平面磨削粗糙表面的微观接触模型

A Micro-contact Model for Rough Surface of Plane Grinding

通过拟合实测平面磨削表面单个微凸体的轮廓数据,提出一种采用半周期余弦曲线回转体等效微凸体的方法。通过对实测表面轮廓的峰谷标记处理,获得了等效微凸体轮廓的尺寸参数。结合高斯分布,建立了能够更加准确表征平面磨削表面形貌特征的模拟表面。在模拟表面的基础上,基于接触力学理论与统计学理论,重新解算了微凸体在弹塑性变形区间的临界压入深度。推导出接触区域内接触参数与接触压力的解析关系,进而建立起一种针对平面磨削表面的微观接触模型。最后将实测平面磨削表面的统计参数作为接触模型数据仿真的初始值,将本文模型与CEB模型以及KE模型就平均距离和真实接触面积的预测结果进行了对比分析。结果显示,在相同接触压力的条件下,该模型相比CEB模型与KE模型所得到的平均距离与真实接触面积的预测值更大,并且三者之间的差值随着接触压力的增加而逐渐增大。结合不同微凸体轮廓假设对平面磨削表面微凸体轮廓数据的拟合结果来看,该模型对于平面磨削表面接触参数的预测结果更加准确且合理。

By fitting the measured topography data of a single asperity on the plane grinding surface, a method of using the semi-periodic cosine curve rotating body equivalent asperity is proposed. The method of calculating the dimension parameters of a single asperity topography is obtained by marking the peak and valley of the measured surface topography. Combining with the Gauss distribution, the simulated surface which can more accurately characterize the actual surface morphology is established. Based on the simulated surface, the critical interference of the asperities in the elastic-plastic deformation region is re-calculated by using contact mechanics theory and statistical theory. The analytical relationship between contact parameters and contact pressure at different deformation stages are obtained. Then, a micro-contact model of rough surface in plane grinding is established. Finally, the statistical parameters of the measured grinding surface are taken as the initial values for the data simulation. The prediction results of average distance and real contact area are compared among present model, CEB model and KE model. The results show that under the same contact pressure, the average distance and the real contact area predicted by the present model are larger than those obtained by CEB model and KE model, and the difference between the three models increases with the increase of contact pressure. According to the fitting results of measured topography data by different asperity topography assumptions, the prediction results of contact parameters of surface grinding in present model are more accurate and reasonable.