Numerical Modeling of Heat Transfer in Steel-concrete Composite Slabs

Abstract

This paper presents detailed and reduced-order numerical modeling of heat transfer in composite floor slabs with profiled steel decking for analysis and design of structures exposed to fire. The detailed modeling approach represents the concrete slab with solid elements and the steel decking with shell elements. The reduced-order modeling approach represents the thick and thin parts of a composite slab with alternating strips of layered shell elements. The detailed modeling approach was validated against experimental results available in the literature, and the reduced-order modeling approach was calibrated and verified against the detailed model results. A parametric study using the detailed modeling approach was conducted to investigate the influence of slab geometry on the temperature distribution within composite slabs. The results show that the rib height of the decking and the width at the top of the rib are key factors governing the temperature distribution in the rib. The paper also presents comparisons with Eurocode 4 calculations of fire resistance of composite slabs. The comparisons indicate that the Eurocode 4 overestimates the fire resistance compared to the numerical results by up to 12 %.