Short Subsurface Cracks Under Conditions of Slip and Stick Caused by a Moving Compressive Load

The mechanism of spalling failure in rolling contact is modeled by an elastic half-plane with a subsurface crack parallel to the surface, loaded by a compressive normal force which moves over the surface. Coulomb friction at the crack faces reduces the Mode II Stress Intensity Factors and results in a number of history-dependent slip-stick configurations. The formulation used to study these involves a singular integral equation in two variables which must be solved numerically, and because of the history dependence, requires in an incremental solution. Only crack lengths and coefficients of friction that result in a maximum of two slip or stick zones for any load location are considered in this paper. It is found that the maximum range of stress intensity factors occurs at the trailing crack tip.