY:Jonathan Bevan (University of Surrey\, GB) DTSTART:20211108T144000Z DTEND:20211108T161000Z DTSTAMP:20260405T094550Z UID:NSCM/39 DESCRIPTION:Title: In terior 'buckling' and non-uniqueness in a class of incompressible variatio nal problems\nby Jonathan Bevan (University of Surrey\, GB) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nThe talk is about a class variational problems whose associated energies $E_{\\eps}$ can be th ought of as perturbations of the Dirichlet energy. These energies have co untably many pairs of planar\, measure-preserving stationary points $u^n_{ \\pm}$ with the properties that (a) $E_{\\eps}(u^n_+)=E_{\\eps}(u^n_-)$ an d (b) the maps $u^n_{\\pm}$ cause `buckling' at the centre $0$ of the unit ball $B$ in $\\mathbb{R}^2$ while acting as the identity on $\\partial B$ . Numerical calculations show that $n$ can be treated as a proxy for the `number of buckles' that occur at $0$\, and that\, as one might expect\, $E_{\\eps}(u^n_{\\pm})$ increases as $n$ does. This is joint work with J. Deane.\n LOCATION:https://researchseminars.org/talk/NSCM/39/ END:VEVENT BEGIN:VEVENT SUMMARY:Daniel Campbell (Universita Hradec Králové) DTSTART:20211129T144000Z DTEND:20211129T161000Z DTSTAMP:20260405T094550Z UID:NSCM/40 DESCRIPTION:Title: Cl osures of planar BV homeomorphisms and the relaxation of functionals with linear growth\nby Daniel Campbell (Universita Hradec Králové) as par t of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nMotivated by rel axation results of Kristensen and Rindler\, and of Benešová\, Krömer an d Kružík for BV maps\, we study the class of strict limits of BV planar homeomorphisms. We show that\, although such maps need not be injective an d are not necessarily continuous on almost every line\, the class has a re asonable behavior expected for limit of elastic deformations. By a charact erization of the classes of strict and area-strict limits of BV homeomorph isms we show that these classes coincide. \n\nThis is based on joint works with S. Hencl\, A. Kauranen and E. Radici.\n LOCATION:https://researchseminars.org/talk/NSCM/40/ END:VEVENT BEGIN:VEVENT SUMMARY:Ulisse Stefanelli (University of Vienna) DTSTART:20211122T144000Z DTEND:20211122T161000Z DTSTAMP:20260405T094550Z UID:NSCM/41 DESCRIPTION:Title: Ex istence results for a morphoelastic model\nby Ulisse Stefanelli (Unive rsity of Vienna) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbs tract\nI will report on a recent work in collaboration with Elisa Davoli ( TU Wien) and Katerina Nik (University of Vienna) on a three-dimensional qu asistatic morpholelastic model. The mechanical response of the body and it s growth are modeled by an interplay of hyperelastic energy minimization a nd growth dynamics. A first existence result is obtained by regularization and time-discretization\, also taking advantage of an exponential-update scheme. We then allow the growth dynamics to depend on an additional scala r field\, say a nutrient\, and formulate an optimal control problem. Event ually\, we tackle the existence of coupled morphoelastic and nutrient solu tions\, when the latter is allowed to diffuse and interact with the growin g body.\n\nThe preprint is available as arXiv:2110.05566.\n LOCATION:https://researchseminars.org/talk/NSCM/41/ END:VEVENT BEGIN:VEVENT SUMMARY:Tomáš Roubíček (Math. Inst. of Charles University) DTSTART:20211101T144000Z DTEND:20211101T161000Z DTSTAMP:20260405T094550Z UID:NSCM/42 DESCRIPTION:Title: Vi sco-plastic elastodynamics and poro-elastodynamics at large deformations b y Eulerian approaches\nby Tomáš Roubíček (Math. Inst. of Charles U niversity) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\ nTwo models of hardening-free plasticity at large deformations\nwill be pr esented in Eulerian rate formulation based on two\nstandard concepts\, Gre en-Naghdi additive decomposition\nand Kroner-Lee-Liu multiplicative decomp osition of the\ntotal strain. Extension towards poroelasticity and\nthermo dynamics will be outlined\, too.\n LOCATION:https://researchseminars.org/talk/NSCM/42/ END:VEVENT BEGIN:VEVENT SUMMARY:Philipp Reiter (TU Chemnitz) DTSTART:20211115T144000Z DTEND:20211115T161000Z DTSTAMP:20260405T094550Z UID:NSCM/43 DESCRIPTION:Title: Sy mmetric elastic knots\nby Philipp Reiter (TU Chemnitz) as part of Neč as Seminar on Continuum Mechanics\n\n\nAbstract\nMinimizing the bending en ergy within knot classes leads to the concept \nof elastic knots. Motivate d by numerical experiments we prescribe \ndihedral symmetry and establish existence of dihedrally symmetric \nelastic knots for knot classes admitti ng this type of symmetry. Among \nother results we prove that the dihedral elastic trefoil is the union of \ntwo circles that form a (planar) figure -eight. We also discuss some \ngeneralizations and limitations regarding o ther symmetries and knot classes.\n\nThis is joint work with Alexandra Gil sbach and Heiko von der Mosel.\n LOCATION:https://researchseminars.org/talk/NSCM/43/ END:VEVENT BEGIN:VEVENT SUMMARY:Stanislav Sysala (Institute of Geonics\, Cz. Acad. Sci.) DTSTART:20211206T144000Z DTEND:20211206T161000Z DTSTAMP:20260405T094550Z UID:NSCM/44 DESCRIPTION:Title: Sa ddle-point problems with bilinear Lagrangian and convex constraints: anal ysis\, numerical solution and applications\nby Stanislav Sysala (Insti tute of Geonics\, Cz. Acad. Sci.) as part of Nečas Seminar on Continuum M echanics\n\n\nAbstract\nThe first part of the talk is concerned with an ab stract inf-sup problem \ngenerated by a bilinear Lagrangian and convex con straints. The \nconditions that guarantee no gap between the inf-sup and r elated sup-inf \nproblems are studied. A particular attention is devoted t o the inf-sup \ncondition defined for convex cones in function spaces. Nex t\, a \nregularization method convenient for solving the inf-sup problem i s \nanalyzed and a computable majorant of the critical (inf-sup) value is \nderived for purposes of a posteriori error analysis of numerical \nresul ts. The second part of the talk is devoted to applications of the \nabstra ct framework to continuum mechanics. In particular\, examples of \nlimit l oad problems and similar ones arising in classical plasticity\, \ngradient plasticity and delamination are introduced. The presented \nresults follo w from the joint work with Daya B. Reddy\, Sergey Repin and \nJaroslav Has linger.\n LOCATION:https://researchseminars.org/talk/NSCM/44/ END:VEVENT BEGIN:VEVENT SUMMARY:Amrita Gosh (University of Bonn) DTSTART:20211213T144000Z DTEND:20211213T161000Z DTSTAMP:20260405T094550Z UID:NSCM/45 DESCRIPTION:Title: On Shikhmurzaev’s approach to the Contact Line Problem\nby Amrita Gosh (University of Bonn) as part of Nečas Seminar on Continuum Mechanics\n\n \nAbstract\nI will discuss the general moving contact line problem\, arisi ng from many fluid mechanics\nphenomena. The classical formulation of this model with the no-slip (Dirichlet) boundary\ncondition for velocities at the liquid-solid interface gives rise to a non-integrable singularity\nof the shear stress\, which is known as the ”moving contact line paradox” . Y. Shikhmurzaev\nproposed (1993) a different approach to solve this issu e. This approach\, apart from the\nclassical conservation equations\, form ulates the boundary conditions for the equations in\nthe bulk phases in an elaborate way\, which can be viewed as a generalization of the existing\n models in the literature\, although generated from a different underlying theory. After giving\nan overview of this model\, I would like to derive a thin film approximation of Shikhmurzaev’s\nmodel to compare with the ot her solution model of the contact line problem.\n LOCATION:https://researchseminars.org/talk/NSCM/45/ END:VEVENT BEGIN:VEVENT SUMMARY:Christmas break (Christmas break) DTSTART:20211227T144000Z DTEND:20211227T161000Z DTSTAMP:20260405T094550Z UID:NSCM/46 DESCRIPTION:Title: Ch ristmas break\nby Christmas break (Christmas break) as part of Nečas Seminar on Continuum Mechanics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/46/ END:VEVENT BEGIN:VEVENT SUMMARY:Christmas break (Christmas break) DTSTART:20211220T144000Z DTEND:20211220T161000Z DTSTAMP:20260405T094550Z UID:NSCM/47 DESCRIPTION:Title: Ch ristmas break\nby Christmas break (Christmas break) as part of Nečas Seminar on Continuum Mechanics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/47/ END:VEVENT BEGIN:VEVENT SUMMARY:Karel Tůma (Mathematical Institute\, Charles University) DTSTART:20220103T144000Z DTEND:20220103T161000Z DTSTAMP:20260405T094550Z UID:NSCM/48 DESCRIPTION:Title: Fi nite strain phase-field model for martensitic transformation: Large-scale finite element simulations\nby Karel Tůma (Mathematical Institute\, C harles University) as part of Nečas Seminar on Continuum Mechanics\n\n\nA bstract\nMartensitic transformation is a first-order solid-solid diffusion less transformation that occurs between the parent phase (austenite) and t he product phase (martensite) and is characterized by the microstructure e volution\, which is accompanied by the formation\, propagation\, and annih ilation of the interfaces. In shape memory alloys\, the microstructure evo lution is the mechanism behind the properties such as pseudoelasticity and shape memory effect. In general\, due to the incompatibility between aust enite and a single variant of martensite\, the martensitic transformation is realized via the formation of complex twinning microstructure. \nA rece ntly developed phase-field model for multivariant martensitic transformati on is implemented using the finite element method and used to compute larg e-scale simulations reaching 150 million degrees of freedom. The computat ional problems are quite expensive due to the fact that high mesh density is needed to capture the detailed microstructure\, see attached figure. Ou r implementation has shown robustness and good parallel scaling performanc e. Having this model\, the goal is to perform a systematic investigation o f the effect of crystal lattice orientation and material anisotropy on the indentation-induced microstructure evolution in CuAlNi shape memory alloy . To our knowledge\, such a comprehensive high-resolution microstructure-b ased modeling study has not been reported before. This is a joint work wit h M. Rezaee-Hajidehi\, S. Stupkiewicz\, J. Hron and P. Farrell.\n LOCATION:https://researchseminars.org/talk/NSCM/48/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20220110T144000Z DTEND:20220110T161000Z DTSTAMP:20260405T094550Z UID:NSCM/49 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/49/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20220117T144000Z DTEND:20220117T161000Z DTSTAMP:20260405T094550Z UID:NSCM/50 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/50/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20220124T144000Z DTEND:20220124T161000Z DTSTAMP:20260405T094550Z UID:NSCM/51 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/51/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20220131T144000Z DTEND:20220131T161000Z DTSTAMP:20260405T094550Z UID:NSCM/52 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/52/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20220207T144000Z DTEND:20220207T161000Z DTSTAMP:20260405T094550Z UID:NSCM/53 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/53/ END:VEVENT BEGIN:VEVENT SUMMARY:Sabrine Chebbi (University of Tunisia\, El MANAR\, UTM) DTSTART:20220221T144000Z DTEND:20220221T161000Z DTSTAMP:20260405T094550Z UID:NSCM/54 DESCRIPTION:Title: Th e Energy decay rate of 1D and 2D Timoshenko systems. Theoretical analysis and numerical simulation\nby Sabrine Chebbi (University of Tunisia\, El MANAR\, UTM) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbs tract\nWe focus on the behavior of the solutions of the Timoshenko systems \nin dimensions 1 and 2 using the lower bound estimates of the energy. We\ nstudy a nonlinear damped one-dimensional thermo-elastic Timoshenko system \nwhere the heat flux is given by the Cattaneo’s law. After deriving the strong\nlower energy estimates\, we show the optimality for some explicit examples.\nFurthermore\, we discuss the well-posedness and the decay rate of the energy\nof the Mindlin-Timoshenko plate equations subject to a non linear dissipation\nacting on the rotation angles’equations. Later\, we perform a numerical sim-\nulation of the one-dimensional Timoshenko system \, our approach is based\non adequate use of the finite element and the fi nite difference methods\ngiving rise to a new scheme which characterizes t he asymptotic behavior of\nthe discrete energy.\n LOCATION:https://researchseminars.org/talk/NSCM/54/ END:VEVENT BEGIN:VEVENT SUMMARY:Giusy Mazzone (Queen's University) DTSTART:20220502T134000Z DTEND:20220502T151000Z DTSTAMP:20260405T094550Z UID:NSCM/55 DESCRIPTION:Title: On partially dissipative systems\nby Giusy Mazzone (Queen's University) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nIn this ta lk\, we will investigate the dynamics of three mechanical systems: a rigid body with a damper\, a system of rigid bodies with a fluid-filled gap\, a nd a harmonic oscillator in a fluid-filled pipe. The equations governing t he motion of these systems are “partially dissipative”\, in that there exists an energy functional that decreases along the trajectories\, while other physical variables are conserved or even excited during the motion. The objective of our investigations is to describe the “stabilization p roperties” of the systems. By “stabilization” we mean either converg ence of each trajectory to a stationary solution or the existence of perio dic solutions to the governing equations corresponding to forces with arbi trary frequencies.\n LOCATION:https://researchseminars.org/talk/NSCM/55/ END:VEVENT BEGIN:VEVENT SUMMARY:Petr Pelech (WIAS Berlin) DTSTART:20220307T144000Z DTEND:20220307T161000Z DTSTAMP:20260405T094550Z UID:NSCM/56 DESCRIPTION:Title: Pe nrose-Fife model with activated phase transformation - Existence and effec tive model for slow-loading regimes.\nby Petr Pelech (WIAS Berlin) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nWe study a no n-autonomous system of two evolutionary PDEs\, an enhanced version of the Penrose-Fife model introduced in 1990\, which first in history coupled the Allen-Cahn phase-field equation with thermal effects in a thermodynamical ly consistent way. In our work we consider an activated phase transformati on which makes the phase-field equation non-linear in time derivative\; it contains an additional term that describes also the Coulomb dry friction and whose analogues appear in rate-independent models of plasticity or dam age. Apart from proving the existence of solutions of the system\, we inve stigate its effective behavior for the so-called slow-loading regimes. The re the internal time-scale introduced by phase-field viscosity and thermal conductivity is much smaller than the time-scale of the loading\, an exte rnal force acting on the system. Hence the system stays almost in its equi librium described by the static solution. However\, the limit of solutions (as the ratio of the time scales tends to zero) may not be characterized by the corresponding rate-independent model where the viscous-like terms h ave been dropped. The reason is that the phase transformation is driven by a non-convex thermodynamic potential and hence the solutions may develop jumps in the limit. In order to resolve the jump's detailed trajectory\, a long which the viscous effects play a crucial role\, we use the so-called Balanced-Viscosity (BV) solutions introduced by Efendiev and Mielke in 200 6. This work is a collaboration with Matthias Liero and Alexander Mielke f rom WIAS Berlin.\n\nPenrose O.\, Fife P. C. - Thermodynamically Consistent Models of Phase-Field Type for the Kinetics of Phase Transitions (1990)\n \nSprekels J.\, Zheng S. M. - Global smooth solutions to a thermodynamical ly consistent model of phase-field type in higher space dimensions (1993)\ n\nEfendiev M.\, Mielke A. - On the rate-independent limit of systems wit h dry friction and small viscosity (2006)\n\nMielke A.\, Roubicek T. - Rat e-independent Systems Theory and Application (2015)\n LOCATION:https://researchseminars.org/talk/NSCM/56/ END:VEVENT BEGIN:VEVENT SUMMARY:Easter Monday DTSTART:20220418T134000Z DTEND:20220418T151000Z DTSTAMP:20260405T094550Z UID:NSCM/57 DESCRIPTION:Title: No lecture\nby Easter Monday as part of Nečas Seminar on Continuum Mech anics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/57/ END:VEVENT BEGIN:VEVENT SUMMARY:George Avalos (UNIVERSITY of NEBRASKA–LINCOLN) DTSTART:20220516T134000Z DTEND:20220516T151000Z DTSTAMP:20260405T094550Z UID:NSCM/58 DESCRIPTION:Title: Co ncerning the strong and uniform decay of solutions to coupled fluid/multi layered structure PDE dynamics\nby George Avalos (UNIVERSITY of NEBRA SKA–LINCOLN) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbstr act\nIn this talk\, we will discuss our recent work on a certain\n multila yered structure-fluid interaction (FSI) which arises in the\n modeling of vascular blood flow. The coupled PDE system under our\n consideration math ematically accounts for the fact that mammalian\n veins and arteries are t ypically composed of various layers of\n tissues: each layer will generall y manifest its own intrinsic material\n properties\, and will moreover be separated from the other layers by\n thin elastic laminae. Consequently\, the resulting modeling FSI system\n will manifest an additional PDE\, whic h evolves on the boundary\n interface\, so as to account for the thin elas tic layer. (This is in\n contrast to the FSI PDE’s which appear in the l iterature\, wherein\n elastic dynamics are largely absent on the boundary interface.) As\n such\, the PDE system will constitute a coupling of 3D fl uid-2D\n elastic-3D elastic dynamics. For this multilayered FSI system\, w e will\n in particular present results of strong stability for finite ener gy\n solutions\, and polynomial decay for sufficiently regular solutions.\ n This is joint work with Pelin Güven Geredeli and Boris Muha.\n LOCATION:https://researchseminars.org/talk/NSCM/58/ END:VEVENT BEGIN:VEVENT SUMMARY:summer break DTSTART:20220523T134000Z DTEND:20220523T151000Z DTSTAMP:20260405T094550Z UID:NSCM/59 DESCRIPTION:Title: We will continue on Monday\, October 3\, 2022\nby summer break as part o f Nečas Seminar on Continuum Mechanics\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/59/ END:VEVENT BEGIN:VEVENT SUMMARY:Václav Mácha (Inst. of Mathematics\, Czech Academy of Sciences) DTSTART:20220228T144000Z DTEND:20220228T161000Z DTSTAMP:20260405T094550Z UID:NSCM/60 DESCRIPTION:Title: Fl uids in moving domains\nby Václav Mácha (Inst. of Mathematics\, Czec h Academy of Sciences) as part of Nečas Seminar on Continuum Mechanics\n\ n\nAbstract\nWe present several results concerning the flow of a\n compres sible heat-conducting fluid in a moving domain. We discuss the\n existence of a weak solution. Next\, we tackle the low-Mach number\n limit and we d educe the target system for the low-stratification case.\n The talk is bas ed on results obtained in collaboration with O. Kreml\,\n S. Nečasová an d A. Wroblewska-Kaminska\n LOCATION:https://researchseminars.org/talk/NSCM/60/ END:VEVENT BEGIN:VEVENT SUMMARY:Justyna Ogorzaly (Jagiellonian University) DTSTART:20220404T134000Z DTEND:20220404T151000Z DTSTAMP:20260405T094550Z UID:NSCM/61 DESCRIPTION:Title: Va riational-Hemivariational Inequalities with Applications to Contact Mechan ics\nby Justyna Ogorzaly (Jagiellonian University) as part of Nečas S eminar on Continuum Mechanics\n\n\nAbstract\nWe will present the existence and uniqueness results for the\nspecial classes of nonlinear variational- hemivariational inequalities.\nThen\, we will consider concrete contact pr oblems and we will show how\nthese problems lead to the different type of variational-hemivariational\ninequalities.\n LOCATION:https://researchseminars.org/talk/NSCM/61/ END:VEVENT BEGIN:VEVENT SUMMARY:Henrik Schumacher (TU Chemnitz) DTSTART:20220509T134000Z DTEND:20220509T151000Z DTSTAMP:20260405T094550Z UID:NSCM/62 DESCRIPTION:Title: Re pulsive Curves and Surfaces\nby Henrik Schumacher (TU Chemnitz) as par t of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nFunctionals that penalize bending or stretching of a surface play a key role in geometric and scientific\ncomputing\, but to date have ignored a very basic requirem ent: in many situations\, surfaces must not pass\nthrough themselves or ea ch other. This paper develops a numerical framework for optimization of su rface\ngeometry while avoiding (self-)collision. The starting point is the tangent-point energy\, which effectively pushes\napart pairs of points th at are close in space but distant along the surface. We develop a discreti zation of\nthis energy for triangle meshes and introduce a novel accelerat ion scheme based on a fractional Sobolev inner\nproduct. In contrast to si milar schemes developed for curves (cf. [2])\, we avoid the complexity of building a\nmultiresolution mesh hierarchy by decomposing our precondition er into two ordinary Poisson equations\, plus\nforward application of a fr actional differential operator. We further accelerate this scheme via hier archical\napproximation and describe how to incorporate a variety of const raints (on area\, volume\, etc.). Finally\, we\nexplore how this machinery might be applied to problems in mathematical visualization\, geometric mo deling\,\nand geometry processing.\nJoint work with: Chris Yu\, Caleb Brak ensiek\, Keenan Crane\nReferences\n[1] C. Yu\, C. Brakensiek\, H. Schumach er\, and C. Keenan Repulsive Surfaces. ACM Trans. Graph.\, 40(6):1–19\,\ n2021.\n[2] C. Yu\, H. Schumacher\, and C. Keenan Repulsive Curves. ACM Tr ans. Graph.\, 40(2):1-21\, 2021.\n LOCATION:https://researchseminars.org/talk/NSCM/62/ END:VEVENT BEGIN:VEVENT SUMMARY:Marta Zoppello (DISMA\, Politecnico di Torino) DTSTART:20220328T134000Z DTEND:20220328T151000Z DTSTAMP:20260405T094550Z UID:NSCM/65 DESCRIPTION:Title: N- link swimmers swimming alone or in pairs\nby Marta Zoppello (DISMA\, P olitecnico di Torino) as part of Nečas Seminar on Continuum Mechanics\n\n \nAbstract\nThis talk presents two models of swimmers immersed in a low Re ynolds number fluid\,\nboth of them involving the so-called N -link swimme r. The first one studies the 3-dimensional N-link swimmer swimming alone [ 1]\, the second focuses on two planar 2-link swimmers\nswimming together [ 2]. Both models rely on Resistive Force Theory\, which is a good approxima tion of hydrodynamic forces at low Reynolds number for slender swimmers an d allows us to cast the equations of motion as ODEs. These equations can b e seen as control systems\nwhere the controls are the velocity of deformat ion of the swimmers.\nWe prove that the 3 dimensional N -link swimmer is f ully controllable and we show the existence of optimal controls for some c ost functionals. Regarding the coupled swimmers\, even\nif\, taken singula rly\, they are non-controllable units (because of Purcell’s celebrated S callop Theorem)\, we prove that taking into account the hydrodynamic inter action they can achieve a net motion after a periodic sequence of shape ch anges. Moreover\, under suitable\napproximations\, we are able to optimize the displacement.\n\n\n[1] R. Marchello\, M\, Morandotti\, H. Shum\, M. Z oppello.\nThe N -link swimmer in three dimensions: controllability and opt imality results.\nAccepted for publication in Acta Applicandae Mathematica e (2022)\n\n\n[2] M. Zoppello\, M. Morandotti\, H. Gadˆelha.\nControlling non-controllable scallops.\nSubmitted.\n LOCATION:https://researchseminars.org/talk/NSCM/65/ END:VEVENT BEGIN:VEVENT SUMMARY:summer break DTSTART:20220523T134000Z DTEND:20220523T151000Z DTSTAMP:20260405T094550Z UID:NSCM/67 DESCRIPTION:by summer break as part of Nečas Seminar on Continuum Mechani cs\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/67/ END:VEVENT BEGIN:VEVENT SUMMARY:Bangwei She (Inst. of Mathematics\, Czech Academy of Sciences) DTSTART:20220321T144000Z DTEND:20220321T161000Z DTSTAMP:20260405T094550Z UID:NSCM/68 DESCRIPTION:Title: On convergence of numerical solutions for the compressible MHD system\nb y Bangwei She (Inst. of Mathematics\, Czech Academy of Sciences) as part o f Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nWe study a general convergence theory for the analysis of numerical\n solutions to a magnetoh ydrodynamic system describing the time\n evolution of compressible\, visco us\, electrically conducting fluids.