混合润滑状态下结合面法向动态接触刚度与阻尼模型  

Normal dynamic contact stiffness and damping model of joint surfaces in mixed lubrication

作　　者：李玲[1] 裴喜永[1] 史小辉 蔡安江[1] 段志善[1] LI Ling;PEI Xi-yong;SHI Xiao-hui;CAI An-jiang;DUAN Zhi-shan(School of Mechanical and Electrical Engineering,Xi′an University of Architecture and Technology,Xi′an 710055,China)

机构地区：[1]西安建筑科技大学机电工程学院,陕西西安710055

出　　处：《振动工程学报》2021年第2期243-252,共10页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(51975449,51305327);陕西省重点研发计划项目(2021GY-309)。

摘　　要：机械结合面的动态接触特性对评估机床整机性能有着重要的意义。针对混合润滑状态下固定结合面复杂的接触特性,提出了一种结合面的法向接触刚度与阻尼模型。采用三维Weierstrass‑Mandelbrot函数获得粗糙表面形貌,并基于分形理论建立了结合面固体部分的接触刚度与接触阻尼模型;根据平均流动的广义雷诺方程建立了液体油膜接触刚度与阻尼模型,其中油膜接触刚度是固体表面接触刚度的函数,实现了油膜接触刚度与固体接触刚度的耦合。通过仿真分析了固体、液体油膜以及结合面的刚度阻尼特性,结果表明:液体油膜接触阻尼远大于固体接触阻尼,结合面的接触阻尼特性主要取决于油膜接触阻尼;在接触前期油膜接触面积所占比例较大,结合面的接触刚度主要由油膜接触刚度主导,随着固体真实接触面积的增加,液体油膜接触刚度占结合面接触刚度的比率越来越小,最后转变为固体接触刚度主导结合面的接触刚度。The dynamic characteristic of joint surfaces is of great significance for evaluating the performance of machine tools.In this paper,a normal contact stiffness and damping model of joint surfaces are proposed for studying the complicated contact characteristics of fixed joint surfaces in mixed lubrication.Firstly,the three-dimensional Weierstrass-Mandelbrot function is used to describe the rough surface,and the solid contact stiffness and damping model is established based on the fractal theory.Then,the contact stiffness and damping model of the lubricant are established based on the mean flow generalized Reynolds equation,in which the lubricant contact stiffness is a function of the solid contact stiffness.Finally,the contact stiffness and damping of the solid part,lubricant part and the joint surfaces are analyzed.The results show that the damping of the lubricant film is much larger than that of the solid part,and the contact damping of joint surfaces is mainly dominated by the damping of the lubricant film.The contact stiffness of joint surfaces is dominated by the lubricant contact stiffness in the early stage of contact.However,the ratio of the lubricant contact stiffness to the stiffness of joint surfaces decreases with increasing the real contact area.At last,the solid contact stiffness dominates joint surfaces.

关 键 词：结合面 混合润滑 等效厚度 接触刚度 接触阻尼 分形理论 

分 类 号：TH113.1[机械工程—机械设计及理论] TB123[理学—工程力学]