Control of intrinsic instability of superelastic deformation

The superelastic deformation of shape memory alloys has intrinsic instability as a result of incompatibility between martensite and austenite phases at stress-induced transformation. This instability leads to the thermodynamic stress–strain hysteresis of the superelastic deformation. It has been shown that the combination of a shape memory active material with a non-transforming passive material can decrease and suppress the instability of superelastic deformation. The stability analysis of superelastic deformation allows one to formulate design principles of adaptive composites with controlled stress–strain hysteresis and potentially large reversible deformation.