The effect of slip regime on fretting wear-induced stress evolution

A numerical approach to simulate fretting wear, based on a modified version of the Archard equation, is applied to a cylinder-on-flat fretting configuration for gross sliding and partial slip conditions. The evolution of contact geometry, surface contact variables, including, contact pressure and relative slip, and sub-surface stresses are predicted. Surface wear damage is predicted to have a significant effect on the near-surface tangential and shear stress distributions for both slip regimes, with significant differences between the partial slip and gross slip cases. The implications of these effects are discussed with respect to fatigue prediction, leading to new insight into experimentally observed effects of slip regime on crack initiation. The more detrimental effects of partial slip conditions, with respect to cracking risk, are demonstrated quantitatively. In addition, the results suggest an explanation for the observed variations in location of crack initiation within the slip zone under partial slip conditions. The work establishes a basis for direct incorporation of the effect of slip amplitude on fretting fatigue life prediction.