Temperature evolution during low-cycle fatigue of ULTIMET ® alloy: experiment and modeling

The temperature variations of a cobalt-based ULTIMET alloy subjected to low-cycle fatigue were characterized by a high-speed, high-resolution infrared thermography. The change of temperature during fatigue, which was due to the thermal-elastic–plastic effect, was utilized to reveal the accumulation of fatigue damage. A constitutive model was developed for predicting the thermal and mechanical responses of ULTIMET alloy subjected to cyclic deformation. The model was constructed in light of internal state variables, which were developed to characterize the inelastic strain of the material during cyclic loading. The predicted stress–strain and temperature responses were found to be in good agreement with the experimental results.