基于块体离散元法的多面体接触重叠算法

The polyhedron overlap algorithm based on the blocky discrete element method

近年来随着非连续介质力学方法的发展,离散元法成为了颗粒材料的物理力学特性研究的重要工具。而对于任意形状复杂块体,精确的接触检测算法一直是离散元法的难题之一。本文基于几何对偶理论,在耦合模拟器CoSim(Coupling Simulator)的块体离散元框架下开发了多面体接触重叠算法。该算法融合了GJK(Gilbert-Johnson-Keerthi)和快速凸包等算法,能够准确计算重叠多面体,进而从接触重叠体中提取接触点、法线方向、接触面积和嵌入深度等接触特性。通过颗粒碰撞测试和砌体结构破坏试验,验证了该算法的准确性和适用性,能够解决多面体的接触问题。

In recent years,with the development of the discontinuous media modelling,a discrete element method has been an important tool to investigate the mechanical response of granular materials.For arbitrarily shaped blocks,accurate contact detection has been one of critical issues.In this study,based on the geometric dualization theory,the polyhedron contact overlap volume algorithm has been developed in the framework of block DEM under Coupling Simulator(CoSim).This algorithm combines Gilbert-Johnson-Keerthi(GJK)and Quickhull algorithms to calculate the contact overlap volume and the contact characteristics such as normal direction,contact area,and penetration depth which can be extracted from the contact overlap volume.Simulations including particle collision and failure of a masonry structure are conducted to verify the algorithm.