Elastic–plastic adhesive contact of rough surfaces with asymmetric distribution of asperity heights

The elastic–plastic adhesive contact of rough surfaces is extended to include asymmetric distribution of asperity heights using the Weibull distribution with skewness as the key parameter to characterize asymmetry. The well-established elastic adhesion index and plasticity index are used to consider the different conditions that arise as a result of varying load and material parameters. The loading and unloading behaviour for different combinations of adhesion index, plasticity index and skewness values are obtained as functions of mean separation between the surfaces. It is seen that surfaces with negative skewness experience higher adhesion compared to surfaces with positive or zero skewness.