关于离散元法计算参数的探讨  

Discussion on the Calculation Parameters of Discrete Element Method

作　　者：焦红光[1] 李靖如[1] 赵继芬[1] 赵跃民[2] 

机构地区：[1]河南理工大学材料科学与工程学院,河南焦作454003 [2]中国矿业大学化工学院,江苏徐州221008

出　　处：《河南理工大学学报（自然科学版）》2007年第1期88-93,共6页Journal of Henan Polytechnic University（Natural Science）

基　　金：国家自然科学基金重大研究计划资助项目(90210035);国家杰出青年科学基金资助项目(50025411)

摘　　要：计算时步、接触刚度等计算参数的选取对离散元法解的正确与否至关重要,目前普遍采用的方法是先确定接触刚度并选取保险系数后,按照经验公式求得计算时步,但在保险系数的设定上有关文献却不尽相同.作者提出了一种新的方法———恢复系数检验法来选定计算参数.采用离散元法最常用的弹性-阻尼-滑动接触模型编制了计算程序,以颗粒同静置平面之间的正碰撞考察了不同计算参数下的模拟结果,除模拟得到恢复系数外,还考察了碰撞过程的总接触时间和总接触时步数.统计分析结果表明:计算时步是影响模拟精度最重要的因素;模拟误差还同恢复系数的设定值有关,设定值越大,模拟误差就越小;计算时步的大小虽然对碰撞过程的总接触时间影响不大,但是却决定了碰撞过程的总接触时步数,二者之间存在对数线性相关关系.Time step and contact rigidity are important calculation parameters of Discrete Element Method. At present, the contact rigidity and the safety factor are firstly determined and then time step is generally calculated by the empirical formula, but the related literatures are different in the safety factor setting. A new method-restitution coefficient verifying method is put forward. By adopting the spring-dashpot-slide contact model, a program is developed and the simulation results under different calculation parameters for vertical collision between particles and immobile plate are studied. Besides the restitution coefficient gained by the simulation, the total contact time and the total contact step in the course of collision are also studied. Statistic analysis result shows that the time step is the most important influence factor of simulation precision, and there is relation between simulation error and the setup value of restitution coefficient which the greater the setup value is, the less the simulation error is. Although there is no effect to the total contact time in the course of collision, the value of the time step decides the total contact step, and there is a logarithmic linear correlativity between them.

关 键 词：离散元法 计算参数 数值模拟 计算时步 接触刚度 

分 类 号：TD94[矿业工程—选矿]