【作者】 李博；

【导师】 谢德馨； 白保东；

【作者基本信息】 沈阳工业大学 ， 电机与电器， 2002， 硕士

【摘要】 随着电磁场有限元法被广泛地应用于各种电磁设备的电磁分析和优化设计之中，用户对电磁场有限元分析提出越来越高的要求。而数据前处理部分已成为电磁场有限元分析发展的瓶颈问题，所以研制快速高质的有限元前处理系统已成为计算电磁学的一个重要研究课题。 本文首先在有限元前处理系统的软件开发设计上，选择了当今软件的主流开发设计方法——面向对象技术，运用这一技术设计出了前处理系统的基本对象类，以对象类为核心编制了相应的软件。在软件开发平台的选择上，采用了Microsoft公司的面向对象的软件开发平台Visual C++，该平台具有完整的面向对象技术软件开发功能，并提供了丰富的基础类库。应用该开发工具成功地编制了有限元前处理软件。 然后，本文把电磁场有限元前处理部分与绘图软件组合起来，集成开发，使有限元模型的几何信息、物理信息和边界条件直接传递给有限元前处理部分。所开发的二维小型绘图软件在绘图功能上比较完善，能完成从直线到圆弧的基本图形的绘制，也能完成各种曲线的绘制，可生成复杂的几何图形；在人机交互上采用了鼠标绘图和数据输入绘图的完整功能；在图形功能操作上，实现了图形的拾取、选择平移、旋转、镜像、复制、拷贝、删除等诸多选项，方便用户快速建立有限元几何模型。 接着采用波前推进法(AFM)自动生成三角形网格，并进行算法改进、网格优化和网格检查。针对多连域剖分问题，本文对以前通过引入切分辅助线的方法来解决多连域剖分问题进行了分析，指出了其不足之处，通过研究波前推进法的算法上的特点，提出了一种新的解决单、多连域转化的问题方法。通过定义动态波前和静态波前，在生成节点和单元时判断是否引入静态波前到动态波前中；当需要引入时，在生成新单元的同时，静态波前与动态波前被合并为新的动态波前，从而使多连域问题化为单连域问题。 最后，本文在电磁场前处理软件系统中采用了最新的工程数据库技术和其面向对象的数据建模方法，使得有限元前处理系统的数据流便于管理硕士学位论文组织。 本文的研究工作证明:所编制的电磁场有限元前处理软件可以快速高质地生成有限元网格。更多还原

【Abstract】 With electromagnetic field FEM extensively applied to the electromagnetic analysis and optimized design of all kinds of electromagnetic devices, users are putting forward higher requirement for electromagnetic field FEM analysis. It is known that the FEM pre-processing is bottleneck for the development of FEM analysis, so that the efficient high-qualified electromagnetic field FEM pre-processing has become an important research topic.Firstly, in the development design of FEM pre-processing system, the paper has designed the foundation class of pre-processing system and developed relevant object-class-centered software with popular method. The software development platform is Microsoft VISUAL C++, which has integral object-oriented software development function and provides rich foundation class library. Therefore FEM pre-processing software is successfully programmed with such development tools.Secondly the part of electromagnetic field FEM pre-processing is combined with plotting software in this paper. Such integration development makes it easy to transfer FEM information such as geometric information, physical information, and boundary conditions into FEM pre-processing part. The finished 2D small-sized plotting software has good plotting function, which could plot not only basic pictures of line and arc, but also all kinds of curves. Both mouse and keyboard are used for interface development. In picture function manipulation, there are many options such as moving, rotating, mirroring, copying, deleting and etc., which are convenient for users to build FEM geometric model.Advanced front method is used to automatically create triangle mesh. At the same time, this paper finishes such works as improving the arithmetic, optimizing and checking meshes. Aiming at multiply connected regionsproblems, the paper analyses the previous method of inducting aided line of syncopation and points out its shortcoming, then proposes a new method of transformation between multiply connected regions and single connected regions by study of AFM arithmetic characteristic. The concepts of static advanced front and dynamic advanced front are defined. When nodes and elements are created, it should be judged whether static advanced front is included into dynamic advanced front. If the inclusion is needed, when new elements are created, static advanced front and dynamic advanced front are integrated into new dynamic advanced front, thus the problem of multiply connected regions can be turned into the problem of single connected regions.Finally, the paper applies the latest engineering database technology and relevant object-oriented data modeling method to the electromagnetic field FEM pre-processing system, which makes data stream of pre-processing easily organized.The results of numerical experiments prove that the finished FEM pre-processing software can successfully create high-qualified meshes with a satisfactory speed.更多还原