Prediction of fretting fatigue crack initiation and propagation lifetime for cylindrical contact configuration

A fretting fatigue failure scenario can be explained by accumulation of damage, which leads to formation of initial macro-cracks at the contact interface and propagation of macro-cracks to sudden rupture of bulk material. The main aim of this study is estimating these two portions by means of a numerical modelling approach. For this purpose, an uncoupled damage model based on a thermodynamic potential function is used to model the crack initiation lifetime. In order to model crack propagation part a linear-elastic fracture mechanics approach under mixed-mode loading conditions has been considered. The crack propagation direction is defined based on experimental observation and compared with some available criteria in the literature, which are usually used for proportional loading conditions. The estimated results are compared with observed experimental lifetime and show good agreement.