Static and dynamic properties of frictional phenomena in a one-dimensional system with randomness

TL;DR

This paper investigates static and kinetic frictional phenomena in a one-dimensional incommensurate system with impurities, revealing that impurities induce finite static friction and affect velocity dependence of kinetic friction.

Contribution

It introduces a two-chain model with randomness to analyze how impurities influence static and dynamic frictional forces, highlighting impurity pinning effects.

Findings

Static friction is always finite with impurities.

Impurity pinning relates to density wave pinning.

Kinetic friction depends on impurity potential strength.

Abstract

Static and dynamic frictional phenomena at the interface with random impurities are investigated in a two-chain model with incommensurate structure. Static frictional force is caused by the impurity pinning and/or by the pinning due to the regular potential, which is responsible for the breaking of analyticity transition for impurity-free cases. It is confirmed that the static frictional force is always finite in the presence of impurities, in contrast to the impurity-free system. The nature of impurity pinning is discussed in connection with that in density waves. The kinetic frictional force of a steady sliding state is also investigated numerically. The relationship between the sliding velocity dependence of the kinetic frictional force and the strength of impurity potential is discussed.