\n \n First\, we introduce the concept of consistent approximation mimicking\n the density positivity\, energy s tability\, and consistency of a\n suitable numerical approximation. Furthe r\, we introduce the concept of\n dissipative weak solution\, which can be obtained as the weak limit of\n the consistent approximation. Here\, by “dissipative" we mean that\n the energy inequality contains energy defec ts that control the\n oscillations in the momentum equation.\n \n Next\, b y using the relative energy functional\, we prove the\n dissipative weak-s trong uniqueness principle\, meaning that a\n dissipative weak solution co incides with a classical solution of the\n same problem as long as the lat ter exists. This indicates that a\n consistent approximation converges unc onditionally to the classical\n solution. As a summary\, we built a nonlin ear variant of the Lax\n equivalence theory for the compressible MHD syste m.\n \n Finally\, to show the application of the convergence theory\, we p ropose\n two numerical methods. We show that the numerical solutions prese rve\n the positivity of density and stability of the total energy. Then by \n using the a priori estimates derived from the energy estimates we\n pro ve that the numerical methods are consistent. Consequently\, our\n numeric al methods belong to the class of consistent approximation.\n Applying the prebuilt convergence theory\, we conclude that the\n solutions of our num erical methods converge to i) the dissipative\n weak solution\; ii) the c lassical solution as long as the classical\n solution exists. As a byprodu ct of the first convergence\, we prove the\n global in-time existence of t he dissipative weak solution.\n LOCATION:https://researchseminars.org/talk/NSCM/68/ END:VEVENT BEGIN:VEVENT SUMMARY:Barbora Benešová (Charles University) DTSTART:20220425T134000Z DTEND:20220425T151000Z DTSTAMP:20260405T094550Z UID:NSCM/69 DESCRIPTION:Title: A model for polycrystalline Ni-Ti shape-memory alloys including plasticity\nby Barbora Benešová (Charles University) as part of Nečas Seminar o n Continuum Mechanics\n\n\nAbstract\nIn this talk\, I will discuss the int erplay between the martensitic transformation and the plastic deformation in polycrystalline NiTi- alloys. I will then propose a phenomenological\, macroscopic model capturing both effects within the generalized standard m aterials modelling framework. Special attention will be paid to distinguis hing dependent and independent processes and their accurate modelling. Thi s is a joint work with Miroslav Frost\, Martin Kružík\, Petr Sedlák and Hanuš Seiner.\n LOCATION:https://researchseminars.org/talk/NSCM/69/ END:VEVENT BEGIN:VEVENT SUMMARY:Rufat Badal (University of Erlangen) DTSTART:20220214T144000Z DTEND:20220214T161000Z DTSTAMP:20260405T094550Z UID:NSCM/70 DESCRIPTION:Title: No nlinear and Linearized Models in Thermoviscoelasticity\nby Rufat Badal (University of Erlangen) as part of Nečas Seminar on Continuum Mechanics \n\n\nAbstract\nWe consider a quasistatic nonlinear model in thermoviscoel asticity at a finite-strain setting in the Kelvin’s-Voigt’s rheology w here both the elastic and viscous stress tensors comply with the principle of frame indifference under rotations. The force balance is formulated in the reference configuration by resorting to the concept of nonsimple mate rials whereas the heat transfer equation is modeled by the Fourier law in the deformed configurations. Weak solutions are obtained by means of a sta ggered in-time discretization where the deformation and the temperature ar e updated alternatingly. Our result refines a recent work by Mielke & Roub íček [1] since our approximation does not require any regularization of the viscosity term. Afterwards\, we focus on the case of deformations near the identity and small temperatures\, and we show by a rigorous lineariza tion procedure that weak solutions of the nonlinear system converge in a s uitable sense to solutions of a system in linearized thermoviscoelasticity . The same property holds for time-discrete approximations and we provide a corresponding commutativity result.\n\n[1] Mielke A.\, Roubíček T.: Th ermoviscoelasticity in Kelvin-Voigt rheology at large strains. (2020)\n LOCATION:https://researchseminars.org/talk/NSCM/70/ END:VEVENT BEGIN:VEVENT SUMMARY:Michele Ruggeri (University of Strathclyde) DTSTART:20220314T144000Z DTEND:20220314T161000Z DTSTAMP:20260405T094550Z UID:NSCM/71 DESCRIPTION:Title: Th e Landau-Lifshitz-Gilbert equation with Dzyaloshinki-Moriya interaction: n umerical aspects\nby Michele Ruggeri (University of Strathclyde) as pa rt of Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nThe talk will b e split into two parts.\nIn the first one\, we discuss the numerical appro ximation of the Landau-Lifshitz-Gilbert equation\n(LLG) for the case in wh ich the energy (and\, hence\, the effective field appearing in LLG) includ es\nthe Dzyaloshinki-Moriya interaction (DMI)\, the fundamental ingredient for the enucleation and stability\nof chiral magnetic skyrmions. In the s econd part\, we discuss a limiting model for micromagnetic thin\nfilms in the presence of bulk DMI\, where we focus on the limiting behavior of the magnetization\nas the thickness of the film goes to zero. We show that the reduced model unveils some physics\nand discuss its practical implication s for computations. The results presented in the talk have been\nobtained together with Giovanni Di Fratta (University of Naples Federico II)\, Elis a Davoli\,\nCarl-Martin Pfeiler\, and Dirk Praetorius (TU Wien).\n LOCATION:https://researchseminars.org/talk/NSCM/71/ END:VEVENT BEGIN:VEVENT SUMMARY:--- DTSTART:20220411T134000Z DTEND:20220411T151000Z DTSTAMP:20260405T094550Z UID:NSCM/72 DESCRIPTION:by --- as part of Nečas Seminar on Continuum Mechanics\n\nAbs tract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/72/ END:VEVENT BEGIN:VEVENT SUMMARY:Rita Ferreira (King Abdullah University of Science and Technology) DTSTART:20221031T144000Z DTEND:20221031T161000Z DTSTAMP:20260405T094550Z UID:NSCM/73 DESCRIPTION:Title: St ructural changes in nonlocal denoising models arising through bi-level par ameter learning\nby Rita Ferreira (King Abdullah University of Science and Technology) as part of Nečas Seminar on Continuum Mechanics\n\n\nAbs tract\nIn this talk\, we will discuss a unified framework based on bi-leve l optimization schemes to deal with parameter learning in the context of i mage processing. The goal is to identify the optimal regularizer within a family depending on a parameter in a general topological space. Of particu lar interest is the non-compact parameter domains case\, which is relevant \, for instance\, when the commonly used box constraints are disregarded. To overcome this lack of compactness\, we propose a natural extension of t he upper-level functional to the closure of the parameter domain via Gamma -convergence\, which captures possible structural changes in the reconstru ction model at the edge of the domain. Under two main assumptions\, Mosco -convergence of the regularizers and uniqueness of minimizers of the lower -level problem\, we prove that the extension coincides with the relaxation \, thus admitting minimizers that relate to the parameter optimization pro blem of interest. To conclude\, we apply this abstract framework to invest igate four practically relevant models in image denoising\, all featuring nonlocality\; moreover\, the associated families of regularizers exhibit q ualitatively different parameter dependence\, describing a weight factor\, an amount of nonlocality\, an integrability exponent\, and a fractional o rder\, respectively. \nThis talk is based on a joint work with Elisa Davol i\, Carolin Kreisbeck\, and Hidde Schönberger.\n LOCATION:https://researchseminars.org/talk/NSCM/73/ END:VEVENT BEGIN:VEVENT SUMMARY:Lennart Machill (University of Muenster\, Germany) DTSTART:20221010T134000Z DTEND:20221010T151000Z DTSTAMP:20260405T094550Z UID:NSCM/74 DESCRIPTION:Title: On e-dimensional viscoelastic von Kármán theories\nby Lennart Machill ( University of Muenster\, Germany) as part of Nečas Seminar on Continuum M echanics\n\n\nAbstract\nWe derive an effective one-dimensional limit from a three-dimensional Kelvin-Voigt model for viscoelastic thin-walled beams\ , in which the elastic and the viscous stress tensor comply with a frame-i ndifference principle. The limiting system of equations comprises stretchi ng\, bending\, and twisting both in the elastic and the viscous stress. It coincides with the model already identified via [Friedrich-Kružík '20] and [Friedrich-Machill '22] by a successive dimension reduction\, first fr om 3D to a 2D theory for von Kármán plates and then from 2D to a 1D theo ry for ribbons. Our arguments rely on the static Gamma-convergence in [Fre ddi-Mora-Paroni '13]\, on the abstract theory of metric gradient flows\, a nd on evolutionary Gamma-convergence by Sandier and Serfaty.\n LOCATION:https://researchseminars.org/talk/NSCM/74/ END:VEVENT BEGIN:VEVENT SUMMARY:Elvira Zappale (University of Rome - I\, Sapienza) DTSTART:20221121T144000Z DTEND:20221121T161000Z DTSTAMP:20260405T094550Z UID:NSCM/75 DESCRIPTION:Title: Va riational formulation for hierarchies of structured deformations\nby E lvira Zappale (University of Rome - I\, Sapienza) as part of Nečas Semina r on Continuum Mechanics\n\n\nAbstract\nThe mechanical theory of first ord er structured deformations formulated in [2] enriches the purely macroscop ic field theory of non-linear elasticity by taking into account the effect s of disarrangements that occur at a single submacroscopic level. In [1] a variational formulation for this theory has been successfully provided in the context of special fields of bounded variation.\nTaking into account that many natural and man-made physical systems have a rich enough geometr ical structure to permit the identification of hierarchies consisting of m ore than one physically meaningful submacroscopic level\, the mechanical t heory of structured deformations has been enriched in [3]. This talk aims at presenting a variational framework of these latter theoretical setting s.\n\n\nReferences:\n\n[1] R. Choksi and I. Fonseca: Bulk and interfacial energy densities for structured deformations of continua. Arch. Rational M ech. Anal. 138 (1997)\, 37-103.\n\n\n[2] G. Del Piero and D. -R. Owen: Str uctured deformations of continua: Arch. Ration. Mech. Anal. 124 (1993)\, 9 9-155.\n\n[3] L. Deseri and D. R. Owen: Elasticity with Hierarchical Disar rangements: A Field Theory That Admits Slips and Separations at Multiple S ubmacroscopic Levels: J.of Elasticity Vol- 135 (2019) Issue 1-2\, 149-180. \n\nJoint project with Ana Cristina Barroso\, José Matias\, Marco Morando tti & David Owen\n LOCATION:https://researchseminars.org/talk/NSCM/75/ END:VEVENT BEGIN:VEVENT SUMMARY:Martin Horák (Faculty of Civil Engineering\, CTU\, ÚTIA AVČR) DTSTART:20221003T134000Z DTEND:20221003T151000Z DTSTAMP:20260405T094550Z UID:NSCM/76 DESCRIPTION:Title: Ef ficient formulation of a two-dimensional geometrically exact Bernoulli bea m\nby Martin Horák (Faculty of Civil Engineering\, CTU\, ÚTIA AVČR ) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in K3 K arlin\, Sokolovska 83\, Praha 8.\n\nAbstract\nIn this talk\, I will focus on a two-dimensional geometrically exact formulation of a Bernoulli beam.\ nThe formulation is based on the integrated form of equilibrium equations\ , which are combined with the\nkinematic equations and generalized materia l equations\, leading to a set of three first-order differential\nequation s. These equations are then discretized by finite differences and the boun dary value problem is\nconverted into an initial value problem using a tec hnique inspired by the shooting method. The accuracy of\nthe numerical app roximation is conveniently increased by refining the integration scheme on the element\nlevel while the number of global degrees of freedom is kept constant\, which leads to high computational\nefficiency. The element has been implemented into an open-source finite element code. I will show a\nf avorable comparison with standard beam elements formulated in the finite-s train framework and with\nanalytical solutions. Several extensions of the proposed approach\, including curved initial geometry\, follower pressure load\, and beam-to-beam contact will be also discussed. This is joint wor k with M. Jirásek and E. La Malfa Ribolla.\n\n\nREFERENCES\n\n\n[1] Jirá sek\, M.\,La Malfa Ribolla\, E.\, and Horák\, M. Efficient finite differe nce formulation of a ge-ometrically nonlinear beam element. International Journal for Numerical Methods in Engineering\,(2021) 122:7013–7053.\n\n\ n[2] Horák\, M.\, La Malfa Ribolla\, E.\, and Jirásek\, M. Efficient for mulation of a two-noded geometrically exact curved beam element. Internati onal Journal for Numerical Methods in Engineering\, (2022)\, accepted for publication.\n LOCATION:https://researchseminars.org/talk/NSCM/76/ END:VEVENT BEGIN:VEVENT SUMMARY:Bohumír Bastl (University of West Bohemia) DTSTART:20221024T134000Z DTEND:20221024T151000Z DTSTAMP:20260405T094550Z UID:NSCM/77 DESCRIPTION:Title: Nu merical simulation of incompressible fluid flow with the help of isogeomet ric analysis\nby Bohumír Bastl (University of West Bohemia) as part o f Nečas Seminar on Continuum Mechanics\n\n\nAbstract\nIsogeometric analys is is a relatively recently introduced concept for numerical\nsolving of p artial differential equations which bridges the gap between\ngeometric mod elling and numerical simulation/analysis.\n\nIn this talk\, the isogeometr ic analysis is used for numerical simulation of\nincompressible fluid flow . We give an overview of the method which shares many\nfeatures with Finit e Element Method\, but different meshes and basis functions\nalso lead to significant differences. We present advantages and drawbacks of the\nmetho d which we have encountered during development of incompressible turbulent \nflow solver and we focus on our results concerning isogeometric mesh gen eration\,\nstabilization methods and solving systems of linear equations i n this context.\n LOCATION:https://researchseminars.org/talk/NSCM/77/ END:VEVENT BEGIN:VEVENT SUMMARY:John Simon (Institute of Mathematics\, Czech Academy of Sciences) DTSTART:20221114T144000Z DTEND:20221114T161000Z DTSTAMP:20260405T094550Z UID:NSCM/78 DESCRIPTION:Title: A NAIVE FORMULATION OF MAXIMIZING THE COMPUTATIONAL CAPABILITY OF THE TWIN V ORTEX COMPUTER VIA SHAPE OPTIMIZATION\nby John Simon (Institute of Mat hematics\, Czech Academy of Sciences) as part of Nečas Seminar on Continu um Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Phys ics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nPhysica l reservoir computing is a new computational paradigm based on recurrent n eural networks\nwhere instead of optimizing nodal connection of the intern al network\, one gets to utilize the nonlinear behavior of\nphysical syste ms and gets to focus on optimizing a minimal number parameters. In 2021\, Goto et al [1] investigated\na physical reservoir computer in the context of a flow past a cylinder and shown that the computer’s computational\nc apability is maximized at the bifurcation point between the generation of twin vortex and the onset of Karman vortex.\nIn this exposition\, the auth ors illustrated how the the dynamics of twin vortex affects the ability of the computer to\naccomplish certain tasks. In particular\, they have show n that the length of the twin vortex is directly proportional to\nthe perf ormance.\nIn this talk\, a shape optimization problem that aims to increas e the said capability will be presented. The op-\ntimization problem is a naive formulation by maximizing two types of functional which has been his torically used a\nquantifiers of vortex\, namely\, the L2-norm of the curl of the velocity and the positivity of the determinant of the velocity\ngr adient. The optimization problem is regularized by a perimeter functional which acts as a Tikhonov regularizer. A\nvolume constraint is also imposed \, which — together with the regularizer — prevents possible topologic al changes in\nthe domain. The analysis of this problem includes existence analysis of the governing state\, establishing the existence\nof shape so lutions\, and sensitivity of the objective functional with respect to doma in perturbation. We shall then utilize\nthe results of the sensitivity ana lysis to a gradient descent-type algorithm for numerical illustrations.\n\ n[1] K. Goto\, K. Nakajima\, and H. Notsu\, Twin vortex computer in fluid flow\, New J. Phys.\, 23 (2021)\, p. 063051\,\nhttps://doi.org/doi.org/10. 1088/1367-2630/ac024d.\n LOCATION:https://researchseminars.org/talk/NSCM/78/ END:VEVENT BEGIN:VEVENT SUMMARY:Jiří Mikyška (Faculty of Nuclear Sciences and Physical Engineer ing\, Czech Tech. University) DTSTART:20221017T134000Z DTEND:20221017T151000Z DTSTAMP:20260405T094550Z UID:NSCM/79 DESCRIPTION:Title: An alternative model of multicomponent diffusion based on a combination of t he Maxwell-Stefan theory and continuum mechanics.\nby Jiří Mikyška (Faculty of Nuclear Sciences and Physical Engineering\, Czech Tech. Univer sity) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokol ovská 83 Prague 8..\n\nAbstract\nI will present a theory of multicompone nt mixtures that do not employ any splitting of component fluxes\ninto con vective and diffusive parts. Instead\, momentum balance is formulated indi vidually for each\ncomponent in which both 1) viscous friction within a co mponent\, and 2) momentum exchange among different\ncomponents\, are taken into account. While viscous friction is described using the Newtonian str ess\ntensor\, the Maxwell-Stefan theory is used to describe the momentum e xchange among different components.\nWhen the viscosity is neglected\, the model of an ideal mixture of ideal gases leads to a hyperbolic system of\ nconservation laws. For the non-ideal mixtures\, we obtain the first-order system in a non-conservative form.\nA simplified version of the model is discretized using a combination of the finite volume method and the\nmixed -hybrid finite element method. Numerical examples are provided to show the typical behavior of the\nsolution of the model equations.\n LOCATION:https://researchseminars.org/talk/NSCM/79/ END:VEVENT BEGIN:VEVENT SUMMARY:Dallas Albritton (Princeton University) DTSTART:20221205T144000Z DTEND:20221205T151000Z DTSTAMP:20260405T094550Z UID:NSCM/80 DESCRIPTION:Title: No n-uniqueness of Leray solutions to the forced Navier-Stokes equations\nby Dallas Albritton (Princeton University) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Institute of Mathematics\, Žitn á 25\, Praha 1\, library.\n\nAbstract\nIn a seminal work\, Leray demonstr ated the existence of\nglobal weak solutions to the Navier-Stokes equation s in three\ndimensions. Are Leray's solutions unique? This is a fundamenta l\nquestion in mathematical hydrodynamics\, which we answer in the\nnegati ve within the `forced' category\, by exhibiting two distinct\nLeray soluti ons with zero initial velocity and identical body force.\n\nThis is joint work with Elia Brué and Maria Colombo.\n LOCATION:https://researchseminars.org/talk/NSCM/80/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20230109T144000Z DTEND:20230109T161000Z DTSTAMP:20260405T094550Z UID:NSCM/81 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/81/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20230116T144000Z DTEND:20230116T161000Z DTSTAMP:20260405T094550Z UID:NSCM/82 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/82/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20230123T144000Z DTEND:20230123T161000Z DTSTAMP:20260405T094550Z UID:NSCM/83 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/83/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20230130T144000Z DTEND:20230130T161000Z DTSTAMP:20260405T094550Z UID:NSCM/84 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/84/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20230206T144000Z DTEND:20230206T161000Z DTSTAMP:20260405T094550Z UID:NSCM/85 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/85/ END:VEVENT BEGIN:VEVENT SUMMARY:Cy Maor (Hebrew University of Jerusalem) DTSTART:20230320T144000Z DTEND:20230320T161000Z DTSTAMP:20260405T094550Z UID:NSCM/86 DESCRIPTION:Title: No n-Euclidean elasticity: shape transitions in non-Euclidean ribbons\nby Cy Maor (Hebrew University of Jerusalem) as part of Nečas Seminar on Con tinuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nMan y bodies in nature that undergo inhomogeneous growth/shrinkage become "pre -strained"\; that is\, they are stressed even in the absence of external f orces. They are typically modeled by having an intrinsic non-flat metric\, giving rise to non-Euclidean elasticity.\nOf particular interest are thin bodies: shell-like\, rod-like or ribbon-like bodies (e.g.\, leaves or sup ramolecular assemblies)\, which exhibit interesting energy-driven patterns . In this talk I will describe the model of non-Euclidean elasticity\, and then focus on thin bodies\, the relations between their intrinsic curvatu re and their elastic behavior\, and specifically on shape transitions in n on-Euclidean ribbons.\n LOCATION:https://researchseminars.org/talk/NSCM/86/ END:VEVENT BEGIN:VEVENT SUMMARY:Easter Monday DTSTART:20230410T134000Z DTEND:20230410T151000Z DTSTAMP:20260405T094550Z UID:NSCM/87 DESCRIPTION:by Easter Monday as part of Nečas Seminar on Continuum Mechan ics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Cha rles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/87/ END:VEVENT BEGIN:VEVENT SUMMARY:Holiday DTSTART:20230501T134000Z DTEND:20230501T151000Z DTSTAMP:20260405T094550Z UID:NSCM/88 DESCRIPTION:by Holiday as part of Nečas Seminar on Continuum Mechanics\n\ nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles U niversity\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/88/ END:VEVENT BEGIN:VEVENT SUMMARY:Holiday DTSTART:20230508T134000Z DTEND:20230508T151000Z DTSTAMP:20260405T094550Z UID:NSCM/89 DESCRIPTION:by Holiday as part of Nečas Seminar on Continuum Mechanics\n\ nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles U niversity\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/89/ END:VEVENT BEGIN:VEVENT SUMMARY:Petr Sváček (Faculty of Mechanical Engineering\, CTU) DTSTART:20230522T134000Z DTEND:20230522T151000Z DTSTAMP:20260405T094550Z UID:NSCM/90 DESCRIPTION:Title: On Application of Finite Element Method for Fluid-Structure-Acoustic Interac tions Related to Human Phonation Process\nby Petr Sváček (Faculty of Mechanical Engineering\, CTU) as part of Nečas Seminar on Continuum Mech anics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, C harles University\, Sokolovská 83 Prague 8..\n\nAbstract\nHuman voice is created by a complex process consisting of mutual\ninteractions of flowin g air\, vibrating vocal folds and the sound propagation\nthrough the vocal tract. The fundamental sound is created by the mutual\ninteraction of the flowing air with vibrations of vocal folds(VFs). The\narising fundamenta l sound is enriched by aeroacoustic sound sources and\npropagated through the vocal tract. In this talk\, mathematical models of a\nsimplified fluid -structure-acoustic interaction problem shall be\,\nnumerically discretize d and numerical results will be presented. In\nparticular the deformation of an elastic body representing the model of\nvocal folds will be consider ed in the interaction with the complex fluid\nflow and aeroacoustics. In p articular the attention will be paid to several\nimportant issues of such a modelling as the inclusion of the VFs contact\,\nchoice of suitable boun dary conditions\, the influence of pre-stressed vocal\nfold on the fundame ntal frequency\, etc. For the flow model the realization\nof the variation al multiscale method is discussed. The numerical\napproximation of the pro blem is presented and numerical results are shown.