A study of elastic–plastic contact of statistical rough surfaces

Abstract

In this article, a study of elastic–plastic contact of statistical rough surfaces is presented. The contact behaviors of a single asperity with deformable substrate are studied by finite element method. The influences of material properties and substrate deformation on the single asperity contact behaviors are investigated. An elastic–plastic contact model of rough surfaces is established based on the proposed single asperity contact model and statistical rough surface contact model. The surface topography plasticity index and material plasticity index are defined to indicate the influences of surface topography and material properties on the contact behaviors of rough surfaces. Comparisons with some exiting models and finite element results show that the proposed formulations can model the single asperity contact behaviors well for a wide interference range. The rough surface contact model in this work is consistent with some existing models for small plasticity indices, and it is slightly different from the existing models for large plasticity indices. The increase of surface topography plasticity index and material plasticity index would result in larger contact area and contact load for given separations.