Tangential load-displacement model of elastic-plastic rough contact surfaces

A tangential load-displacement model between rough contact surfaces is developed in this paper. Elastically and plastically deformed asperities are considered simultaneously. For the elastically deformed asperities, the classic Hertz elastic contact solution and Mindlin micro-slip model are used to model the load-displacement relationship. For the plastically deformed asperities, the fully plastic contact theory of Abbott and Firestone, and the Fujimoto tangential contact model are implemented. The tangential load-displacement relationship between rough surfaces is formulated by GW probability statistics approach. The proposed model is compared with the model where only elastically deformed asperities are considered. The effects of model parameters on the tangential load-displacement behaviors are investigated. The results show that the proposed model can describe the nonlinear behavior of the tangential load-displacement relationship between rough surfaces more rationally. With the increase of roughness, the tangential load-displacement relationship is controlled by plastic contact asperities. The slope of the tangential load-displacement curve increases with the average contact distance when the roughness parameter holds constant.