局部加卸载下散粒体中接触力的残留特性及细观机理

发布时间：2018-02-25 06:05

本文关键词： 散粒体局部加卸载残留接触力颗粒位移光弹试验　出处：《同济大学学报(自然科学版)》2015年11期 　论文类型：期刊论文

【摘要】：基于光弹试验分析了正五棱柱颗粒体系在一个分级加卸载周期下力链和颗粒位移的演化过程.结果表明,强力链上的接触力和颗粒位移在卸载释放时均存在"残留"现象,卸载阶段颗粒位移正响应区域大于加载阶段.定义量纲一化的位移恢复率ηd(-1ηd1)描述颗粒运动轨迹,并给出颗粒运动的五种类型所对应的ηd取值;随着深度的增大,ηd逐渐增大.力链和颗粒位移的演化特性表明,存在一个临界荷载值,当附加荷载高于临界值时,散粒体内残留接触力处于稳定平衡状态;当卸载至临界值时,残留接触力达到极限平衡状态,进一步卸载残留接触力将快速释放,并引起颗粒位置重分布.
[Abstract]:Based on photoelastic experiments, the evolution process of force chain and particle displacement of a pentacrystalline particle system under a staged loading and unloading period is analyzed. The results show that the contact force and particle displacement on the strong chain both exist "residual" phenomenon during unloading release. The positive response region of particle displacement in unloading stage is larger than that in loading stage. The dimensionally normalized displacement recovery rate 畏 dn-1 畏 D1) is defined to describe the trajectory of particle motion, and the corresponding 畏 d values of five types of particle motion are given. The evolution characteristics of force chain and particle displacement show that there is a critical load value. When the additional load is above the critical value, the residual contact force is in a stable equilibrium state, and when unloading to the critical value, the residual contact force is in a stable equilibrium state. The residual contact force reaches the limit equilibrium state, and further unloading the residual contact force will release rapidly and cause the distribution of particle position redistribution.
【作者单位】：同济大学道路与交通工程教育部重点实验室;麦克马斯特大学土木工程学院;
【基金】：国家自然科学基金(41472247)
【分类号】：TU43

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