金属晶体间微观静摩擦特性的分子动力学模拟研究

Molecular dynamics simulation of static friction characteristics between micro metal crystals

以光滑干摩擦接触平面为对象,利用金属晶体间的强体积效应特征,建立了简化计算静摩擦力的界面势能模型.根据第一性原理的方法模拟得出界面分子势能的变化,通过界面分子势能计算出静摩擦力大小,并将数据结果通过通用黏附能量函数计算出的静摩擦力大小进行验证,也将计算结果与超高真空原子力显微镜试验结果进行对比.最后拟合出最大静摩擦力与法向载荷的线性函数关系,得出摩擦力的数值为真实接触面积的函数,并与法向载荷成正比的结论.从微观上对同种金属材料间库伦摩擦定律进行验证与研究.

This study focuses on smooth dry friction contact plane, we use metal crystals of strong volume effect features to construct interface potential model calculating static friction force. Based on the theory of first-principle, we simulate the changes of potential energy between molecular interface, using the interface molecular potential to calculate the static friction force, and the data results will be validated by the value of static friction force which are calculated by general adhesion energy function, it will be also compared with ultra-high vacuum atomic force microscope test results. Finally we fit out linear function about max static friction along with normal load,obtain a result that friction is a func- tion of real contact area, and get a conclusion that it is proportional to normal load. From this micro perspective, we validate and research on Coulomb friction law between the same kinds of metal materi- als.