The Extension Map And Multi-state Model-based Engineering Cad Modeling Techniques

AEC (Architecture, Engineering and Construction) is one of the important domains of Computer Aided Design. It is a challenge to traditional CAD technologies and methodologies, as well as its great value. Not like mechanical design, AEC CAD modeling involves the layout of tremendous number of components under complex constraints, so the new modeling technique that according to AEC designs must be applied.Background of this paper is process plant design system (PDS), which covers almost all AEC design fields. The paper focus on the thorough research of AEC CAD modeling technique, including: Modeling of piping network. By analyzing model of piping design, which is the leading field of plant design, a new approach to describe the topological structure of components in piping model is presented. The parametric description of component and the method of definition component then are introduced. It is also thoroughly discussed that, when a component is inserted, how to maintain integral topological relationships. Above discussions involve the whole progress from the definition of component to the generation of model data. During this progress, descriptions of all kinds of components are uniform. By using templates based on smart line, the modeling module can be both efficient and flexible, while the application of design templates can improve both design efficiency and quality sufficiently. Implementation of PDSOFT Piping software, including the implementation of modeling system, the design, interpretation and management of smart line based templates, the design of engineering database and the...