\n LOCATION:https://researchseminars.org/talk/NSCM/90/ END:VEVENT BEGIN:VEVENT SUMMARY:Xmas DTSTART:20221226T144000Z DTEND:20221226T161000Z DTSTAMP:20260405T094550Z UID:NSCM/91 DESCRIPTION:Title: no talk\nby Xmas as part of Nečas Seminar on Continuum Mechanics\n\nLec ture held in Room K3\, Faculty of Mathematics and Physics\, Charles Unive rsity\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/91/ END:VEVENT BEGIN:VEVENT SUMMARY:Gabriel Pathó (Dlubal Software CS) DTSTART:20221107T144000Z DTEND:20221107T161000Z DTSTAMP:20260405T094550Z UID:NSCM/92 DESCRIPTION:Title: Co nstitutive modelling of masonry for civil engineering\nby Gabriel Path ó (Dlubal Software CS) as part of Nečas Seminar on Continuum Mechanics\n \nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe discuss the macros cale modeling of masonry consisting of brick and mortar as a brittle mater ial and its implementation in the commercial software RFEM 6 which is conv enient for practical civil engineers and complies with both Eurocode 6 and available test data.\n LOCATION:https://researchseminars.org/talk/NSCM/92/ END:VEVENT BEGIN:VEVENT SUMMARY:cancelled DTSTART:20221128T144000Z DTEND:20221128T161000Z DTSTAMP:20260405T094550Z UID:NSCM/93 DESCRIPTION:Title: se minar is cancelled\nby cancelled as part of Nečas Seminar on Continuu m Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physi cs\, Charles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/93/ END:VEVENT BEGIN:VEVENT SUMMARY:Michael Růžička (University of Freiburg) DTSTART:20221205T161000Z DTEND:20221205T171000Z DTSTAMP:20260405T094550Z UID:NSCM/94 DESCRIPTION:Title: Ex istence proofs for pseudomonotone parabolic problems\nby Michael Růž ička (University of Freiburg) as part of Nečas Seminar on Continuum Mech anics\n\nLecture held in Institute of Mathematics\, Žitná 25\, Praha 1\ , library.\n\nAbstract\nIn the talk we discuss nonlinear parabolic problem s which \ncontain a pseudomonotone operator. A new notion of Bochner pseud omonotonicity is introduced and \napplied. Extensions to quasi non-conform ing and non-conforming Bochner pseudomonotonicity yield\nconvergence proo fs for fully discrete Rothe–Galerkin schemes in the framework of discre tely divergence free FE and DG methods.\n\nReferences\n[1] E. Baumle and M . Růžička: Note on the existence theory for evolution \nequations with pseudomonotone operators\, Ric. Mat.\, 2017.\n\n[2] S. Bartels\, M. Růži čka: Convergence of fully discrete implicit and \nsemi-implicit approxima tions of singular parabolic equations\, SIAM J. Numer. Anal.\, 2020.\n\n[3 ] A. Kaltenbach\, M. Růžička: Note on the existence theory for \npseudo -monotone evolution problems\, J. Evol. Equ.\, 2021.\n\n[4] L.C. Berselli\ , A. Kaltenbach\, M. Růžička: Analysis of fully \ndiscrete\, quasi non- conforming approximations of evolution equations and applications\, Math. Models \nMethods Appl. Sci.\, 2021.\n\n[5] A. Kaltenbach\, M. Růžička: Analysis of fully discrete\, non-conforming approximation of evolution eq uations and applications\, in preparation\, 2022.\n LOCATION:https://researchseminars.org/talk/NSCM/94/ END:VEVENT BEGIN:VEVENT SUMMARY:Sourav Mitra (Institute of Mathematics\, Czech Academy of Sciences ) DTSTART:20221212T144000Z DTEND:20221212T161000Z DTSTAMP:20260405T094550Z UID:NSCM/95 DESCRIPTION:Title: Ex istence of a weak solution for a compressible multicomponent fluid-structu re interaction problem\nby Sourav Mitra (Institute of Mathematics\, Cz ech Academy of Sciences) as part of Nečas Seminar on Continuum Mechanics\ n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nI will speak about o ur recent work on the analysis of a system of PDEs governing the interacti on between two compressible mutually noninteracting fluids and a shell of Koiter type encompassing a time-dependent 3D domain filled by the fluids. The dynamics of the fluids is modeled by compressible\nNavier-Stokes equat ions with a physically realistic pressure depending on the densities of bo th fluids. The shell constitutes the boundary of the fluid domain\, and it possesses a non-linear\, non-convex Koiter energy (of a quite general for m). We are interested in the existence of a weak solution to the system\nu ntil the time-dependent boundary approaches a self-intersection. We first prove a global existence result (until a degeneracy occurs) when the adiab atic exponents solve max{γ\, β} > 2 and min{γ\, β} > 0\, and further\, the densities are comparable. Next\, with a slightly extra regularity ass umption on the\ninitial structural displacement\, we extend our global exi stence result to the case max{γ\, β} ≥ 2 and min{γ\, β} > 0.\nIn the first part of the talk\, I will try to introduce the classical theory on the existence of weak solutions for compressible mono-fluid models. Next\, I will talk about our work on the multi-component FSI problem. This is jo int work with M. Kalousek and Š. Nečasová.\n LOCATION:https://researchseminars.org/talk/NSCM/95/ END:VEVENT BEGIN:VEVENT SUMMARY:Nilasis Chaudhuri (Imperial College London) DTSTART:20221219T144000Z DTEND:20221219T161000Z DTSTAMP:20260405T094550Z UID:NSCM/96 DESCRIPTION:Title: Na vier--Stokes--Fourier system with Dirichlet boundary conditions for temper ature\nby Nilasis Chaudhuri (Imperial College London) as part of Neča s Seminar on Continuum Mechanics\n\n\nAbstract\nIn this talk\, we consider the Navier--Stokes--Fourier system\,\ndescribing the motion of a compress ible\, viscous\, and heat conducting\nfluid in a bounded domain $\\Omega \ \subset R^d$\, $d =2\,3$\, with general\nnon-homogeneous Dirichlet boundar y conditions for the absolute\ntemperature. We introduce a new concept of weak solution based on the\nsatisfaction of the entropy inequality togethe r with a balance law for\nthe ballistic energy. We show the existence of g lobal-in-time weak\nsolutions\, as well as the weak--strong uniqueness pri nciple.\n LOCATION:https://researchseminars.org/talk/NSCM/96/ END:VEVENT BEGIN:VEVENT SUMMARY:Jiří Outrata (Czech Academy of Sciences\, Institute of Informati on Theory and Automation) DTSTART:20230102T144000Z DTEND:20230102T161000Z DTSTAMP:20260405T094550Z UID:NSCM/97 DESCRIPTION:Title: On the application of the SCD semismooth* Newton method to variational inequ alities of the second kind\nby Jiří Outrata (Czech Academy of Scienc es\, Institute of Information Theory and Automation) as part of Nečas Sem inar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathe matics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAb stract\nThe first part of the lecture deals with a description of the SCD (subspace containing\nderivative) mappings and the SCD semismooth* Newton method for the solution of general\ninclusions. This method is then applie d to a class of variational inequalities of the second\nkind. As a result\ , one obtains an implementable algorithm exhibiting a locally superlinear\ nconvergence. Finally\, we demonstrate the efficiency of a globalized vers ion of this method\nvia a Cournot-Nash equilibrium in which the objectives of the players (firms) are nonsmooth\ndue to the presence of the so-calle d cost of change. The problem is modeled as a variational\ninequality of t he second kind and\, to test the performance of the applied method\, one a dmits\nreally large numbers of players and produced commodities.\nJoint wo rk with: Helmut Gfrerer and Jan Valdman.\n LOCATION:https://researchseminars.org/talk/NSCM/97/ END:VEVENT BEGIN:VEVENT SUMMARY:Malte Kampschulte (Faculty of Mathematics and Physics\, Charles Un iversity) DTSTART:20230213T144000Z DTEND:20230213T161000Z DTSTAMP:20260405T094550Z UID:NSCM/98 DESCRIPTION:Title: Se lf-contact for inertial problems in continuum mechanics\nby Malte Kamp schulte (Faculty of Mathematics and Physics\, Charles University) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Fac ulty of Mathematics and Physics\, Charles University\, Sokolovská 83 Pra gue 8..\n\nAbstract\nThere are many theories about elastic collisions of s olids and the resulting inertial evolution. What unifies most of them is t hat they involve some phenomenological assumption. The aim of this talk is to present a recent result which shows that for the self-collision of ela stic bulk solids\, it is in fact sufficient to consider matter non-interpe netration. Based only on this\, we are able to derive existence of weak so lutions including contact with obstacles and self-contact for arbitrary la rge times and for large deformations. Additionally we are able to precisel y characterize the contact forces as a vector-valued measure. This is base d on joint works with A. Češík\, and G. Gravina.\n LOCATION:https://researchseminars.org/talk/NSCM/98/ END:VEVENT BEGIN:VEVENT SUMMARY:Ivan Gudoshnikov (Institute of Mathematics\, Czech Academy of Scie nces) DTSTART:20230220T144000Z DTEND:20230220T161000Z DTSTAMP:20260405T094550Z UID:NSCM/99 DESCRIPTION:Title: El astoplasticity with softening in spring network models: a state-dependent sweeping process approach\nby Ivan Gudoshnikov (Institute of Mathemat ics\, Czech Academy of Sciences) as part of Nečas Seminar on Continuum Me chanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nSoftening pl asticity and Gurson model of damage in particular lead to ill-posed mathem atical\nproblems due to the loss of monotonicity. Multiple co-existing sol utions are possible when softening\nelements are coupled together\, and so lutions cannot be continued beyond the point of complete\nfailure of a mat erial. Moreover\, spatially continuous models with softening suffer from l ocalization\nof strains and stresses to measure-zero submanifolds.\nWe for mulate a problem of quasistatic evolution of elasto-plastic spring network s (Lattice Spring\nModels) with a plastic flow rule which describes linear hardening\, linear softening and perfectly\nplastic springs in a uniform manner. The fundamental kinematic and static characteristics of the\nnetwo rk are described by the rigidity theory and structural mechanics.\nTo solv e the evolution problem we convert it to a type of a differential quasi-va riational inequality known as the state-dependent sweeping process. We pro ve the existence of solution to the\nassociated time-stepping problem (imp licit catch-up algorithm)\, and the estimates we obtain imply\nthe existen ce of a solution to the (time-continuous) sweeping process.\nUsing numeric al simulations of regular grid-shaped networks with softening we demonstra te\nthe development of non-symmetric shear bands. At the same time\, in to y examples it is easy to\nanalytically derive multiple co-existing solutio ns\, appearing in a bifurcation which happens when\nthe parameters of the networks continuously change from hardening through perfect plasticity to\ nsoftening.\n LOCATION:https://researchseminars.org/talk/NSCM/99/ END:VEVENT BEGIN:VEVENT SUMMARY:Pei Su (Charles University\, Faculty of Mathematics and Physics) DTSTART:20230227T144000Z DTEND:20230227T161000Z DTSTAMP:20260405T094550Z UID:NSCM/100 DESCRIPTION:Title: A symptotic analysis of the system describing a small moving rigid body in v iscous incompressible fluid\nby Pei Su (Charles University\, Faculty o f Mathematics and Physics) as part of Nečas Seminar on Continuum Mechanic s\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charl es University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe consider the in teraction between a viscous incompressible fluid and a\nsmall rigid body\, which is immersed in the fluid. The fluid is modeled by\nthe 3D Navier-St okes equations. The motion of the body obeys the conservation of linear an d angular momentum. We assume that the density of the\nbody is constant wh ich is independent of the size of the body ε. Based on\nthe L\np − L\nq \nestimate of the so-called fluid-structure semigroup\, we obtain a\nunifo rm estimate for the velocity of the body. In particular\, we show that\nth ese estimates are ε-invariant. This help us to construct an approximation \nsequence of the test functions of the fluid-body system. We prove that t he solution of the fluid-body system\, in appropriate sense\, converges to a solution\nof the Navier-Stokes equations as ε → 0.\nThis is a joint work with Jiao He (Univerist´e Paris-Sud).\n LOCATION:https://researchseminars.org/talk/NSCM/100/ END:VEVENT BEGIN:VEVENT SUMMARY:Edoardo Mainini (University of Genoa) DTSTART:20230306T144000Z DTEND:20230306T161000Z DTSTAMP:20260405T094550Z UID:NSCM/101 DESCRIPTION:Title: S tability conditions for the linearization of pure traction problems of fin ite elasticity.\nby Edoardo Mainini (University of Genoa) as part of N ečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe discuss the linearization of finite elasticity by mean s of Gamma-convergence for the case of pure traction problems. For hyperel astic bodies subject to equilibrated force fields\, the limit energy can b e different from the global energy of linear elasticity subject to the sam e force field. However\, under a suitable curl constraint\, we show that t he linear elastic equilibrium can be obtained as limit of local minimizers of finite elasticity. This is joint work with Roberto Ognibene and Danilo Percivale.\n LOCATION:https://researchseminars.org/talk/NSCM/101/ END:VEVENT BEGIN:VEVENT SUMMARY:Monika Balaszová (Facaulty of Mathematics and Physics\, Charles U niversity) DTSTART:20230515T134000Z DTEND:20230515T151000Z DTSTAMP:20260405T094550Z UID:NSCM/102 DESCRIPTION:Title: D iscontinuous Galerkin method for problems in time-depend domains – theor y and applications\nby Monika Balaszová (Facaulty of Mathematics and Physics\, Charles University) as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\n\nAbstract\nMost of the the oretical mathematical results on the solvability and numerical analysis of nonstationary partial differential equations are obtained under the assum ption that a space domain is independent of time. However\, problems in ti me-dependent domains are important in a number of areas of science and tec hnology. This is particularly the case of fluid-structure interaction prob lems\, when the flow is solved in a domain deformed due to the coupling wi th an elastic structure. There are various approaches to the solution of p roblems in time-dependent domains\, a very popular technique is the arbitr ary Lagrangian-Eulerian (ALE) method. In this talk we present an ALE versi on of the space-time discontinuous Galerkin method\, which is based on pie cewise polynomial approximations over finite element meshes\, in general d iscontinuous on interfaces between neighbouring elements. We show that the proposed method is numerically unconditionally stable and demonstrate its robustness on a numerical solution of the nonlinear elasticity benchmark problem. The developed method is also applied to the numerical simulation of air flow in a simplified model of human vocal tract and flow induced vo cal folds vibrations.\n LOCATION:https://researchseminars.org/talk/NSCM/102/ END:VEVENT BEGIN:VEVENT SUMMARY:Florian Oschmann (Institute of Mathematics AS CR) DTSTART:20230313T144000Z DTEND:20230313T161000Z DTSTAMP:20260405T094550Z UID:NSCM/103 DESCRIPTION:Title: S ome insides in homogenization of compressible Navier-Stokes equations\ nby Florian Oschmann (Institute of Mathematics AS CR) as part of Nečas Se minar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Math ematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nA bstract\nWe investigate the homogenization of the two- and\nthree-dimensio nal unsteady compressible Navier-Stokes equations\, and\nshow (i) the conv ergence result for the 2D case\, and (ii) a better lower\nbound for the ad iabatic exponent occurring in the pressure law for the\n3D case. The latte r will be covered with two different proofs. Lastly\,\nwe briefly discuss the optimality of the achieved bounds for the\nadiabatic exponent in terms of the underlying space-time dimension. This\nis joint work with Šárka Nečasová (CAS) and Milan Pokorný\n(Charles University).\n LOCATION:https://researchseminars.org/talk/NSCM/103/ END:VEVENT BEGIN:VEVENT SUMMARY:Marco Morandotti (Politecnico di Torino) DTSTART:20230403T134000Z DTEND:20230403T151000Z DTSTAMP:20260405T094550Z UID:NSCM/104 DESCRIPTION:Title: S emi-discrete modeling of systems of disclinations and dislocations\nby Marco Morandotti (Politecnico di Torino) as part of Nečas Seminar on Con tinuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nDis clinations in crystalline materials are point defects that are responsible for rotational kinematic incompatibility. They are characterised by the s o-called Frank angle\, measuring the severity of the lattice mismatch. In a two-dimensional medium under the assumption of plain strain\, the Airy s tress function can be used to translate the measure of incompatibility int o a fourth-order PDE with measure data. \n\nWe propose a variational model for disclinations in two-dimensional materials by means of the core-radiu s approach. Moreover\, we identify a good scaling regime in which we study the effective behaviour of dipoles of disclinations (of opposite signs)\, thus validating analytically the results obtained in [Eshelby\, 1966]: a dipole of plane disclinations generates an edge dislocation with Burgers v ector perpendicular to the dipole axis. Finally\, we study the energy of a system of a finite number of dipoles of disclinations and recover the res ults of [Cermelli-Leoni\, 2005] for edge dislocations.\n\n \n\nThis is wor k in collaboration with Pierluigi Cesana (Kyushu University) and Lucia De Luca (CNR Rome).\n LOCATION:https://researchseminars.org/talk/NSCM/104/ END:VEVENT BEGIN:VEVENT SUMMARY:Franco Tomarelli (Politecnico di Milano) DTSTART:20230424T134000Z DTEND:20230424T151000Z DTSTAMP:20260405T094550Z UID:NSCM/105 DESCRIPTION:Title: P ure traction and Signorini problem between linear and finite elasticity\nby Franco Tomarelli (Politecnico di Milano) as part of Nečas Seminar o n Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract \nA limit elastic energy for pure traction problem is derived from re-scal ed nonlinear energies of a\nhyper-elastic material body subject to an equi librated force field.\nWe show that the strains of minimizing sequences as sociated to re-scaled nonlinear energies weakly\nconverge\, up to subseque nces\, to the strains of minimizers of a limit energy.\nThe limit energy f unctional exhibits a gap that makes it different from the classical linear elasticity\nfunctional. Nevertheless a suitable compatibility condition e ntails the coincidence of related minima\nand minimizers\, hence the rigor ous validation of linear elasticity. Strong violation of this condition\np rovides a limit energy which is unbounded from below\, while a mild violat ion may produce\nunboundedness of strains and a limit energy which has inf initely many extra minimizers which are\nnot minimizers of standard linear elastic energy. As a consequence\, a rigorous validation of linear\nelast icity fails for compressive force fields that infringe such a compatibilit y condition.\nThis phenomenon has relevant consequences also on the valida tion of the Signorini problem in\nlinear elasticity: there are loads pushi ng the body against the obstacle\, but unfit for the geometry of\nthe whol e system body-obstacle\, so that the corresponding variational limit turns out to be different\nfrom the classical Signorini problem. However\, if t he force field acting on the body fulfils an\nappropriate geometric admiss ibility condition\, we can show coincidence of related solutions.\nThe asy mptotic analysis provides a sharp and rigorous variational justification o f the unilateral\nproblem in linear elasticity\, together with an accurate analysis of the unilateral constraint.\nThese results were obtained in a joint research with Francesco Maddalena (Politecnico di Bari) and\nDanilo Percivale (Università di Genova).\n LOCATION:https://researchseminars.org/talk/NSCM/105/ END:VEVENT BEGIN:VEVENT SUMMARY:Manuel Friedrich (University of Erlangen) DTSTART:20230327T134000Z DTEND:20230327T151000Z DTSTAMP:20260405T094550Z UID:NSCM/106 DESCRIPTION:Title: F inite crystallization via stratification\nby Manuel Friedrich (Univers ity of Erlangen) as part of Nečas Seminar on Continuum Mechanics\n\nLectu re held in Room K3\, Faculty of Mathematics and Physics\, Charles Univers ity\, Sokolovská 83 Prague 8..\n\nAbstract\nIn this talk\, I present a n ew technique to prove two-dimensional\ncrystallization results in the squa re lattice for finite particle\nsystems. We consider configurational energ ies featuring two-body\nshort-ranged particle interactions and three-body angular potentials\nfavoring bond-angles of the square lattice. To each co nfiguration\, we\nassociate its bond graph which is then suitably modified by identifying\nchains of successive atoms. This method\, called stratifi cation\, reduces\nthe crystallization problem to a simple minimization tha t corresponds to\na proof via slicing of the isoperimetric inequality in l 1. Based on\njoint work with Leonard Kreutz.\n LOCATION:https://researchseminars.org/talk/NSCM/106/ END:VEVENT BEGIN:VEVENT SUMMARY:Katerina Nik (University of Vienna) DTSTART:20230417T134000Z DTEND:20230417T151000Z DTSTAMP:20260405T094550Z UID:NSCM/107 DESCRIPTION:Title: A nalysis of a three-dimensional model for MEMS with a hinged upper plate\nby Katerina Nik (University of Vienna) as part of Nečas Seminar on Con tinuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nAn idealized electrostatic microelectromechanical system (MEMS) consists of a rigid ground plate above which a thin elastic plate is suspended. The ela stic plate is assumed to be hinged on its boundary. Applying a voltage dif ference between the two plates induces a Coulomb force that deforms the el astic plate. The corresponding mathematical model couples a fourth-order p arabolic equation for the vertical deformation of the elastic plate to the harmonic electrostatic potential in the free domain between the two plate s. In this talk\, I will present some recent results on local and global w ell-posedness of the model as well as on existence and non-existence of st ationary solutions.\n LOCATION:https://researchseminars.org/talk/NSCM/107/ END:VEVENT BEGIN:VEVENT SUMMARY:Semester break DTSTART:20230529T134000Z DTEND:20230529T151000Z DTSTAMP:20260405T094550Z UID:NSCM/108 DESCRIPTION:Title: W e'll go on in October 2023\nby Semester break as part of Nečas Semina r on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathemat ics and Physics\, Charles University\, Sokolovská 83 Prague 8..