Analysis, Design & Performance
Full Session with Abstracts
342793-1 - Modeling of components and sub-systems of composite floors under combined structural and fire loads
Saturday, April 21
10:00 AM - 11:30 AM
Computational modeling of composite floor systems subjected to structurally significant fires is challenging, since these systems exhibit complex nonlinear response histories driven by temperature-dependent degradation in the materials combined with potentially large forces induced by thermal gradients and restraint of thermal expansion. Such response mechanisms may ultimately result in runaway plastic deformations, local buckling of beam sections at the connections, or even global buckling of framing members and potential destabilization of the floor system. Accurately evaluating the global response of composite floor systems under combined structural and fire loads requires thermal and structural analysis that accounts for the temperature-dependent behaviors of the individual system components as well as the interactions between these components. This paper describes a reduced-order modeling approach for composite floor systems that uses the same model for both thermal and structural analysis and considers the temperature-dependent behavior of the following components and sub-systems: (i) materials, including structural steel, structural bolts, steel decking, concrete and spray-applied fire resistive materials, (ii) beam-to-column connections, (iii) shear stud connectors, and (iv) composite slabs including steel decking and concrete topping. The paper also discusses the assembly of these components into a single model for thermal and structural analysis of a composite floor system under various fire scenarios.
The topic of this presentation is of current national and international interest. The target audience for this presentation includes (i) researchers interested in performance-based fire design, engineered fire protection, steel connection behavior, and structural robustness, and (ii) design professionals interested in the design of composite floor systems for fire loads, beyond the currently specified prescriptive requirements. This presentation will provide the audience with an improved understanding of the key issues influencing the performance of composite floor systems subjected to fires and demonstrate methods for analyzing these systems to characterize their system-level response, capacity, and failure modes.