双层插值边界面法研究进展
ADVANCE ON DUAL INTERPOLATION BOUNDARY FACE METHOD
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摘要:CAD/CAE一体化以及CAE分析的自动化是CAE软件发展的必然趋势, 一直以来也是众多软件开发商以及算法研究人员不断追寻的目标. 尽管国际市场已经在该领域投入相当多的人力以及物力成本, 却未能在关键技术方面给出彻底的解决方案. 实现CAD/CAE一体化以及CAE分析自动化的关键在于完整实体分析与网格的全自动划分. 以往, 基于连续网格(结构化网格和非结构化网格)的数值算法, 要做到网格的全自动划分, 至少要求CAD模型“干净”, 这往往需要对CAD模型进行几何修复, 而几何修复又是一个甚至比网格划分更困难且更难以自动化的课题. 而双层插值边界面法以及非连续网格的出现, 使得CAD/CAE一体化以及CAE分析的自动化成为可能. 非连续网格能够有效地实现自动化的CAE分析; 双层插值边界面法为非连续网格的应用以及CAD/CAE一体化的实现提供了理论支持. 对于边界积分方程中的奇异以及近奇异积分, 提出了球面细分法来提升数值积分的准确性以及稳定性. 几何映射交叉近似算法和几何交叉近似算法, 能够有效地降低稠密矩阵的存储量近似远场矩阵, 满足大规模计算需要. 基于以上理论的“5aCAE仿真软件”能够直接在原CAD模型上, 采用非连续网格进行CAE分析, 无需进行几何模型的简化与修复等工作, 而现存的商业软件很难做到这一点. 文章全面综述了双层插值边界面法的发展历程, 系统地介绍了“5aCAE仿真软件”的技术亮点, 为解决我国在CAE领域的“卡脖子”问题提供了技术支持.Abstract:CAD/CAE integration and automatic CAE are the inevitable tendency for future development of CAE software and have been the target for a number of software developers and algorithm researchers. Although a considerable amount of manpower and material costs has been invested in this field, it has failed to provide real solutions to crucial issues. The key to CAD/CAE integration and automatic CAE analysis lies in the automatic mesh division and complete entity analysis. Previous algorithms based on continuous meshes (the structured and unstructured meshes) required at least a "clean" CAD model to achieve automatic mesh generation, often requiring geometric repair, which is even more difficult to automate than mesh generation. However, the appearance of the dual interpolation boundary face method and discontinuous mesh makes it possible for CAD/CAE integration and automatic CAE analysis. Discontinuous mesh can effectively promote automatic CAE analysis development, while the dual interpolation boundary face provides theoretical support for the application of discontinuous mesh and the realization of CAD/CAE integration. A spherical subdivision method is proposed to improve the accuracy and stability of singular and near-singular integrals in boundary integral equation (BIE). Geometric mapping cross approximation algorithm and geometric cross approximation algorithm can reduce the storage of the dense coefficient matrix effectively and approximate the far-field matrix for large-scale computation. "5aCAE simulation software" based on the above theories can directly carry out CAE analysis on the CAD model using discontinuous mesh without geometric simplifying and repairing, which is difficult for existing commercial software. This paper presents a comprehensive overview of the dual interpolation boundary surface method and introduces the highlights of "5aCAE simulation software", which can provide technical support for national CAE software development.