Effect of Spring Stiffness on Resonance of Nanoscale Sliding Friction

Friction is a main form of energy dissipation at the atomic scale. However, the mechanism of how nanofriction converts mechanical energy into thermal energy remains to be studied. Some experts and scholars believe that the excess phonons are mainly excited at the washboard frequency, and then the thermalization of these nonequilibrium phonons leads to the completion of energy dissipation. Through molecular dynamics simulation, we find that the interaction between sliding tip and substrate is nonlinear in the process of friction. The nonlinear interaction can produce excess phonons at the washboard frequency and its harmonics, resulting in the resonance of the tip. With the gradual increase of the sliding velocity of tip, several peaks appear on the friction curve. Then by adjusting the spring stiffness in the model, it is found that the peak value also changes. This means that different resonances can be controlled and produced by changing the spring stiffness.