Studies of Low-loading Micro-slip Contacts on Rough Surfaces with GW Model

Lateral loading and interfacial slip of multi-asperity (i.e., rough) elastic contacts are studied for micro-slip contact conditions. The Mindlin micro-slip model for smooth surfaces is generalized to rough surface contacts using the Greenwood-Williamson (GW) approach, and the general relations of lateral contact force and related stiffness are obtained. The method extends previous approaches by incorporating micro-slip, allowing application to rough surfaces and providing simple expressions for experimental analysis by use of the Greenwood-Williams roughness parameters. As applications, the numerical results of micro-slip contacts on rough surfaces for Gaussian and exponential asperity height distributions, respectively, are obtained based on the general relations of the extended model, and are compared and discussed for low load cases.