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

Abstract This study delves into the mechanism of dynamic sliding friction between layers of graphene and its strain effect, through numerical analysis using molecular dynamics simulations. To eliminate the influence of commensurability and edge effect, a friction pair model with annular graphene as a slider is established. The research explores the quantifying effects of temperature, normal load, sliding velocity, support stiffness, and axial strain on the friction between graphene layers. The coupling effect of temperature and other influencing factors is also clarified. The results indicate that the interlayer friction increases with normal load by decreasing the interlayer spacing and increasing the atomic vibration amplitude. The ploughing phenomenon does not appear since the edge effect is eliminated by the model. Friction is initially enhanced at higher sliding velocities, but is later reduced by severe residual deformation and lattice resonance frequency. The support stiffness regulates interlayer friction by affecting the atomic vibration amplitude of the graphene lattice. Mechanism analysis shows that the number of effective contact atoms increases under axial strain, and the lattice vibration frequency is the main way to regulate the interlayer friction by strain effect. Our findings provide a fundamental understanding of the strains engineering of nanoscale friction and reveal the influence mechanism of affecting factors on the dynamic friction of graphene.