粗糙表面接触力学问题的重新分析  

REANALYSIS OF THE CONTACT MECHANICS FOR ROUGH SURFACES

作　　者：孙见君[1] 嵇正波[1] 马晨波[1] Sun Jianjun;Ji Zhengbo;Ma Chenbo(College of Mechanical and Electrical Engineering,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学机械电子工程学院,南京210037

出　　处：《力学学报》2018年第1期68-77,共10页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金(51375245;51505230);博士后基金(2017M611822)资助项目

摘　　要：为了克服基于统计学参数的接触模型的尺度依赖性以及现有接触分形模型推导过程中初始轮廓表征受控于接触面积或取样长度的不足,基于粗糙表面轮廓分形维数D、尺度系数G和最大微凸体轮廓基底尺寸l,建立了新的粗糙表面接触分形模型,探讨了微凸体变形机制、粗糙表面的真实接触面积和接触载荷的关系,揭示了接触界面的孔隙率和真实接触面积随端面形貌、表面接触压力等参数变化的规律,给出了不同形貌界面被压实的最大变形量.结果表明:微凸体变形从弹性变形开始,并随着平均接触压力pm的增大逐步向弹塑性变形和完全塑性变形转变;接触界面的初始孔隙率φ_0随D的增大而增大,压实孔隙所需要的最大变形量δ也随之增大;接触压力p_c增大,孔隙率φ减小,并随着D的增大和G减小,φ快速减小,直至填实,变为零;D较小时,G的增大对真实接触面积的增大影响较小;D较大时,G的增大对真实接触面积的增大作用明显.研究成果为端面摩擦副的润滑与密封设计提供了理论基础.To overcome the scale dependence of the contact model based on statistical parameters and the shortcoming that the initial profile of existing fractal contact models depends on contact area or sampling length,a new fractal contact model for rough surface was established based on fractal dimension D,fractal roughnessG and the base size l of the largest asperity.The asperity deformation mechanism and the relationship between the true contact area and contact load were explored.The variation law of porosity of the contact interface and real contact area under di erent surface topographies and normal forces were discussed.The maximum deformation δ that characterizes the deformation to compact the profile pores for di erent morphology interfaces was also given.The results show that the asperity deformation initiates from elastic deformation to elastoplastic deformation,and then transforms into full plastic deformation with the increase of average contact pressure pm.The initial porosity 0 of the contact interface increases with increasing D and then the maximum deformation also increases.The porosity  decreases with the increase of contact pressure pc,and rapidly decreases with increasing D and decreasing G until it becomes zero.The e ect of the increase of G on the increase of the real contact area can be ignored when D is small.However,when D is large,an obvious increase of the real contact area can be found as G increase.The research could provide a theoretical basis for the lubrication and sealing design of friction pairs.

关 键 词：粗糙表面 接触力学模型 分形 接触面积 孔隙率 

分 类 号：TH113[机械工程—机械设计及理论]