  We propose a Ginzburg-Landau theory for the elastic properties of shape
memory polycrystals. A single crystal elastic free energy for a system that
undergoes a square-to-rectangle transformation is generalized to a polycrystal
by introducing a crystal orientational field that is determined from a
continuum phase field model. The coupled system is used to study domain
morphology and mechanical properties of shape memory alloys in different
temperature regimes.
