Performance of bolted angle connections in progressive collapse of steel frames

Abstract

This paper is mainly focused on the behaviour of bolted top-seat angle connections with double web angles, categorized as partially restrained connections, in progressive collapse of semi-rigid steel frames due to sudden column loss. The main characteristics of this type of loading are declared and the effect of the imposed boundary conditions on the motivated elements is depicted. To study the performance of frame connections under these conditions, refined nonlinear finite element modelling technique is used. The models are created based on the previous experimental studies and their accuracy is examined through a comparison to the results of these tests. New models are created under conditions of the progressive collapse and the behaviour of the connections is studied. The study showed that due to the applied boundary conditions, the connections behave stiffer and show a higher moment capacity. Based on the results of the numerical models, equations are presented to estimate the moment-rotation response of the studied connections under progressive collapse conditions based on the beam and connection mechanical and geometrical properties and the connection rotation. Copyright © 2009 John Wiley & Sons, Ltd. Copyright © 2009 John Wiley & Sons, Ltd.