\nAbstrac t: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/108/ END:VEVENT BEGIN:VEVENT SUMMARY:semestr break DTSTART:20230904T134000Z DTEND:20230904T151000Z DTSTAMP:20260405T094550Z UID:NSCM/109 DESCRIPTION:by semestr break as part of Nečas Seminar on Continuum Mechan ics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Cha rles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/109/ END:VEVENT BEGIN:VEVENT SUMMARY:semestr break DTSTART:20230911T134000Z DTEND:20230911T151000Z DTSTAMP:20260405T094550Z UID:NSCM/110 DESCRIPTION:by semestr break as part of Nečas Seminar on Continuum Mechan ics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Cha rles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/110/ END:VEVENT BEGIN:VEVENT SUMMARY:semestr break DTSTART:20230918T134000Z DTEND:20230918T151000Z DTSTAMP:20260405T094550Z UID:NSCM/111 DESCRIPTION:by semestr break as part of Nečas Seminar on Continuum Mechan ics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Cha rles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/111/ END:VEVENT BEGIN:VEVENT SUMMARY:semestr break DTSTART:20230925T134000Z DTEND:20230925T151000Z DTSTAMP:20260405T094550Z UID:NSCM/112 DESCRIPTION:by semestr break as part of Nečas Seminar on Continuum Mechan ics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Cha rles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/112/ END:VEVENT BEGIN:VEVENT SUMMARY:Angkana Rüland (University of Bonn) DTSTART:20231002T134000Z DTEND:20231002T151000Z DTSTAMP:20260405T094550Z UID:NSCM/113 DESCRIPTION:Title: R igidity and Flexibility in the Modelling of Shape-Memory Alloys\nby An gkana Rüland (University of Bonn) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics \, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nIn the mod elling of shape-memory alloys\, a striking dichotomy between rigid and fle xible behaviour emerges: On the one hand\, in many physically relevant set tings\, exactly stress-free structures of sufficiently high regularity can be shown to satisfy the kinematic compatibility conditions given by the c haracteristics of the compatibility equations. The solutions are rigid. On the other hand\, when dropping these regularity conditions\, the method o f convex integration shows that a plethora of wild\, irregular solutions e xist which do not satisfy the kinematic conditions in general. These solut ions can approximate a large class of boundary data and are thus flexible. In this talk\, I discuss an approach towards investigating this dichotomy in more detail based on scaling laws. For a class of simplified models\, we show that the complexity of the microstructure is captured by these sca ling laws both in settings with displacement and with nucleation boundary conditions.\n\nThe talk is based on joint work with P. Cesana\, F. Della P orta\, J. M. Taylor\, A. Tribuzio\, Ch. Zillinger\, B. Zwicknagl.\n LOCATION:https://researchseminars.org/talk/NSCM/113/ END:VEVENT BEGIN:VEVENT SUMMARY:Illia Donhauzer (La Trobe University) DTSTART:20231009T134000Z DTEND:20231009T151000Z DTSTAMP:20260405T094550Z UID:NSCM/114 DESCRIPTION:Title: L imit theorems for multifractal products of random fields\nby Illia D onhauzer (La Trobe University) as part of Nečas Seminar on Continuum Mech anics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, C harles University\, Sokolovská 83 Prague 8..\n\nAbstract\nThe talk is ab out random functions with changing local regularity\n exponent (multifract al processes and multifractal fields in multidimensional\n cases). This ty pe of random function has been observed in various areas\n including commu nication systems\, precipitation fields\, econometrics\, and so\n on. The goal of this talk is to present new results in the modeling of\n multifrac tal random functions. One of the possible approaches to obtain\n multifrac tal random functions is as limits of multifractal products of\n random fun ctions (roughly speaking\, integrals of infinite products of random\n func tions). In the talk\, I will show new results on the existence of those\n limits in the spaces Lq as well as new results on the rate of convergence. \n The developed methodology is also applied to multidimensional multifrac tal\n measures. Finally\, I will show a new class of examples of geometric \n φ-sub-Gaussian random functions when the general assumptions have a si mple\n form and can be expressed in terms of covariance functions only.\n LOCATION:https://researchseminars.org/talk/NSCM/114/ END:VEVENT BEGIN:VEVENT SUMMARY:Kerrek Stinson (University of Bonn) DTSTART:20240108T144000Z DTEND:20240108T161000Z DTSTAMP:20260405T094550Z UID:NSCM/115 DESCRIPTION:Title: R egularity for minimizers of the Griffith fracture energy\nby Kerrek St inson (University of Bonn) as part of Nečas Seminar on Continuum Mechanic s\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charl es University\, Sokolovská 83 Prague 8..\n\nAbstract\nThe Griffith crite rion says that the energy to crack a brittle\nelastic material is proporti onal to the length of the crack. Understanding\nthe regularity of minimize rs requires unraveling the complex interplay of\nbulk (elastic) and surfac e (crack) energies in the vectorial setting of\nlinearized frame indiffere nce. In dimension 2\, we prove that the crack of a\nminimizer is given by a $C^{1\,\\alpha}$ surface outside of a singular set of\npoints that has d imension strictly less than 1\, analogous to results for the\nscalar Mumfo rd-Shah functional. Joint work with Manuel Friedrich (FAU) and\nCamille La bourie (UPS).\n LOCATION:https://researchseminars.org/talk/NSCM/115/ END:VEVENT BEGIN:VEVENT SUMMARY:Valentin Calisti (Institute of Mathematics\, Czech Academy of Scie nces) DTSTART:20231030T144000Z DTEND:20231030T161000Z DTSTAMP:20260405T094550Z UID:NSCM/116 DESCRIPTION:Title: M inimization of blood damage induced by non-Newtonian fluid flows in moving domains\nby Valentin Calisti (Institute of Mathematics\, Czech Academ y of Sciences) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Universit y\, Sokolovská 83 Prague 8..\n\nAbstract\nMany engineering works are int erested in the parametric optimization of\nblood pumps to minimize hemolys is (destruction of red blood cells).\nIn order to generalize this approach \, we study the shape continuity of a\ncoupled system of PDEs modeling blo od flows and hemolysis evolution in\nmoving domains\, governed respectivel y by generalized Navier-Stokes and\ntransport equations.\n\nFirst\, the sh ape continuity of the blood flow solutions is shown. This\ndevelopment\, w hich extends the one led in (Sokolowski\, Stebel\, Evol.\nEqu. Control The ory\, 2014) to the case of shear thinning fluids\, is\nbased on the recent progress made in (Nägele\, Ružička\, J. Differential\nEquations\, 2018 )\, adapted to the present framework of a sequence of\nconverging moving d omains.\n\nAfter calculating blood flows solutions\, the velocity and stre ss fields\nare used as coefficients and r.h.s for the transport equation g overning\nthe evolution of the hemolysis rate. From this\, the shape conti nuity of\nthe hemolysis rate is also proved.\n\nFinally\, these results al low to show the existence of minimum for a\nclass of shape optimization pr oblems based on the minimization of the\nhemolysis rate\, in the framework of moving domains.\n LOCATION:https://researchseminars.org/talk/NSCM/116/ END:VEVENT BEGIN:VEVENT SUMMARY:CANCELLED DTSTART:20231211T144000Z DTEND:20231211T161000Z DTSTAMP:20260405T094550Z UID:NSCM/117 DESCRIPTION:by CANCELLED as part of Nečas Seminar on Continuum Mechanics\ n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe discuss the stabi lity of objective structures of interacting atoms that form a far-reaching generalization of crystal lattices. To this end\, we use methods from har monic analysis to set up a second derivative test of the configurational e nergy at equilibria\, a key point being the identification of a carefully chosen seminorm with respect to which coercivity is estimated. In particul ar\, a novel discrete Korn-type inequality is established in the setting o f objective structures. We also provide an efficient algorithm to check fo r atomistic stability\, which we illustrate numerically for a general carb on nanotube. (This is joint work with M. Steinbach\, Augsburg).\n LOCATION:https://researchseminars.org/talk/NSCM/117/ END:VEVENT BEGIN:VEVENT SUMMARY:Anastasia Molchanova (University of Vienna) DTSTART:20231204T144000Z DTEND:20231204T161000Z DTSTAMP:20260405T094550Z UID:NSCM/118 DESCRIPTION:Title: V ariational Model of a Hyperelastic Capacitor\nby Anastasia Molchanova (University of Vienna) as part of Nečas Seminar on Continuum Mechanics\n\ nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles U niversity\, Sokolovská 83 Prague 8..\n\nAbstract\nThis talk discusses an interplay between elastic deformations and electrostatic capacitance for charged elastic materials. We consider a variational model\, where electro elastic energy involves coupling elastic response and electrostatics using a capacitary term naturally defined in Eulerian coordinates. The ensuing electroelastic energy is then of mixed Lagrangian-Eulerian type. We study the continuity properties of the capacitary terms under the convergence of the deformations and prove the existence of minimizers.\n LOCATION:https://researchseminars.org/talk/NSCM/118/ END:VEVENT BEGIN:VEVENT SUMMARY:Jiří Zeman (Faculty of Mathematics and Physics\, Charles Univers ity) DTSTART:20231106T144000Z DTEND:20231106T161000Z DTSTAMP:20260405T094550Z UID:NSCM/119 DESCRIPTION:Title: B ending-torsion theories for elastic and brittle nanowires as Gamma-limits of atomistic models\nby Jiří Zeman (Faculty of Mathematics and Physi cs\, Charles University) as part of Nečas Seminar on Continuum Mechanics\ n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nNanotechnology has r anked among paradigm-shifting and the fastest growing research areas over the last 30 years. To benefit from the wide application prospects of engin eered nanoworld objects\, it is important to study their mechanical respon se\, which often differs from that of macroscopic bodies\, though (because of size or structure effects for example). In particular\, there exist ro d-like structures in nanoengineering which are long enough in one directio n for continuum theories to be applicable\, but in the perpendicular direc tion\, they have a diameter on the scale of tens to hundreds of atoms. In this talk\, derivation of nonlinear continuum models for thin and ultrathi n rods will be presented. We start from a 3D crystalline lattice with shor t-range interactions and study simultaneous limits of vanishing rod thickn ess and interatomic distance. Gamma-convergence especially yields a novel theory for inextensible rods that undergo bending\, torsion\, and brittle fracture. New discrete and surface terms appear in the limiting energy fun ctional\, whose fracture part is expressed by an implicit cell formula tha t covers different modes of fracture\, including (complete) cracks\, folds and torsional cracks. Joint work with Bernd Schmidt (Augsburg).\n LOCATION:https://researchseminars.org/talk/NSCM/119/ END:VEVENT BEGIN:VEVENT SUMMARY:Stefano Almi (University of Naples) DTSTART:20231127T144000Z DTEND:20231127T161000Z DTSTAMP:20260405T094550Z UID:NSCM/120 DESCRIPTION:Title: S train gradient plasticity and multi-well potentials\nby Stefano Almi ( University of Naples) as part of Nečas Seminar on Continuum Mechanics\n\n Lecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Un iversity\, Sokolovská 83 Prague 8..\n\nAbstract\nI will present a strain -gradient plasticity model obtained as\n$\\Gamma$-limit of a nonlinear fin ite dislocation model characterised by\na multiple-well potential and a si ngular perturbation term accounting\nfor the divergence of the strain fiel d. The analysis builds upon a new\nquantitative rigidity estimate for inco mpatible fields in presence of a\nmultiwell elastic energy\, showing that the $L^{1^{*}}$-distance of a\nstrain field from a single well is controll ed in terms of the\n$L^{1^{*}}$-distance from a finite set of wells\, of c url $\\beta$\, and\nof ${\\rm div} \\beta$. This is a joint work with Dari o Reggiani (Scuola\nSuperiore Meridionale) and Francesco Solombrino (Unive rsity of Naples\nFederico II).\n LOCATION:https://researchseminars.org/talk/NSCM/120/ END:VEVENT BEGIN:VEVENT SUMMARY:Xmas DTSTART:20231225T144000Z DTEND:20231225T161000Z DTSTAMP:20260405T094550Z UID:NSCM/121 DESCRIPTION:by Xmas as part of Nečas Seminar on Continuum Mechanics\n\nLe cture held in Room K3\, Faculty of Mathematics and Physics\, Charles Univ ersity\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/121/ END:VEVENT BEGIN:VEVENT SUMMARY:Raffaele Grande (Czech Academy of Sciences\, Institute of Informat ion Theory and Automation) DTSTART:20231023T134000Z DTEND:20231023T151000Z DTSTAMP:20260405T094550Z UID:NSCM/122 DESCRIPTION:Title: S tochastic control problems and a convergence result for horizontal mean cu rvature flow\nby Raffaele Grande (Czech Academy of Sciences\, Institut e of Information Theory and Automation) as part of Nečas Seminar on Conti nuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Ph ysics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nThe e volution by horizontal mean curvature flow was broadly studied for its app lications in neurogeometry and in image processing (e.g. Citti-Sarti model ). It represents the contracting evolution of a hypersurface embedded in a particular geometrical setting\, called sub-Riemannian geometry\, in whic h only some curves (called horizontal curves) are admissible by definition . This may lead to the existence of some points of the hypersurface\, call ed characteristic\, in which is not possible to define the so-called horiz ontal normal. To avoid this problem\, it is possible to use the notion of Riemannian approximation of a sub-Riemannian geometry applied to the horiz ontal mean curvature flow.\n\nI will show the connection between the evolu tion of a generic hypersurface in this setting and the associated stochast ic optimal control problem. Then\, I will show some results of asymptotic optimal controls in the Heisenberg group and use them to show later a conv ergence result between the solutions of the approximated mean curvature fl ow and the horizontal ones. This is from some joint works with N. Dirr and F. Dragoni.\n LOCATION:https://researchseminars.org/talk/NSCM/122/ END:VEVENT BEGIN:VEVENT SUMMARY:Tomáš Bodnár (Faculty of Mechanical Engineering\, Czech Technic al University) DTSTART:20231016T134000Z DTEND:20231016T151000Z DTSTAMP:20260405T094550Z UID:NSCM/123 DESCRIPTION:Title: O n the estimation of blood hemolysis index from viscoelastic stretch model< /a>\nby Tomáš Bodnár (Faculty of Mechanical Engineering\, Czech Technic al University) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Universit y\, Sokolovská 83 Prague 8..\n\nAbstract\nThis contribution presents an alternative way of estimating the blood damage\nhemolysis index using the viscoelastic stretch tensor. This tensor is obtained\nby solving a set of coupled partial differential equations describing the\nrheology of shear-t hinning viscoelastic fluid. The main advantage of the chosen\napproach is that the already calculated and known stretch tensor is just reused\nand p ostprocessed to assess the local deformation of red blood cells\, that can \nin certain cases lead to degradation of the cell membranes and consequen t\nrelease of hemoglobin. The algorithm of solving the viscoelastic stretc h tensor\nequations and hemolysis index postprocessing will be outlined an d discussed in\ndetail. Some initial numerical simulations for an axisymme tric idealized\nstenosed blood vessel\, obtained using an in-house finite- volume solver\, will be\npresented.\n LOCATION:https://researchseminars.org/talk/NSCM/123/ END:VEVENT BEGIN:VEVENT SUMMARY:Marco Bresciani (Department of Mathematics\, University of Erlange n) DTSTART:20231113T144000Z DTEND:20231113T161000Z DTSTAMP:20260405T094550Z UID:NSCM/124 DESCRIPTION:Title: C ANCELED\nby Marco Bresciani (Department of Mathematics\, University of Erlangen) as part of Nečas Seminar on Continuum Mechanics\n\nLecture hel d in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe study a variational model for f erromagnetic elastomers featuring a mixed Eulerian-Lagrangian formulation. The magnetic variable is defined on the deformed configuration\nin the ac tual space and the saturation constraint involves the Jacobian determinant of\ndeformations.\nFirst\, in the case for purely elastic materials\, we discuss the existence of equilibrium\nconfigurations and we investigate th e model under quasistatic evolution in the rate-independent setting. Subse quently\, we address the extension of the existence theory for\nthe static problem to a framework allowing for cavitation.\nThe talk is partly based on joint work with Manuel Friedrich (FAU Erlangen-Nuernberg)\nand Carlos Mora-Corral (Universidad Autonoma de Madrid).\n LOCATION:https://researchseminars.org/talk/NSCM/124/ END:VEVENT BEGIN:VEVENT SUMMARY:Jaroslav Kruis (Department of Mechanics\, Faculty of Civil Enginee ring\, Czech Technical University) DTSTART:20231120T144000Z DTEND:20231120T161000Z DTSTAMP:20260405T094550Z UID:NSCM/125 DESCRIPTION:Title: H ydro-thermo-mechanical simulation of deep geological repository of radioac tive waste\nby Jaroslav Kruis (Department of Mechanics\, Faculty of Ci vil Engineering\, Czech Technical University) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\ nPossible variants of deep geological repository will be introduced. Selec ted\nengineering problems connected with the deep repositories will be sum marized\nand the appropriate mathematical models and numerical methods for their\nsolution will be described. The first problem is heat transfer cau sed by the\nradioactive waste in steel-based containers of length about 5 meters. The\nsizes of studied domain are approximately one kilometer and t he investigated\nperiod is thousands of years long. A combination of suita ble numerical\nmethods has to be used in order to finish the numerical sim ulations in\nreasonable time. The second problem is thermo-hydro-mechanica l (THM)\nanalysis of a system container-bentonite layer-surrounding rock m assif. It\nis based on the balance equation of momentum\, mass and energy together with\nvarious constitutive relationships. The THM analysis is for mulated for 2D\nand 3D.\n LOCATION:https://researchseminars.org/talk/NSCM/125/ END:VEVENT BEGIN:VEVENT SUMMARY:Xmas DTSTART:20231218T144000Z DTEND:20231218T161000Z DTSTAMP:20260405T094550Z UID:NSCM/126 DESCRIPTION:by Xmas as part of Nečas Seminar on Continuum Mechanics\n\nLe cture held in Room K3\, Faculty of Mathematics and Physics\, Charles Univ ersity\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/126/ END:VEVENT BEGIN:VEVENT SUMMARY:New Year DTSTART:20240101T144000Z DTEND:20240101T161000Z DTSTAMP:20260405T094550Z UID:NSCM/127 DESCRIPTION:by New Year as part of Nečas Seminar on Continuum Mechanics\n \nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/127/ END:VEVENT BEGIN:VEVENT SUMMARY:Leon Happ (TU Wien) DTSTART:20240311T144000Z DTEND:20240311T161000Z DTSTAMP:20260405T094550Z UID:NSCM/128 DESCRIPTION:Title: E xtension operators for homogenization that preserve target manifold constr aints\nby Leon Happ (TU Wien) as part of Nečas Seminar on Continuum M echanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\ , Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nMotivated b y homogenization problems in micro-magnetics and plasticity\, we study the existence of extension operators for W^{1\,p} Sobolev maps on periodicall y perforated domains\, where the maps are only allowed to range in some pr escribed Riemannian manifold. For applications\, one demands that separate L^p bounds for the extension and its gradient\, independent of the scale of the perforations\, hold. We stress that the main novelty of our work li es in the fact that all functions are subject to a manifold constrained in the target space. The challenge is then to find an extension operator pre serving this feature. It turns out that this is a problem sitting right at the interface between analysis and algebraic topology.\n\nThe unconstrain ed case was famously treated in an influential paper by E. Acerbi\, V. C. Piat\, G. Dal Maso\, and D. Percivale from 1992\, providing a positive ans wer for all p except infinity. However\, as soon as one starts to include manifold constraints\, the existence problem of extensions becomes highly sensitive towards the relation between p and d and calls for a case differ entiation. It can be shown that\, due to Sobolev embeddings\, for p bigger or equal than d the question whether every Sobolev function on a perforat ed domain possesses an extension reduces to a similar question for continu ous functions. This is a problem well studied in algebraic topology and\, in theory\, there are tools available to determine its answer.\n\nThese ob servations lead us to focus on the case that p is smaller than d (e.g.\, i n the physically relevant instance that p=2\, d=3). Then\, for p>1\, we ca n indeed proof the existence of an extension operator as described above\, and under the additional assumption that the target manifold is [p-1] con nected (where [] is the floor function)\, meaning that the first [p-1] fun damental groups of N are trivial. The proof builds upon the already allude d result by E. Acerbi\, V. C. Piat\, G. Dal Maso\, and D. Percivale\, comb ining it with an appropriate retraction onto the target manifold\, firstly suggested by R. Hardt and F.-H. Lin in 1987\, and originating again from algebraic topology. It is important to note that the extension operator wi ll not be linear. Already the target manifold constraint is not compatible with linearity. \n\nIn my talk\, I will put a special emphasis on illumin ating the [p-1]-connectedness condition that arises from the construction of the retraction onto N. The same assumption is already well-known in the context of the Sobolev functions between manifolds\, where\, for instance \, it determines the surjectivity of the trace operator. This is only one example of a deeper connection that I will unveil.\n LOCATION:https://researchseminars.org/talk/NSCM/128/ END:VEVENT BEGIN:VEVENT SUMMARY:Marco Morandotti (Politecnico di Torino) DTSTART:20240219T144000Z DTEND:20240219T161000Z DTSTAMP:20260405T094550Z UID:NSCM/129 DESCRIPTION:Title: F rom game theory to the control of multi-agent systems\nby Marco Morand otti (Politecnico di Torino) as part of Nečas Seminar on Continuum Mechan ics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Cha rles University\, Sokolovská 83 Prague 8..\n\nAbstract\nMotivated by the analysis of evolutive systems of agents with strategies\, we enrich the s tructure of the celebrated replicator equation to include more realistic s cenarios suitable for game-theoretic applications. In this context\, non-l inear continuity equations arise to describe the evolution of the mean-fie ld limit of such systems. Starting from simple cases\, we discuss more sop histicated models\, which include the interplay between the evolution of t he position of the players and the evolution of their strategies\; the add ition of a control factor that models the presence of a policy maker in mu lti-population dynamics\, together with the rise and fall of leadership\; the effects of an entropic regularisation in the system\, as well as that of fluctuations.\n\nWe present the derivation of these equations\, togethe r with some well-posedness results.\n LOCATION:https://researchseminars.org/talk/NSCM/129/ END:VEVENT BEGIN:VEVENT SUMMARY:Bernd Schmidt (University of Augsburg) DTSTART:20240226T144000Z DTEND:20240226T161000Z DTSTAMP:20260405T094550Z UID:NSCM/130 DESCRIPTION:Title: O n the Stability of Objective Structures\nby Bernd Schmidt (University of Augsburg) as part of Nečas Seminar on Continuum Mechanics\n\nLecture h eld in Room K3\, Faculty of Mathematics and Physics\, Charles University\ , Sokolovská 83 Prague 8..\n\nAbstract\nWe discuss the stability of obje ctive structures of interacting atoms that form a far reaching generalizat ion of crystal lattices. To this end\, we use methods from harmonic analys is to set up a second derivative test of the configurational energy at equ ilibria\, a key point being the identification of a carefully chosen semin orm with respect to which coercivity is estimated. In particular\, a novel discrete Korn type inequality is established in the setting of objective structures. We also provide an efficient algorithm to check for atomistic stability which we illustrate numerically for a general carbon nanotube. ( This is joint work with M. Steinbach\, Augsburg)\n LOCATION:https://researchseminars.org/talk/NSCM/130/ END:VEVENT BEGIN:VEVENT SUMMARY:Marco Bresciani (University of Erlangen) DTSTART:20240415T134000Z DTEND:20240415T151000Z DTSTAMP:20260405T094550Z UID:NSCM/131 DESCRIPTION:Title: V ariational models with Eulerian-Lagrangian formulation allowing for materi al failure\nby Marco Bresciani (University of Erlangen) as part of Ne čas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8 ..