CAD Technology Based On Knowledge And Application In Aeronautic Tube Design

Based on the research of the fusion of product design knowledge and CADpackage, a knowledge-based CAD package, orienting trade and typical product, isdeveloped to realize the reuse of design knowledge. It is the foundation forcorporations to shorten the development period of product and improve thecapability for technology innovation. According to the geometry-associativity of design knowledge, the knowledgemanagement of product designs is divided into management of the geometry-relativeknowledge and management of the geometry-irrelative knowledge. The managementof geometry-relative knowledge includes: geometrical model can be driven byknowledge, through building engineering rules and relating them to productgeometrical model; product not only can be designed by parameter, but also can bedesigned by structure through the transfer of different User-Defined Features;different kinds of knowledge can be reused through connecting with data library andExcel sheets. The management of the geometry-irrelative knowledge adopts theconception of product information model, and all kinds of geometry-irrelativeknowledge are supplied to meet the demand for knowledge in every phase ofproduct design. On the basis of above way, a knowledge-based design package for aeronautictube is developed on the UG platform. Through the engineering rules compiled byUG/KF language, the parameters of aeronautic tube can be driven by knowledge,and the flange can be design by structure. At the same time, the information for titleblock will be filled in automatically through the management of geometry-irrelativeknowledge. This package has been applied and used well in the Cheng FeiCorporation.