Thermomechanical couplings and pseudoelasticity of shape memory alloys

Energy balances of a polycrystalline CuZnAl Shape Memory Alloy are performed using infrared and calorimetric techniques. The experiments underline the main role of temperature variations induced by deformation process on the stress-strain curves. A thermodynamic analysis shows variations essentially due to the latent heat of phase change and indicates a very small intrinsic dissipated energy compared with deformation work or latent heat. Oil the basis of these results, a behaviour model that takes account of thermomechanical couplings is proposed. Implemented in a finite elements code, this model is used to verify the consistency and the potentialities of such an approach by means of numerical experiments. (C) 1998 Elsevier Science Ltd. All rights reserved.