\n\nAbstract\nWe investigate the existence of minimizers of variational models with Eulerian-Lagrangian\nformulations. Similar models arise natura lly in many multi-physics problems such as\nthe modeling of nematic and fe rromagnetic elastomers. We consider energy functionals\ndepending on the d eformation of a body\, defined on its reference configuration\, and an\nEu lerian map defined on the unknown deformed configuration in the actual spa ce. Our\nexistence theory moves beyond the purely elastic setting and acco unts for material failure\nby addressing free-discontinuity problems where both deformations and Eulerian fields are\nallowed to jump. To do so\, we build upon the work of Henao and Mora-Corral regarding\nthe variational m odeling of cavitation and fracture in nonlinear elasticity. Two main\nsett ings are considered by modeling deformations as Sobolev and SBV -maps\, re spectively.\nThe regularity of Eulerian maps is specified in each of these two settings according to the\ngeometric and topological properties of th e deformed configuration. Effectiveness and\nlimitations of the theory are illustrated by means of explicit examples.\nThe talk is based on joint wo rk with Manuel Friedrich (FAU Erlangen-Nuremberg) and\nCarlos Mora-Corral (Universidad Autonoma de Madrid).\n LOCATION:https://researchseminars.org/talk/NSCM/131/ END:VEVENT BEGIN:VEVENT SUMMARY:Giovanni Fantuzzi (University of Erlangen) DTSTART:20240513T134000Z DTEND:20240513T151000Z DTSTAMP:20260405T094550Z UID:NSCM/132 DESCRIPTION:Title: M oment-Sum-of-Squares relaxations for variational problems\nby Giovanni Fantuzzi (University of Erlangen) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics \, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nMoment-Sum -of-Squares (moment-SOS) relaxations are an established technique to compu te converging sequences of lower bounds on the global minimum of finite-di mensional polynomial optimization problems. In this talk\, I will discuss two recent extensions of moment-SOS relaxations to infinite-dimensional va riational problems\, where a (possibly nonconvex) integral functional is t o be minimized over functions from a Sobolev space. The first extension op timizes so-called "null Lagrangian translations" and returns certified low er bounds on the global minimum of the variational problem. The second ext ension\, instead\, produces upper bounds by approximating minimizers of fi nite element discretizations of the variational problem. Conditions that e nsure the convergence of these upper and lower bounds to the desired globa l minimum will be discussed\, and current gaps between theory and practice will be illustrated by means of examples.\n LOCATION:https://researchseminars.org/talk/NSCM/132/ END:VEVENT BEGIN:VEVENT SUMMARY:Hywel Normington (University of Strathclyde) DTSTART:20240422T134000Z DTEND:20240422T151000Z DTSTAMP:20260405T094550Z UID:NSCM/133 DESCRIPTION:Title: A decoupled\, convergent and fully linear algorithm for the Landau-Lifshitz -Gilbert equation with magnetoelastic effects\nby Hywel Normington (Un iversity of Strathclyde) as part of Nečas Seminar on Continuum Mechanics\ n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nThe mechanical and m agnetic properties of ferromagnetic materials are strongly coupled. Applyi ng a stress to a ferromagnetic material changes the magnetic state\, and a pplying a magnetic field deforms it. These fall collectively under the phe nomena of "magnetostriction". We consider the coupled system of the Landau -Lifshitz-Gilbert (LLG) equation and conservation of momentum to describe magnetostrictive processes. For this nonlinear system of time-dependent pa rtial differential equations\, we present a decoupled and unconditionally convergent integrator based on linear finite elements in space and a one-s tep method in time. Compared to previous works on this problem\, for our m ethod\, we prove a discrete energy law that mimics that of the continuous problem. Moreover\, we do not employ a nodal projection to impose the unit -length constraint on the discrete magnetization\, so that the stability o f the method does not require weakly acute meshes. Furthermore\, our integ rator and its analysis hold for a more general setting\, including body fo rces and traction\, and a more general representation of the magnetostrain .\n\nH. Normington and M. Ruggeri\, A decoupled\, convergent and fully lin ear algorithm for the Landau--Lifshitz--Gilbert equation with magnetoelast ic effects.\n(under review)\,\nhttps://arxiv.org/abs/2309.00605v2\n LOCATION:https://researchseminars.org/talk/NSCM/133/ END:VEVENT BEGIN:VEVENT SUMMARY:break DTSTART:20240129T144000Z DTEND:20240129T161000Z DTSTAMP:20260405T094550Z UID:NSCM/134 DESCRIPTION:by break as part of Nečas Seminar on Continuum Mechanics\n\nL ecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Uni versity\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/134/ END:VEVENT BEGIN:VEVENT SUMMARY:break DTSTART:20240205T144000Z DTEND:20240205T161000Z DTSTAMP:20260405T094550Z UID:NSCM/135 DESCRIPTION:by break as part of Nečas Seminar on Continuum Mechanics\n\nL ecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Uni versity\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/135/ END:VEVENT BEGIN:VEVENT SUMMARY:break DTSTART:20240212T144000Z DTEND:20240212T161000Z DTSTAMP:20260405T094550Z UID:NSCM/136 DESCRIPTION:by break as part of Nečas Seminar on Continuum Mechanics\n\nL ecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Uni versity\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/136/ END:VEVENT BEGIN:VEVENT SUMMARY:Jan Scherz (University of Wuerzburg) DTSTART:20240408T134000Z DTEND:20240408T151000Z DTSTAMP:20260405T094550Z UID:NSCM/137 DESCRIPTION:Title: W eak Solutions to Mathematical Models of the Interaction between Fluids\, S olids and Electromagnetic Fields\nby Jan Scherz (University of Wuerzbu rg) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Ro om K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolov ská 83 Prague 8..\n\nAbstract\nWe prove the existence of weak solutions to two systems of PDEs modeling interactions between fluids\, solids and e lectromagnetic fields. The first problem we consider describes the motion of an insulating rigid body through an electrically conducting incompressi ble fluid. The existence of weak solutions to this problem is achieved via a time discretization and an application of the Brinkman penalization. Th e second considered problem deals with the evolution of the deformation an d the magnetization of a magnetoelastic material and is solved via an appl ication of De Giorgi's minimizing movements scheme.\n LOCATION:https://researchseminars.org/talk/NSCM/137/ END:VEVENT BEGIN:VEVENT SUMMARY:Easter Monday DTSTART:20240401T134000Z DTEND:20240401T151000Z DTSTAMP:20260405T094550Z UID:NSCM/138 DESCRIPTION:Title: n o talk\nby Easter Monday as part of Nečas Seminar on Continuum Mechan ics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Cha rles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/138/ END:VEVENT BEGIN:VEVENT SUMMARY:Eduard Rohan (University of West Bohemia\, Pilsen) DTSTART:20240325T144000Z DTEND:20240325T161000Z DTSTAMP:20260405T094550Z UID:NSCM/139 DESCRIPTION:Title: H omogenization based model of flows in piezoelectric porous metamaterials d riven by peristaltic deformation\nby Eduard Rohan (University of West Bohemia\, Pilsen) as part of Nečas Seminar on Continuum Mechanics\n\nLect ure held in Room K3\, Faculty of Mathematics and Physics\, Charles Univer sity\, Sokolovská 83 Prague 8..\n\nAbstract\nThe seminar talk is devoted to the multiscale modelling of an electroactive porous material intended for fluid transport. Its functionality is based on the peristaltic flow wh ich is induced by deforming pore walls. This phenomenon is of a great impo rtance in physiology and biomechanics\, however\, as a driving mechanism o f fluid transport\, it presents and important and challenging issue in the design of smart ``bio-inspired'' materials. We consider locally periodic porous structures saturated by a Newtonian fluid. The peristaltic deforma tion wave of the microchannels is induced by a convenient local control of piezoelectric segments. Several issues related to the construction of a c omputationally efficient two-scale metamaterial model within the homogeniz ation framework will be presented. We consider relatively small deformatio n which enables to use the linear kinematic framework. The poro-piezoelect ric model derived in [1] is extended for the viscous fluid flow while resp ecting the inertia effects in both the phases. Using the homogenization ba sed on the classic asymptotic analysis\, cell problems (at the microlevel) are obtained which provide characteristic responses of the microstructure s with respect to macroscopic strains\, fluid pressure and electric potent ials. These responses are needed to compute the effective (homogenized) pa rameters of the macroscopic problem which depend on the microconfiguration . The numerical studies demonstrate that such a linear model cannot captur e the desired pumping effect of the homogenized continuum. To achieve this functionality of the model\, it is necessary to account for the nonlinear ity associated with deformation-dependent microconfigurations. To avoid hu rdles associated with a fully nonlinear two-scale model\, we apply a linea rization procedure based on the sensitivity analysis of the local characte ristic responses with respect to the deformation induced by the macroscopi c quantities. In this way\, by virtue of the methodology introduced in [2] \, we get first-order expansions of all the homogenized coefficients. The dynamic effects lead to the macroscopic flow model in a convolution form. For this option\, a special treatment of the deformation-dependent dynamic permeability is needed. Numerical examples illustrate efficiency of the p roposed computational approach [3].\n\n\n[1] E. Rohan\, V. Lukeš. On mode lling nonlinear phenomena in deforming heterogeneous media using homogeniz ation and sensitivity analysis concepts. Applied Mathematics and Computati on (2015) 267:583-595.\n\n[2] E. Rohan\, V. Lukeš. Homogenization of the fluid-saturated piezoelectric porous media. Int. Jour. Solids and Structur es (2018) 147:110-125.\n\n[3] E. Rohan\, V. Lukeš. Homogenization of peri staltic flows in piezoelectric porous media. (2023) arXiv:2304.05393v1\, h ttps://doi.org/10.48550/arXiv.2304.05393\n LOCATION:https://researchseminars.org/talk/NSCM/139/ END:VEVENT BEGIN:VEVENT SUMMARY:Chiara Gavioli (Czech Technical University\, Prague) DTSTART:20240429T134000Z DTEND:20240429T151000Z DTSTAMP:20260405T094550Z UID:NSCM/140 DESCRIPTION:Title: A model for lime consolidation of porous solids\nby Chiara Gavioli (Cze ch Technical University\, Prague) as part of Nečas Seminar on Continuum M echanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\ , Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe present the first mathematical 3D model describing the process of filling the pore s of a building material with a water-lime-mixture\, with the goal to impr ove the consistency of the porous solid. Chemical reactions produce calciu m carbonate which glues the solid particles together at some distance from the boundary and strengthens the whole structure. The model consists of a reaction-diffusion system with a nonlinear non-smooth boundary condition\ , coupled with the mass balance equations for the chemical reaction. The m ain result consists in proving that the system has a solution for each ini tial data from a physically relevant class. A 1D numerical test shows a qu alitative agreement with experimental observations.\nThis is a joint work with B. Detmann (Universität Duisburg-Essen)\, P. Krejčí\, J. Lamač\, and Y. Namlyeyeva (Czech Technical University Prague).\n LOCATION:https://researchseminars.org/talk/NSCM/140/ END:VEVENT BEGIN:VEVENT SUMMARY:Johannes Zimmer (Technical University of Munich) DTSTART:20240506T134000Z DTEND:20240506T151000Z DTSTAMP:20260405T094550Z UID:NSCM/141 DESCRIPTION:Title: D eriving a GENERIC system from a Hamiltonian system\nby Johannes Zimmer (Technical University of Munich) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics \, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe reconsi der the problem of coarse-graining infinite-dimensional Hamiltonian dynami cs to obtain a macroscopic system that includes dissipative mechanisms. In particular\, we study the thermodynamical implications concerning Hamilto nians\, energy\, and entropy and the induced geometric structures. The Ham iltonian model is described by a unitary group\, and is time-reversible. T he coarse-grained description includes dissipative effects\, is described by a contraction semigroup\, and is thus irreversible. The concepts of dil ations and contractions will be described as they provide a link between d issipative semigroups and unitary groups. The coarse-grained version will be shown to have GENERIC (General Equations for Non-Equilibrium Reversible Irreversibe Coupling) structure\, with conserved energy\, nondecreasing e ntropy and an Onsager operator describing the dissipation.\n\n This is joi nt work with Alex Mielke and Mark Peletier.\n LOCATION:https://researchseminars.org/talk/NSCM/141/ END:VEVENT BEGIN:VEVENT SUMMARY:Giuseppe Tomassetti (University of Roma Tre) DTSTART:20240318T144000Z DTEND:20240318T161000Z DTSTAMP:20260405T094550Z UID:NSCM/142 DESCRIPTION:Title: A mechanical model of ocular bulb vibrations and implications for acoustic tonometry\nby Giuseppe Tomassetti (University of Roma Tre) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Facult y of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe propose a comprehensive mechanical model of ocular bu lb vibrations and discuss its implications for acoustic tonometry. The mod el describes the eye wall as a spherical\, pre-stressed elastic shell cont aining a viscoelastic material and accounts for the interaction between th e elastic corneoscleral shell and the viscoelastic vitreous humor. We inve stigate the natural frequencies of the system and the corresponding vibrat ion modes\, expanding the solution in terms of scalar and vector spherical harmonics. From a quantitative point of view\, our findings reveal that t he eyebulb vibration frequencies significantly depend on IOP. This depende ncy has two origins: "geometric" stiffening\, due to an increase of the pr e-stress\, and "material" stiffening\, due to the nonlinearity of the stre ss-strain curve of the sclera. The model shows that the second effect is b y far dominant. We also find that the oscillation frequencies depend on oc ular rigidity\, but this dependency is important only at relatively large values of IOP. Thus close to physiological conditions\, IOP is the main de terminant of ocular vibration frequencies. The vitreous rheological proper ties are found to mostly influence vibration damping. This study contribut es to the understanding of the mechanical behavior of the eye under dynami c conditions and thus has implications for non-contact intraocular pressur e measurement techniques\, such as acoustic tonometry. The model can also be relevant for other ocular pathological conditions\, such as traumatic r etinal detachment\, which are believed to be influenced by the dynamic beh avior of the eye.\n LOCATION:https://researchseminars.org/talk/NSCM/142/ END:VEVENT BEGIN:VEVENT SUMMARY:Václav Mácha (Institute of Mathematics\, Czech Academy of Scienc es) DTSTART:20240304T144000Z DTEND:20240304T161000Z DTSTAMP:20260405T094550Z UID:NSCM/143 DESCRIPTION:Title: A NALYSIS OF A SYSTEM MODELLING THE INTERACTION BETWEEN THE MOTION OF PISTON -SPRING AND A VISCOUS GAS\nby Václav Mácha (Institute of Mathematics \, Czech Academy of Sciences) as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe are concerne d with a one-dimensional flow of a compressible\nfluid which may be seen\n as a simplification of the flow of fluid in a long\, thin pipe. We assume\ nthe pipe is on one side\,\nending by a spring. The other side of the pipe is left open – there\, we\nassume either inflow or outflow\nboundary co nditions. Such a situation can be understood as a toy model for\nhuman lun gs. We tackle\nthe question of uniqueness and the existence of a strong so lution for a\nsystem modeling the above process\,\nspecial emphasis is lai d upon the estimate of the maximal time of\nexistence.\nThis is a joint wo rk with Sabrine Chebbi and Šárka Nečasová\n LOCATION:https://researchseminars.org/talk/NSCM/143/ END:VEVENT BEGIN:VEVENT SUMMARY:Pavel Krejčí (Czech Technical University in Prague\, Faculty of Civil Engineering) DTSTART:20240520T134000Z DTEND:20240520T151000Z DTSTAMP:20260405T094550Z UID:NSCM/144 DESCRIPTION:Title: H ysteresis in porous media\nby Pavel Krejčí (Czech Technical Universi ty in Prague\, Faculty of Civil Engineering) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics a nd Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\n We propose a model for fluid diffusion in partially saturated porous media taking\ninto account saturation-dependent permeability as well as hystere sis effects in the pressure saturation relation. The resulting mathematica l problem leads to a diffusion equation for\nthe pressure in an N-dimensio nal domain with a Preisach hysteresis operator under the time\nderivative and in the diffusion coefficient. The problem is doubly degenerate in the sense\nthat the saturation range is bounded\, and no a priori control of t he time derivative of the\npressure is available. We discuss the condition s for existence and uniqueness of a solution\nto the problem with or witho ut gravity effects in appropriate function spaces\, as well as the\nquesti on of bounded speed of propagation. This is a joint work with Chiara Gavio li.\n LOCATION:https://researchseminars.org/talk/NSCM/144/ END:VEVENT BEGIN:VEVENT SUMMARY:summer break DTSTART:20240527T134000Z DTEND:20240527T151000Z DTSTAMP:20260405T094550Z UID:NSCM/145 DESCRIPTION:Title: W e'll continue on September 30\, 2024\nby summer break as part of Neč as Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8.. \nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/145/ END:VEVENT BEGIN:VEVENT SUMMARY:Matteo Negri (University of Pavia) DTSTART:20241021T134000Z DTEND:20241021T151000Z DTSTAMP:20260405T094550Z UID:NSCM/146 DESCRIPTION:Title: R ate-independent evolutions in phase-field fracture generated by equilibriu m configurations\nby Matteo Negri (University of Pavia) as part of Ne čas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8 ..\n\nAbstract\nIn the phase-field approach\, and in other regularized fra cture models\, rate-independent (quasi-static) evolutions are usually obta ined by means of time-discrete schemes\, providing at each time an equilib rium configuration of the system. Numerically\, equilibria are computed b y descent methods for the free energy (e.g. staggered\, monolithic etc.) e ndowed with a suitable irreversibility constraint on phase-field parameter (e.g. monotonicity in time). The time-continuous limit evolution is char acterized in terms of evolutionary variational inequalities and in terms o f Griffith's criterion. The study of the limit evolution reveals a couple of propagation regimes: stable (or steady state) and unstable (or catastro phic). In the stable regime the evolution is simultaneous (in displacement and phase field parameter) and satisfies Griffith's criterion in terms of toughness and phase field energy release rate. In the unstable regime the evolution is not necessarily simultaneous and may not satisfy Griffith's criterion. Energy identity holds in general with an instantaneous drop of energy in unstable times. The monotonicity constraint turns out to be full y thermodynamically consistent along the whole evolution. Technically\, th e proof relies on: (a) the strong convergence of the phase field parameter \, (b) Kuratowski convergence of parametrized discrete times\, (c) the lim it of the power identity. The result is very general since it works indepe ndently of the scheme employed in the incremental problem\, it holds for i nstance for AT1 and AT2 energies\, in plane strain and plane stress settin gs. Numerically\, we compare energies\, energy release rates and evolution s computed in the sharp crack and in the phase field setting for a couple of reference benchmarks: the double cantilever beam (for steady state prop agation) and the single edge notch under tension (for unstable propagation ).\n LOCATION:https://researchseminars.org/talk/NSCM/146/ END:VEVENT BEGIN:VEVENT SUMMARY:Vladislav Mantič (University of Sevilla) DTSTART:20240930T134000Z DTEND:20240930T151000Z DTSTAMP:20260405T094550Z UID:NSCM/147 DESCRIPTION:Title: S tress singularities in BVPs with Robin and Ventcel boundary conditions. Ap plications in FEM modeling\nby Vladislav Mantič (University of Sevill a) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Roo m K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovs ká 83 Prague 8..\n\nAbstract\nLinear-elastic antiplane-strain problems g overned by the 2D Laplace equation are considered in domains with corners and cracks. First\, power-logarithmic stress singularities in Neumann-Robi n BVPs in infinite corner (polar sector) type domains are studied. Asympto tic solutions given by a double asymptotic series with the main and the as sociated shadow terms are presented. An application of such an asymptotic series to the numerical solution of the BVP of a crack in a thin adhesive interface layer modeled by the spring interface is shown by implementing a finite element method (FEM) procedure. Second\, similar asymptotic analys is of power-logarithmic stress singularities in Dirichlet-Robin BVPs in in finite corners with a power-law variation (with the distance to the corner apex) of the governing coefficient in the Robin boundary condition is pre sented. An application of such an asymptotic solution to the BVPs of bridg ed cracks with a power-law variation of the stiffness of linear-elastic sp ring distribution is presented. Finally\, a power-logarithmic stress singu larity in a Dirichlet-Ventcel BVP in half domain is studied by a similar a symptotic procedure. An application of this asymptotic solution to the FEM solution of a BVP with a finite and open Gurtin-Murdoch material surface is presented.\n LOCATION:https://researchseminars.org/talk/NSCM/147/ END:VEVENT BEGIN:VEVENT SUMMARY:Pablo Pedregal (University of Castilla-La Mancha) DTSTART:20241118T144000Z DTEND:20241118T161000Z DTSTAMP:20260405T094550Z UID:NSCM/148 DESCRIPTION:Title: D iscoveries and surprises in the non-local Calculus of Variations\nby P ablo Pedregal (University of Castilla-La Mancha) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathemati cs and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstra ct\nPeridynamics stands as a main application of non-local variational pro blems in Continuum Mechanics. Yet from the mathematical point of view many of the important issues behind are formally similar\, after suitable non- local reinterpretation of tools\, to the classic local framework. Though t his is no doubt surprising and reassuring\, we will try to push non-locali ty to find some situations where things are really different. Some of the simplest examples will serve to illustrate how different things may be.\n LOCATION:https://researchseminars.org/talk/NSCM/148/ END:VEVENT BEGIN:VEVENT SUMMARY:Cristiana De Filippis (University of Parma\, Italy) DTSTART:20241125T144000Z DTEND:20241125T161000Z DTSTAMP:20260405T094550Z UID:NSCM/149 DESCRIPTION:Title: R egularity problems in the Calculus of Variations\nby Cristiana De Fili ppis (University of Parma\, Italy) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics \, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nRegularity theory and the Calculus of Variations are unavoidably linked to each othe r\,\n as in fact\, regularity techniques essentially serve to show weak or distributional solutions are in\n fact classical solutions. Therefore\, r egularity ensures solvability. This is a topic that has been tremendously developed over the last 100 years\, and I will try to give an overview sta rting from very\n classical results\, passing through the fundamental con tributions of De Giorig and Nash\, eventually\n approaching some of the mo st recent developments involving nonuniformly elliptic problems.