多点加载下单颗粒破碎特性的离散单元法模拟  

DEM simulation of single particle breakage under multi⁃point loading

作　　者：何金龙 杨阳[2] 刘晓星[2,3] HE Jinlong;YANG Yang;LIU Xiaoxing(SINOPEC Research Institute of Petroleum Processing Co.,Ltd.,Beijing 100083,China;State Key Laboratory of Mesoscience and Engineering,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China;School of Chemical Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中石化石油化工科学研究院有限公司,北京100083 [2]中国科学院过程工程研究所介科学与工程全国重点实验室,北京100190 [3]中国科学院大学化学与化工学院,北京100049

出　　处：《中国粉体技术》2025年第3期89-100,共12页China Powder Science and Technology

基　　金：国家重点研发计划项目,编号:2022YFB4101703;炼油工艺与催化剂国家工程研究中心(中国石油化工股份有限公司石油化工科学研究院)开发基金课题,编号:KFA2022-051;介科学与工程全国重点实验室自主部署课题,编号:MESO-23-A05。

摘　　要：【目的】评估平均主应力准则、最大主应力准则、最大剪应力准则和最大接触力准则等4种颗粒破碎准则的适用性,探究颗粒的破碎机制。【方法】基于三维离散单元法数值模拟,考察随机多点加载以及单、双、三轴加载作用下球形和圆盘型颗粒试样的破碎特性,统计分析平均主应力、最大主应力、最大剪切应力以及最大接触力随加载点数目的变化规律。【结果】随着加载的进行,加载点附近逐渐形成拉应力集中,导致颗粒试样的拉伸破坏;无论是随机加载构型还是确定加载构型,颗粒破碎时的平均主应力和最大主应力都是加载点数目的函数;对于随机加载构型,模拟得到的最大剪应力和最大接触力的平均值都与加载数目无关,但确定加载构型下2个参数都随加载点数目而变化,说明加载点数目和空间排列方式会影响颗粒的临界破碎强度。【结论】考察的4种颗粒破碎准则都不能唯一确定颗粒的临界应力状态,基于4个参数建立颗粒破碎准则时,须要考虑加载构型的影响。Objective The four main criteria for particle breakage are the mean principal stress,maximum principal stress,maximum shear stress,and maximum contact force.Currently,there is no consensus on which particle breakage criterion is more reasonable.The aim of this study is to assess the applicability of these four particle breakage criteria and to discuss the possible reasons for the inconsistent conclusions reported in the literature.Methods Based on a self-developed(discrete element method)DEM program,the critical state of macroscopic particles was evaluated by simulating the breakage of aggregate samples.To simulate arbitrary loading configuration,particle materials were first prepared through gravitational deposition.For a given number of loading points,particles with the same number of contacts were randomly selected from the material and replaced with aggregates.The surrounding particles were then moved centripetally to apply compressive loading.In this study,uniaxial,biaxial,and triaxial loading tests were also conducted to investigate the critical state of aggregates under specific loading configurations.Results The DEM simulation results demonstrated that the mean principal stress and maximum principal stress at the moment of aggregate breakage varied with the number of loading points,regardless of whether the loading configuration was random or predetermined.The simulation results for the random loading configuration suggested that the average maximum shear stress and maximum contact force were approximately independent of the number of loading points.However,the simulation results for the predetermined loading configuration showed that these two parameters were related to the number of loading points,indicating that the maximum shear stress and maximum contact force were influenced by both the number and spatial arrangement of the loading points.The uniaxial compression results of the disc-shaped aggregate samples revealed that,in the direction perpendicular to the loading axis,tensile stress concentration

关 键 词：颗粒破碎 破碎准则 多点加载 单轴加载 离散单元法 

分 类 号：TB44[一般工业技术]