Study on metal-rubber contact behavior based on a reconstructed 3D topography of contact surface

In frictional wear study of shaft seal, a refined description of contact surface topography is needed, but it is difficult to directly obtain the contact characteristics like the actual contact area and the corresponding contact states due to a tiny contact gap of metalrubber contact. Traditionally, a measuring observation apparatus is used to collect the surface information during the dynamic contact, but is limited by the accuracy and more cost. In this paper, a new method is proposed to investigate a refined contact area of rubber surface during the dynamic contact through reconstructing the micro topography. A metal-rubber contact model is established based on the coordinate cloud built by the height distribution function of the asperities. According to the model, the finite element simulation on metal-rubber contact is conducted in ANSYS APDL and the frictional contact behavior under different roughness is discussed. The result shows there is a power exponent relation between the actual contact area and the external pressure, and four contact states, no contact, initial contact, adhesion contact and sliding contact, exist in the process. It gives an effective way to determine the dynamic actual contact area in the frictional wear study of rubber material, and offers an effective modelling method with quantitative scale to study the micro contact properties for rigid-flexible contact situations.