Effect of heat conduction on rapid evaluation of fatigue limit based on temperature evolution due to cyclic loading

Abstract

The rapid evaluation technique of fatigue limit using infrared thermography has been developed during the past 30 years. In this technique, the fatigue limit is evaluated on the basis of the temperature evolution associated with cyclic loading. However, this technique is still not reliable enough because the temperature evolution has not been verified quantitatively very well. In previous studies, the authors conducted numerical analysis to simulate the temperature evolution. The results of fatigue limit evaluation were compared fairy well with experimental ones. However, the temperature evolution was significantly larger compared to experimental results due to adiabatic assumption. In this paper, heat conduction within the specimen is taken into account in order to conduct more realistic simulation of temperature evolution. The results are compared quantitatively to those obtained in experiment. The fatigue limit obtained from simulation is compared with those determined by Wöhler method and thermography experiment.

Temperature change and fatigue crack initiation associated with local cyclic slip deformation in a single crystal material

“…This measurement method is called the 2f lock-in thermography method. Ly et al [14][15][16] conducted a numerical analysis to simulate the temperature change for fatigue limit evaluations considering heat conduction as well as the stress concentration effect. The evaluated results were quantitatively compared with a thermography experiment at a macroscopic scale.…”