The Effect of Out of Plane Perpendicular Beams on the Ductility Demand of Steel Moment Framed Structures during Progressive Collapse

Unexpected loading, induced by severe earthquake or blast, could cause local damage to a structure. In this case, the structure has the potential of progressive collapse phenomenon. Hence, further consideration is required to mitigate the consequences of such loading. This study is aimed to evaluate the progressive collapse capacity of steel moment frames with different heights under column removal conditions. Seven and twelve story buildings modeled in different conditions in order to view effects of various parameters like the out of plane frames, column removal location, and the height of buildings in the results. One of the middle column and/or the corner columns is removed in order to evaluate the effect of column removal location in response of structures. The General Services Administration and the Department of Defense guidelines are considered for defining load combination for the analysis of the collapse. Nonlinear dynamic analysis is conducted in order to obtain the ductility demand of structures when the out of plane effect is considered. The structures have welded cover plate connections, designed for high-seismic zone area. For evaluating the response of the structures, for each connection at the point of column removal, maximum vertical displacement is measured. For Finite Element analysis, a sub-assemblage of structures is modeled using ABAQUS software and the ability of beams deformation and its out of plane effect is measured.