Optimal Design Based on Approximate Scaling

A new optimal design procedure, intended to reduce the number of exact analyses during the solution process, is proposed. High quality explicit approximations of the structural behaviour and a scaling procedure are combined to achieve this goal. Explicit behavior models are introduced for a set of lines (directios of move) in the design space. Some algorithms for selecting these lines are presented. For each checked design along a given line the structural behavior is evaluated. The design is then scaled. This procedure, which involves small computational effort, is repeated the various step sizes until the best constrained design is obtained. A new direction of move is selected and a modified approximate model is introduced. Each selected direction requires only a single exact analysis of the structure. The result is an efficient path to the optimum with a relatively small number of exact analyses. Simple examples illustrate the solution process, the quality and the efficiency of the explicit behavior model, and the potential of the proposed procedure.