金属晶体间微观滑动摩擦特性的分子动力学模拟  

Molecular Dynamics Simulation of Sliding Friction Characteristics Between Micro Metal Crystals

作　　者：肖乾[1] 穆明[1] 周新建[1] 

机构地区：[1]华东交通大学载运工具与装备教育部重点实验室,南昌330013

出　　处：《中国表面工程》2011年第6期78-82,共5页China Surface Engineering

基　　金：国家自然科学基金(51005075);江西省自然科学基金(2010GQC0034)

摘　　要：根据独立振子模型的能量耗散机理,以光滑干摩擦接触平面为对象,利用金属晶体的强体积效应特征,构造了简化计算的界面势能模型,分析了在界面摩擦状态下能量非连续耗散过程,建立了简化计算滑动摩擦力与摩擦因数模型。从瞬间原子位置图和系统能量方面,进行计算模拟和试验对比验证,结果表明:当接触界面势能处在某个谷底时,滑块受静摩擦力,界面间发生相对运动,滑块变为受滑动摩擦力作用;摩擦力按基本不变的斜率增加到某一值后突然降低,而后变化呈现一定的周期性;随着滑动的逐渐进行,运动体与基体表面的温度逐渐增加而后趋于稳定,两表面存在温度差;滑动后界面平均接触压力明显下降,而后趋于平缓。The contact interface potential model was constructed based on energy dissipation mechanism of independent oscillator model and the strong volume effect of metal crystals and the non-continuous energy dissipation process in the interface friction state was analyzed. A sliding friction coefficient calculation model on smooth dry friction contact plane was proposed. Experiments was also carried out to validate the procedures on the instant atomic locations and system en- ergy. The results indicated that static friction force applied to the surface before contact interface overcome potential bar- rier. Sliding friction force raised after interface potential over certain value to initiate sliding. Simultaneously, the friction force increased linearly to a certain value, then dropped abruptly in the process. It was found that the temperature of both the moving surface and the substrate surface increased gradually to a stable state with the sliding. However, there was a temperature difference between two surfaces. The average interface contact pressure was found to decrease significantly after the sliding initiated and became stable with the sliding proceeded.

关 键 词：分子动力学 界面势能 滑动摩擦 能量耗散 

分 类 号：TH171[机械工程—机械制造及自动化]