Thermomechanical modeling on cyclic deformation and localization of superelastic NiTi shape memory alloy

Stress-induced martensitic transformation of superelastic NiTi leads to inhomogeneous deformation under primarily tensile state. In this study, a constitutive model is developed to describe thermomechanical coupling of cyclically deformed NiTi at various strain rates. Martensitic transformation, strain localization, and the evolution of mechanical properties upon cycling are taken into consideration. The model is implemented implicitly into a finite element code, so that the global thermomechanical response, i.e. stress-strain response and average temperature, and the local thermomechanical response, i.e. band pattern and temperature contour, are achieved. It is demonstrated that band pattern is not only affected by strain rate but also by cycling number. The consistence between simulation and experiment verifies that the proposed approach reproduces the complicated thermomechanical response of cyclically deformed NiTi reasonably.

Automated summary

A constitutive model has been developed to describe the thermomechanical coupling of cyclically deformed NiTi at different strain rates, considering martensitic transformation, strain localization, and the evolution of mechanical properties. The model has been implemented implicitly into a finite element code to achieve the simulation of global and local thermomechanical responses.