Influence of Composite Slab on the Nonlinear Response of Extended End-Plate Beam-to-Column Joints

Extended stiffened end-plate connections are widely used in seismic area due to their good performance in terms of both resistance and ductility. The most of existing studies focused on the all-steel behavior of these joints, disregarding the composite action of the concrete slab that is generally disconnected. However, the presence of the concrete slab can have beneficial effects on the structural stiffness for both gravity and lateral loads. Hence, most of the building frames are usually designed considering steel-concrete composite solution. However, the slab can strongly influence the hierarchy between beam and column and the ductility of the joint. In this paper the influence of composite deck on the response of extended stiffened end-plate joins has been investigated by means of finite element analyses (FEAs). In particular, the following details have been investigated: (i) all steel joints without slab; (ii) steel joint with disconnected slab; (iii) composite joint.