粗糙表面塑性变形对弹流润滑性能的影响

The Influences of Elastic-plastic Deformation of Rough Surfaces on Elastohydrodynamic Lubrication for Line Contacts

利用弹塑性动压润滑理论来分析线接触条件下粗糙表面的塑性变形对润滑性能的影响。首先计算总变形量,然后根据弹塑性理论对总变形量进行修正获得弹塑性变形量。计算中采用直接迭代法对雷诺方程进行数值求解,用多重网格法得到弹塑性变形量。为定量分析塑性变形的影响,采用余弦粗糙度来代替实际的粗糙表面,通过改变余弦粗糙度的峰高、波长和相位来表征粗糙度的变化,以此来分析粗糙度对弹塑性流体润滑的影响。计算结果表明:考虑塑性因素后,在接触的高压区膜厚变小,油膜分布曲线变得平坦,同时接触区域的油膜压力也明显变小;此外塑性变形因素的存在使得接触区的压力和油膜分布宽度增加,第二压力峰和最小膜厚点后移。

A line contact elasto-plasto-hydrodynamic lubrication （EPHL） analysis was carried out to investigate the effects of elastic-plastic deformation of rough surfaces. According to elastic theory, the total deformation was gained. When the pressure was over the yield limit, elasto-plastic line strengthening relationship was adopted. Then the total deformation was remodified to obtain the elasto-plastic deformation. A multi-grid technique was used to reduce calculation interval. In order to have quantitative analysis of the rough effects, the means of changing the peak height, wavelength and phase of roughness were used to investigate the influence on EPHL. The results,with considering plastic factors,show that the film thickness becomes thin and distribution becomes plat at the high-pressure contact regions. The distribution width of pressure and film profile is increased, secondary pressure peak and minimum film thickness shift rearward in the case of considering plastic factor.