Structural optimization of multiple attributes

This paper presents a methodology for structural design optimization of multiple objectives, or attributes. The method represents an improvement over Pareto optimizationbased methods by quantitatively representing trade-offs between conflicting objectives in a single multi-attribute objective function. Classical utility analysis is first used to determine a multi-attribute evaluation function for a particular structure from the designer's viewpoint. This viewpoint takes into account the attribute tradeoffs that are appropriate for a specific project. Since attributes are controlled only indirectly through specification of design decision variables, a new objective function is then formulated which expresses design utility directly in terms of those parameters over which the designer has direct control. A one-bay, three storey steel frame building example demonstrates the methodology for determining the design configuration with the best combination of cost and drift index.