声子摩擦能量耗散机理研究

Energy dissipation mechanism of phononic friction

以界面摩擦为研究对象,分析了黏滑过程中的能量积累和耗散问题.基于晶格热动力学理论,通过分析界面原子在周期性势场中跳跃前后的势能差,推导了界面原子温升公式.理论表明,界面温升与摩擦系统的接触状态和材料特性有关,界面交互势能是其中影响较大的因素之一.在滑动阶段初期,由于界面原子处于非热平衡状态,晶格的热振动将通过激发出新声子而耗散能量,从而使得非热平衡向平衡状态转变.通过引入量子力学和热力学理论,分析了界面摩擦能量的耗散规律.结果表明,当声子振动频率较大时,黏着阶段存储于界面振子上的弹性势能在滑动阶段就很快完全耗散,耗散时间远小于滑动阶段的时间.

Focusing on the interfacial friction,the energy accumulation and dissipation mechanisms are analyzed in the present paper. Based on the lattice thermokinetics theory,the potential difference of interfacial atom during the jumping process is calculated,then the formula of interfacial temperature rise is deduced successfully. The analysis indicates that the interfacial temperature depends on the contact status and material properties of the friction system,and the interfacial interactive potential is an important factor. In the initial stage of slipping process,as the interfacial atoms are in the non-equilibrium thermal state,new phonon are excited to enable the friction energy dissipation,which finally makes the non-thermal equilibrium transit to equilibrium state. Based on the quantum mechanics and the thermodynamics,the energy dissipation mechanism of interfacial friction is studied. The results show that the elastic potential energy stored during the sticking process dissipates more quickly with higher vibration frequency,and the dissipation time is much shorter than the slip time in one cycle.