Systemic Design And Study On Post-Processing System Of FASTAMP

The field of numerical simulation for sheet metal forming nowadays is more active and more attractive because of its enormous importance to the economies of the industrialized countries. With the development of finite element technique , numerical simulation has gradually been the powerful tool for process analysis and optimal design. In recent years, the developments of computer hardware and computer graphics, as well as the theory of finite element, have made it possible that finite element simulation plays a very important role in the process of sheet metal forming.This research is supported by NSF and named as:"The Independent Research of High-speed Simulation and Optimal Process Design aiming at the Formability of Automobile Panel"(NO.50575080).Based on the software of FASTAMP, which is developed on finite element algorithm by State Key Laboratory of Plastic Forming Simulation and Die & Mould Technology of HUST, the ideology of software engineering was applied in the post-processing subsystem developing, including customer's demand analysis, outline design and detail design. And since the framework of post-processing subsystem is based on the method of Object-Oriented, the subsystem presents good features for reuse and expansion.First, the software developing process, methods and tools are discussed in this thesis. The whole task is impenetrated by the developing process based on object-oriented method. It also uses the architecture methods, such as the design patterns and UML(Unified Modeling Language), to create software model. Especially, the application of design patterns are presented in detail, and, the examples, such as Abstract Factory, Mediator, Singleton and etc., show how design patterns help to construct the framework of the subsystem.Secondly, the key technologies in the post-processing subsystem of finite element simulation of sheet metal forming are discussed and some new algorithms are proposed.In order to prevent the coupling of the high-level clients to low-level classes, the thesis studied how to encapsulate graphic operations into low-level classes, and how the high-level clients access the low-level classes through interface. This breaks the dependence of the clients on methods that they don't invoke, and it allows the clients to be independent of each other. Moreover, this facilitates the later combination of graphic platforms of post and pre processing subsystems.The application of multithread in post-processing subsystem is also discussed. The technology of multithread programming will not only make UI(User Interface) more sensitive, but make CPU more efficient. Therefore, the application of the technology is significant to post-processing subsystem for its high demand of interaction.In the post-processing subsystem, an algorithm to display physical quantity on a section based on mesh topology was proposed. It could accurately obtain the intersect line between the specified section and the mesh. Moreover, the algorithm can be applied for both the adaptive refined mesh and common mesh. The implementation of the algorithm in the post-processing system FASTAMP shows that it is more precise and more rapid. The thesis also studied the technologies about graphics in the graphic platform of the post-processing subsystem, including transition among several coordinate systems, the display of Chinese font, animation and output of file in the formation of avi.It proves that the software engineering ideas and technologies proposed in this thesis can guide software developing, help to establish refined and practical models and make it easy to implement and maintain. And the application in practice showed that the subsystem is stable, and can meet the need of engineering.