Recent knowledge-based expert systems for structural engineering design have focused on design-independent knowledge (abstract reasoning rules for designing), and while great strides have been made in that area, there is still a significant need to develop systems to take advantage of the wealth of knowledge contained in every substantial structural design. On the other hand, previous database-oriented design efforts have focused primarily on knowledge-poor databases of solutions, in which the traditional engineering handbook of solutions has simply been replaced by digital data. The challenge is to find a way to capture and apply the kind of case-based, design-dependent knowledge that structural engineers have traditionally used. The long-term results will be better structural designs and better structural designers. This paper discusses the character of the design-dependent knowledge in a structural engineering context, describes two initial applications of case-based reasoning to component design, and presents a general paradigm for a knowledge-based design system integrating rule-based and case-based reasoning.

In wind-resistant design of structures, the calculation of wind coefficients is usually based on data from wind tunnel tests. The process is very time-consuming and expensive. In order to predict wind coefficients of rectangular buildings, polynomial and nonlinear regression were studied. Also, artificial neural networks (ANNs) were used as well to train, simulate and forecast wind coefficients using terrain, side ratio (D/B) and aspect ratio (H/B) as inputs. The neural networks used include BP (Back Propagation), RBF (Radial Basis Function) and GR (General Regression) neural networks. According to the investigation presented in this paper, RBF neural network is the most effective mean to predict wind coefficients.

Human designers often adopt strategies from previous similar cases to guide their search in new design tasks. We have developed an approach for automated design strategy capture and reuse. That approach has been implemented in DDIS, a prototype structural design system that uses a blackboard framework to integrate case-based and domain-based reasoning. Plans, goals, and critical constraints from user-selected previous cases are combined with case-independent reasoning to solve underconstrained parametric structural design problems. This article presents a detailed example of design strategy recording and reuse in base plate design for electrical transmission poles.

Abstract. This paper reports the development of a web-based wind environment simulation and pedestrian wind assessment system using computational fluid dynamics (CFD). Graphical user interfaces were built using Internet browsers to link to the server side CFD programs, which hides the complexity of CFD programs and makes the tool accessible to engineers at the early architectural design stage for quick evaluation of wind field around buildings. The paper describes the system function and architecture, case testing and comparison, and possible future improvement and expansion.

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