Finite element analysis of superelastic, large deformation behavior of shape memory alloy helical springs

Brinsonʹs one-dimensional constitutive modeling for shape memory alloy (SMA) is extended to consider the asymmetric tensile and compressive behavior as well as the torsional behavior. The incremental finite element method using linear Timoshenko beam elements is formulated by the total Lagrangian approach for the superelastic, large deformation analysis of SMA helical springs. The NiTi helical springs are analyzed and the calculated results are compared with the experimental results to show the validity of the present computational procedure in actual design of SMA actuators.