Research on macro-mesoscopic normal dynamic characteristics of sliding joint surface

The dynamic characteristics of the sliding surface will affect the dynamic properties of the mechanical structure in a great degree. For the sliding surface in lubricating condition, the normal equivalent stiffness and normal equivalent damping mathematical analysis model of the joint surface were deduced based on the fractal theory and the mean flow generalized Reynolds equation with boundary lubrication. After simulation analysis, the equivalent normal stiffness of the solid portion, oil film portion and the comprehensive stiffness, and the comprehensive normal equivalent damping were obtained when the lubrication is on the partial film state. The results show, the contact stiffness and contact damping of the joint surface will be in an ideal state when their actual contact area ratio reached a certain value. At the same time, the dynamic and static stiffness and damping parameters of the sliding guide rail experimental device under the condition of lubrication were identified. The results show that the normal stiffness and normal damping of the guide rail will be in good state under the appropriate normal load. It is consistent well with the simulation analysis results of the mesoscopic dynamic characteristics of the sliding surface under lubrication condition.