Anisothermal cyclic plasticity modelling of martensitic steels

Tempered martensitic steels were investigated in isothermal and thermomechanical fatigue conditions and general features of their cyclic behaviour are reported. A cyclic anisothermal constitutive model with internal variables was formulated to describe their behaviour; it allows the description of the Baushinger effect, the continuous cyclic softening, the strain rate dependence and the plastic strain memorisation. When compared to experimental results, isothermal and anisothermal model predictions show good coherence. This model is helpful to understand and explain some experimental results such as the increase in strain softening when strain rate decreases in isothermal testing, as well as the relations between mean stress and temperature range or cyclic softening with strain amplitude in anisothermal conditions.