A Shape Memory Alloy (SMA) material can undergo repeated loading and unloading cycles under large deformations and still retain elastic behavior with no residual strains (pseudoelasticity or superelasticity). Residual strains in SMAs caused by deformation at low temperatures can be removed when heated up (shape memory effect).

This pseudoelasticity and the shape memory effect are material characteristics that are especially useful for aeronautical, biomedical, and structural engineering applications. Although progress has been made with SMA material analysis and design, many challenges still exist for precisely controlling SMAs due to highly nonlinear hysteretic transformation, material degradation, and thermomechanical fatigue. Finite element analysis has been widely used to simulate SMA material and provides a valuable tool for designing products using SMA materials. For information on the governing equations used to model the nonlinear material properties of shape memory alloys, see Shape Memory Alloy (SMA) in the Material Reference.