微接触区中边界膜滑移效应分析:微接触区宽度和表面粗糙度的影响  

ANALYSIS OF THE BOUNDARY FILM SLIPPAGE EFFECT IN A MICRO CONTACT:INFLUENCES OF THE MICRO CONTACT WIDTH AND SURFACE ROUGHNESS

作　　者：张勇斌[1] 

机构地区：[1]江苏工业学院机械与能源工程学院,江苏常州213164

出　　处：《工程力学》2010年第6期215-222,共8页Engineering Mechanics

基　　金：江苏省自然科学基金项目(BK2008189)

摘　　要：分析研究了微接触区宽度和表面粗糙度对微接触区中边界膜滑移效应的影响。微接触属混合接触,微接触区由边界膜区和传统流体膜区组成。当膜厚较大时,这里边界膜可看成纳米级薄膜。边界膜滑移由较大载荷下边界膜区大的压力梯度引起,在两接触表面同时发生。研究结果表明,微接触区宽度的增大使边界膜滑移效应增强,而表面粗糙度增大使边界膜滑移效应减弱甚至可使边界膜不发生滑移。边界膜滑移对微接触性能的影响是:边界膜滑移使通过微接触区的流体流量明显增大,使微接触区的承载能力减小,使微接触区局部压力降低。当边界膜厚度处于1nm量级时,微接触性能分析应考虑边界膜滑移效应,因为此时边界膜滑移可显著降低微接触区局部压力,考虑到实际接触表面为弹性表面,这种压力降低可显著改变接触表面弹性变形量进而影响微接触区的局部膜厚。The influences of micro contact width and surface roughness on the boundary film slippage effect in a micro contact are analytically studied.The micro contact is a mixed contact and composed of the boundary film area and continuum fluid film area.When the film thickness is relatively high,the boundary film here can be regarded as the nanometer-scale thin film.The boundary film slippage is caused by the large pressure gradient in the boundary film area under relatively heavy loads,and it occurs simultaneously at both of the contact surfaces.The obtained results show that the boundary film slippage effect is strengthened with the increase of the micro contact width,while the increase of the surface roughness reduces and even vanishes the boundary film slippage.The influence of the boundary film slippage on the performance of the micro contact is that the boundary film slippage significantly increases the mass flow through the micro contact,reduces the load-carrying capacity of the micro contact,and drops the local pressure in the micro contact.When the boundary film thickness is on the scale of 1nm,the analysis of the performance of the micro contact should incorporate the boundary film slippage effect,since in this case the boundary film slippage effect can significantly reduce the local pressure in the micro contact and this pressure reduction can significantly change the local contact surface elastic deformations and then further influence the local film thickness in the micro contact,by considering the elasticity of the actual contact surfaces.

关 键 词：边界膜 纳米级薄膜 滑移 微接触 表面粗糙度 膜厚 

分 类 号：O357.4[理学—流体力学]