A physical mechanism based constitutive model for temperature-dependent transformation ratchetting of NiTi shape memory alloy: One-dimensional model

• A physical mechanism based constitutive model is constructed.
• Two kinds of inelastic mechanisms are considered together in the model.
• Effect of dislocation slipping in austenite near the austenite–martensite interface on the transformation is involved.
• Uniaxial temperature-dependent ratchetting of NiTi alloy is reasonably predicted by the model.

In this paper, the effect of test temperature on the transformation ratchetting of super-elastic NiTi shape memory alloy was first investigated in the cyclic tension-unloading tests. It is shown that all the residual strain, dissipation energy, the start stress of martensite transformation and their evolutions during the cyclic loading depend greatly upon the test temperature. Based on the experimental observations, a new one-dimensional constitutive model is constructed by considering two different inelastic deformation mechanisms (i.e., martensite transformation and transformation-induced plasticity). The proposed model employs a new evolution rule of transformation-induced plasticity which considers the physical mechanism of the plastic deformation, i.e., the dislocation slipping in the austenite phase near the austenite–martensite interfaces. Furthermore, the interaction between dislocation and martensite transformation is also taken into account in the proposed model. The capability of the proposed model to predict the uniaxial temperature-dependent transformation ratchetting of NiTi shape memory alloy is verified by comparing the predictions with the experimental data.