空间弹性体有限单元计算的面向对象方法研究

【作者】 李余江；

【导师】 殷际英；

【作者基本信息】 北方工业大学 ， 机械电子工程， 2004， 硕士

【摘要】 有限元方法是求解数理方程的一种数值计算方法。是解决工程实际问题的一种有力的数值计算工具。它在经典的力学理论基础上，以计算机为工具，通过有限元软件来具体实现其应用。有限元软件的应用领域非常广泛，为了满足它多方面的功能和性能的要求，必须采用一种合适的软件开发方法来研制大量的高质量的有限元软件。有限元自身的模块性特点又使得有限元软件非常适合采用面向对象的程序设计方法来开发。 与传统的有限元程序(通常采用Fortran)相比，面向对象有限元程序更加结构化、更易于编写、更易于维护与扩充、程序代码的可重用成分更大，它为开发大型有限元分析软件提供了一条新的途径。 本文在静态线性有限元系统中引入了面向对象的程序设计方法，介绍了面向对象方法的基本概念及特征，并通过有限元的面向对象分析和设计，确定了一套基本的有限元对象类及有限元的面向对象模型，本文设计的所有类均采用C++编程语言进行了实现，最终形成了一套FEM类库，它们以动态连接库的形式存在。C++语言作为C语言的扩展，既具有灵活高效的特点，又具有面向对象的特征，因而被广泛用于软件设计。动态连接库是适应Windows多任务应用程序的出现而产生的一种代码和数据共享技术。动态连接库加载后，多个应用程序可以共享它在内存中的一份拷贝，从而减小了可执行文件的大小并提高了代码的共享程度。 在设计面向对象有限元程序中运用了基于ANSI／ISO C++标准模板库(STL)的技术，以向量模板类的特化继承对象为变容量数据容器，实现了可按计算实例的离散结点数量动态存取数据的机制和数据容器的零容量启动，从而避免了运算时系统对静态内存空间的超量占用。更多还原

【Abstract】 The Finite element method (FEM) is a kind of numerical calculation method to resolve numerical equation. It’s also a power tool to resolve actual problem in engineering. Base on the classical mechanical theory, it uses the computer as a tool to realize its special application by FEM software. The field of the software’s application is very extensive. In order to satisfy its various requests on function and capability, a appropriate method must be adopt to develop a mass of high quality FEM software. The modularity character of the FEM makes it very appropriate to adopt the Object-Oriented programming method (OOPFEM) to develop FEM software.Compared with the traditional FEM (uasally in Fortran ).The OOPFEM is more structured,more easily to be written,more easily to be maintained ,expanded and more reausable,OOP gives a good approach for the development of large scale finite element analysis software system.This paper introduces the basic concepts of Object-Oriented programming to the finite element method for linear static analysis. In the view of OOAD(Object-Oriented Analysis and Design) method,a set of basic classes for the FEM system are founded and their relationship is discussed too. All these FEM classes are implemented in C++ language because the hybrid language C++ is an object-oriented extension of C.(This language includes all the feature of c and is well suited to solve numerical problems because of its efficiency.) They exist in the form of DLL(Dynamic Link Library).Some example are employed in the sixth chapter to show use the FEM class library.The 00 (Object-Oriented) technique of standard template library with ANSI/ISO C++ is used in designing the program ,and the dynamic access mechanism and the startup with zero content are realized by using the specialization and Inheritance object of vector template class as the data container which can change the content itself according to the number of discretization node data of a computing practicality. So,the fact that the use of the static EMS memory which is not necessary is avoided.The advantage of object-oriented programming method in the field of finite element method and the advantage of C++ language in programming are demonstrated in this paper.更多还原