Selection of the Optimal Cross-Sectional Shape of Profiled Steel Decking for Steel–Concrete Composite Floor Systems

Abstract

Steel–concrete composite floor systems incorporating profiled steel decking and cast-in-place concrete slabs are widely used in modern building construction due to their structural efficiency, reduced material consumption, and accelerated construction schedules. However, the geometric optimization of profiled decking remains insuffi-ciently investigated, particularly with regard to the influence of flange width ratios on flexural stiffness and load-bearing capacity at different stages of structural perfor-mance.This study investigates the optimal cross-sectional configuration of profiled steel decking by analyzing the relationship between the widths of the upper and lower flanges, decking height, and wave length. Analytical expressions for the centroid lo-cation and moment of inertia are derived, and optimization criteria are formulated for both the installation stage (prior to concrete hardening) and the service stage (compo-site action). The results demonstrate that maximum flexural stiffness during installa-tion is achieved when the top and bottom flange widths are equal, resulting in a sym-metric cross-section. In contrast, during the operational stage, the optimal flange width ratio depends strongly on the magnitude of the live load. Practical recommen-dations are provided for the orientation and design of asymmetric profiled decking under varying load conditions.