Numerical analysis of the influence of micro-voids on fretting fatigue crack initiation lifetime

In this paper, the influence of the heterogeneity in the predicted crack initiation lifetime under fretting fatigue conditions is analysed for a regular and a random distribution of micro-voids. A critical plane analysis with two multiaxial damage criteria is performed to assess the crack initiation lifetime. The predicted initiation lifetime in the heterogeneous material is compared with the results obtained in the homogeneous case. The numerical results show that the heterogeneity has a noticeable influence on the predicted initiation lifetime. Furthermore, the numerical model suggests that a crack may firstly initiate at the upper edge of the micro-voids located close to the contact edge, leading to a mean reduction of the predicted crack initiation lifetime. However, in some cases, the introduction of micro-voids reduces the stress intensity at the contact edge and thus decreasing the predicted crack initiation lifetime.The authors gratefully acknowledge the financial support given by the Spanish Ministry of Economy and Competitiveness and the FEDER program through the projects DPI2017-89197-C2-1-R, DPI2017-89197-C2-2-R and the FPI subprogram with the reference BES-2015-072070. The support of the Generalitat Valenciana, Programme PROMETEO 2016/007, is also acknowledged.r The last author would like to acknowledge the financial support of the Research Foundation-Flanders (FWO), The Luxembourg National Research Fund (FNR) and Slovenian Research Agency (ARRS) in the framework of the FWO Lead Agency project: G018916N 'Multi-analysis of fretting fatigue using physical and virtual experiments'