BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Jan Zeman (Faculty of Civil Engineering\, Czech Tech. Uni.) DTSTART:20211004T134000Z DTEND:20211004T151000Z DTSTAMP:20260405T174623Z 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 END:VCALENDAR