BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Hanuš Seiner (Inst. of Thermomechanics\, CAS) DTSTART:20211018T134000Z DTEND:20211018T151000Z DTSTAMP:20260405T174648Z 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 END:VCALENDAR