二维成分无序颗粒体系中法向力的分布  

Normal force distribution in two-dimensional granular system of compositional disorder

作　　者：张兴刚[1] 胡林[1] 

机构地区：[1]贵州大学理学院,贵阳550025

出　　处：《物理学报》2012年第10期244-251,共8页Acta Physica Sinica

基　　金：贵州大学自然科学青年基金(批准号:2009011);贵州省自然科学基金(批准号:2011-2103);贵州省长专项基金(批准号:2010-5)资助的课题~~

摘　　要：运用离散元法研究成分无序体系中法向力的几率分布,该体系由两种不同刚度系数的颗粒规则堆积而成,体系的无序程度由缺陷率控制.模拟发现,无缺陷时体系的力网几乎是均匀的,而有缺陷时力网变得不均匀.提出了主法向力与次法向力的概念,并对它们分别进行统计;随着缺陷率的增加,主法向力的分布经历了比较复杂的变化过程,而次法向力总是指数型分布.模拟结果表明,缺陷率较小时成分无序体系中的法向力分布与随机堆积体系很不相同,而缺陷率较大时得到了与随机堆积类似的结果.这些结果有助于理解力网的不均匀性与体系无序性的关系.Point defects are implanted in an ordered granular system by randomly selecting granules and changing their stiffness coefficients. The discrete element method is used to research the normal force probability distribution. Simulation result shows that force network is almost homogeneous without defects whereas force network will become inhomogeneous with defects. The concepts of primary normal force and secondary normal force are proposed and their statistics are analyzed separately. As the rate of defects increases, the changing process of primary normal force distribution is complex, whereas the secondary normal force distribution is always exponential distribution. Our simulation shows that normal force distributions are different between randomly packing system and compositional disordered system of low defect rate. But when defect rate is large, the distributions are similar. These results are beneficial to the understanding of the relationship between inhomogeneous force network and disordered system.

关 键 词：静态颗粒体系 离散元法模拟 无序体系 力分布 

分 类 号：O469[理学—凝聚态物理]