Author(s)

N. Buhner

Abstract

Shape memory alloys (SMA) exhibit first order phase tran- sitions between the two occurring phases, Austenite (A) and Martensite (M). In deformation-driven experiments, I. Muller and his co-workers did not only observe load-deformation hys- teresis loops, but also small loops inside these hysteresis loops. Up to now there is neither theoretical understanding of these "inner loops" nor have they been observed in numerical simula- tions. We present a Landau-Ginzburg model describing these deformation-driven martensitic phase transitions and consider a thin rod of SMA which is clamped on one side and pulled and pushed in the course of time on the other side. Local and global existence results are established. We show numerical simulations of the experiments for a CuZnAl single crystal. 1

Keywords