多面体颗粒的接触识别及离散元动力学建模  

Contact detection and dynamic model for polyhedral particles based on discrete element method

作　　者：洪俊[1,2] 李建兴 沈月 王潇[1,2] Hong Jun;Li Jianxing;Shen Yue;Wang Xiao(School of Civil Engineering,Southeast University,Nanjing 211189,China;Jiangsu Key Laboratory of Engineering Mechanics,Southeast University,Nanjing 211189,China)

机构地区：[1]东南大学土木工程学院,南京211189 [2]东南大学江苏省工程力学分析重点实验室,南京211189

出　　处：《东南大学学报（自然科学版）》2018年第6期1082-1087,共6页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(11772091)

摘　　要：为了模拟多面体颗粒的真实形状和运动过程,基于离散元法,采用有效的接触识别算法对多面体颗粒系统进行动力学建模.利用连接线性目录法建立可能接触颗粒对的邻居目录,采用改进的射线穿透法判断邻居目录中颗粒对是否真正接触.建立颗粒间的接触力模型,通过Verlet积分获得单个颗粒的运动轨迹,最终获得颗粒系统的整体运动状态,并对2个多面体颗粒系统自由堆积过程进行了数值模拟.模拟结果表明,对于多面体颗粒,连接线性目录法能够快速建立颗粒系统的邻居目录,改进的射线穿透法能有效地识别颗粒间各种复杂的接触情况,动力学模型能够真实地反映颗粒系统运动状态.改进的射线穿透法可以有效解决考虑多面体颗粒真实形状的颗粒系统离散元动力学建模问题.In order to simulate the real shape and the motion of polyhedral particles,the dynamic model for a polyhedral particle system based on the discrete element method(DEM)was proposed by an efficient collision detection algorithm.The linked linear list method was used to establish the neighbor list of the adjacent particle pairs which may be in contact.The improved ray crossing method was applied to determine whether the particle pairs in the neighbor list were actually in contact.The model of the contact force between particles was established,and the motion of the single particle was described by the Verlet integral.Finally,the motion state of the whole particle system was obtained,and two numerical simulations of the packing of polyhedral particle system under gravity were carried out.The simulation results show that,for polyhedral particles,the linked linear list method can establish the neighbor list of the particle system at a high efficiency.The improved ray crossing method can efficiently detect various complex contacts between polyhedral particles.The dynamic model can objectively reflect the motion state of the polyhedral particle system.The improved ray crossing method can effectively solve the dynamic model problem of the polyhedral particle system considering the real shape of polyhedral particles.

关 键 词：多面体颗粒 接触识别 离散元法 接触力 

分 类 号：O347.7[理学—固体力学]