\n LOCATION:https://researchseminars.org/talk/NSCM/149/ END:VEVENT BEGIN:VEVENT SUMMARY://////////////// DTSTART:20241028T144000Z DTEND:20241028T161000Z DTSTAMP:20260405T094550Z UID:NSCM/150 DESCRIPTION:Title: N ational Holiday - no seminar lecture\nby //////////////// as part of N ečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/150/ END:VEVENT BEGIN:VEVENT SUMMARY:X-mas DTSTART:20241223T144000Z DTEND:20241223T161000Z DTSTAMP:20260405T094550Z UID:NSCM/151 DESCRIPTION:by X-mas as part of Nečas Seminar on Continuum Mechanics\n\nL ecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Uni versity\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/151/ END:VEVENT BEGIN:VEVENT SUMMARY:Anna Hundertmark (Rheinland-Pfälzische Technische Universität) DTSTART:20241007T134000Z DTEND:20241007T151000Z DTSTAMP:20260405T094550Z UID:NSCM/152 DESCRIPTION:Title: M odeling of carotid artery hemodynamics towards a CFD database for stroke r isk assessment\nby Anna Hundertmark (Rheinland-Pfälzische Technische Universität) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Universit y\, Sokolovská 83 Prague 8..\n\nAbstract\nIn medicine\, the risk assessm ent of strokes caused by pathological\nirregularities in the bifurcation o f the carotid artery plays a major\nrole in the patient's optimal treatmen t decision.\nThis decision-making process can be greatly enhanced by detai led flow\nfield data obtained from simulations using patient-specific arte rial\nmorphologies. We present our numerical modeling approach to create a CFD\ndatabase that can guide stroke risk assessment\, including hemodynam ic shear risk\nmetrics. We investigate the multi-directional behavior of w all shear\nstress (WSS) based on specially\nconstructed longitudinal tange nt vectors using a center-line projection\napproach and present the utilit y of longitudinal WSS evaluation for\ndetecting opposing or transverse WSS in slow patient-specific flow. In\nour fluid-structure interaction model \,\nwe generalize the assumption of linear elasticity by a strain-dependen t\nelastic modulus that is consistent with laboratory measurements of\ncom pliance and distensibility. Finally\, we present the established\nworking pipeline to generate CFD\ndata for a large number of patient-specific geom etries. Created\nhemodynamic datasets can be used for visual atlases and c omparative\nanalysis or explored by neural networks.\n LOCATION:https://researchseminars.org/talk/NSCM/152/ END:VEVENT BEGIN:VEVENT SUMMARY:Matteo Caggio (Institute of mathematics\, Czech Academy of Science s) DTSTART:20241014T134000Z DTEND:20241014T151000Z DTSTAMP:20260405T094550Z UID:NSCM/153 DESCRIPTION:Title: V anishing viscosity limit for the compressible Navier-Stokes equations with non-linear density dependent viscosities\nby Matteo Caggio (Institute of mathematics\, Czech Academy of Sciences) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics a nd Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\n In a three-dimensional bounded domain\, we consider the compressible\nNavi er-Stokes equations for a barotropic fluid with general non-linear\ndensit y dependent viscosities and no- slip boundary conditions. A\nnonlinear dra g term is added to the momentum equation. We establish two\nconditional Ka to-type criteria for the convergence of the weak solutions\nto such a syst em towards the strong solution of the compressible Euler\nsystem when the viscosity coefficient and the drag term parameter tend\nto zero.\n LOCATION:https://researchseminars.org/talk/NSCM/153/ END:VEVENT BEGIN:VEVENT SUMMARY:Angela Bašič-Šiško (University of Rijeka) DTSTART:20241104T144000Z DTEND:20241104T161000Z DTSTAMP:20260405T094550Z UID:NSCM/154 DESCRIPTION:Title: R eal micropolar gas flow model\nby Angela Bašič-Šiško (University o f Rijeka) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, S okolovská 83 Prague 8..\n\nAbstract\nThe micropolar real gas model\, whi ch extends the traditional fluid\n dynamics model to account for micro-eff ects\, is explored. This model\n introduces additional rotational degrees of freedom to capture the\n behavior of the internal fluid structure. By i ncorporating the\n equation\n of state for real gases\, a shift from the i deal gas model to a more\n general case is achieved. The mathematical fram ework of this model is\n discussed\, and results on the existence\, unique ness\, and large-time\n behavior of the solution for one-dimensional and s pherically symmetric\n flows are presented.\n Furthermore\, we consider co mbustion within the fluid to form the\n reactive micropolar real gas model . This model additionally\n incorporates\n the chemical reactivity of the gas mixture\, enabling the simulation of\n reactive flows such as fuel com bustion\, detonation in aerospace\n engineering\, and the modeling of gase ous stars. Results on the\n well-posedness of this model are also presente d.\n LOCATION:https://researchseminars.org/talk/NSCM/154/ END:VEVENT BEGIN:VEVENT SUMMARY:X-mas DTSTART:20241216T144000Z DTEND:20241216T161000Z DTSTAMP:20260405T094550Z UID:NSCM/155 DESCRIPTION:by X-mas as part of Nečas Seminar on Continuum Mechanics\n\nL ecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Uni versity\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/155/ END:VEVENT BEGIN:VEVENT SUMMARY:X-mas DTSTART:20241230T144000Z DTEND:20241230T161000Z DTSTAMP:20260405T094550Z UID:NSCM/156 DESCRIPTION:by X-mas as part of Nečas Seminar on Continuum Mechanics\n\nL ecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Uni versity\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/156/ END:VEVENT BEGIN:VEVENT SUMMARY:Riccardo Voso (University of Vienna) DTSTART:20241111T144000Z DTEND:20241111T161000Z DTSTAMP:20260405T094550Z UID:NSCM/157 DESCRIPTION:Title: W eighted Energy-Dissipation approach to gradient flows\nby Riccardo Vos o (University of Vienna) as part of Nečas Seminar on Continuum Mechanics\ n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nThe Weighted Energy- Dissipation variational approach has been extensively applied to gradient flows in the last decade. A family of parameter-dependent functionals defi ned over entire trajectories is introduced and proved to admit global mi nimizers. These global minimizers correspond to solutions of elliptic-in-t ime regularizations of the limiting causal problem. By passing to the limi t in the parameter\, such global minimizers converge\, up to subsequences\ , to a solution of the gradient flow. After discussing such variational fo rmulation in the context of classical gradient flows\, we will focus on th e semilinear gradient flows with state-dependent dissipation.\nThis is par tly based on a joint work with Goro Akagi and Ulisse Stefanelli.\n LOCATION:https://researchseminars.org/talk/NSCM/157/ END:VEVENT BEGIN:VEVENT SUMMARY:Gabriele Sbaiz (University of Trieste) DTSTART:20241209T144000Z DTEND:20241209T161000Z DTSTAMP:20260405T094550Z UID:NSCM/158 DESCRIPTION:Title: F ast rotation and inviscid limits for the SQG equation with general ill-pre pared initial data\nby Gabriele Sbaiz (University of Trieste) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Fac ulty of Mathematics and Physics\, Charles University\, Sokolovská 83 Pra gue 8..\n\nAbstract\nIn the talk\, we study the fast rotation and inviscid limits for the 2-D dissipative surface quasi-\ngeostrophic equation with a dispersive forcing term\, in the domain Ω = T1 × R. In the case\nwhen we perform the fast rotation limit (keeping the viscosity fixed)\, in the context of general\nill-prepared initial data\, we prove that the limit dy namics is described by a linear equation with\nparabolic structure. Conver sely\, performing the combined fast rotation and inviscid limits\, we\nsho w that the means of the target initial datum ϑ0 are conserved along the m otion. The proof\nof the convergence is based on a compensated compactness argument which allows\, on the one\nhand\, to get compactness properties for suitable quantities hidden in the wave system and\, on\nthe other hand \, to exclude the oscillatory part of waves at the limit.\n LOCATION:https://researchseminars.org/talk/NSCM/158/ END:VEVENT BEGIN:VEVENT SUMMARY:Pavel Krejčí (Faculty of Civil Engineering\, CTU & Institute of Mathematics\, CAS) DTSTART:20241202T144000Z DTEND:20241202T161000Z DTSTAMP:20260405T094550Z UID:NSCM/159 DESCRIPTION:Title: N on-convex variational inequalities in contact mechanics\nby Pavel Krej čí (Faculty of Civil Engineering\, CTU & Institute of Mathematics\, CAS ) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovsk á 83 Prague 8..\n\nAbstract\nWe propose a new mathematical model for the dynamics of a rail\nrepresented by a straight elastic or elastoplastic be am in contact with\nthe foundation and subject to a moving load. The found ation consists of\na granular material which undergoes irreversible struct ural changes such\nas grain degradation and decreasing void ratio. The the ory of non-convex\nsweeping processes makes it possible to evaluate the en ergy exchange\nbetween the rail and the foundation\, and to exploit the en ergy balance\nequation to prove existence and uniqueness of solutions to t he full\nsystem consisting of a fourth order PDE coupled with a variationa l\ninequality with a non-convex state-dependent constraint.\n LOCATION:https://researchseminars.org/talk/NSCM/159/ END:VEVENT BEGIN:VEVENT SUMMARY:Winter Break DTSTART:20250106T144000Z DTEND:20250106T161000Z DTSTAMP:20260405T094550Z UID:NSCM/160 DESCRIPTION:by Winter Break as part of Nečas Seminar on Continuum Mechani cs\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Char les University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/160/ END:VEVENT BEGIN:VEVENT SUMMARY:Winter Break DTSTART:20250113T144000Z DTEND:20250113T161000Z DTSTAMP:20260405T094550Z UID:NSCM/161 DESCRIPTION:by Winter Break as part of Nečas Seminar on Continuum Mechani cs\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Char les University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/161/ END:VEVENT BEGIN:VEVENT SUMMARY:Winter Break DTSTART:20250120T144000Z DTEND:20250120T161000Z DTSTAMP:20260405T094550Z UID:NSCM/162 DESCRIPTION:by Winter Break as part of Nečas Seminar on Continuum Mechani cs\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Char les University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/162/ END:VEVENT BEGIN:VEVENT SUMMARY:Winter Break DTSTART:20250127T144000Z DTEND:20250127T161000Z DTSTAMP:20260405T094550Z UID:NSCM/163 DESCRIPTION:by Winter Break as part of Nečas Seminar on Continuum Mechani cs\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Char les University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/163/ END:VEVENT BEGIN:VEVENT SUMMARY:Winter Break DTSTART:20250203T144000Z DTEND:20250203T161000Z DTSTAMP:20260405T094550Z UID:NSCM/164 DESCRIPTION:by Winter Break as part of Nečas Seminar on Continuum Mechani cs\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Char les University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/164/ END:VEVENT BEGIN:VEVENT SUMMARY:Winter Break DTSTART:20250210T144000Z DTEND:20250210T161000Z DTSTAMP:20260405T094550Z UID:NSCM/165 DESCRIPTION:by Winter Break as part of Nečas Seminar on Continuum Mechani cs\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Char les University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/165/ END:VEVENT BEGIN:VEVENT SUMMARY:Jan Kristensen (University of Oxford) DTSTART:20250303T144000Z DTEND:20250303T161000Z DTSTAMP:20260405T094550Z UID:NSCM/166 DESCRIPTION:Title: E xistence results in elasticity beyond polyconvexity\nby Jan Kristensen (University of Oxford) as part of Nečas Seminar on Continuum Mechanics\n \nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nIn this talk I discus s some recent results in the calculus of variations that yield existence o f minimizers in spaces of Sobolev homeomorphisms for a natural class of el astic energies.\nThe presented results are part of a joint work with Kari Astala\, Daniel Faraco\, Andre Guerra\nand Aleksis Koski.\n LOCATION:https://researchseminars.org/talk/NSCM/166/ END:VEVENT BEGIN:VEVENT SUMMARY:Kai Richter (Institute of Scientific Computing\, TU Dresden) DTSTART:20250310T144000Z DTEND:20250310T161000Z DTSTAMP:20260405T094550Z UID:NSCM/167 DESCRIPTION:Title: D imension reduction for elastoplastic rods in the bending regime\nby Ka i Richter (Institute of Scientific Computing\, TU Dresden) as part of Neč as Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8.. \n\nAbstract\nIn our work we rigorously derive a limiting bending model fo r thin rods\, starting from a full 3D model for finite elastoplasticity. F or the derivation we lean on the framework of evolutionary Gamma-convergen ce for rate-independent systems\, introduced by Mielke\, Roubíček and St efanelli in 2008. The main difficulty here is to establish a mutual recove ry sequence for the stored energy and dissipation. Strategies have been de veloped by various authors in order to construct such a sequence\, e.g. fo r linearization or in the von Kármán regime. However\, these rely on con sidering infinitesimal deformations in the limit\, which we cannot expect in the bending regime. Our approach relies on a construction based on a mu ltiplicative decomposition of the rotation fields obtained via the rigidit y estimate from Friesecke\, James and Müller. In order to achieve enough regularity\, we consider strain gradient terms in the energy\, which act o n the two parts of the polar decomposition individually. These terms vanis h in the limit.\nThis is joined work with Stefan Neukamm.\n LOCATION:https://researchseminars.org/talk/NSCM/167/ END:VEVENT BEGIN:VEVENT SUMMARY:Marco Morandotti (Politecnico di Torino) DTSTART:20250324T144000Z DTEND:20250324T161000Z DTSTAMP:20260405T094550Z UID:NSCM/168 DESCRIPTION:Title: R eplicator dynamics as the large population limit of a discrete Moran proce ss\nby Marco Morandotti (Politecnico di Torino) as part of Nečas Semi nar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathem atics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbs tract\nThe replicator dynamics accomplishes the task of modelling the evol ution of strategies in a population by subjecting the probability of repro duction to their fitness: The higher the fitness\, the higher the chance o f being selected to reproduce. Yet\, the criterion followed by individual agents to select their strategies is latent in the replicator equation\, w hich describes the continuous-time evolution of the proportions of strateg ies in an averaged fashion.\n\nIn this talk\, we provide a mathematical fr amework to derive the replicator equation as a mean-field limit of a discr ete stochastic process modelling this evolutionary mechanism from the poin t of view of individual agents and their pairwise interactions. In this co ntext\, the classical Moran process is a prototypical example of discrete stochastic process that models natural selection in finite populations wit h two strategies (alleles\, in biology) competing for dominance. We study the mean-field limit of a generalised Moran process as the number of agent s diverges and we show that\, in the weak selection regime\, it converges to the replicator dynamics.\n LOCATION:https://researchseminars.org/talk/NSCM/168/ END:VEVENT BEGIN:VEVENT SUMMARY:Matteo Caggio (Mathematićal Institute\, CAS) DTSTART:20250331T134000Z DTEND:20250331T151000Z DTSTAMP:20260405T094550Z UID:NSCM/169 DESCRIPTION:Title: M ach number regimes for capillary fluids\nby Matteo Caggio (Mathematić al Institute\, CAS) as part of Nečas Seminar on Continuum Mechanics\n\nLe cture held in Room K3\, Faculty of Mathematics and Physics\, Charles Univ ersity\, Sokolovská 83 Prague 8..\n\nAbstract\nThe talk will be devoted to the high and low Mach number limit for\ncompressible capillary fluids w ith density dependent viscosity.\nWe will present recent results concernin g weak-strong uniqueness\nproperty and dispersion of the acoustic waves.\n LOCATION:https://researchseminars.org/talk/NSCM/169/ END:VEVENT BEGIN:VEVENT SUMMARY:Andreas Vikelis (Faculty of Civil Engineering\, CTU) DTSTART:20250217T144000Z DTEND:20250217T161000Z DTSTAMP:20260405T094550Z UID:NSCM/170 DESCRIPTION:Title: V ARIATIONAL APPROACH FOR THERMODYNAMICS OUT OF EQUILIBRIUM\nby Andreas Vikelis (Faculty of Civil Engineering\, CTU) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics a nd Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\n The study of dynamic elasticity is a mainstay in Applied Mathematics and\n Mechanics as it models materials able to accommodate large deformations\nw hich are abundant in different physical and biological applications. While \nthere is a vast body of literature on the static case in vectorial elast icity\, particularly within the fields of calculus of variations and ellip tic partial differential equations\, the dynamic case has traditionally re ceived less attention.\nIn the first part of the talk\, we present recent findings regarding the stability\nand uniqueness properties of the evolut ion equations in (thermo)elasticity\,\nwhile in the second part we discuss the variational structure of such systems\nand present schemes to constru ct consistent solutions\, i.e. dissipating entropy and conserving energy.\ nJoint work with Myrto Galanopoulou\, Konstantinos Koumatos and Athanasios Tzavaras.\n LOCATION:https://researchseminars.org/talk/NSCM/170/ END:VEVENT BEGIN:VEVENT SUMMARY:Ondřej Kreml (Institute of Mathematics\, CAS) DTSTART:20250224T144000Z DTEND:20250224T161000Z DTSTAMP:20260405T094550Z UID:NSCM/171 DESCRIPTION:Title: T ime-periodic solutions to an interaction problem between compressible visc ous fluids and viscoelastic beams\nby Ondřej Kreml (Institute of Math ematics\, CAS) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Universit y\, Sokolovská 83 Prague 8..\n\nAbstract\nWe study a nonlinear fluid-str ucture interaction problem\nbetween a viscoelastic beam\nand a compressibl e viscous fluid. The beam is immersed in the fluid\nwhich fills a two-\ndi mensional rectangular domain with periodic boundary conditions in both\ndi rections\,\nwhile both the beam and the fluid are under the effect of time -periodic\nforces. By using\na decoupling approach\, at least one time-per iodic weak solution to this\nproblem is con-\nstructed which has a bounded energy and a fixed prescribed mass. The\nlack of a priori\nenergy bounds is overcome by a series of estimates based on a careful\nchoice of paramet ers.\nThe time-periodic solution is constructed by a series of limit\nproc edures.\nThis is a joint work with V. Mácha\, Š. Nečasová and S. Trifu nović.\n LOCATION:https://researchseminars.org/talk/NSCM/171/ END:VEVENT BEGIN:VEVENT SUMMARY:Jaroslav Hron (Mathematical Institute\, Charles University) DTSTART:20250317T144000Z DTEND:20250317T161000Z DTSTAMP:20260405T094550Z UID:NSCM/172 DESCRIPTION:Title: N umerical investigation of blood flows with slip boundary conditions\nb y Jaroslav Hron (Mathematical Institute\, Charles University) as part of N ečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nMost studies of patient-specific blood flow models prescr ibe a no-slip boundary condition at the walls. Although its implementation is straightforward\, its validity at the blood-vessel wall interface is q uestionable. It has been suggested in (Nubar\, 1971) for example\, that a slip boundary condition can be considered for blood flow in certain situat ions. We will discuss some effects of prescribing the Navier-type slip bou ndary condition\, which assumes a linear proportionality between the tange ntial part of the wall velocity and the shear stress using an additional p arameter. Given some measured flow data\, for example modern 4D-PC MRI ima ge\, we use variational data assimilation approach to estimate the Navier' s slip parameter on the wall for real data.\n LOCATION:https://researchseminars.org/talk/NSCM/172/ END:VEVENT BEGIN:VEVENT SUMMARY:Easter Monday DTSTART:20250421T134000Z DTEND:20250421T151000Z DTSTAMP:20260405T094550Z UID:NSCM/173 DESCRIPTION:Title: n o seminar\nby Easter Monday as part of Nečas Seminar on Continuum Mec hanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/173/ END:VEVENT BEGIN:VEVENT SUMMARY:Noy Cohen (Technion\, Haifa) DTSTART:20250408T134000Z DTEND:20250408T151000Z DTSTAMP:20260405T094550Z UID:NSCM/174 DESCRIPTION:Title: F rom micro to macro: Unraveling the origin of the counterintuitive response in spider silk fibers\nby Noy Cohen (Technion\, Haifa) as part of Ne čas Seminar on Continuum Mechanics\n\nLecture held in Faculty of Civil En gineering\, CTU\, Thákurova 7\, Praha 6\, Room B-168 EXCEPTIONALLY.\n\nA bstract\nSpider silk is an extraordinary protein material characterized by high strength and toughness. Upon exposure to high humidity\, silk fibers experience a reduction in stiffness of several orders of magnitude\, supe rcontraction (i.e.\, a shortening of up to ~60% in length)\, and twist. Th ese counterintuitive responses originate from a unique polymeric structure made of crystalline domains that are embedded in a highly aligned amorpho us matrix. Broadly\, high humidity leads to water uptake by the silk\, whi ch in turn motivates the dissociation of intermolecular hydrogen cross-lin king bonds. \nIn this talk\, I will present energetically motivated models based on tools from statistical mechanics that shed light on the relation s between the microstructure and the macroscopic behavior and capture the overall response of silk fibers. The models are validated through a compar ison to experimental findings. The insights from these models provide a me thod to characterize the microstructural evolution of hydrogen-bond domina ted networks and pave the way to the design of novel biomimetic fibers wit h non-trivial properties. \n\n1) R. Olive and N. Cohen\, “Deformation an d failure mechanisms in spider silk fibers”\, Journal of the Mechanics a nd Physics of Solids\, 182:105480\, 2024.\n\n2) N. Cohen\, “The underlyi ng mechanisms behind the hydration-induced and mechanical response of spid er silk”\, Journal of the Mechanics and Physics of Solids\, 172:105141\, 2023.\n\n3) N. Cohen and C.D. Eisenbach\, “Humidity-Driven Supercontrac tion and Twist in Spider Silk”\, Physical Review Letters\, 128:098101\, 2022.\n\n4) N. Cohen\, M. Levin\, and C.D. Eisenbach\, “On the origin of supercontraction in spider silk”\, Biomacromolecules\, 22:993-1000\, 20 21.\n\nPlease note the time and location change for this talk !!!\n LOCATION:https://researchseminars.org/talk/NSCM/174/ END:VEVENT BEGIN:VEVENT SUMMARY:seminar meets on Tue DTSTART:20250407T134000Z DTEND:20250407T151000Z DTSTAMP:20260405T094550Z UID:NSCM/175 DESCRIPTION:Title: W e meet onTuesday\, April 8\nby seminar meets on Tue as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Ma thematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\nA bstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/175/ END:VEVENT BEGIN:VEVENT SUMMARY:Marco Amato (Faculty of Civil Engineering\, CTU) DTSTART:20250414T134000Z DTEND:20250414T151000Z DTSTAMP:20260405T094550Z UID:NSCM/176 DESCRIPTION:Title: E lastic solids under frictionless rigid contact and configurational force\nby Marco Amato (Faculty of Civil Engineering\, CTU) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Ma thematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\ nAbstract\nA homogeneous elastic solid\, bounded by a flat surface in its unstressed configuration\, undergoes a finite\nstrain when in frictionless contact against a rigid and rectilinear constraint\, ending with a rounde d or sharp\ncorner\, in a two-dimensional formulation. With a strong analo gy to fracture mechanics\, it is shown that (i.) a\npath-independent J–i ntegral can be defined for frictionless contact problems\, (ii.) which is equal to the energy\nrelease rate G associated with an infinitesimal growt h in the size of the frictionless constraint\, and thus gives the\nvalue o f the configurational force component along the sliding direction. Further more\, it is found that (iii.) such a configurational sliding force is the Newtonian force component exerted by the elastic solid on the constraint at the frictionless contact. Assuming the kinematics of an Euler-Bernoulli rod for an elastic body of rectangularshape\, the results (i.)