Influence of self-affine roughness on the adhesive friction coefficient of a rubber body sliding on a solid substrate

In this work we investigate characteristics of the adhesive friction during sliding of a rubber body on a rough self-affined surface. The latter is characterized by the rms roughness amplitude w, the in-plane correlation length ξ, and the roughness exponent H (0 < H < 1). The friction coefficient is shown to be proportional to the roughness amplitude w. Moreover, the friction coefficient is shown to depend strongly on the roughness exponent H. The influence of the latter is more prominent at intermediate slidding velocities, where the friction coefficient is independent of the slidding velocity. Similar, but weaker in magnitude, is the influence of correlation length ξ on μad. In any case, our work shows that understanding of the adhesive friction should take properly into account of the precise roughness nature both at all lateral roughness wavelengths.