A Hybrid Approach for Heat Source Identification and Heat Diffusion–Related Issues in the Fatigue Loading

Over the past decades, thermographic methods have become a viable substitute for conventional approaches in the analysis of material fatigue behavior, due to their efficiency, cost-effectiveness, and nondestructive nature. By examining the temperature signature generated by intrinsic heat dissipations during the fatigue loading, valuable insights into the behavior of the materials can be investigated. Substantial intrinsic dissipation—a marker of material damage—is linked to a transition from anelastic to inelastic strains. The main aim of this work is to explore heat dissipations during fatigue of materials by combining experimental techniques and numerical simulations, focusing on the fundamental temperature component in fully reversed loading, known as the second amplitude harmonic (SAH) of temperature. The hybrid method combines experimental data with numerical modeling to identify the specific volume generating heat during fatigue testing. Additionally, the effect of the mechanical loading frequency on SAH of temperature was also examined.