Research On Design Method Of Mechanical Products Based Virtual Prototyping And Its Application

Facing dynamically changeful and global market competition, manufacturing enterprises have to change their product design and fabrication modes. With the developments of web and information technology which giving support to the realizing virtual design, it is possible for the realization of virtual design which having the character of rapid response, function integration and distributing cooperation. Virtual design combines the computer technology with virtual reality, entity modeling technology and workflow management technology, and provides digital design environment of product design process development and management based on virtual prototyping. The objections of researching on virtual design method are coping with changing markets and competition, increasing enterprises product development efficiency and global competition ability by developing mechanical product virtual design software system fitting for the needs of small and medium manufacturing enterprises.Analyzing the current developing trend of the virtual design, based on our work of developing blower CAD system, the key technologies in building the system of virtual design of product development are discussed. The structure of the virtual design system of mechanical product development is dissertated, and conceptual model of virtual design, the product virtual prototyping information modeling method and the methods of mechanical product virtual design process management and application based on virtual prototyping. The major characteristics of this thesis in terms of both theory and practice are as follows:(1) Virtual prototyping is the kernel of the virtual design of mechanical products. After probing into the conception of virtual prototyping, its characteristics, its compositions and structure and its gradual process of generation, the structure of this cooperative design system based on the virtual prototyping is discussed. At the same time, the structures and contents of every subsystem including the information model generation subsystem of virtual prototype, the process model generation subsystem of virtual design, the subsystem of virtual design of mechanical product and subsystem of virtual assemblage of mechanical product are analyzing.(2) The definition and characteristics of the conceptual design of virtual prototyping are expounded, the generating process of information model of virtual design prototyping is explored, the characteristic definition of the conceptual design model based on the virtualprototyping and its modeling method are discussed emphatically, and the assessment system of conceptual design schemes is constructed. Based on this, the building of the information model of virtual design prototyping and the methods of utilizing the object programming language C++ to symbolize the object models of product information are elaborated.(3) In order to meet the requirements of the computer's digital expression in the process of virtual design, the two basic problems of digital expressions of both product and its design process are combined by establishing a proper model for design process. Based on the study on workflow technology, two different kinds of flowing including horizontal workflow and vertical workflow are defined, which then display the arrangements of the workflow, and thus make clear the relationship between workflows and make easier the reuse of them. Simultaneously, the executive model of workflow in accordance with rules so as to prop the variations in the executive process is defined.(4) Based on the basic design principles and the designing methods of its key parts, the blower CAD system structure based on virtual prototyping is established. The blower parts design virtual prototyping building process is discussed. The building process of vane type, the axle virtual prototyping design method based on features and the feature expressions facing the object form are discussed.(5) Since virtual assembly design is a part of the virtual prototype design, based on the principle and method of the virtual assembly...