摘要
颗粒物质生产、储存和输送等研究已经有悠久的历史,近些年来,虽然开展了关于颗粒物质的多方面的实验和模拟计算,但对其运动规律研究还很肤浅,描述颗粒物质的基本理论尚未建立。基于离散元法(discrete element method,DEM),用PFC软件生成了压强分别为0.1、1、10、100、1000、10000 Pa的不同维度的无摩擦颗粒体系,基于Hessian矩阵的简正模式分析法,编写了计算不同维度和压强下颗粒体系态密度的程序,进一步分析了维度和压强对颗粒体系态密度的影响。结果表明:一维颗粒体系的态密度不受压强影响。在低频下态密度几乎不随频率变化,在高频下态密度曲线随频率呈现振荡上升趋势。二维颗粒体系态密度曲线在某个特征频率之上出现一个平台,且该平台随着压强的增加而增加。低于某个特征频率下,三维颗粒态密度随频率呈幂率标度,随着压强增加曲线向高频移动。
There has been a long history of research on the production,storage and transport of particulate matter.Although experiments and simulations on various aspects of particulate matter have been carried out in recent years,the study of its laws of motion is still superficial,and the basic theory describing particulate matter has not yet been established.Based on the discrete element method(DEM),the frictionless particle systems with different dimensions under pressure 0.1,1,10,100,1000,10000 Pa were generated by PFC software.The procedure to calculate the density of states of the particle system under different dimension and pressure was written based on the normal mode analysis of Hessian matrix,and the effect of dimension and pressure on the density of states of the particle system was further analyzed.The results show that the density of states of the one-dimensional particle system is not affected by the pressure.The density of states hardly varies with frequency at low frequencies,and the density of states curve shows an oscillating upward trend with frequency at high frequencies.The density of states curve of the two-dimensional particle system appears a plateau above a certain characteristic frequency,and the plateau increases with the increase of the pressure.Below a certain characteristic frequency,the density of states of the three-dimensional particles shows a power rate scale with frequency,and the curve shifts to high frequencies with increasing pressure.
作者
李歌天
曾援
张波
张国华
LI Ge-tian;ZENG Yuan;ZHANG Bo;ZHANG Guo-hua(School of Mathematics and Physics,University of Science and Technology Beijing,Beijing 100083,China)
出处
《科学技术与工程》
北大核心
2023年第20期8515-8520,共6页
Science Technology and Engineering
基金
国家自然科学基金(91634202)。
关键词
颗粒物质
态密度
维度
压强
particle system
density of states
dimension
pressure