–(iii.) l ead to a new interpretation from a nonlinear solid mechanics perspective o f the\nconfigurational forces recently disclosed for one-dimensional struc tures of variable length. Finally\, approximate\nbut closed-form solutions (validated with finite element simulations) are exploited to provide furt her insight into\nthe effect of configurational forces. In particular\, tw o applications are presented which show that a transverse\ncompression can lead to Eulerian buckling or to longitudinal dynamic motion\, both realiz ing novel examples of\nsoft actuation mechanisms. As an application to bio logy\, our results may provide a mechanical explanation for\nthe observed phenomenon of negative durotaxis\, where cells migrate from stiffer to sof ter environments. Joint work with F. Dal Corso and D. Bigoni.\n\n[1] Franc esco Dal Corso\, Marco Amato\, and Davide Bigoni. “Elastic solids under frictionless rigid contact and\nconfigurational force”. In: Journal of t he Mechanics and Physics of Solids 188 (2024)\, p. 105673\n LOCATION:https://researchseminars.org/talk/NSCM/176/ END:VEVENT BEGIN:VEVENT SUMMARY:Michael Dumbser (University of Trento) DTSTART:20250526T134000Z DTEND:20250526T151000Z DTSTAMP:20260405T094550Z UID:NSCM/177 DESCRIPTION:Title: O n well-balanced finite difference\, finite volume and discontinuous Galerk in schemes for the Einstein-Euler system of general relativity\nby Mic hael Dumbser (University of Trento) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physic s\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nIn this t alk we present a new family of well-balanced conservative CWENO finite dif ference schemes and discontinuous Galerkin (DG) finite element schemes wit h subcell finite volume (FV) limiter for the numerical solution of the Ein stein–Euler equations of general relativity based on a first order hyper bolic reformulation of the Z4 formalism. The first order Einstein-Euler Z4 system\, which is composed of 64 equations\, is analysed and proven to be strongly hyperbolic for a general metric. The well-balancing is achieved for arbitrary but a priori known equilibria by subtracting a discrete vers ion of the equilibrium solution from the discretized time-dependent PDE sy stem. Special care has also been taken in the design of the numerical visc osity so that the well-balancing property is achieved. As for the treatmen t of low density matter\, e.g. when simulating massive compact objects lik e neutron stars surrounded by vacuum\, we have introduced a new filter in the conversion from the conserved to the primitive variables\, preventing superluminal velocities when the density drops below a certain threshold\, and being potentially also very useful for the numerical investigation of highly rarefied relativistic astrophysical flows.\n\nWe furthermore prese nt a novel family of central WENO finite difference schemes for a new firs t order reformulation of the classical BSSNOK system.\n\nThanks to these i mprovements\, all standard tests of numerical relativity are successfully reproduced\, reaching four main achievements: (i) we are able to obtain st able long term simulations of stationary black holes\, including Kerr blac k holes with extreme spin\, which after an initial perturbation return per fectly back to the equilibrium solution up to machine precision\; (ii) a ( standard) TOV star under perturbation is evolved in pure vacuum (ρ = p = 0) up to t = 1000 with no need to introduce any artificial atmosphere arou nd the star\; and\, (iii) we solve the head on collision of two punctures black holes\, that was previously considered untractable within the FO-Z4 formalism\, (iv) we perform a stable long-time evolution of a rotating bin ary black hole merger based on the new CWENO schemes for first order refor mulation of the BSSNOK system.\n\nReferences\n\n[1] M. Dumbser\, O. Zanott i\, E. Gaburro and I. Peshkov\, A well-balanced discontinuous Galerkin met hod for the first–order Z4 formulation of the Einstein–Euler system\, Journal of Computational Physics 504 (2024)\, 112875.\n\n[2] M. Dumbser\, O. Zanotti and I. Peshkov. High order discontinuous Galerkin schemes with subcell finite volume limiter and AMR for a monolithic first-order BSSNOK formulation of the Einstein-Euler equations\, Physical Review D 110 (2024) \, 084015.\n\n[3] M. Dumbser\, O. Zanotti and G. Puppo\, A monolithic firs t–order BSSNOK formulation of the Einstein–Euler equations and its sol ution with conservative finite difference CWENO schemes\, Physical Review D\, submitted.\n LOCATION:https://researchseminars.org/talk/NSCM/177/ END:VEVENT BEGIN:VEVENT SUMMARY:Maria Neuss-Radu (University of Erlangen) DTSTART:20250428T134000Z DTEND:20250428T151000Z DTSTAMP:20260405T094550Z UID:NSCM/178 DESCRIPTION:Title: E ffective interface laws for fluid flow and transport through reactive poro us membranes\nby Maria Neuss-Radu (University of Erlangen) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Facult y of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe consider a coupled model for fluid flow and transport in a domain consisting of two bulk regions separated by a thin porous lay er. The thickness of the layer is of order $\\varepsilon$ and the microsco pic structure of the layer is periodic in the tangential direction also wi th period $\\varepsilon$. The fluid flow is described by an instationary S tokes system\, properly scaled in the fluid part of the thin layer. The ev olution of the solute concentrations is described by a reaction-diffusion- advection equation in the fluid part of the domain and a diffusion equatio n (allowing different scaling in the diffusion coefficients) in the solid part of the layer. At the microscopic fluid-solid interface inside the lay er nonlinear reactions take place. This system is rigorously homogenized i n the limit $\\varepsilon \\to 0$\, based on weak and strong (two-scale) c ompactness results for the solutions. These are based on new embedding ine qualities for thin perforated layers including coupling to bulk domains. I n the limit\, effective interface laws for flow and transport are derived at the interface separating the two bulk regions. These interface laws ena ble effective mass transport through the membrane\, which is also an impor tant feature from an application point of view. This is a joint work with Markus Gahn (Universität Heidelberg).\n LOCATION:https://researchseminars.org/talk/NSCM/178/ END:VEVENT BEGIN:VEVENT SUMMARY:Christoph Allolio (Mathematical Institute\, Charles University) DTSTART:20250505T134000Z DTEND:20250505T151000Z DTSTAMP:20260405T094550Z UID:NSCM/179 DESCRIPTION:Title: A pplied Continuum Modeling of (Sub)cellular Morphogenesis\nby Christoph Allolio (Mathematical Institute\, Charles University) as part of Nečas S eminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mat hematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\n Abstract\nCellular phenomena at the microscopic level are usually modeled via molecular simulations. These simulations have the advantage of giving an accurate description of the molecular interactions that give rise to bi ological phenomena. However\, they are computationally expensive and hard to interpret. In particular\, they are not capable of giving a satisfactor y view of slow processes\, such as organelle morphogenesis or cell divisio n. For this purpose\, continuum models are preferable. These models can be validated by structural data (e.g. electron microscopy). However\, they c an also be directly parametrized by molecular simulations. I present such a "data-driven" model for large membrane deformations\, e.g. induced by ce ll penetrating peptides as well as a more reductive morphoelastic model fo r bacterial division.\n LOCATION:https://researchseminars.org/talk/NSCM/179/ END:VEVENT BEGIN:VEVENT SUMMARY:Karel Tůma (Mathematical Institute\, Charles University) DTSTART:20250512T134000Z DTEND:20250512T151000Z DTSTAMP:20260405T094550Z UID:NSCM/180 DESCRIPTION:Title: P hase-field model for beta-to-omega transformation in titanium alloys\n by Karel Tůma (Mathematical Institute\, Charles University) as part of Ne čas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8 ..\n\nAbstract\nIn this talk\, we revisit a phase separation model involvi ng multiple wells\, focusing on $\\beta-\\omega$ transformations observed in titanium alloys. We introduce a novel approach that alters the algebrai c form of the interfacial free energy. This modification relaxes the conve ntional coercivity requirements on surface tensions within total-spreading scenarios and\, crucially\, eliminates the emergence of $\\omega-\\omega$ mixed phases—structures that are crystallographically forbidden. The ca pabilities of the new model are illustrated through basic numerical experi ments\, and we also describe the next steps toward more comprehensive\, th ree-dimensional simulations of $\\beta-\\omega$ phase evolution in titaniu m systems.\n LOCATION:https://researchseminars.org/talk/NSCM/180/ END:VEVENT BEGIN:VEVENT SUMMARY:summer break (We start again) DTSTART:20250602T134000Z DTEND:20250602T151000Z DTSTAMP:20260405T094550Z UID:NSCM/181 DESCRIPTION:Title: i n the fall\nby summer break (We start again) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathemati cs and Physics\, Charles University\, Sokolovská 83 Prague 8..\nAbstract : TBA\n LOCATION:https://researchseminars.org/talk/NSCM/181/ END:VEVENT BEGIN:VEVENT SUMMARY:Vladislav Mantič (University of Sevilla) DTSTART:20251006T134000Z DTEND:20251006T151000Z DTSTAMP:20260405T094550Z UID:NSCM/182 DESCRIPTION:Title: A symptotic Solutions at the Tip of Interface Cracks and Multi-Material Corn ers with Frictional Contact in Linear Elastic Anisotropic Solids\nby V ladislav Mantič (University of Sevilla) as part of Nečas Seminar on Cont inuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and P hysics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nThis study focuses on point singularities in the solutions of linear elastic B VPs for anisotropic solids in 2.5D (generalised plane strain). The stresse s in these BVPs can be unbounded at singular points\, also known as corner s\, where discontinuities exist in the solid geometry\, material propertie s or boundary/interface conditions. The behaviour of elastic solutions at singular points is described by asymptotic expansions expressed as series of products of power-logarithmic terms in the radial coordinate and charac teristic angular functions. The exponents of these terms are known as sing ularity exponents\, while the coefficients of the series are referred to a s generalised stress intensity factors (GSIFs).\n\nThis work aims to devel op:\n\n1) a specific semi-analytic procedure to determine the terms of the se asymptotic series at the tip of interface cracks with frictional slidin g contact between the crack faces\; and\n\n2) a general semi-analytic proc edure to determine the terms of these asymptotic series at the tip of mult i-material corners with frictional sliding contact at the outer faces and/ or interfaces between the wedges\, considering the Coulomb friction law.\n \nThese procedures are novel in that they lead to nonlinear eigenproblems for both the singularity exponents and the angles of frictional shear stre sses in frictional contact zones. Both procedures are based on the Stroh f ormalism in complex variable for linear anisotropic elasticity.\n\nThe app lication of these procedures is demonstrated by some interesting examples. Finally\, SingSol\, an online app that implements the general semi-analyt ic procedure for singularity analysis of multimaterial corners\, is briefl y presented.\n LOCATION:https://researchseminars.org/talk/NSCM/182/ END:VEVENT BEGIN:VEVENT SUMMARY:Michael Stingl (University of Erlangen) DTSTART:20251103T144000Z DTEND:20251103T161000Z DTSTAMP:20260405T094550Z UID:NSCM/183 DESCRIPTION:Title: O n a new class of separable models in topology and material optimization\nby Michael Stingl (University of Erlangen) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\ nSeparable models are used in specialized optimization solvers\nfor struct ural optimization like the method of moving asymptotes (MMA)\nfor many yea rs. In this presentation\, we derive a so called exact\nseparable models u sing the Sherman-Morrison-Woodbury-Formula. In this\ncontext\, exact means that the model matches an approximated function\nexactly\, as long as the design of only one element is varied. In simple\ncases\, there is a 1-to- 1 correspondence to the MMA model. In more\ngeneral situations\, non-linea r material parametrizations cause the exact\nseparable model to be non-con vex\, non-smooth or even discontinuous. To\ncope with that\, the sequentia l global programming (SGP) algorithm is used.\nIn the first part of the ta lk the concepts of exact separable models and\nthe SGP method are introduc ed and some theoretical results like a link\nto the calculus of topologica l derivatives and convergence properties\nare briefly discussed. In the se cond part\, applications from various\nareas of material and topology opti mization are used to demonstrate the\naccuracy and efficiency of the new a pproach.\n LOCATION:https://researchseminars.org/talk/NSCM/183/ END:VEVENT BEGIN:VEVENT SUMMARY:Marco Bresciani (University of Erlangen and JKU Linz) DTSTART:20251110T144000Z DTEND:20251110T161000Z DTSTAMP:20260405T094550Z UID:NSCM/184 DESCRIPTION:Title: Q uasistatic growth of cavities and cracks in the plane\nby Marco Bresci ani (University of Erlangen and JKU Linz) as part of Nečas Seminar on Con tinuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe propose a model for the quasistatic growth of cavities and cracks in two-d imensional nonlinear elasticity. Cavities and cracks are modeled as discre te and compact subsets of a planar domain\, respectively\, and deformation s are defined only outside of cracks. The model accounts for the irreversi bility of both processes of cavitation and fracture\, and it allows for th e coalescence of cavities into cracks. Our main result shows the existence of quasistatic evolutions in the case of a finite number of cavities unde r an a priori bound on the number of connected crack components. This is j oint work with Manuel Friedrich (JKU Linz).\n LOCATION:https://researchseminars.org/talk/NSCM/184/ END:VEVENT BEGIN:VEVENT SUMMARY:State holiday DTSTART:20251117T144000Z DTEND:20251117T161000Z DTSTAMP:20260405T094550Z UID:NSCM/185 DESCRIPTION:Title: W e do not meet this week\nby State holiday as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\nAbstract: T BA\n LOCATION:https://researchseminars.org/talk/NSCM/185/ END:VEVENT BEGIN:VEVENT SUMMARY:Tomáš Kozubek (Technical University of Ostrava) DTSTART:20251013T134000Z DTEND:20251013T151000Z DTSTAMP:20260405T094550Z UID:NSCM/186 DESCRIPTION:Title: F rom Scalable AI to Hybrid Quantum: The IT4Innovations Computing Continuum< /a>\nby Tomáš Kozubek (Technical University of Ostrava) as part of Neča s Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\ n\nAbstract\nThe presentation focuses on the AI- and QC-centred computing continuum at IT4Innovations (IT4I)\, showing how GPU-accelerated HPC\, dat a services\, and emerging quantum resources are being integrated to suppor t modern AI workflows and near-term quantum experimentation. On the AI sid e\, we outline platforms and tools that raise productivity for training an d inference at scale (e.g.\, HyperQueue for heterogeneous scheduling\, HEA ppE and LEXIS for HPC-as-a-Service and federated workflows) and describe a ccess routes that connect Czech users to EuroHPC capacity\, including LUMI and forthcoming AI-Factory services. On the QC side\, we detail the VLQ s uperconducting quantum computer (24 qubits\, star-shaped topology) and its role in hybrid HPC–QC pipelines for optimisation\, small-scale quantum chemistry\, and quantum-enhanced ML\, alongside practical enablers such as error-mitigation strategies and classical pre/post-processing on Karolina and partner EuroHPC systems. We position these capabilities within e-INFR A CZ and the EuroHPC ecosystem\, highlight representative impacts across s cience\, industry\, and public administration (from crisis-management anal ytics to drug-discovery workflows)\, and sketch next steps: federating AI factories and quantum systems\, operationalising VLQ within EuroHPC access schemes\, and commissioning Barbora NG to expand AI-ready throughput. Tog ether\, these developments advance a usable path from today’s large-scal e AI to tomorrow’s hybrid quantum-accelerated applications.\n LOCATION:https://researchseminars.org/talk/NSCM/186/ END:VEVENT BEGIN:VEVENT SUMMARY:Filippo Riva (Faculty of Mathematics and Physics\, Charles Univers ity) DTSTART:20251020T134000Z DTEND:20251020T151000Z DTSTAMP:20260405T094550Z UID:NSCM/187 DESCRIPTION:Title: A free boundary approach to quasistatic debonding\nby Filippo Riva (Fac ulty of Mathematics and Physics\, Charles University) as part of Nečas Se minar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Math ematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nA bstract\nDebonding models describe the evolution of an adhesive membrane p eeled away from a planar rigid substrate. When the process is sufficiently slow\, inertial and viscous effects can be neglected\, leading to a quasi static setting. In this framework\, debonding can be formulated as a varia tional evolution of sets. In the talk\, I will present how to prove the ex istence of so-called energetic solutions for this formulation—based on g lobal minimizers of a suitable functional together with an energy balance —by exploiting an equivalent rewriting of the model in terms of the cele brated one-phase Bernoulli free boundary problem. This is based on a joint work with E. Maggiorelli and E. Tolotti.\nIf time permits\, I will also d iscuss the dynamic version of the problem\, in which inertial effects are taken into account. In this setting\, a wave equation on moving domains is coupled with a suitable criterion governing the evolution of such domains . The problem\, formulated in collaboration with G. Lazzaroni\, R. Molinar olo\, and F. Solombrino\, is still open.\n LOCATION:https://researchseminars.org/talk/NSCM/187/ END:VEVENT BEGIN:VEVENT SUMMARY:Jan Valášek (Faculty of Mechanical Engineering\, CTU) DTSTART:20251124T144000Z DTEND:20251124T161000Z DTSTAMP:20260405T094550Z UID:NSCM/188 DESCRIPTION:Title: M athematical modelling of human phonation process\nby Jan Valášek (Fa culty of Mechanical Engineering\, CTU) as part of Nečas Seminar on Contin uum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Phy sics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nIn thi s talk the fluid-structure-acoustic interaction (FSAI) problem with a part icular interest in application on the problem of human phonation is addres sed. This problem consists of the three physical fields: a highly complex airflow\, a vibrating elastic structure (vocal folds) and acoustics and th eir mutual interactions. The general mathematical model of FSAI problem wi ll be described and the later simplifications of it will be discussed. Si nce the main sound source of the human phonation is generated by an unstea dy flow in the complex configuration of vocal tract the aeroacoustics as a separate branch of acoustics will be introduced. The ultimate goal of the aeroacoustics is to establish a well solvable simplification of the full description provided by the Navier-Stokes equations (for compressible flui d). Due to recent advantages the computational aeroacoustics has attained also a high interest in the field of technical applications. In the end th e numerical simulations of flow-induced vibrations of vocal folds and the propagation of sound through human vocal tract based on the previously men tioned approaches will be shown.\n LOCATION:https://researchseminars.org/talk/NSCM/188/ END:VEVENT BEGIN:VEVENT SUMMARY:Miroslav Kolář (Faculty of Nuclear Sciences and Physical Enginee ring Czech Technical University in Prague) DTSTART:20250929T134000Z DTEND:20250929T151000Z DTSTAMP:20260405T094550Z UID:NSCM/189 DESCRIPTION:Title: M odeling of discrete dislocation dynamics by means of the mathematical theo ry of evolving curves\nby Miroslav Kolář (Faculty of Nuclear Science s and Physical Engineering Czech Technical University in Prague) as part o f Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Facu lty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prag ue 8..\n\nAbstract\nDislocation dynamics (DD) has become a standard tool f or analyzing\ndeformation microstructures. Fundamentals of dislocation the ory have been\nestablished in 1930s and later verified by first TEM experi ments in 1950s.\nThe ultimate objective of DD is to fill the gap between f ully continuous\nmodels in the macroscopic scale based on crystal plastici ty\, and atomistic\nmodels in nanoscale usually treated by the molecular d ynamics methods. \n\nIn crystalline solids\, dislocations represent irreg ularities or defects in\nthe crystal structure. Such defects are usually o f the line character and\nthe characteristic unit of length of such defect s is microns. These line\ndefects are the subject of both external forces applied on the crystal as\nwell as various internal mechanisms\, and they evolve in the so-called slip\nplanes given by particular crystallographic orientation. \n\nOur research interest is in the detailed and precise mode ling of fundamental\nmechanisms involving single or very few dislocations. Such a topic is\ntypically referred to as a discrete dislocation dynamics (DDD). \n\nIn our approach to DDD\, a single dislocation carrying the pla stic flow in\nits respective slip plane is represented as an evolving plan ar curve. The\nexperimentally observed mechanism how dislocations evolve i s of a\nnon-Newtonian type and can be schematically described as\n\nnormal velocity = curvature + external force\, \n\nwhere the curvature term appr oximates the self-stress of the dislocation\ngenerated by a line tension. We treat this kind of evolution equation by the\ndirect (Lagrangian) appro ach resulting in the system of two degenerate\nparabolic equations for par ametrization of the single dislocation curve. We\nsolve this problem numer ically by means of the flowing finite-volume method\,\nand we improve the stability of the numerical scheme by the suitable choice\nof the external tangential velocity which helps to redistribute the\ndiscretization points along the dislocation in an appropriate way.\n\nWe demonstrate our approa ch in several computational examples covering the\nfundamental dislocation mechanisms and then we focus on the dislocation\ncross-slip\, which is co nsidered as one of the key mechanisms of\nmicroplasticity and still an ope n problem in general. We show how we modify\nour method by the geodesic de scription of curves to treat the cross-slip\nwithin our framework.\n LOCATION:https://researchseminars.org/talk/NSCM/189/ END:VEVENT BEGIN:VEVENT SUMMARY:seminar cancelled DTSTART:20251027T144000Z DTEND:20251027T161000Z DTSTAMP:20260405T094550Z UID:NSCM/190 DESCRIPTION:Title: W e do not meet this week.\nby seminar cancelled as part of Nečas Semin ar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathema tics and Physics\, Charles University\, Sokolovská 83 Prague 8..\nAbstra ct: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/190/ END:VEVENT BEGIN:VEVENT SUMMARY:Matteo Caggio (Institute of Mathematics\, CAS) DTSTART:20251208T144000Z DTEND:20251208T161000Z DTSTAMP:20260405T094550Z UID:NSCM/191 DESCRIPTION:Title: B etween low and strong stratification regimes for rotating heat-conducting fluids\nby Matteo Caggio (Institute of Mathematics\, CAS) as part of N ečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe consider the Navier-Stokes-Fourier system for a heat c onducting\ncompressible fluid under the effects of rotation and stratifica tion. We\ninvestigate the low Mach\, Rossby and Froude number limit toward s a\nquasi-geostrophic balance in a stratification range between the\nso-c alled low and strong stratification regimes. The limit is studied in\nthe context of weak solutions with ill-prepared initial data. This is a\njoint work with Gabriele Sbaiz (Trieste).