随机抽样在粗糙表面接触力学行为分析中的应用

为研究表面粗糙度对接触表面力学行为的影响规律,结合表面粗糙度的加工参数和随机抽样方法,对服从正态分布和预设粗糙度的表面轮廓曲线进行了模拟.根据统计得到的模拟轮廓曲线几何形态的共性特征,建立了基于圆锥与平面接触的三维粗糙表面接触力学模型,推导出平面几何压力与粗糙表面微凸体变形间的定量关系.分析结果表明:服从正态分布的轮廓高度曲线中的峰角顶点数目约为样本容量的1/3；圆锥压入平面时平均压力/材料纯剪应力的比值与其半角呈二次方关系；表面粗糙度越大,轮廓曲线的起伏越大,两接触面相互嵌合越容易；表面粗糙度越大,材料屈服强度对接触微凸体变形的影响也越明显.

Contact Behavior Analysis for Rough Surfaces with Random Sampling

The influences of surface roughness on the contact behavior are investigated.The profile curves obeying normal distribution and with preset surface roughness are simulated by the processing parameters of surface roughness and Monte Carlo random sampling.From the microgeometric characteristics of the simulated profile curves with different surface roughness,3D contact model is constructed with the cone as asperity,and the quantitative relationships between the plane pressure and the asperity deformation are obtained.The analysis reveals that the number of peaks in simulated profile curve with normal distribution accounts for about a third of the sample size;the ratios of the plane pressure to the material pure shear stress vary quadratically with the half core angle;the asperities get higher with the increasing in surface roughness,and the two rough surfaces implant each other more easily;with the increasing surface roughness,the material yield strength impacts the asperity deformation even more apparently.