The Structural Dynamic Program Development Of Finite Element Method Based On Object Oriented Program

The FEM (Finite Element Method) is a widely used numerical tool in engineering. Coupled with the development of computer hardware and software has been the development of FEM programs. As the programs become bigger and bigger, the defects of traditional program languages, that they have low reusability and maintainability, are exposed. The OOP(Object-Oriented Programming) that appears in 80s can solve the problem well. How to apply the encapsulation, inheritance and the polymorphism of the OOP to the FEM programs, and what benefits it can bring are both the projects of this paper.OOP has been applied to the field of FEM programming. However it can hardly been seen in the area of structure dynamic analysis. The structure dynamical analysis is the important aspect of the applying fields of FEM. It not only consists of the regular analyzing procedures but also has its special characteristics. This paper discussed the complexity of the program developing of the FEM structural dynamical analysis" and pointed out the inherent contradictions of the traditional program language. This paper recalled the developing history of the programming theory and pointed out the advantages of the OOP. It discusses how to applying the concept of OOP in developing the programs of structural dynamics analysis when designing the three modules: -preprocessor, postprocessor and calculator. On concerning with the problems of the preprocessing and the post processing, it briefly introduces the theories of the computer graphics and discusses how to apply the interactive graphic technology in developing the FEM analysis programs. On concern with the computing, it classifies the computing tasks of FEM analysis programs with the concepts of OOP and points out the hierarchy of the tasks. It also presents the ideas of constructing the structural analyzing storehouse.The interactive technology of graphics is widely applied to the preprocessing and the post processing modules of the modern FEM software.This paper discussed the interactive graphic method of FEM model construction and developed the corresponding programs: the preprocessing program of Dragon and the post processing program of Postdeal.The precise integration method that appears in recent years has been greatly developed in the research area of structural dynamic analysis. Professor Zhang Senwen from Jinan University created a new direct integration method which makes use of the precise integration method. This paper discussed the principles of the classical direct integration methods and Zhang's method and provided the corresponding programs. And then it contrasts the new method with the old ones. Finally it discussed the new method's applying technology.After applying OOP to the FEM programs of structural dynamical analysis, and contrasting the new direct integration method with the traditional direct integration method, it can be concluded that:(l) Under the guide of OOP, the FEM program developing becomes more reusable and easier. (2) The interactive graphic method of FEM model construction makes the construction easier and more credible; (3) The new direct integration method is very precise but its computing cost is too high.