弹塑性微峰接触的部分膜点EHL数值分析

Numerical analysis of partial point EHL problems considering elastic-plastic asperity contact model

在部分膜EHL润滑下 ,摩擦副表面微峰接触状况对零件表面应力及失效形式有直接的影响 .为此 ,在部分膜点接触EHL模型中引入更符合实际的表面微峰弹塑性接触模型来考察微峰接触载荷 ;并应用多重网格法针对多种表面微峰结构参数的影响进行了完全数值分析 .结果表明 ,粗糙度对油膜厚度的影响和表面纹理方向有关 ;相同粗糙度情况下 ,纵向纹理表面的接触载荷 >各向同性纹理表面的接触载荷 >横向纹理表面的接触载荷 .表面粗糙度较大时 ,峰顶参数对油膜压力和微峰接触压力有一定的影响 ,而对油膜形状影响甚微 ;表面越粗糙、表面凸峰越尖锐 ,微峰接触载荷则越大 .

Under the partial elastohydrodynamic lubrication (EHL) condition, the performance of asperity contacts between the surfaces of machine elements has a significant effects on the sub surface stress and thus the failure mode. The more realistic elastic plastic contacts model between surface asperities was introduced into partial point EHL systems to examine the asperity contact load, and the model problems were fully solved and analyzed by using the multi grid method for some surface structure parameters. The numerical results show that, the effects of surface roughness on oil film characteristics are related to the surface orientation. For surfaces with same surface roughness, the asperity contact load between longitudinal surfaces > that of homogeneous surfaces > that of transverse ones. For surfaces with larger surface roughness, the asperity summit profile parameter shows somewhat influences on oil film pressure and asperity contact pressure, but little effects on oil film profile. The larger the surface roughness and the sharper the asperities, the greater the asperity contact load.