具有连续光滑特性的结合面接触刚度模型  

A Continuous and Smooth Contact Stiffness Model for Mechanical Joint Surfaces

作　　者：李玲[1] 云强强 王晶晶 东亚斌[1] 史小辉 LI Ling;YUN Qiangqiang;WANG Jingjing;DONG Yabin;SHI Xiaohui(School of Mechanical and Electrical Engineering,Xi'an University of Architecture and Technology,Xi’an 710055)

机构地区：[1]西安建筑科技大学机电工程学院,西安710055

出　　处：《机械工程学报》2021年第7期117-124,共8页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51975449,51305327);陕西省自然科学基金(2018JM5066)资助项目。

摘　　要：结合面接触刚度直接影响着机械系统的静、动态力学性能和精度保持性水平。基于微凸体在弹性、弹塑性以及完全塑性接触变形过程中,接触刚度具有连续、光滑特性的思想,首先提出利用Hermite多项式插值函数,来弥补单一微凸体接触刚度建模时存在的不连续等缺陷,建立了具有连续光滑特性的单一微凸体接触刚度新模型;然后基于统计学方法,建立了结合面的法向接触刚度模型;最后将所建模型与GW、ZMC、KE和BRAKE模型进行对比分析。结果表明:本文模型实现了单一微凸体接触刚度在不同接触状态之间连续且光滑地转变;对于光滑表面形貌,基于GW、ZMC、KE以及BRAKE模型预测的接触刚度与本文模型结果的差异较小,其中本文模型最接近于纯弹性的GW模型;当表面粗糙度增大时,GW模型与其他几种模型的差异逐渐增大,此时本文模型与考虑微凸体多种变形阶段的ZMC模型吻合较好;再次表明载荷与表面粗糙度是影响刚度的两个主要因素,即随着载荷的增大或表面粗糙度的减小,接触刚度递增。The contact stiffness of the joint surface directly affects the static and dynamic properties and accuracy levels of the mechanical system. Based on the concept that the transitions from elastic, through elastoplastic, to fully plastic deformation of the asperity contact stiffness is continuous and smooth. The Hermite polynomial interpolation method is employed to correct the defect of discontinuity in the traditional asperity stiffness model, and a new stiffness model of a single asperity is proposed, which changes continuously and smoothly at transit points. Then, a normal contact stiffness model of the joint surface is developed based on statistical methods. Finally, the differences between the GW, ZMC, KE, BRAKE models and the proposed model are analyzed. The results show that the proposed model realizes the asperity contact stiffness changes continuously and smoothly between different deformation regimes. For smooth surface, the difference between different models is small, and the proposed model is close to the GW model. However, the difference between the GW model and other models becomes larger as the roughness increases, and the proposed model agrees well with the ZMC model that consider the multiple deformation regimes of the asperity. It is shown again that load and surface roughness are the two main influencing factors of contact stiffness, the contact stiffness increases with the increase of contact load or the decrease of surface roughness.

关 键 词：结合面 Hermite多项式插值函数 弹塑性状态 接触刚度 接触载荷 

分 类 号：TH113[机械工程—机械设计及理论]