Research And Programming Development Of Visual Algorithm For Post-processing Of 3D Finite Element Method

By taking advantage of vividly describing multifarious computing data field through the basic figures or color images and easy to operate the interactive techniques, the classical Visualization in Scientific Computing (ViSC) has been always a powerful tools in finding and analyzing various objects & phenomena emerging during the numerical computational process. Even nowadays, in any research fields applying the Finite Element Method (FEM), such as civil engineering, mechanical engineering, shipbuilding and space engineering, visualization technique plays a more and more important role and has universal application prospects, particularly for the irreplaceable functions in interactive modeling (Pre-processing) and evidently showing the data distributions by images (Post-processing).Adopting the new parent-element drawing algorithms, the contents of this thesis focus on the programming development of visualization techniques in the FEM Post-processing. Accordingly, core components of the new algorithms and their program implementations have been discussed in detail, which can basically satisfy all the various arithmetic requirements of Computing Visualization. Based on systematically comparisons with the traditional triangle visualization drawing method, theory and application practices evidently indicate that the new proposed visual algorithms have high computational efficiencies and greatly improve the visual precision, especially for the high-order interpolation data fields.On the basis of interpolation mechanism of isoparametric parent element, by changing the traditional techniques of only substituting various FE fields with simple triangle linear interpolation field, the new visualization processing is induced to be primely accord with the intrinsic characteristics of finite elements, and the purpose of achieving the same precisions between visualization and numerical calculation procedures is naturally realized. Therefore, it can be also concluded that, as long as the reasonable data interpolation forms exist in a field, the parent-element visual algorithm would be an efficient visual means to describe the corresponding distributions, which brings a good way for the researchers to quickly and actually hold the impersonal distribution characteristics, and may provides a strict numerical analyses basis for the subsequent engineering designs.And then, by means of the tool Visual C++ 6.0, using the normal computer program development mo-del, and adopting object-oriented programming (OOP) language, the contents of this thesis discus:; and analysis most aspects of the related program development, varying from the total ideas of soitware design to the detail subroutine codes. Thus, the corresponding developed computer program has better programming activity, good run activity and maintainability, as well as easy to expand its functions. Accordingly the contents studied in this dissertation may be summarized as the following three main parts.(1) The bcisic implementation procedure of FEM and the main filiations of FE models are summarized, providing the different interpolation forms of Various FE models. In addition, some related knowledge about the software engineering, mixedly programming and the OOP are alsopresented. This part constructs the theoretical foundation of the new visualization algorithm and its program development.(2) Within the framework of computer graphics, according to some application examples, the whole procedures of projective transformations from the 3D solid to the 2D screen display are completely discussed in this part. Especially, many detail algorithms for the main image geometry transformation operations, such as translation, zoom and rotation transform, as well as some related programming keys, are explained. This part mainly describes the basic drawing techniques to implement the final visualization algorithm.(3) The 2D parent-element drawing algorithms are systematically summarized and developed in this part, and its main idea is certainly extended to deal with most parts...