Towards a Universal Scaling for the Elastic Contact Between Anisotropic and Non-gaussian Surfaces

Contact between elastic rough surfaces is one of the fundamental problems in tribology. We study with a Boundary Element Method the influence of anisotropy of roughness on the real contact area and on load-separation for both a classical gaussian height distribution and a weibull one, in the common case of power law PSD. We find that anisotropy affects contact area and load-separation similarly for gaussian or non-gaussian surfaces, and therefore the effect can be captured by a single parameter which we extract from Persson’s theory. We further use the results to extend BAM theory of long-range adhesion to gaussian and non-gaussian (weibull) surfaces both isotropic or anisotropic. For the real contact area, results for weibull surfaces are known in the literature.