【作者】 金建海；

【导师】 冷文浩；

【作者基本信息】 江南大学 ， 轻工信息技术与工程， 2012， 博士

【摘要】 CAE软件已成为众多工程领域不可或缺的计算工具,CAE技术在现代工业技术发展和高新技术创新等方面具有重要的地位和作用,良好的CAE前后处理支持是CAE技术走向工程应用的前提和基础。本文以研发具有自主知识产权的船舶CAE前后处理系统为目标,系统地研究了CAE前后处理系统的设计与实现、关键算法、在船舶领域内的应用。具体内容如下:(1)绪论部分,从CAE前后处理的基本概念和相关背景入手,简述了本文工作的研究背景、研究目的和研究内容。(2)在CAE前处理方面,首先介绍了CAE前处理软件的设计与实现。按照软件工程的要求,从软件需求、设计和实现几个方面阐述了CAE前处理软件的整个实现过程,重点介绍了CAE前处理软件的总体架构和软件工程模块化设计,以及关键模块的设计方案,包括模型定义、网格划分、材料定义、属性定义、LBC(载荷和边界条件)定义等,并将最终实现的CAE前处理软件,与国际领先的软件MSC.Patran、Femap前处理部分进行比较,说明本软件在功能方面已经满足船舶结构CAE分析的前处理要求,且在某些方面超过Femap等国外知名软件。然后分别介绍了CAE前处理软件中的两大重难点:CAD/CAE模型转换与有限元网格自动生成。在CAD/CAE模型转换方面,本文自定义了一套采用离散边界法表示的模型数据结构,通过多种不同的CAD/CAE接口实现模型数据转换功能:通过统一数据接口实现了主流通用CAD文件如IGES, STEP等模型数据的读取和转换;通过研究、解析STL文件和Tribon的XML文件,实现了STL模型和船舶专用CAD模型数据的转换;通过拓扑重建解决了目前CAD/CAE模型数据转换过程中普遍存在的拓扑信息丢失问题。在有限元网格自动生成方面,本文结合自定义模型数据的特点,尤其是船舶模型的特点,采用了波前推进法(AFT)进行改进,实现了组合复杂离散曲面的有限元面网格自动生成算法,并给出几个典型算例予以验证。(3)在CAE后处理方面,首先给出了CAE后处理软件的总体实现思路。考虑到CAE软件繁多,本文自定义了一套船舶领域内CAE后处理标准文件格式,开发相应转换接口,实现了不同CAE计算结果文件到标准格式文件的转换,并完成结果数据的常用后处理功能。然后阐述了CAE后处理软件实现过程中的关键算法:大规模模型的快速显示、云图显示、任意截面及其结果云图显示等。其中在普通PC机器上即可实现千万级别节点自由度模型的快速显示也是本文的创新点之一,其显示速度远远超过目前国际上通用的MSC.Patran和Femap等前后处理软件。(4)在应用方面,基于前文的研究成果,通过模块选择与改进,完成了多个CAE软性集成软件等。最后对所做工作与主要研究成果进行了简要总结,并提出了进一步的研究方向。更多还原

【Abstract】 CAE software has become an indispensable computational tool in many engineering fields. CAE technology plays an important role in the development of modern industrial technology and high-tech innovation. Good support of pre and post processing is the premise and foundation of CAE technology heading to engineering application.To develop the pre and post processing software system for ship CAE with independent intellectual property rights, the system design and implementation of the software are systematically studied in the thesis. The key algorithm of the main functions, as well as the application in ship field, is further discussed. The detail is as follows:(1)The concept and background of CAE pre-post processing is introduced first to explain the research background, objectives and research content of this thesis.(2)As for the CAE pre-processing, the design and implementation of pre-process of CAE software are first introduced. According to the demand of software engineering, the software requirements, design and implementation are introduced to explain how the entire pre-process of CAE software are fulfiled. The main modules include the geometric modeling, mesh, material definition, property definition, LBC (loads and boundary conditions) definition and so on. By comparison to the MSC.Patran, Femap, in terms of functionality, the software has already met requirements of the pre-process of CAE analysis in ship FEA area, and in some ways is better than them.Then the two key and difficult points in pre process part are introduced, i.e. CAD/CAE model data transforming and automatic mesh generation.Concerning CAD/CAE model data transforming, a set of self-defined model data structure using discrete boundary representation is designed, based which the model data is transformed from CAD to CAE by different interfaces. By the unified data interface, model data is read and transformed from a variety of mainstream and standard CAD model files such as IGES, STEP and so on. By Studing and parsing the STL file and Tribon XML file format, the STL model file and ship CAD model data conversion is realized. Topology reconstruction is used to solve the topology information loss problem in the CAD/CAE model data conversion process.Concerning mesh generation, according to the model data structure, the Advancing Front Technique (AFT) is improved to generate finite element mesh from complex discrete surface like ship model automaticly, which is validated by some typical examples given at last, and the CAD/CAE model data transforming function is also test implicitly.(3)As for the CAE post-processing, likewise, the overall realization ideas of the CAE post-processing software is discussed first. In consideration of the large variety of CAE software, a standard file format of post-processing application data is defined, especially for ship field. The model and result data are converted from all kinds of CAE result files to it to realize basic post functions.Then the implementation of the key features in the CAE post-processing software are described, using a series of custom algorithms or improving existing algorithms to achieve fast display of large-scale model, contour display, arbitrary cross section and its contour display. One of the innovations of this thesis is the rapid display of large-scale model, which realizes quick display of degree freedom model of the 10 million level nodes on the ordinary PC machine, far more pre-post processing software in the world like Patran, Femap, etc.(4)As for the application, based on the research results above, a number of CAE software products are developed through the module selection and improvement, including the pre-process of Jifex for Dalian University of Technology, ship cabin noise prediction software and three-dimensional hydroelastic integrated software.Finally, the main contributions in this work are summarized and further research considerations are proposed.更多还原