MB模型的修正及应用

由于MB模型存在3个缺陷,工程上会引入无法接受的误差.本文修正了MB模型的后两个缺陷.针对第2个缺陷,提出了实际临界接触面积、最小有效分形维数、量纲一的最大有效分形粗糙度参数、最小有效材料特性等术语.根据MB模型和提出的计算术语,对两弹塑性接触粗糙表面的接触行为及界面的静摩擦因数进行了研究.研究结果表明：界面的静摩擦因数首先随分形维数的增加而增加,然后随分形维数的增加而减小;界面的静摩擦因数随分形粗糙度参数的增加而减小,但随材料特性的增加而增加,也随总法向载荷的增加而增加;当分形维数较小或分形粗糙度参数较大或材料特性较小时,静摩擦因数-量纲一的总法向载荷曲线为凸弧.

Modification of MB Model and Its Application

MB model,which gives rise to the unacceptable error in engineering,has 3 shortcomings.The latter two shortcomings in MB model were modified.The second shortcoming taken into account,such nomenclatures as the real critical contact area,minimum effective fractal dimension,dimensionless maximum effective fractal roughness parameter and minimum effective material property were presented.According to MB model and calculation nomenclatures previously proposed,the contact behavior of two elastoplastic contact rough surfaces and the interfacial static friction coefficient were studied.The results indicate that as the value of fractal dimension is increased,the interfacial static friction coefficient first increases and then decreases;the interfacial static friction coefficient decreases as the fractal roughness parameter increases;while the interfacial static friction coefficient increases as the material property or total normal load increases;the curve of static friction coefficient versus dimensionless total normal load is convex when the fractal dimension becomes smaller or fractal roughness parameter is larger or material property becomes smaller.