循环荷载作用下粗粒料颗粒破碎数值模拟分析

Numerical Analysis on Particle Breakage of Coarse Material under Cyclic Loading

基于二维颗粒流程序建立颗粒破碎模型,开展粗粒料循环荷载作用下的颗粒破碎数值模拟研究,分析初始应力状态对粗粒料颗粒破碎的影响。数值模拟结果表明,初始应力状态对颗粒破碎影响较大,颗粒破碎率随着围压的增大而增大;相同围压条件下,动应力引起的颗粒破碎率随着固结应力比的增大而减小;竖向总应力相等条件下,颗粒破碎率随着固结应力比的增大而增大;颗粒破碎不仅发生在加载阶段,在卸载阶段也会有少量的颗粒破碎发生;在一个循环荷载加载周期内,随着循环荷载的施加,颗粒破碎率先缓慢增加,再急剧增加,最后趋于平缓;随着循环周次的增大,试样内部的颗粒破碎率先增加,后趋于稳定。

Based on 2D particle flow program, the breakage numerical model is established to study the particle breakage properties of coarse material under cyclic loading. The simulation results show that the initial stress conditions have significance effect on particle breakage ratio which increases with the increasing of confining pressure, and the particle breakage ratio decreases with the increasing of consolidation stress ratio under same confining pressure and increases with the increasing of consolidation stress ratio under same vertical stress. The particle not only breaks during the loading, but also breaks during the unloading. The particle breakage ratio in one cyclic loading process slowly increases firstly, then rapidly increases and finally trends towards stability with the action of cyclic loading. The particle breakage ratio also firstly increases and then trends towards stability with the increasing of cyclic loading number.