Abstract:An elastic-plastic mechanical model is proposed to characterize the contact load and area of rough surface. FEM is used to analyze the elastic-plastic contact of asperity against the rigid mass, with several different plastic constitutive equations. According to the contact stress distribution of different contact load, the asperity contact regime is divided into the elastic regime, the mixed elastic plastic regime and the fully plastic regime. The increasing change of contact stress is considered to obtain the relation between contact load with contact deformation. Statistical analysis of GW model is then applied to integrate the formulations of contact load over the rough surface. The model is compared with the previous elastic model, CEB model, ZMC model, KE model and JG model, and the effect of plastic index on the relation between contact load and mean contact separation of rough surface is also investigated. The results show that the proposed model can better model the relations of contact load and deformation, and agree well with KE model and ZMC model. With the increasing of mean contact separations, the total contact load will become less and less. The plastic index has a great effect on the contact load of different model, and larger plastic index will induce more difference.