摘要:
利用分子动力学方法,模拟了5000个表面轻微摩擦（μ=1×10-4）的弹性颗粒组成的体系在各向同性压缩过程中的堵塞（jamming）现象,研究了颗粒体系对边壁压强P和对关联函数第一个峰的高度g1随体积分数的变化规律.结果表明,当体系的体积分数大于临界体积分数c时,P（）曲线表现出明显的黏滑（stick-slip）行为,法向的力-力关联函数、切向的力-力关联函数和颗粒的位置-位置关联函数同时发生跳变,说明宏观黏滑现象源自内部的力位形和几何构形的调整.体系在缓慢增大过程中得到了不同的堵塞态,随着颗粒粒径的缓慢减小,体系得以松弛（unjamming）,实现松弛过程并得到相应的c.对于不同堵塞态,其边壁压强P与-c遵从幂律标度P∝（-c）0.964.
Abstract:
In this paper,the jamming/unjamming processes of the system composed of 5000 elastic disks with small friction μ=1×10-4 are simulated by using the molecular dynamics method.The variations of sidewall pressure P and the height of the first peak of the pair correlation function,g1,with packing fraction are studied.The result shows that the P（） curve exhibits an obvious stick-slip-like behavior.The normal force-force correlation function,the tangential force-force correlation function,and the position-position correlation function are found to jump simultaneously during the stick-slip process.By relaxing jammed states obtained as the system undergoes the compression process,we observe that the P is related to -c by the power scaling law P∝（-c）0.964,although the different sidewall pressures corresponds to different values of c.
首页
登录
注册
下载: