Contact of rough surfaces under normal and tangential loading.

Contact between a deformable, random rough surface and a rigid flat counterpart was investigated experimentally and theoretically. In the experimental setup, two modes of rough surface flattening were performed, namely normal compression and sliding (tangential load) in presence of normal compression. The load-approach relationship and friction coefficient were measured. After unloading the surface, the topography was measured using scanning profilometry. The deformation of roughness zone, i.e. evolution of the real contact area (RCA), and roughness parameters were analysed. A model based on statistical analysis and a finite element solution was applied to predict the load–approach relationship. The numerical and experimental results were compared. The effect of friction coefficient was discussed. • The contact of rough surface under tangential and normal load is investigated in elastic-plastic range. • The variation of roughness parameters, real contact area, approach and friction coefficient are specified experimentally. • The local deformation of single asperity is analysed numerically for different modes of load. • The model of contact is proposed in which two kinds of load are taken into account. [ABSTRACT FROM AUTHOR]