Author(s)

I. Merta, S. Kravanja & U. Klanšek

Abstract

This paper presents the optimization based cost comparison between reinforced concrete and doubly-symmetrical welded steel I beams. The task of the research was to define the spans at which each of two different considered structures would show its advantages. The optimization/comparison was performed for simply supported beams for spans between 5 and 30 meters and for a uniformly distributed variable imposed load of 5 kN/m. The structural optimization was performed by the nonlinear programming (NLP) approach. The cost objective function was defined for the optimization and subjected to structural analysis constraints. The structures were designed in accordance with Eurocodes for both the ultimate and serviceability limit states. Beside the optimal self-manufacturing costs, the results also include the optimal masses for the different considered structures. Keywords: structural optimization, non-linear programming, reinforced concrete beams, steel beams. 1 Introduction The paper presents the optimization based cost comparison between reinforced concrete (RC) and doubly-symmetrical welded steel I beams. In order to determine the spans at which the individual structure shows its advantages, the cost comparison was carried out on the basis of the obtained optimal selfmanufacturing costs. The structural optimization was performed by the nonlinear programming (NLP) approach.

Keywords

structural optimization, non-linear programming, reinforced concrete beams, steel beams.