A SIMPLIFIED SIMULATION METHOD FOR PROGRESSIVE COLLAPSE OF REINFORCED CONCRETE SLABS

Floor slabs are important components of frame structures which largely affect the structural progressive collapse performance. This paper presents a simplified numerical simulation method for reinforced concrete (RC) slabs. A RC slab is discretized along two directions transferring into a beam network. The meshes at each direction are simulated by fiber beam elements to consider the composite mechanical behavior of steel reinforcement and concrete. In this method, beam-slab joints at the edge area of slabs are simulated by fiber beam elements with T/L sections, by which the effects of slabs on the bending behavior and the damage mode of the beams under small deformation in progressive collapse are considered. On the other hand, fiber beam elements with rectangle sections are used to simulate the interior area of slabs, by which the tensile membrane action of slabs under large deformation can be considered. This method can not only avoid the high stiffness problem when using shell elements, but also greatly improve the efficiency of the calculation of the whole structure. Finally, existing tests on special-shaped columns (T/L cross sections), one-way slabs and two-way slabs are simulated, respectively. The results show that the simplified method can efficiently and accurately simulate the reinforced concrete slabs under large deformation, providing a powerful tool for the simulation of progressive collapse analysis of whole structures.