面向复杂结构真实焊缝应力分析的T样条边界元等几何方法研究

In the application of traditional CAE method for analysis of welded structure, the welded structure is approximated by elements, and the real weld geometry can not be accurately depicted. Its mesh generation needs to interact repeatedly with the CAD system, this process is time-consuming and laborious.The utilization of traditional CAE method results in that the welding stress analysis is difficult to be performed and the numerical result is incredible. However, the welding stress evaluation is still an important scientific problem in engineering, which needs to be solved in the engineering field. Therefore, this project is planned to study the method of curved and surface modeling for complex structures, and study the approximation method for boundary physical field based on T-mesh of initial control points, and study the method for adaptive and fast solution of BIE for multi-domain problem, in the T-spline isogeometric BEM. Through this study, we plan to implement accurate geometric modeling of welding, and the BIE solution of linear elasticity problem for complex structure,and the solution of singular and nearly singular integral on T-mesh. Based on UG open interface, the isogeometric framework will be built that integrates CAD and CAE tightly, and will be used to solve linear elasticity problem in which the geometry for analysis is whole and exact. In the framework, subdivision of the initial T-mesh and its iteration has no need interacting with CAD again, and the geometry for analysis is complete and accurate. Finally, the accurate stress analysis of the whole welding for complex structure will be realized, and an analysis technology will be put forward in which the mechanics performance evaluation for real weld of complex structure will be realized. It has important guiding significance on science and engineering for the design and optimization of complex welded structures and other structure parts of large equipment.

传统CAE方法分析焊接结构时采用单元近似几何，无法刻画真实焊缝几何，且网格生成需反复与CAD系统交互，过程费时费力，导致焊缝应力计算困难且结果不可信，而焊缝应力评估一直是工程界需解决的重要科学问题。为此，本项目拟通过研究T样条边界元等几何法中T样条复杂结构曲面建模方法、基于初始控制点T网格的边界物理场插值方法及多域下边界积分方程快速自适应求解方法，以解决真实焊缝精确几何建模、T网格下奇异与近奇异积分求解以及复杂结构线弹性边界积分方程求解等问题。基于UG二次开发平台，搭建用于处理完整精确几何线弹性问题的CAD/CAE高度集成等几何框架，使初始T网格细分迭代无需与CAD再次交互，且分析的几何实体是完整精确的，最终实现复杂结构真实焊缝的精确应力分析，提出一种实现复杂结构真实焊缝力学性能评估的分析技术，对复杂焊接结构及其它大型装备结构件的设计与优化将具有重要的科学与工程指导意义。