Parameter-free dissipation in simulated sliding friction

TL;DR

This paper introduces a parameter-free, non-markovian stochastic method for accurately removing Joule heat in molecular dynamics simulations of sliding friction, improving upon traditional empirical schemes.

Contribution

It develops a realistic, parameter-free dissipation approach that precisely absorbs Joule heat, enhancing the accuracy of friction simulations compared to empirical methods.

Findings

Exact frictional results closely match with optimized viscous Langevin dissipation.

Traditional empirical dissipation schemes often produce serious errors.

The method provides a more realistic simulation of heat removal in frictional systems.

Abstract

Non-equilibrium molecular dynamics simulations, of crucial importance in sliding friction, are hampered by arbitrariness and uncertainties in the way Joule heat is removed. We implement in a realistic frictional simulation a parameter-free, non-markovian, stochastic dynamics, which, as expected from theory, absorbs Joule heat precisely as a semi-infinite harmonic substrate would. Simulating stick-slip friction of a slider over a 2D Lennard-Jones solid, we compare our virtually exact frictional results with approximate ones from commonly adopted empirical dissipation schemes. While the latter are generally in serious error, we show that the exact results can be closely reproduced by a viscous Langevin dissipation at the boundary layer, once the back-reflected frictional energy is variationally optimized.