A revised Majumdar and Bushan model of elastoplastic contact between rough surfaces

Abstract

A revision of the elastoplastic contact model of fractal rough surfaces, initiated by Majumdar and Bushan, is further developed in this paper. According to the revised contact model, the critical contact areas of a single asperity are scale dependent. With an increase in contact load and contact area, a transition from elastic, elastoplastic to full plastic deformation takes place in this order. The relation between size distribution function for all level asperities and size distribution function for each level asperity is given. The total contact load, real contact area, contact load of each level asperity and contact area of each level asperity are obtained. The revised model shows that mechanical property of rough surface depends on asperity levels. The minimum level asperities and sequential five levels asperities are major contribution to rough surface. When asperity levels nmin and nmin+5 are less than elastic critical level nec, the rough surface appears to have elastic property under contact load. When asperity level nmin is greater than the second elastoplastic critical level npc, the rough surface appears to be carrying inelastic properties because the ratio of elastic deformation to inelastic deformation is very small.