Numerical investigations of composite slab-beam floor systems exposed to ISO fire
Nguyen, Tuan Trung
Tan, Kang Hai
Date of Issue2011
International Conference Applications of Structural Fire Engineering (2011 : Prague, Czech)
School of Civil and Environmental Engineering
Due to Basingstoke and Broadgate fire incidents, composite slabs consisting of steel beams and lightly reinforced concrete slabs with steel decking showed remarkable resilience by mobilizing tensile membrane action (TMA) at large displacements. The conditions necessary for the mobilisation of TMA are two-way bending of the slab and vertical support along all four edges. Over past 20 years, a number of research works on TMA of composite slabs in fire have been conducted. Almost all the previous studies utilise the assumption of continuous vertical restraint at all times during a fire. However, at elevated temperatures the edge beams will deform, and will experience large deflections. Therefore, further research studies are necessary to consider the effects of slab-beam interactions on the development of TMA in slabs. Parameters such as perimeter beam deflections, effect of stiffness and strength of fire-protected boundary beams as well as different slab configurations will be studied. This paper presents finite element (FE) investigations on the behaviour of composite slab-beam systems under fire conditions. A simplified FE model is developed using ABAQUS because of its capabilities for static loading, thermal analysis, and a robust concrete material model. The model is first validated against published test data. A parametric study is then undertaken using this validated model. The investigated parameters are: stiffness of perimeter beams and aspect ratios of slab panels.
© 2011 International Conference Applications of Structural Fire Engineering.