Crack Propagation and Initiation Lives for Surface Pitting Due to Rolling/Sliding Contact

Abstract

The stress intensity factors of a multiply kinked crack in a half-space are analyzed under rolling/sliding contact with frictional heat. On the basis of these analytical results, rolling contact propagation fatigue life is predicted numerically for the case of high carbon-chromium bearing steel. The initial crack is assumed to be inclined at the angle of maximum energy release rate, and the initial crack length can be determined by the threshold value criterion of the energy release rate. Applying the maximum energy release rate criterion to each kinked angle, the crack growth path can be described, and employing a mixed mode fatigue crack growth law, the associated propagation fatigue life can be predicted. Making use of the dislocation dipole accumulation model to the assumed initial crack, the crack initiation life also can be estimated. Combining the initiation life and the propagation life, the total rolling contact fatigue life for surface pitting can be predicted. The thermomechanical effects on these lives and induced surface pitting are considered.

Keywords:

• Crack initiation
• Crack propagation
• Fatigue life
• Rolling contact
• Thermal stresses

Communicated by Naotake Noda on 17 January 2010.