Seismic Response of Composite Eccentrically Braced Frames with Short Dissipative Element

Abstract

Eccentrically braced frames (EBF) in steel and composite solution are very well suited structural assemblies for buildings in areas with high seismicity. Due to their good energy dissipation capacity, they can undergo important lateral deformations by plastic hinge formation in the dissipative element (link element) without impacting the structural integrity of the system. The dissipative link elements can be short, medium or long (according to modern design norms, such as Eurocode 8), based on the ratio between shear force and bending moment. If the dissipative element length is smaller than 1.6(Mpl/Vpl) [mm], it is considered to be a short element and is predominantly subjected to shear. The links can be realized on steel solutions or composite with the concrete slab. However, the steel behavior is assumed for composite link. The current article presents the results of extensive numerical testing based on experimental results on the behavior of composite EBF with short link elements subjected to seismic-like lateral loads. The results will present the main differences in strength, stiffness and ductility between the responses of steel and composite EBFs. Finally, a parametrical study will show the influence of link length, influence of number of stiffeners and of the web slenderness.