INTERACTIVE KNOWLEDGE-BASED ASSISTANCE. FOR CONCEPTUAL DESIGN OF BUILDING STRUCTURES
ETS, 1100 Notre-Dame Street West, Montreal, Canada, H3C 1K3
E-mail: hugues. rivard@etsmtl. ca
During conceptual structural design the engineer proposes initial structural solutions to early architectural designs. At this stage, the decisions made by the engineer are based mostly on knowledge about structural behaviours and experience on the applicability of available construction technologies and materials to different design situations. This research proposes a knowledge-based computer approach to assist the engineer in proposing feasible structural solutions to the architect interactively. With this approach a structural solution is developed by the engineer from an overall description to a specific one through the progressive use of knowledge. A first prototype has been implemented and is being enhanced with a knowledge-base for design exploration. Therefore, an example of envisioned computer support is used to illustrate the capabilities of the proposed approach.
Conceptual design is explorative in nature. During conceptual structural design, the engineer devises and compares feasible structural solutions to transfer loads to the ground safely and efficiently within a building architectural context (i. e. structural synthesis). The decisions made by the engineer are based mostly on knowledge about structural behaviours and experience on the applicability of available construction technologies and materials to different design situations. Due to the limited availability of resources, knowledge and experience minimize the need for time consuming analysis for decision making at this stage. However, the trade-off between knowledge and analysis depends on the building complexity (i. e. the more complex the building, the more analysis may be required to verify and evaluate proposed conceptual structural solutions).
Nowadays, advanced computer modeling tools are available to support structural system generation, analysis, and the integration to the architecture (Khemlani K, 2005). This kind of support is model – based since it relies on the geometric and data modeling capabilities of a building information model (BIM) that combines the building architecture with other disciplines. It has been demonstrated in practice (Solibri Inc., 2005) that explicit knowledge can be used in conjunction with BIM models in the form of requirements. These requirements constrain the model and maintain its consistency when changes take place. This type of knowledge support could be called passive since it validates or confirms design decisions that have already been made. However, these tools lack the knowledge required to assist the engineer to explore design alternatives and make decisions actively.
This paper proposes a knowledge-based approach that aims at providing interactive support for decision-making to help the engineer in the exploration of design alternatives and efficient generation of structural solutions. With this approach a structural solution is developed by the engineer from an abstract description to a specific one, through the progressive application of knowledge. Thus, knowledge is used by the engineer to refine conceptual structural design descriptions interactively. The approach is applicable to most typical buildings, such as office, apartment and institutional buildings of standard shape. “Sculptural” buildings such as the Guggenheim Museum in Bilbao, Spain are thus excluded. The paper is organized as follows: the next section summarizes relevant research in assisting structural design exploration. Then, the proposed approach for interactive knowledge-based
M. Pandey et al. (eds), Advances in Engineering Structures, Mechanics & Construction, 571-582.
© 2006 Springer. Printed in the Netherlands.
support is presented, followed by the components used for its implementation. Next an example illustrates the advantages of the approach. An example of envisioned computer support is used to illustrate the capabilities of the proposed approach because a working prototype for knowledge-based support is currently being implemented.