Subsurface fatigue crack growth under contact loading

A computational model simulation of subsurface fatigue growth under contact loading is presented. The equivalent contact model is proposed, which enables general simulation of the process of surface pitting on contacting mechanical elements. Only smooth contact surfaces with good lubrication conditions are considered, which results in the appearance of the initial cracks at some distance from the surface. The Virtual Crack Extension method in the framework of the Finite Element Analysis is used for simulation of the fatigue crack growth from the initial crack up to the formation of a surface pit. The pit shapes and relationships between the stress intensity factor and the crack length are determined for various combinations of contacting surface curvatures and loadings. The model has proved to be capable to accurately simulate the actual surface fatigue process of gear teeth flanks.