三维块体接触检索算法改进研究

IMPROVEMENT OF CONTACT DETECTION ALGORITHM OF THREE-DIMENSIONAL BLOCKS

在三维非连续变形分析中,快速准确的块体接触检索算法是控制计算效率和分析结果正确性的关键因素之一。基于直接法和公共面法的思想,将接触类型归纳为点–面、边–边2种接触,并结合块体的外包围盒、块体切割面和接触继承对块体接触检索做进一步的改进。引入块体角点运动探针思想,对接触的正确性做进一步的识别,以确保块体的接触关系符合模型的力学运动要求,这弥补了以往接触算法中未考虑块体运动趋势的不足。该算法已在同济曙光三维块体分析软件中实现,算例结果表明,该算法具有良好的适应性、鲁棒性和可实现性,对于凸体和凹体均适用,能有效地解决现有方法存在的不足。

Contact retrieval algorithm is one of the key factors to guarantee the computational efficiency and accuracy in three-dimensional discontinuous deformation analysis(3D-DDA). Based on the idea of the direct method and the common plane(C-P) method, the algorithm searching the block contacts was improved by transforming all the contact types into two basic ones,the vertex-face contact and the edge-edge contact using the bounding box outside the block,the block cutting surface and the contact inheritance. The probe to the movement of block corners was firstly introduced to identify the correctness of the contact which overcome the weakness of the existing contact algorithms without considering the movement trend of blocks. The algorithm was implemented in a three-dimensional analysis block software TJSG. The results of the examples indicated that the algorithm exhibited good adaptability and robustness for both the convex and concave blocks.