固-液结合面法向动态接触刚度及阻尼的理论模型与实验分析  

Theoretical Model and Experimental Analysis of Normal Dynamic Contact Stiffness and Damping of Solid-liquid Mechanical Joint

作　　者：高志强[1] 路泽鑫 傅卫平[1] 王雯[1] 班兆阳 王双琦 Zhiqiang Gao;Zexin Lu;Weiping Fu;Wen Wang;Zhaoyang Ban;Shuangqi Wang(College of Mechanical and Precision Instrument Engineering,Xi’an University of Technology,Xi'an,710048)

机构地区：[1]西安理工大学机械与精密仪器工程学院,西安710048

出　　处：《固体力学学报》2021年第6期682-696,共15页Chinese Journal of Solid Mechanics

基　　金：国家自然科学基金项目(52005401);中国博士后科学基金项目(2019M663782);陕西省自然科学基础研究计划项目(2020JQ-629);陕西省教育厅专项科研计划项目(20JK0800)资助。

摘　　要：固-液接触状态广泛存在于机床核心单元关键零部件的接触运动副中,精确获得固-液结合面法向接触刚度及阻尼参数是高档数控机床产品在研发阶段就存在的一个关键理论与技术问题,并且仍然尚未根本解决.固-液结合面在介观层面上表现为两个粗糙表面的接触,在微观层面上表现为微凸体之间的接触,并在中/重载荷作用下微凸体可能会发生弹性/弹塑性/塑性变形.为了揭示静动态外载荷对固-液结合面接触刚度及阻尼的影响,分别基于GW模型、KKE模型和AF模型对接触微凸体弹性/弹塑性/塑性变形展开研究,并结合流体动力润滑REYNOLDS方程,建立了考虑接触微凸体弹性/弹塑性/塑性变形的固-液结合面接触刚度及阻尼模型.并对其进行实验验证,结果表明:随着预载荷的增大固-液结合面法向动态接触刚度表现出先减小后增大的规律,当接触载荷小于某阈值时动态接触刚度较大,反之静态接触刚度较大;法向动态接触刚度随着法向相对位移幅值的增大而增大,在低载荷时呈线性规律,而高载荷呈非线性规律;法向动态接触刚度随激振频率增大呈线性增大,且载荷越大线性斜率越小.对于法向接触阻尼,随着法向相对位移幅值和接触载荷增大呈非线性增大,随着激振频率增大几乎不变.精确获得固-液结合面法向接触刚度和阻尼及其关键因素的影响规律,对机械系统的分析、设计、优化以及静、动态性能控制都具有重要的理论意义.The solid-liquid contact state widely exists in the contact kinematic pairs of the key components of the core units of machine tools.The acquisition of normal contact stiffness and damping parameters of solid-liquid interface is a key theoretical and technical problem in the research and development stage of high-end computer numerical controlled(CNC) machine tools,which has yet to be fundamentally solved.The interface is the contact between two rough surfaces at the mesoscopic level,and is the contact between asperities at the microscopic level.Asperities of rough surfaces may produce elastic/elasto-plastic/plastic deformation under medium/heavy loads.In order to reveal the influence of static and dynamic external loads on the contact stiffness and damping of solid-liquid interface,the elastic/elasto-plastic/plastic deformation of contact asperity is studied based on the GW model,the KKE model and the AF model,respectively.And then,the contact stiffness and damping models of solid-liquid interface considering elastic/elasto-plastic/plastic deformation of contact asperity are established by combining with the Reynolds equation of hydrodynamic lubrication.Finally,it is verified by experiments.It is found that the normal dynamic contact stiffness of solid-liquid mechanical joints decreases quickly and then increases with the increase of preload.The dynamic contact stiffness is smaller than the static contact stiffness when the contact load exceeds a certain threshold.The normal dynamic contact stiffness increases with the increase of the amplitude of normal relative displacement.The normal dynamic contact stiffness increases linearly with the increase of excitation frequency.The normal contact damping increases nonlinearly with the increases of normal relative displacement amplitude and the contact load,but stays almost unchanged with the variation of excitation frequency.To accurately obtain the normal contact stiffness and damping of solid-liquid mechanical joints and the key influencing factors is of great theor

关 键 词：固-液结合面 法向 动态 接触刚度 接触阻尼 

分 类 号：TG502.14[金属学及工艺—金属切削加工及机床]