Analysis of a Surface Crack Subject to a Rolling/Sliding Contact

The behavior of a surface crack that is perpendicular to the contact surface was investigated by using the finite element method. The analysis was two-dimensional, plane strain, and linear elastic. The finite element model was a combination of 6-node triangular and 8-node isoparametric solid elements. A Hertzian pressure was applied at the contact surface. The contact pressure was moved incrementally on the surface to simulate rolling and sliding contacts.. Stress intensity factors were calculated as functions of the position of the Hertzian contact, coefficient of friction on the rolling/sliding surface, and the amount of residual stress in the subsurface. The results suggest Mode I type of growth under tensile residual stresses and Mode II type of growth under compressive residual stresses. There is mixed mode crack growth when the contact pressure moves very close to the crack under tensile residual stresses and also when there is high traction at the contact surface under no residual stress.