Application of intelligent CAD paradigms to preliminary structural design

Structural design is the synthesis of structural systems and components in such a way that the system behaves as intended by the designer and meets the constraints imposed by physical laws and project requirements. The reasoning inherent in the design process is to be carried out on different levels and with different degrees of abstraction, uncertainty and impact on further design decisions. The nature of design operations ranges from schematic decisions based on heuristic considerations concerning system types and topology to parameter definitions concerning member material and geometry inferred from numerical computations. In our approach we explicitly distinguish between strategy and related expectations, design actions on a tactical level and local design modifications due to untypical conditions. Artificial intelligence techniques are applied such as planning methods, heuristic search and constraint programming which are used in a distinct manner on the different levels. The approach is discussed by examples taken from a prototype implementation for preliminary structural design. (C) 1997 Elsevier Science Limited.