Cost Optimization of Steel-concrete Composite Floor Systems with Castellated Steel Beams

Performance of cost optimization program of composite steel deck-slabs (DS) and supporting castellated beams (CB) consisting of interior beams, edge beams and girders is proposed in this paper. The program applies the vibrating particle system (VPS) meta-heuristic algorithm, which imitates the free vibration of ideal one-story frame structures with viscous damping. The program is also furnished with an advanced cost function, which takes into account both material and fabrication costs of all parts of the floor system. The effect of four major cost reduction procedures and additional cost-saving techniques are studied on the cost function. Considering various DS profiles, altering the dimensions of hexagonal openings, different number of floor divisions and choosing costlier DSs except the optimal deck are the major cost reduction procedures. Inclusion of partial composite action for CBs, infilling certain openings of CBs and applying camber are the supplementary economizing techniques. To realize the economy of LRFD method, a meticulous design theory of composite CBs in adherence with LRFD principles of AISC 360-16 specifications is applied to the formulation of the strength constraints. Due to excessive deflections and due emphasis on vibration control of CBs, we implement accurate design procedures for the formulation of the serviceability constraints. Performance and superiority of the proposed optimization program is validated by studying three distinct real-size design examples taken from the literatures.