Author(s)

S. Kravanja & U. Klanšek

Abstract

The paper presents the cost optimization of composite floors. The composite structure consists of a reinforced concrete slab and welded steel Pratt trusses built up of hot rolled channel sections. The structural optimization is performed by the nonlinear programming (NLP) approach taking into account design constraints defined according to Eurocodes. A detailed objective function of the manufacturing material, power and labour costs is subjected to structural analysis constraints. In this way, the obtained optimal structural design satisfied the conditions of both the ultimate and the serviceability limit states. An example of the optimization of the composite truss floor system is presented at the end of the paper in order to show the applicability of the proposed approach. Keywords: structural optimization, non-linear programming, composite structures, costs. 1 Introduction The economy of construction is commonly handled in engineering practice by the time-consuming structural analysis of various design alternatives. In the conceptual design stage, the costs related with a change in the structural design are low. The possibilities of such a change to decrease (or increase) the costs in the construction stage are numerous. Since the significant cost savings may be obtained on account of effective conceptual design, the importance of accurate structural cost optimization cannot be overemphasized. Over the last three decades, researches and engineers have mainly considered the cost optimization of composite structures from the viewpoint of the development and application of different optimization techniques [1–4]. Majority of the performed research works include simplified cost objective functions with fixed cost parameters.

Keywords

structural optimization, non-linear programming, composite structures, costs.