Due to strong thermo-mechanical coupling in shape memory alloys (SMAs), heat generation/absorption during forward/reverse phase transformation can cause temperature variations in the material; influencing its mechanical behaviour. It is usually assumed that this coupling is only affected by the loading rate. But, recently studies have shown that the size of the structure and the boundary conditions are also important. Therefore, only the definition of quasistatic or slow loading rate can not guarantee an isothermal process and so further considerations need to be made. Based on the powerful model, proposed by Lagoudas et al. [1] and later improved for computer programming using the return mapping algorithm by Qidwai and Lagoudas [2], this contribution presents a three-dimensional thermo-mechanically coupled extension which describes two important typical phenomena of material model of SMAs: superelasticity and superplasticity (shape memory effect). An algorithm is then proposed to implement the coupled model into a finite element code. Performed simulations with different boundary conditions demonstrate that the both loading rate and the size dependency can be captured within the proposed framework. The results are in good agreement with available data in the literature
