基于微凸体接触压力分布的粗糙表面法向接触建模

提出一种考虑微凸体弹塑性接触变形影响的粗糙表面法向接触力学模型。采用有限元模拟微凸体弹塑性接触过程，分析不同塑性屈服条件对微凸体接触载荷和实际接触面积的影响。再根据微凸体接触面上压力分布的变化规律，将微凸体的接触状态分为完全弹性接触阶段、弹塑性接触阶段、完全塑性接触阶段。分析接触面压力变化规律对微凸体法向接触载荷-变形的影响，再利用GW模型的数理统计分析的方法得到粗糙表面的法向接触载荷。将本文提出的模型与完全弹性模型、CEB模型、ZMC模型、KE模型、JG模型进行对比，并且研究了塑性指数对粗糙面接触载荷-平均高度距离的影响。结果表明，本文提出的模型能够更好地描述微凸体法向接触载荷与接触变形的变化趋势，模型预测粗糙表面法向载荷与ZMC、KE模型具有较好的一致性；粗糙面接触载荷随着平均接触距离增加而减少，随着塑性指数的增加，不同模型预测的法向接触载荷差异逐渐增大。

Modeling for Normal Contact of Rough Surface Based on Stress Distribution of Asperity Contact

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.