Modeling Solid Contact between Smooth and Rough Surfaces with Non-Gaussian Distributions

In this study, we constructed a solid contact asperity distribution model based on height and curvature that is capable of considering surface properties, such as skewness and kurtosis, corresponding to actual wear surfaces. Our model is in good agreement with actual measurements of asperity height distribution on wear surfaces with various skewness and kurtosis values. We applied our distribution model to the Greenwood-Williamson model to develop a formula for real contact area and contact force between a rough surface and a smooth surface. Although the tendencies of the change in contact area with respect to the film thickness ratio differ depending on skewness and kurtosis, the contact area predicted by the model agrees well with theoretical solutions when pure plastic deformation is assumed. Additionally, we calculated the mean real contact pressure (the ratio of contact force to real contact area) with skewness and kurtosis and confirmed that the tendencies of change with respect to the film thickness ratio change significantly. This appears to suggest that the tendencies of friction and wear characteristics differ according to the skewness and kurtosis.