3-D finite element modeling of extended single plate shear connections: Predicting the mode of failure

Twisting and lateral-torsional stability of extended shear-plate connections could be a design issue due to the relatively long distance between the weld and the bolt centroid of the shear tab, and the eccentricity between the thickness of the connection plate and web of the supported beam. The 13^th edition of the Steel Construction Manual did not include checks for determining whether or not twisting would have to be considered as a controlling design limit state. However, the current edition (i.e., the 14^th edition) provides a methodology for evaluating the need for stiffeners (also called stabilizer plates) that based on the amount of twisting of the connection plate. This paper presents the results of three-dimensional non-linear finite element analyses of a number of extended single plate connections in which the floor slab, which braces the top flange of the supported member, was incorporated. The primary goal of the reported research was to examine the need for stabilizer plates, and to investigate twist in extended shear tabs.