Molecular dynamics study on dynamic interlayer friction of graphene and its strain effect

Abstract

The mechanism of dynamic sliding friction between graphene layers and its strain effect is theoretically analyzed in this paper. A friction pair model with an annular graphene as slider is built to eliminate the influence of commensurability and edge effect. The effects of temperature, normal load, sliding velocity, support stiffness and axial strain on the friction between graphene layers are investigated. The coupling effect of temperature and other influencing factors are clarified. The results show that normal load increases the friction force by decreasing layer spacing. The friction is firstly enhanced as the sliding velocity increase and then is reduced by severe interlayer residual deformation and lattice resonance frequency at high sliding velocity. The support stiffness regulates the interlayer friction by affecting the atomic vibration amplitude of the graphene lattice. By mechanism analysis, it is found that by changing the number of atoms in friction region between layers and the frequency of lattice vibration, the strain can effectively regulate the dynamic friction between graphene layers. Our findings reveal the influence mechanism of affecting factor on dynamic friction of graphene and provide a fundamental understanding for the strains engineering of nanoscale friction.