Unified viscoplastic constitutive model under axial-torsional thermo-mechanical cyclic loading

A unified viscoplastic constitutive model, which can consider the influences of non-proportional hardening and dynamic strain aging on the responded stress, was proposed under axial-torsional thermo-mechanical cyclic loading. In the proposed model, the rotation factor and the non-proportional hardening coefficient were considered in the kinematic hardening rule. And the dynamic strain aging influence factor was also proposed to further modify the kinematic hardening rule, which can consider the induced dynamic strain aging under special strain rate and temperature conditions. Moreover, the simulation using the proposed model can achieve a better fit with the measured data under isothermal and non-isothermal axial-torsional cyclic loadings.