多点接触对单颗粒破碎影响的离散元研究
Influence of multi-point contact on single grain crushing via DEM simulation
摘要
Abstract
Ballast particle crushing is one of the important problems in the stability study of railroad engineering,and most of the existing studies on particle crushing are based on single particle crushing experiments at two contact points,while in fact the particles are subjected to multiple contacts at the same time,and the crushing characteristics of particles depend largely on the number of their contact points(coordination number,CN),and so far the criteria and modes of particle crushing under multi-contact conditions have not yet been understood completely.In order to solve these problems,the single particle crushing experiment of ballast was carried out to obtain the crushing strength and crushing energy,and a numerical model of single particle bonded polyhedral was established by using discrete elements,and the micro-parameters of the numerical model were calibrated by the results of the single particle crushing experiments.A rigid shielding wall was installed on the particle surface to reflect the mechanical constraint effect of neighboring grains.Based on the calibrated numerical model,the effects of CN on crushing strength,contact force chain,crushing mode and crushing criterion were investigated for different particle sizes.The results show that the particle crushing strength increases with the increase of CN,and the smaller the particle size,the larger the increase.When the CN is lower,the particles tend to be crushed into several pieces,and with the increase of the CN,the particles tend to be pulverized,the sub-particle volume distribution has a normal distribution to Gamma distribution shift,and the contact force chain extends gradually to the shielding wall;when the CN is larger than 10,the particle breakage criterion based on the stress tensor(maximum principal stress criterion σ1,octahedral shear stress criterion q,mean stress criterion p)and local contact force(maximum contact force criterion Fmax)is no longer applicable.The obtained conclusions are of some guidance for engineering practice and further study of crushable granular materials by discrete element method.关键词
离散元法/颗粒破碎/配位数/道砟/破碎准则Key words
discrete element method/particle breakage/coordination number/ballast/breakage criterion分类
建筑与水利引用本文复制引用
谭攀,肖源杰,王萌,华文俊,王小明,彭友全..多点接触对单颗粒破碎影响的离散元研究[J].中南大学学报（自然科学版）,2025,56(4):1405-1416,12.基金项目
国家自然科学基金资助项目(U1934209,51878673) （U1934209,51878673）
中国铁道科学研究院科技研究开发计划重大课题(2020YJ022,2019YJ026) （2020YJ022,2019YJ026）
重载铁路工程结构教育部重点实验室(中南大学)开放课题(2021JZZ01,2021JZZ02,2022JZZ03) （中南大学）
中南大学研究生自主探索创新项目(2023ZZTS0368)(Projects(U1934209,51878673)supported by the National Natural Science Foundation of China （2023ZZTS0368）
Projects(2020YJ022,2019YJ026)supported by the Key Research Development Program of Chinese Academy of Railway Sciences （2020YJ022,2019YJ026）
Projects(2021JZZ01,2021JZZ02,2022JZZ03)supported by the Heavy Railway Engineering Structures Key Laboratory of the Ministry of Education(Central South University)Open Program （2021JZZ01,2021JZZ02,2022JZZ03）
Project(2023ZZTS0368)supported by the Graduate Students Independent Exploration and Innovation Program of Central South University) （2023ZZTS0368）
