Thermomechanical coupling in shape memory alloys under cyclic loadings: Experimental analysis and constitutive modeling

► We examine the influence of thermomechanical coupling on the cyclic behavior of SMAs. ► We find that the hysteresis area does not evolve monotonically with loading rate. ► A new model reproduces observed variation in hysteresis to good accord. ► Variations in temperature are reproduced by the model for lower strain rates. In this paper, we examine the influence of thermomechanical coupling on the behavior of superelastic shape memory alloys subjected to cyclic loading at different loading rates. Special focus is given to the determination of the area of the stress-strain hysteresis loop once the material has achieved a stabilized state. It is found that this area does not evolve monotonically with the loading rate for either transient or asymptotic states. In order to reproduce this observation analytically, a new model is developed based on the ZM model for shape memory alloys which was modified to account for thermomechanical coupling. The model is shown to predict the non-monotonic variation in hysteresis area to good accord. Experimentally observed variations in the temperature of SMA test samples are also correctly reproduced for lower strain rates.