ADHESIVE CONTACT MODELLING BASED ON LENNARD-JONES FORCE LAW

At diminishing separations, the load carrying capacity of opposing rough surfaces is distributed among asperities across a smaller contact area as compared with the apparent contact area. An improved understanding on asperity interactions is therefore required in order to better predict the tribological behaviour of a rough surface contact. In this paper, based on Weir's method for computing the work of adhesion, a simplistic adhesive contact model is proposed, applying the Lennard-Jones force law, to study an asperity pair interaction. Assuming that the tip represents an asperity, the numerical model is subsequently applied to simulate a Tungsten Carbide (WC) coated AFM tip indenting on a Diamond (111) surface. It was found that the simulated pull-off force agrees with the measured value by Enachescu et al for a WC AFM tip on a Diamond (111).