基于可见性和后修圆的三维块体域接触算法

在离散元等三维非连续介质数值分析方法中，快速高效的接触检索算法是控制计算效率的关键性因素之一。在直接接触检索算法的基础上引入域分解、外接球判断、可视化检测以及后修圆方法，提出一种新的三维凸多面体接触检索算法。首先阐述该算法的基本原理，分析邻近块体的识别方法以及接触类型和接触方向的确定方法，而后以承受冲击作用的双柱碰撞过程为例表明该接触检索方法计算工作量小，鲁棒性好，易于计算机实现。

3D BLOCK FIELD CONTACT DETECTION ALGORITHM BASED ON VISIBILITY AND POST-ROUND

Fast and efficient contact detection algorithm is one of the most important key techniques to control computational efficiency in 3D discontinuous analysis such as the distinct element method.Based on direct contact detection method,field-decomposition,circumscribed-sphere detection,visibility and post-round are induced to develop a new contact detection algorithm for 3D convex polyhedron:Herein,the fundamental principle of the contact detection algorithm is described;and the methods to identify the neighboring block and to define the contact types and contact direction are analyzed.The algorithm is then applied to analyze the colliding process of a pair of columns subjected to impact loading.The result demonstrates that the contact detection algorithm is less cost,robust and apt to be realized.