Computational Modeling of Superelastic Behaviors of Shape Memory Alloy Devices Under Combined Stresses

Abstract

The three-dimensional incremental finite element formulation for the multiaxial behavior of shape memory alloy devices is proposed in the present study by considering the coupling effect of the axial and torsional behaviors of shape memory alloys. The previously proposed one-dimensional constitutive model for shape memory alloy devices is extended to take account of the multiaxial stress state introducing some new material constants. The calculated results are compared with the uniaxial, purely torsional and multiaxial test results for NiTi tubes to illustrate the validity of the proposed computational modeling.