\n LOCATION:https://researchseminars.org/talk/NSCM/191/ END:VEVENT BEGIN:VEVENT SUMMARY:Ondřej Marek (Faculty of Nuclear Sciences\, CTU) DTSTART:20251201T144000Z DTEND:20251201T161000Z DTSTAMP:20260405T094550Z UID:NSCM/192 DESCRIPTION:Title: L attice Boltzmann method for compressible fluid flow and drag simulations\nby Ondřej Marek (Faculty of Nuclear Sciences\, CTU) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of M athematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n \nAbstract\nThis talk discusses the use of the lattice Boltzmann method (L BM) for\ncompressible fluid flow and its application in approximating drag and lift\ncoefficients of objects. A brief overview of fluid dynamics is followed by\nan explanation of the LBM. Entropic LBM and multi-speed veloc ity models\nused to simulate compressible fluid flow are described\, along with a\ngeneralization of their boundary conditions and a benchmark probl em. Next\,\nan algorithm for numerically computing the drag and lift coeff icients\nspecific for the LBM grid is derived for both incompressible and\ ncompressible flows. Finally\, a numerical study is performed for flow\nar ound a cylinder and a NACA profile with the multi-speed ELBM model\,\nrefe rence single-speed LBM models and the finite volume method compared\nwith results from published studies.\n LOCATION:https://researchseminars.org/talk/NSCM/192/ END:VEVENT BEGIN:VEVENT SUMMARY:X-mas break (we do not meet) DTSTART:20251215T144000Z DTEND:20251215T161000Z DTSTAMP:20260405T094550Z UID:NSCM/193 DESCRIPTION:by X-mas break (we do not meet) as part of Nečas Seminar on C ontinuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics an d Physics\, Charles University\, Sokolovská 83 Prague 8..\nAbstract: TBA \n LOCATION:https://researchseminars.org/talk/NSCM/193/ END:VEVENT BEGIN:VEVENT SUMMARY:X-mas break (we do not meet) DTSTART:20251222T144000Z DTEND:20251222T161000Z DTSTAMP:20260405T094550Z UID:NSCM/194 DESCRIPTION:by X-mas break (we do not meet) as part of Nečas Seminar on C ontinuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics an d Physics\, Charles University\, Sokolovská 83 Prague 8..\nAbstract: TBA \n LOCATION:https://researchseminars.org/talk/NSCM/194/ END:VEVENT BEGIN:VEVENT SUMMARY:X-mas break (we do not meet) DTSTART:20251229T144000Z DTEND:20251229T161000Z DTSTAMP:20260405T094550Z UID:NSCM/195 DESCRIPTION:by X-mas break (we do not meet) as part of Nečas Seminar on C ontinuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics an d Physics\, Charles University\, Sokolovská 83 Prague 8..\nAbstract: TBA \n LOCATION:https://researchseminars.org/talk/NSCM/195/ END:VEVENT BEGIN:VEVENT SUMMARY:Anna Doležalová (Institute of Information Theory and Automation\ , CAS) DTSTART:20260105T144000Z DTEND:20260105T161000Z DTSTAMP:20260405T094550Z UID:NSCM/196 DESCRIPTION:Title: M ission p smaller than n-1: Possible - Nonlinear Elasticity Beyond Conventi onal Limits\nby Anna Doležalová (Institute of Information Theory and Automation\, CAS) as part of Nečas Seminar on Continuum Mechanics\n\nLec ture held in Room K3\, Faculty of Mathematics and Physics\, Charles Unive rsity\, Sokolovská 83 Prague 8..\n\nAbstract\nIn models of Nonlinear Ela sticity\, the natural physical deformation is a minimizer of an energy fun ctional containing the integral of $|Df(x)|^p$\, and we search for the min imizer in the Sobolev space $W^{1\,p}(\\Omega\, R^n)$. In the previous re sults\, one assumes that p is at least n-1 to ensure the non-interpenetrat ion of matter.\nIn this talk we prove the lower semicontinuity of an energ y functional that allows\, for the first time\, for $p$ less than $n-1$. O ur class of admissible deformations consists of weak limits of Sobolev hom eomorphisms. We also introduce a model that allows for cavitations by stud ying weak limits of homeomorphisms that can open cavities at some points. In that model we add the measure of the created surface to the energy func tional and we again prove lower semicontinuity.\nThis is a joint work with Daniel Campbell and Stanislav Hencl.\n LOCATION:https://researchseminars.org/talk/NSCM/196/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20260112T144000Z DTEND:20260112T161000Z DTSTAMP:20260405T094550Z UID:NSCM/197 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/197/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20260119T144000Z DTEND:20260119T161000Z DTSTAMP:20260405T094550Z UID:NSCM/198 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/198/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20260126T144000Z DTEND:20260126T161000Z DTSTAMP:20260405T094550Z UID:NSCM/199 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/199/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20260202T144000Z DTEND:20260202T161000Z DTSTAMP:20260405T094550Z UID:NSCM/200 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/200/ END:VEVENT BEGIN:VEVENT SUMMARY:semester break DTSTART:20260209T144000Z DTEND:20260209T161000Z DTSTAMP:20260405T094550Z UID:NSCM/201 DESCRIPTION:by semester break as part of Nečas Seminar on Continuum Mecha nics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Ch arles University\, Sokolovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/201/ END:VEVENT BEGIN:VEVENT SUMMARY:Michele Zaccaron (UMA\, ENSTA Paris) DTSTART:20260216T144000Z DTEND:20260216T161000Z DTSTAMP:20260405T094550Z UID:NSCM/202 DESCRIPTION:Title: B ending and twisting of electromagnetic waveguides\nby Michele Zaccaron (UMA\, ENSTA Paris) as part of Nečas Seminar on Continuum Mechanics\n\nL ecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Uni versity\, Sokolovská 83 Prague 8..\n\nAbstract\nConsider a reference hom ogeneous and isotropic electromagnetic waveguide\nwith a simply connected cross-section embedded in a perfect conductor. In\nthis setting\, when the waveguide is straight\, the spectrum of the associated\nself-adjoint Maxw ell operator with a constant twist (which may be zero) is\nentirely essent ial\, lies on the real line and is symmetric with respect to zero\,\nexhib iting a gap around the origin.\nIn this talk\, we present new results on t he effects of the geometric defor-\nmations of bending and twisting on the spectrum of the Maxwell operator.\nMore precisely\, we provide\, on the o ne hand\, sufficient conditions on the\nasymptotic behaviour of the curvat ure and twist of a perturbed waveguide\nensuring the preservation of the e ssential spectrum. Our approach relies on\na Birman-Schwinger-type princip le which has an interest of its own. On the\nother hand\, we give sufficie nt conditions\, involving in particular the shape of\nthe cross-section\, so that the geometrical deformation creates discrete spec-\ntrum within th e gap\, and give some insight into its localization. Finally\, we\nshow so me theoretical and numerical results further investigating the suffi-\ncie nt condition involving the geometry of the cross-section.\nBased on joint work with Philippe Briet\, Maxence Cassier and Thomas Ourmieres-Bonafos.\n LOCATION:https://researchseminars.org/talk/NSCM/202/ END:VEVENT BEGIN:VEVENT SUMMARY:Easter Monday DTSTART:20260406T134000Z DTEND:20260406T151000Z DTSTAMP:20260405T094550Z UID:NSCM/203 DESCRIPTION:by Easter Monday as part of Nečas Seminar on Continuum Mechan ics\n\nInteractive livestream: https://cesnet.zoom.us/j/94319936814?pwd=Y0 pRL0FpWEhhQ1U4TzZGc2FDQVM4Zz09\nView-only livestream: https://www.youtube. com/channel/UCn9vmevniyXXLEr7VBp5cCQ\nLecture held in Room K3\, Faculty o f Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8. .\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/203/ URL:https://cesnet.zoom.us/j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Z z09 URL:https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ END:VEVENT BEGIN:VEVENT SUMMARY:P.Podio-Guidugli/L. Truskinovsky DTSTART:20260413T134000Z DTEND:20260413T151000Z DTSTAMP:20260405T094550Z UID:NSCM/204 DESCRIPTION:by P.Podio-Guidugli/L. Truskinovsky as part of Nečas Seminar on Continuum Mechanics\n\nInteractive livestream: https://cesnet.zoom.us/j /94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Zz09\nView-only livestream: h ttps://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ\nLecture held in R oom K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolo vská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/204/ URL:https://cesnet.zoom.us/j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Z z09 URL:https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ END:VEVENT BEGIN:VEVENT SUMMARY:Jonathan Bevan DTSTART:20260420T134000Z DTEND:20260420T151000Z DTSTAMP:20260405T094550Z UID:NSCM/205 DESCRIPTION:by Jonathan Bevan as part of Nečas Seminar on Continuum Mecha nics\n\nInteractive livestream: https://cesnet.zoom.us/j/94319936814?pwd=Y 0pRL0FpWEhhQ1U4TzZGc2FDQVM4Zz09\nView-only livestream: https://www.youtube .com/channel/UCn9vmevniyXXLEr7VBp5cCQ\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8 ..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/205/ URL:https://cesnet.zoom.us/j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Z z09 URL:https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ END:VEVENT BEGIN:VEVENT SUMMARY:Lukáš Horný (Faculty of Mechanical Engineering\, CTU Prague) DTSTART:20260427T134000Z DTEND:20260427T151000Z DTSTAMP:20260405T094550Z UID:NSCM/206 DESCRIPTION:Title: M echanics of nonlinearly elastic tubes: Effect of axial prestretching and c onsequences for the biomechanics of human arteries\nby Lukáš Horný (Faculty of Mechanical Engineering\, CTU Prague) as part of Nečas Seminar on Continuum Mechanics\n\nInteractive livestream: https://cesnet.zoom.us/ j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Zz09\nView-only livestream: https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokol ovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/206/ URL:https://cesnet.zoom.us/j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Z z09 URL:https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ END:VEVENT BEGIN:VEVENT SUMMARY:Giacomo Vianello (Institute of Information Theory and Automation\, CAS) DTSTART:20260223T144000Z DTEND:20260223T161000Z DTSTAMP:20260405T094550Z UID:NSCM/207 DESCRIPTION:Title: T he behavior of an almost-minimizer of the relative perimeter near a bounda ry vertex of the container.\nby Giacomo Vianello (Institute of Informa tion Theory and Automation\, CAS) as part of Nečas Seminar on Continuum M echanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\ , Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nIt is known that the boundary of an almost-minimizer of the relative perimeter inside a smooth container satisfies Young's Law\, namely\, it meets the containe r boundary orthogonally. Much less is known when the container is nonsmoot h. In this talk\, I will describe some recent results concerning the behav ior of an almost-minimizer of the relative perimeter near an isolated sing ularity (vertex) of its container boundary. I will show that\, in dimensio n three\, a phenomenon we call vertex-skipping occurs\, that is\, the boun dary of an almost-minimizer cannot pass through a vertex of its container\ , while in higher dimensions the situation is more intricate\, and a relat ion between the "aperture" of the vertex and the avoidance of the singular ity emerges. I will conclude by discussing some related open questions. Th is is part of a joint project with Gian Paolo Leonardi (University of Tren to).\n LOCATION:https://researchseminars.org/talk/NSCM/207/ END:VEVENT BEGIN:VEVENT SUMMARY:Helmut Abels DTSTART:20260518T134000Z DTEND:20260518T151000Z DTSTAMP:20260405T094550Z UID:NSCM/208 DESCRIPTION:by Helmut Abels as part of Nečas Seminar on Continuum Mechani cs\n\nInteractive livestream: https://cesnet.zoom.us/j/94319936814?pwd=Y0p RL0FpWEhhQ1U4TzZGc2FDQVM4Zz09\nView-only livestream: https://www.youtube.c om/channel/UCn9vmevniyXXLEr7VBp5cCQ\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8.. \nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/208/ URL:https://cesnet.zoom.us/j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Z z09 URL:https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ END:VEVENT BEGIN:VEVENT SUMMARY:summer break DTSTART:20260525T134000Z DTEND:20260525T151000Z DTSTAMP:20260405T094550Z UID:NSCM/209 DESCRIPTION:Title: w e meet again in October 2026\nby summer break as part of Nečas Semina r on Continuum Mechanics\n\nInteractive livestream: https://cesnet.zoom.us /j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Zz09\nView-only livestream: https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Soko lovská 83 Prague 8..\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/209/ URL:https://cesnet.zoom.us/j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Z z09 URL:https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ END:VEVENT BEGIN:VEVENT SUMMARY:Giuseppe Tomassetti (University Roma Tre) DTSTART:20260309T144000Z DTEND:20260309T161000Z DTSTAMP:20260405T094550Z UID:NSCM/210 DESCRIPTION:Title: O n the single field formulation in magnetostatics\nby Giuseppe Tomasset ti (University Roma Tre) as part of Nečas Seminar on Continuum Mechanics\ n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nWe systematically di scuss the equivalence of two variational formulations of magnetostatics\, in terms of the fields (H\,M) on the one hand and the single field formula tion using only B on the other hand. To demonstrate that this link is stab le also when the magnetic laws are coupled with other variational static m odels\, elasticity is included in the models as well. Interestingly\, desp ite the fact that the corresponding magnetoelastic energy densities in the material can be computed via Legendre-Fenchel transform in the magnetic s tate variables\, the two formulations are not linked by standard convex du ality on the level of the functionals. In addition\, convexity and coerciv ity of the given functional are neither required for the transformation no r always preserved by it.\n LOCATION:https://researchseminars.org/talk/NSCM/210/ END:VEVENT BEGIN:VEVENT SUMMARY:Michele Ruggeri (University of Bologna) DTSTART:20260316T144000Z DTEND:20260316T161000Z DTSTAMP:20260405T094550Z UID:NSCM/211 DESCRIPTION:Title: C onvergent finite element methods for nematic liquid crystals\nby Miche le Ruggeri (University of Bologna) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics \, Charles University\, Sokolovská 83 Prague 8..\n\nAbstract\nThe Ericks en model describes nematic liquid crystals (LCs) in terms of a unit-length vector field (director) and a scalar function (degree of orientation). Co mpared to the classical Oseen-Frank model\, it allows for the description of a larger class of defects. Equilibrium states of the LC are given by ad missible pairs that minimize an energy functional\, which consists of the sum of Oseen-Frank-like energies and a double well potential. The resultin g Euler-Lagrange equations are degenerate for the director\, which poses s erious difficulties to formulate mathematically sound algorithms for their approximation. We propose a simple but novel finite element approximation of the problem that does not employ a projection to impose the unit-lengt h constraint on the director and thus circumvents the use of weakly acute meshes\,quite restrictive in 3D. We show stability and Gamma-convergence p roperties of the new method in the presence of defects. We also discuss an effective nested gradient flow algorithm for computing minimizers that co ntrols the violation of the unit-length constraint. We present several sim ulations in 2D and 3D that document the performance of the proposed scheme and its ability to capture quite intriguing defects. This is joint work w ith Ricardo H. Nochetto (University of Maryland) and Shuo Yang (BIMSA).\n LOCATION:https://researchseminars.org/talk/NSCM/211/ END:VEVENT BEGIN:VEVENT SUMMARY:Martin Stýblo (SIMONE Research Group s.r.o.) DTSTART:20260323T144000Z DTEND:20260323T161000Z DTSTAMP:20260405T094550Z UID:NSCM/212 DESCRIPTION:Title: T he heart of industrial pipeline simulators - background\, history\, equati ons and numerical methods\nby Martin Stýblo (SIMONE Research Group s. r.o.) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Faculty of Mathematics and Physics\, Charles University\, Sokol ovská 83 Prague 8..\n\nAbstract\nThe lecture aims to illustrate the cont ext of the pipeline simulation industry - underlying physics\, governing e quations\, and numerical methods used by main packages. A brief overview o f current research and possible future trends will be presented as well.\n LOCATION:https://researchseminars.org/talk/NSCM/212/ END:VEVENT BEGIN:VEVENT SUMMARY:Jan Stebel DTSTART:20260504T134000Z DTEND:20260504T151000Z DTSTAMP:20260405T094550Z UID:NSCM/213 DESCRIPTION:by Jan Stebel as part of Nečas Seminar on Continuum Mechanics \n\nInteractive livestream: https://cesnet.zoom.us/j/94319936814?pwd=Y0pRL 0FpWEhhQ1U4TzZGc2FDQVM4Zz09\nView-only livestream: https://www.youtube.com /channel/UCn9vmevniyXXLEr7VBp5cCQ\nLecture held in Room K3\, Faculty of M athematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n Abstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/213/ URL:https://cesnet.zoom.us/j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Z z09 URL:https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ END:VEVENT BEGIN:VEVENT SUMMARY:Jakub Cach DTSTART:20260511T134000Z DTEND:20260511T151000Z DTSTAMP:20260405T094550Z UID:NSCM/214 DESCRIPTION:by Jakub Cach as part of Nečas Seminar on Continuum Mechanics \n\nInteractive livestream: https://cesnet.zoom.us/j/94319936814?pwd=Y0pRL 0FpWEhhQ1U4TzZGc2FDQVM4Zz09\nView-only livestream: https://www.youtube.com /channel/UCn9vmevniyXXLEr7VBp5cCQ\nLecture held in Room K3\, Faculty of M athematics and Physics\, Charles University\, Sokolovská 83 Prague 8..\n Abstract: TBA\n LOCATION:https://researchseminars.org/talk/NSCM/214/ URL:https://cesnet.zoom.us/j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Z z09 URL:https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ END:VEVENT BEGIN:VEVENT SUMMARY:Mariya Ptashnyk (Heriot-Watt University Edinburgh) DTSTART:20260330T134000Z DTEND:20260330T151000Z DTSTAMP:20260405T094550Z UID:NSCM/215 DESCRIPTION:Title: M ultiscale modelling\, analysis and simulation of plant biomechanics and gr owth\nby Mariya Ptashnyk (Heriot-Watt University Edinburgh) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in Room K3\, Facul ty of Mathematics and Physics\, Charles University\, Sokolovská 83 Pragu e 8..\n\nAbstract\nThe interplay between the complex microscopic structure s and microscopic (cellular) processes enables many biological tissues to combine the ability to resist high pressure and mechanical forces with the flexibility required for large expansions and growth. To analyse the inte ractions between the mechanics\, microscopic structure\, and the chemistry we derive microscopic models for plant biomechanics\, assuming that the e lastic/viscoelastic properties of plant cell walls depend on the chemical processes and chemical reactions depend on the mechanical stresses. Multip licative decomposition of the deformation gradient into elastic and growth parts is used to model the stress or strain-based growth. To analyse and simulate the complex multiscale models\, the macroscopic effective equatio ns are derived using homogenization techniques. Numerical solutions for th e macroscopic models demonstrate the impact of the microscopic structure a nd tissue heterogeneity on deformation and growth.\n LOCATION:https://researchseminars.org/talk/NSCM/215/ END:VEVENT BEGIN:VEVENT SUMMARY:Tomáš Bodnár (Department of Technical Mathematics\, Czech Tech nical University in Prague) DTSTART:20260302T144000Z DTEND:20260302T161000Z DTSTAMP:20260405T094550Z UID:NSCM/216 DESCRIPTION:Title: N umerical simulations of hemodynamics and hemolysis\nby Tomáš Bodnár (Department of Technical Mathematics\, Czech Technical University in Pra gue) as part of Nečas Seminar on Continuum Mechanics\n\nLecture held in R oom K3\, Faculty of Mathematics and Physics\, Charles University\, Sokolo vská 83 Prague 8..\n\nAbstract\nThe development of blood contacting devi ces\, such as Ventricular Assist Devices (VAD) became one of the most chal lenging tasks in modern bioengineering. The models of blood rheology\, str ess- and strain- based models of hemolysis\, models of turbulence need to be solved at high resolution in complex geometries. The talk will present an overview of our current work in design of computational test case for V AD development and some of the recent results on combining the models of v iscoelastic rheology with strain based models of hemolysis. This is a part of an ongoing joint work with Anna Lancmanova\, Nico Dirkes\, Alberto Gir elli\, Adelia Sequeira and Giulia Giantesio.\n LOCATION:https://researchseminars.org/talk/NSCM/216/ END:VEVENT BEGIN:VEVENT SUMMARY:Nico Dirkes (RWTH Aachen) DTSTART:20260622T134000Z DTEND:20260622T151000Z DTSTAMP:20260405T094550Z UID:NSCM/217 DESCRIPTION:Title: C omputational Prediction of Red Blood Cell Damage: Mathematical Modeling an d Uncertainty Quantification\nby Nico Dirkes (RWTH Aachen) as part of Nečas Seminar on Continuum Mechanics\n\nInteractive livestream: https://c esnet.zoom.us/j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Zz09\nView-onl y livestream: https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ\nLe cture held in Room K3\, Faculty of Mathematics and Physics\, Charles Univ ersity\, Sokolovská 83 Prague 8..\n\nAbstract\nComputational simulations have become an important tool for the design of mechanical circulatory su pport devices as well as surgical planning ahead of implantation. While co mputational fluid dynamics can accurately predict flow fields\, the predic tion of hemolysis (red blood cell damage) remains challenging. Absolute pr edictions of hemolysis indices often deviate by multiple orders of magnitu de from experimental measurements. This discrepancy can be attributed to t wo issues. First\, most existing models for hemolysis employ a simple powe r law relationship between shear stress\, exposure time\, and hemolysis in dex\, with model parameters fitted to experimental data. Second\, experime ntal data often exhibits large variability between donors and between stud ies\, leading to significant uncertainty in the fitted model parameters. T his is due to individual differences in red blood cell properties and high sensitivity to experimental conditions. Consequently\, the predictive cap abilities of these models are limited\, especially when applied to flow co nditions that differ from those used in experiments.\n\nWe propose a two-s ided approach to enhance the predictive capabilities of hemolysis models. First\, we introduce a more physiological model that incorporates two impo rtant effects of the red blood cell membrane: viscoelastic deformation and pore formation. We highlight the differences between the Lagrangian and E ulerian model formulations. The Eulerian formulation enables a stabilized finite element discretization\, which we apply to various benchmark cases. Second\, we show how uncertainty quantification techniques can be employe d to account for the variability in experimental data when fitting model p arameters. This facilitates the integration of new experimental data as it becomes available\, thereby enabling patient-specific predictions of hemo lysis. Overall\, this two-sided approach allows for more accurate and unce rtainty-aware predictions of hemolysis to support the development process of future generations of biomedical devices.\n LOCATION:https://researchseminars.org/talk/NSCM/217/ URL:https://cesnet.zoom.us/j/94319936814?pwd=Y0pRL0FpWEhhQ1U4TzZGc2FDQVM4Z z09 URL:https://www.youtube.com/channel/UCn9vmevniyXXLEr7VBp5cCQ END:VEVENT END:VCALENDAR