基于微凸体接触压力分布的粗糙表面法向接触建模  

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

作　　者：王东[1] 徐超[2] 万强[1] 胡杰[1] Dong Wang;Chao Xu;Qiang Wan;Jie Hu(Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang , 621999;School of Astronautics, Northwestern Polytechnical University, Xi＇ an , 710072)

机构地区：[1]中国工程物理研究院总体工程研究所,绵阳621999 [2]西北工业大学航天学院,西安710072

出　　处：《固体力学学报》2017年第6期521-529,共9页Chinese Journal of Solid Mechanics

基　　金：科学挑战专题项目(领域七);国家自然科学基金(11472256);中国工程物理研究院院长基金(YZ2015011)资助

摘　　要：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.将论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,论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.An elasto-plastic contact modeling approach is proposed to characterize the total contact load and real contact area of rough surface.The finite element method（FEM）is firstly used to analyze the elasto-plastic contact behaviors of asperity against the rigid flat.The effects of four different plastic yielding equations on the load and real area of asperity contact are analyzed.The relations between the dimensionless contact load and the dimensionless deformation calculated with four different plastic yielding equations are the same,and the solutions vary between the Hertz solution and the AF model.Based on the contact stress distributions of different contact loads,the asperity contact regime is divided into the elastic regime,the mixed elasto-plastic regime and the fully plastic regime.The increasing change of contact stress distribution is considered when obtaining the relation between the contact load and the contact deformation.Statistical analysis of the GW（Greenwood J A and Williamson J B P）model is then applied to integrate the formulations of contact load over the rough surface.The model is compared with the purely elastic model,the CEB model,the ZMC model,the KE model and the JG model,and the effect of plasticity index on the relation between the contact load and the mean contact separation of rough surface is also investigated.The results show that the proposed model can better describe the relation between contact load and deformation.The total contact load of rough surface predicted by the proposed method agrees well with the KE model and the ZMC model.With the increase of mean contact separation,the total contact load becomes smaller.The plasticity index has a great effect on the contact load predicted by different models.The difference between the total contact load of rough surface calculated by 6 elasto-plastic models is small at a lower plasticity index,while the difference is greater at a higher plasticity index,especially for the CEB model;and the CEB model predicts the largest contact l

关 键 词：粗糙表面 接触压力 概率统计分析 弹塑性 微凸体 

分 类 号：O343.3[理学—固体力学]