Simulation of pseudoelastic behaviour of SMA under cyclic loading

A simple modification to an existing constitutive model for SMA materials is proposed to include the effects of loading frequency. The proposed model is based on the behaviour of experimental results of SMA wires subjected to cyclic strains. Numerical simulations based on the modified constitutive model show good qualitative agreement with experimental results. The influence of loading frequency, temperature, static strain offset and strain amplitude on pseudoelastic hysteresis loops and energy dissipation is studied. Dynamic response of a single degree of freedom system with an SMA element is examined by using the modified constitutive model and Newmark's time integration method. Basic features of the displacement and SMA element stress time histories are studied. The frequency-response curve of a SDOF is investigated. (C) 2003 Elsevier B.V. All rights reserved.