Effects of stick-slip on stress intensity factors for subsurface short cracks in rolling contact

This paper theoretically investigates the effects of stick-slip in rolling contact zone on stress intensity factors (SIFs) for subsurface short cracks. New mathematical models for SIFs including stick-slip ratio are deduced in two cases. One is a subsurface short crack parallel to surface, and the numerical analysis shows that the value of K _II increases with the increase of stick-slip ratio; the other is a subsurface short crack perpendicular to the surface, and the numerical analysis indicates that the positive value of K _I decreases with the increase of stick-slip ratio. As ΔK _I and ΔK _II are necessary to evaluate the fatigue crack propagation rate or fatigue lifetime, the influences of stick-slip ratio on them are then discussed. It is found that the maximum variations of ΔK _I and ΔK _II are both around 3.0% due to stick-slip ratio variation.