不同尺度的接触行为对表面功能属性有着明显不同的影响,为了研究金属表面在各个尺度的接触行为,提出了基于确定性模型的粗糙表面各尺度接触行为分析方法,通过设备实测得到加工表面的形貌数据,通过小波滤波器对粗糙表面进行多尺度分解,采用有限元方法建立各个尺度的确定性接触模型,并分析得到金属表面在各尺度下的接触面积随法向接触压力的演变规律。结果显示,伪周期较小的表面分量上量纲一接触面积随量纲一法向载荷近似成斜率相同的线性增长关系,而伪周期较大的表面分量上量纲一接触面积随量纲一法向载荷近似呈现出类指数增长趋势,并随着伪周期的增大曲线更加陡峭。同时分析了不同材料屈服强度对接触行为的影响,最后通过求解高斯表面的接触过程验证了确定性模型和所发现规律的有效性。
The multi-scale contact behavior has distinct impact on surface functional performances.To study the multi-scale contact behavior of metal surfaces,a method based on deterministic model of rough surfaces is presented.In this method,the surface data is measured using the profilometer,then the wavelet filter is used to decompose the measured rough surface.Based on the filtered data,the deterministic models of rough surfaces can be built using finite element method.The method is used to analyze the variation of dimensionless contact area with dimensionless contact load.The results show that the curves rise linearly with the same slope in a small pseudo-period,while the curves in a large pseudo-period rise in an exponential trend and rise with a steeper ratio as the pseudo-period increases.The effects of material properties on contact behavior in different scales are also analyzed.At last,the presented model and the results are validated by solving the Gaussian surface.