The Dynamics of Loading and Growth of Fatigue Cracks in the Proximity to Rolling Contact of Elements with Defects on Their Surface

Abstract This paper highlights the analysis of the development of fatigue cracks under loading in the region of rolling contact. A surface defect is taken as an irregularity of a convex circular profile on an otherwise regular contact track, on which a rolling element is moving. 2D numerical models with different lengths of cracks were analysed. The results provided an estimation of the influence of the irregularity height and the length of a crack on the stress intensity factors (SIF) at the crack tip, and, as a consequence, on the crack growth rate and direction. A simplified model of contact was used in which the rolling element was replaced by the distribution of displacements equivalent to its interaction. It was assumed that an element in a contact pair having a large mass and moving with a high velocity would not deviate from its initial path while rolling over the irregularity on the track. This allowed the dynamic contact interaction and corresponding crack tip loading to be estimated, despite th...