应用改进分形几何理论的结合部切向刚度模型  

Tangential Stiffness Model for Joint Interface Adopting the Revised Fractal Geometric Theory

作　　者：田红亮[1] 陈从平[1] 方子帆[1] 赵春华[1] 朱大林[1] 刘加伟[1] 林卫共[1] 郭江洪[1] 晏红[1] 

机构地区：[1]三峡大学机械与动力学院,湖北宜昌443002

出　　处：《西安交通大学学报》2014年第7期46-52,共7页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51275273);三峡大学博士科研启动基金资助项目(KJ2012B013)

摘　　要：针对现有分形接触理论对2个机械部件粗糙表面相互接触形成的结合部的切向接触刚度分形模型存在违反赫兹法向接触力学的缺陷,以改进分形几何理论为基础、在严格应用赫兹法向接触力学的基础上,推导出结合部总切向接触静弹性条件刚度、总条件法向载荷的分析解。数值仿真表明:结合部的切向接触静弹性刚度随着总法向载荷的增加基本上呈线性增加的态势,随着表面轮廓分形维数的增加而增大,随着分形粗糙度的减小而增大;在恒定法向载荷作用下,最初作用于结合部的切向载荷使得切向接触静弹性刚度最大,该刚度随着切向载荷的增加而减小,随着静摩擦系数的增加而增大;随着法向载荷的增加,法向接触静弹性刚度的增量加大。该结果可为进一步研究粗糙表面的分形特性提供参考。Aiming at the existing shortcoming violating Hertz normal contact mechanics in the present fractal contact theory for solving the tangential contact stiffness fractal model of joint interface formed through mutual contact between two mechanical components＇ rough surfaces,the analytical solutions to the joint interface overall tangential contact static elastic stiffness with a definite term and the livelong normal load with a given one were built up following the revised fractal geometric theory and applying rigorously Hertz normal contact mechanics.Numerical simulation indicates that when the entire normal load is increased,the joint interface tangential contact static elastic stiffness rises linearly in all.Also,the joint interface tangential contact static elastic stiffness increases as fractal dimension of a surface profile increases and fractal roughness shrinks.However,when the joint interface is under the action of the constant normal load,this tangential contact static elastic stiffness is the maximum when the tangential load is initially applied and it reduces with the increase in the applied tangential load.The joint interface tangential contact static elastic stiffness increases with the increasing static friction coefficient.The normal loading character is contrary to the tangential loading character,where the incremental normal contact static elastic stiffness increases with the increase in the applied normalload.These results may lay the consultation for research on the fractal characterization of rough surface.

关 键 词：结合部 分形理论 切向接触刚度 表面轮廓分形维数 

分 类 号：TH113.13[机械工程—机械设计及理论]