An investigation into the effect of elevated temperatures on fretting fatigue response under cyclic normal contact loading

In this investigation, the effect of elevated temperature on fretting fatigue life of Al7075-T6 under cyclic normal contact loading was investigated by experiment using a new testing apparatus. A Finite Element model using FRANC2D® was developed to study the influence of elevated temperature on crack propagation lifetime. The crack initiation life was calculated by a combination of numerical and experimental results. It was found that, elevated temperature has reducing effect on fretting fatigue life, particularly for Low Cycle Fatigue (LCF) regime. The reduction was about 29-44% and 30-46% depending on stress level for temperatures of 100 and 200 °C, respectively. The results of FE simulation showed that elevated temperature significantly diminishes both the crack propagation and initiation lives. At lower bulk stresses where the life is dominated by the crack initiation phase, the detrimental effect of elevated temperature was more profound for crack propagation lifetime. In contrast, at higher bulk stresses where the life is dominated by the crack propagation phase, the effect of elevated temperature was more profound for crack initiation lifetime. Finally, the FE simulation was validated by a comparison between the numerical crack growth rate and the experimental measurements using replica.