OPTIMIZATION FOR LARGE-SCALE STEEL STRUCTURES WITH DISCRETE SECTIONS

Abstract

An optimization method has been developed to find the minimum weight design of steel building structures which consist of discrete sections that are commercially available. In this study, emphasis is placed particularly on the practical applicability of optimization algorithm in engineering practice. The structure is optimized through element optimization under the element level constraints first, and if there is any violation of structural level constraints, it is adequately compensated by the constraint error correction vector obtained from the sensitivity analysis. A scaling procedure is introduced for the problems of large violated displacement constraints. The oscillation control in the objective function is also discussed. Dividing the available WF sections into two groups based on their sectional characteristics, improved relationships between section variables are obtained and used efficiently in the search for the optimum section in the section table. Numerical examples are included to demonstrate the usefulness of the proposed algorithm.