We present a version of the Discrete Element Method considering the particles as rigid polyhedra. The Principle of Virtual Work is employed as basis for a multibody dynamics model. Each particle surface is split into sub-regions, which are tracked for contact with other sub-regions of neighboring particles. Contact interactions are modeled pointwise, considering vertex-face, edge-edge, vertex-edge and vertex-vertex interactions. General polyhedra with triangular faces are considered as particles, permitting multiple pointwise interactions which are automatically detected along the model evolution. We propose a combined interface law composed of a penalty and a barrier approach, to fulfill the contact constraints. Numerical examples demonstrate that the model can handle normal and frictional contact effects in a robust manner. These include simulations of convex and non-convex particles, showing the potential of applicability to materials with complex shaped particles such as sand and railway ballast.

我们提出了一个版本的离散元方法，将粒子视为刚性多面体。虚拟工作原理被用作多体动力学模型的基础。每个粒子表面被分成子区域，这些子区域被跟踪以与相邻粒子的其他子区域接触。接触相互作用是逐点建模的，考虑到顶点-面、边-边、顶点-边和顶点-顶点相互作用。具有三角形面的一般多面体被视为粒子，允许在模型演化过程中自动检测到多个逐点相互作用。我们提出了一种由惩罚和障碍方法组成的组合界面法则，以实现接触约束。数值例子表明该模型可以以稳健的方式处理法向和摩擦接触效应。