BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Martin Doskar (Czech Technical University) DTSTART:20201019T134000Z DTEND:20201019T151000Z DTSTAMP:20260405T174410Z 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 END:VCALENDAR