颗粒离散元数值模拟中的宏细观接触力计算方法

Macroscopic and Microscopic Contact Force Calculation Method in Particle Discrete Element Numerical Simulation

基于颗粒离散单元模拟理论,提出一种在宏观层面定量化描述颗粒离散单元法中接触力的方法。构造到各个颗粒的切线长度相等的点集,可以形成一个平面图。该平面图的"边"可表示2个颗粒之间的接触。在二维情况下,宏观接触面可以用图论中的"路"来表示。将颗粒之间细观接触力的值作为平面图中边的权重,则颗粒集合体的宏观接触力可以通过计算表征宏观接触的"路"内部的"边"的权重矢量和来得到。以一个边坡工程为实例,比较传统理论法的计算结果与本文方法的差异,发现计算结果基本一致,且本文的计算结果更能反映岩土体内部接触力分布不均的特点。

Based on the theory of particle discrete element simulation,a method for quantitatively describing the contact force in particle discrete element method at macro level was proposed.A plan can be formed by constructing a set of points with equal tangent lengths for each particle.The “edge” of the plan can represent the contact between two particles.In the two-dimensional case,the macroscopic contact surface can be represented by the “path” in graph theory.If the value of the microscopic contact force between particles is taken as the weight of the edge in the plan,the macroscopic contact force of the aggregate of particles can be obtained by calculating the weight vectors sum of the “edge” in the “road” representing the macroscopic contact.Taking a slope as an engineering example,the difference between the calculation results of the traditional theoretical method and that of the method presented in this paper was compared,and it is found that the calculation results are basically the same,and the calculation results in this paper can better ref lect the characteristics of uneven distribution of internal contact forces in rock and soil.