Contact mechanics with adhesion: Interfacial separation and contact area

TL;DR

This paper investigates the contact mechanics of elastic solids with rough surfaces, combining molecular dynamics simulations and Persson's theory, showing good agreement and minimal adhesion effects in polymer contacts.

Contribution

The study validates Persson's contact mechanics theory against MD simulations for rough surfaces with adhesion, extending understanding to polymer systems.

Findings

Good agreement between MD simulations and theory.

Adhesion causes only small changes in interfacial separation.

Polymer-polymer contact shows minimal adhesion effects.

Abstract

We study the adhesive contact between elastic solids with randomly rough, self affine fractal surfaces. We present molecular dynamics (MD) simulation results for the interfacial stress distribution and the wall-wall separation. We compare the MD results for the relative contact area and the average interfacial separation, with the prediction of the contact mechanics theory of Persson. We find good agreement between theory and the simulation results. We apply the theory to the system studied by Benz et al. involving polymer in contact with polymer, but in this case the adhesion gives only a small modification of the interfacial separation as a function of the squeezing pressure.