中文摘要：

为实现由边界的二维CAD模型（二维CAD软件设计图）建立边界的二维离散元法分析模型，提出一种基于图元的二维边界离散元法仿真算法。该算法采用Bresenham方法设置边界图元信息以进行邻居搜索，采用几何和数值方法进行颗粒与边界图元的接触检测、接触点求解和接触叠合量的计算．实例验证证明了该算法的正确性和有效性，为实现由机械部件的CAD模型进行机械部件工作过程的离散元法仿真分析奠定了基础。

英文摘要：

A two-dimensional boundary DEM simulation algorithm based on graphic element was put forward, in order to realize two-dimensional Discrete Element Method （DEM） analyzing model built by boundary two-dimensional CAD model （CAD software plan）. This algorithm adopts Bresenham arithmetic to set boundary graphic element information so as to process proximity query, utilizes geometrical and numerical method to process the calculation of contact-detection, contact-points solution and contact-overlaps between particles and boundaries. Test results prove the correctness and validity of the algorithm, the algorithm provides a foundation for DEM simulation analyzing of machine parts working process by machine parts CAD model.