Experimental and finite element analyses of contact behaviors between non-transparent rough surfaces

The real contact area and separation between rough surfaces are significant parameters in sealing, tribology, and lubrication. However, it is challenging to experimentally observe the contact behaviors between rough surfaces because the materials of rough surfaces are usually non-transparent and not accessible for direct visual observation. In this study, X-ray computed tomography was used to directly measure the contact behaviors between rough surfaces. The real contact area and three-dimensional surface separation of contact pairs made of aluminum and polycarbonate were experimentally measured. In addition, finite element models were developed to simulate the contact behaviors of the same contact pairs. The results obtained from the finite element analyses and the experiments were compared. The simulation results were in good agreement with the experimental observations when the material properties of the rough surfaces were consistent.