The simulation and classification of contact clusters between rough surfaces

The contact area of rough surfaces has a great influence on many mechanical process in tribology. In this report, we used the simulation method to study the contact area between two rough surfaces and its evolution when sliding. We generated artificial self-affine rough surfaces by regularizing the power-spectrum density. We also developed a 3-dimensional connectivity model to deal with the problem of contact cluster classification. The model is able to assign correct labels to all contact clusters even if there are merging or spliting among clusters. The following sliding test shows that the remaining contact area in cluster scale follows a new pattern while evolving with slidng distance, which is different from the exponential-decay rule in macroscopic scale.