An incremental contact model for line contact of elastic rough surfaces

In this paper, an incremental contact model is developed for the elastic self-affine fractal rough surfaces under plane strain condition. The contact between a rough surface and a rigid plane is simplified by the accumulation of identical line contacts with half-width given by the truncated area divided by the contact patch number at varying heights. Based on the contact stiffness of two-dimensional flat punch, the total stiffness of rough surface is estimated, and then the normal load is calculated by an incremental method. For various rough surfaces, the approximately linear load-area relationships predicted by the proposed model agree well with the results of finite element simulations. It is found that the real average contact pressure depends significantly on profile properties.