A multiscale Molecular Dynamics approach to Contact Mechanics

TL;DR

This paper introduces a multiscale molecular dynamics method to study contact mechanics of rough surfaces, revealing linear contact area-load relation and analyzing contact morphology across scales, with comparisons to continuum models.

Contribution

It develops a novel multiscale molecular dynamics approach for contact mechanics applicable to rough surfaces across multiple length scales.

Findings

Contact area varies linearly with load at small loads.

Contact morphology and pressure distribution depend on magnification.

Results agree with continuum mechanics models.

Abstract

The friction and adhesion between elastic bodies are strongly influenced by the roughness of the surfaces in contact. Here we develop a multiscale molecular dynamics approach to contact mechanics, which can be used also when the surfaces have roughness on many different length-scales, e.g., for self affine fractal surfaces. As an illustration we consider the contact between randomly rough surfaces, and show that the contact area varies linearly with the load for small load. We also analyze the contact morphology and the pressure distribution at different magnification, both with and without adhesion. The calculations are compared with analytical contact mechanics models based on continuum mechanics.