The effect of material defect orientation on rolling contact fatigue of a ball bearing

In this study, finite element method (FEM) is applied to investigate the effect of material defect orientation on subsurface crack initiation in rolling bearings. First, the history of stress intensity factors (SIFs) of a subsurface cubic material defect is calculated. SIFs calculation is conducted when it is parallel to the rolling surface of a bearing ring ([Formula: see text] ) under a ball rolling on the ring. Then, the effect of defect orientation, varying from [Formula: see text] to [Formula: see text] , on the history of SIFs is investigated. It is deduced that changing the defect orientation results in a threefold increase in the equivalent SIF range compared to parallel orientation.