Propagation of Semi-Elliptical Surface Cracks in Lubricated Rolling/Sliding Elliptical Contacts

In this paper the three-dimensional mixed mode stress intensity factors for semi-elliptical inclined cracks formed on elliptical Hertzian contact surfaces are calculated. This analysis accounts for both the frictional forces between the contact surfaces and between the crack faces, as well as including fluid pressure acting on the crack faces. Various factors affecting the crack growth are discussed and possible growth modes are investigated. In particular, the analytical results predict that the crack has a faster growth rate when the major axis of the contact ellipse is in the direction of motion of the load as compared to the minor axis being in the direction of motion of the load.