Thermo-mechanical behavior associated with pseudoelastic transformation of shape memory alloys

We have performed a simulation analysis of the pseudoelastic behavior of a NiTi shape memory alloy wire placed in air, subjected to tensile cyclic loads over a range of low strain rates. Thermomechanical interactions, such as energy dissipation, latent heat and heat transfer, are accounted for in a one-dimensional thermomechanical model based on the phase interaction energy function which was introduced in our previous analyses. The interaction energy function was numerically determined so as to make an analytical constitutive relationship fit available experimental stress-strain curves. Numerical results show that the loading strain rate is influential on changes in the stress-strain characteristics and the temperature of the wire. Good agreement between experiment and analysis was obtained, and the effectiveness of the thermomechanical model proposed here has been confirmed.