Wear in Partial Slip Contact

An analytical method that evaluates the evolution of stress and surface profile in fretting under the partial slip conditions is presented. The repeated slip occurring near the edges of contact generates wear that changes the contact geometry and contact stresses. The method is based on two scales of time: time for one cycle of the oscillating tangential force and time corresponding to the number of cycles. Archard’s wear law is used to evaluate wear and gap variation within the slip zones during one cycle. The governing integral equations are reduced to calculate the contact pressure after each cycle. Evolution of the contact characteristics (contact pressure and shear stress, contact width, gap and slip functions) in fretting is calculated using a stepwise procedure. It is shown that the size of stick zone does not change in wear process of bodies with similar elastic properties under the constant amplitude load conditions, and that an asymptotic solution corresponding to the number of cycles approaching to infinity exists. Analytical expressions for the asymptotic contact pressure, shear and tensile stress, and the gap function are presented. It is proved that the asymptotic contact pressure and shear stress are singular at the ends of stick zone. Detailed results are given for two initial shapes of elastic indenter contacting with an elastic half-space: for the parabolic cylinder and for the indenter having a flat base with rounded edges.