Effect of roughness geometries in contact mechanics

In this work, we study the influence of roughness geometries on the contact force, contact area and pressure distribution during a static contact between a rough surface and a smooth rigid plane by using two elastic geometrical models. The first one is spherical where each asperity can be characterised by the height and the radius of curvature. The second approach is a conical where the rough contact is modelled by cones. In order to discuss the validity of these two geometrical models, they are compared with a numerical solution of the Boussinesq equation which does not take into account the local geometry of the asperities. The results show clearly that the conical model allows having more realistic values of the contact parameters and model correctly the elastic rough contact. However, the spherical approach of the asperities overestimates the pressures undergone by the asperities.