Abstract: Due to the thermal-elastic-plastic effect, the temperature of specimen will be changed during low cycle fatigue loading, and the temperature can be utilized to reveal the accumulation of fatigue damage. A constitutive model composed of isotropic and nonlinear kinematic hardening model is used to predict the mechanical responses of material subjected to cyclic deformation, the ANSYS software is adopted to simulate temperature evolution of SS304 stainless steel flat plate specimen during strain controlled cyclic loading, and the mechanisms causing the temperature change are analyzed. The results show that, in the elastic region, when a material is subjected to tensile loading, the material undergoes cooling and when a material is subjected to compressive loading, it undergoes heating. While in the elastic-plastic region, plastic tension, elastic compression and plastic compression correspond to temperature increase and only elastic tension corresponds to temperature decrease. During the whole loading period, the thermal-elastic effect caused the temperature to oscillate, and the thermal-plastic effect caused the mean temperature to increase. The results also show that, from the temperature evolution and the stress-strain curve data, the yield points can be identified, and it is possible to identify the state of stress of material during cyclic loading, such as elastic tension, plastic tension, elastic compression and plastic compression from the thermal data.

Key words: Finite element method, Low-cycle fatigue, Thermal-elastic-plastic effect