Contact area calculation between elastic solids bounded by mound rough surfaces

In this work, we investigate the influence of mound roughness on the contact area between elastic bodies. The mound roughness is described by the r.m.s. roughness amplitude w, the average mound separation Λ, and the system correlation length ζ. In general, the real contact area has a complex dependence on the lateral parameters ζ and Λ. As a function of the contact length scale λ, the contact area approaches macroscopic values rather fast for contact lengths λ≥Λ and significant system correlation lengths ζ (≥Λ). Finally, as a function of the applied load σo the contact area increases significantly with increasing load if ζ≥Λ, while for ζ⪡Λ it approaches macroscopic values even for very weak loads (⪡E; with E the solid body elastic modulus).