基于Kelvin振子的界面摩擦系数计算方法

为了解决界面摩擦系数计算方法问题,假设接触界面的摩擦能量以声子的形式向外传播,因此接触界面微观振子所耗散的能量等于宏观界面向外传递的热能,应用等效阻尼方法可求出等效黏性阻尼;同时提出了Kelvin振子摩擦耗散模型,通过此模型得到表面能变化的损耗率;最后应用"鹅卵石"模型求出摩擦系数.采用此公式计算的结果与前苏联学者Крагепьский等提出的摩擦系数与相对滑动速度试验中极大载荷情况下的摩擦系数变化趋势非常相似.另外,摩擦力计算公式所得数值与Lantz等利用超高真空原子力显微镜研究硅探针在NbSe2试样表面接触和摩擦时的试验结果比较接近.因此证明了此摩擦系数计算公式具有一定的可靠性.

Calculation Method of Interfacial Friction Coefficient Based on Kelvin Oscillator

In order to solve the problem of the calculation method of the interracial friction coefficient, it was assumed that the energy of the contact interface spread in the form of a phonon, and therefore the energy dissipated by the micro-oscillator on contact interface is equal to the heat which is passed by the macro-interface. The equivalent damping method was applied to calculate the viscous damping. The Kelvin oscillator friction dissipation model was proposed, and by this model, the loss rate of the surface energy was obtained. Finally, the ＂cobblestone＂ model was applied to calculate the friction coefficient. There is a very similar trend between the result calculated by this formula and the test result proposed by the former Soviet Union scholar Крагепьский et al in the great load test of the friction coefficient with the change of relative sliding velocity. In addition, the results conform to the test result which has been proposed by Lantz, using the ultra-high vacuum atomic force microscopy （AFM）, in the process of Lantz＇s studies of the contact and friction of the silicon probe on the NbSe2 specimen surface. Therefore, the formula of the friction coefficient is proved to have certain reliability.