A Load-Dependent Model to Investigate the Velocity Dependence of Friction Coefficient: ZrO2/Polymer Nanocomposite

Using dynamic finite simulations, we investigate how the friction coefficient of ZrO₂/polymer nanocomposite depends on the sliding speed. The load-dependent model we developed corresponds to common friction systems, where the friction couples are sliding under fixed load for various speeds. Here, we study the effect of the sliding speed on the contact distance between two contacting bodies. In accordance with experimental observations and theoretical arguments, we find the contact distance increased with the sliding speed. We show that the dependence of the reaction force on sliding speed can be rationalized by assuming that the frequency dependence of the polymer chains relaxation times is affected by the damping effects of contact stress. By investigating the energy dissipation, we show how the friction coefficient is affected by the sliding speed. The deformation volume and relaxation times decreased with the increasing sliding speed, which result in the decreasing of energy dissipation. Then, the work in pushing the top cylinder across the bottom plateau decreases, results in a reduction of the mean horizontal reaction force and friction coefficient.