Numerical Studies on the Flexural Behavior of Steel-Timber Composite Floor Systems

Steel-timber composite floor systems pose an advantageous alternative to traditional systems for steel frame structures due to their improved environmental benefits, ease of construction, and decreased unit weight. However, there lacks guidance as to what levels of composite action can be achieved within the system based on the type and spacing of fasteners used to connect the timber deck to the steel element. A higher degree of composite action between the timber and steel increases the beam strength and stiffness, which is expected to result in an optimized and economical structural design. To highlight the impact of composite action on the flexural behavior of steel-timber composite floor members, a numerical parametric study is conducted in this study. The numerical model is a section fiber model that accounts for partial composite action to predict the flexural behavior. The model used to conduct the parametric study was validated against an experimental database compiled from available literature on steel-timber composite beam tests, with comparisons focusing on sectional stress and strain, interfacial slip, end rotation, and mid-span deflection. Finally, the section model was used to conduct a numerical parametric study investigating the influence of critical design parameters on the flexural performance of steel-timber composite systems. The experimental database was also used for evaluating the applicability of existing strength and stiffness design equations for similar composite systems.