A Finite Element Analysis of Slab Opening Effects on the Column Removal Scenarios in Large Buildings

Rigid diaphragms play an important role in structural integrity against progressive collapse scenarios. Several studies have been conducted to evaluate the effect of floor slab details on progressive collapse resistance. The main intention of this paper is to investigate the behavior of medium-raised steel buildings with various slab opening conditions in progressive collapse. Numerical studies were carried out by considering different locations and dimensions of the slab openings using the ABAQUS FE software. The highlight of this work is to utilize a nonlinear dynamic analysis to survey the diaphragm condition in load redistribution for column removal scenarios. The axial force variations of columns and diaphragm displacements are compared for different slab opening sizes and locations. The validity of the finite element method is examined using the moment rotation results of an experimental program conducted on a 3D frame covered by a reinforced concrete slab. Generally, the openings placed in the middle and the corner of the structure govern a different after-shock behavior on the structure. In contrast to the middle openings, the corner openings lead to negative effects on the load-resisting capacity of the structure. Moreover, the vulnerability of the columns placed in the vicinity of the corner openings is more than the column around the middle openings. The effect of the opening dimension depends on the opening location.