混合润滑状态下非高斯表面法向接触刚度研究
Study on Normal Contact Stiffness of Non-Gaussian Surface Under Mixed Lubrication Condition
高志强 1席云鹏 1彭丽霞 1傅卫平 1王雯 1王双琦1
作者信息
- 1. 西安理工大学机械与精密仪器工程学院,西安 710048
- 折叠
摘要
为了揭示混合润滑状态下表面形貌特征对接触特性的影响,针对微凸体高度非高斯分布粗糙表面在法向静载荷作用下的固-液接触问题展开研究.固-液接触结合面包括微凸体的固体接触和润滑介质的流体接触.对于固体接触部分,基于弹塑性固体力学对非高斯等效粗糙表面接触展开接触特性分析,建立了考虑微凸体弹塑性变形的非高斯粗糙表面法向接触刚度计算模型;对于流体接触部分,提出了一种考虑微凸体峰度/偏度分布影响的密闭油坑接触模型.通过仿真分析,揭示了法向压力、非高斯表面粗糙度参数及润滑油黏度系数对混合润滑固-液结合面法向接触刚度的影响规律,并对比分析了无润滑介质的固-固结合面和存在润滑介质时的固-液结合面法向接触刚度.研究表明:固-液和固-固结合面法向接触刚度均随着法向载荷的增大呈非线性增大,且固-液结合面相对固-固结合面的接触刚度略大;润滑介质黏度越大,接触刚度越大;非高斯分布的峰度和偏度对混合润滑结合面接触刚度具有显著影响,相对于零偏度分布的高斯分布表面,呈负偏度分布的非高斯表面通常具有较大的接触刚度;在轻载时,峰度对接触刚度的影响不容忽视.因此,通过改变接触表面峰度/偏度、增大法向载荷、提高润滑介质黏度,可有效改善混合润滑状态固-液结合面法向接触刚度.
Abstract
In order to reveal the influence of surface morphology characteristics on contact characteristics under mixed lubrication state,the solid-liquid contact problem of non-Gaussian rough surface with micro-convex height under normal static load was studied.Solid-liquid contact interface includes solid contact of asperity and fluid contact of medium.For the solid contact part,the contact characteristics of non-Gaussian equivalent rough surface were analyzed based on elastic-plastic solid mechanics,and the normal contact stiffness calculation model of non-Gaussian rough surface was established considering the elastic-plastic deformation of asperity.For fluid contact,a closed oil pit contact model considering the kurtosis/skewness distribution of asperity is proposed.The effects of normal pressure,non-Gaussian surface roughness parameters and lubricating oil viscosity coefficient on the normal contact stiffness of the solid-liquid interface of mixed lubrication were revealed by simulation analysis.The normal contact stiffness of the solid-solid interface without lubrication medium and that of the solid-liquid interface with lubrication medium were compared and analyzed.The results show that the normal contact stiffness of solid-liquid interface and solid-solid interface increases non-linearly with the increase of normal load,and the contact stiffness of solid-liquid interface is slightly larger than that of solid-solid interface.The greater the viscosity of lubricating medium,the greater the contact stiffness;The kurtosis and skewness of non-Gaussian distribution have significant influence on the contact stiffness of the joint surface of mixed lubrication.Compared with the Gaussian surface with zero skewness distribution,the non-Gaussian surface with negative skewness distribution usually has larger contact stiffness.Under light load,the influence of kurtosis on contact stiffness cannot be ignored.Therefore,by changing the kurtosis/skewness of the contact surface,increasing the normal load and increasing the viscosity of the lubricating medium,the normal contact stiffness of the solid-liquid interface in mixed lubrication state can be effectively improved.
关键词
机械结合面/非高斯粗糙表面/混合润滑/固-液结合面/接触刚度Key words
mechanical interface/non-Gaussian rough surface/mixed lubrication/solid-liquid interface/contact stiffness引用本文复制引用
基金项目
国家自然科学基金面上项目(52375127)
陕西省青年科技新星项目(2024ZC-KJXX-057)
出版年
2024
国家科技期刊平台
NSTL
万方数据