Experimental assessment of the ductility of extended end plate connections

An experimental investigation of eight statically loaded extended end plate moment connections was undertaken at the Delft University of Technology to provide insight into the behaviour of this joint type up to collapse. The specimens were designed to confine failure to the end plate and/or bolts without development of the full plastic moment capacity of the beam. The parameters investigated were the end plate thickness and steel grade. The results show that an increase in end plate thickness results in an increase in the connection flexural strength and stiffness and a decrease in rotation capacity. Similar conclusions are drawn for the effect of the end plate steel grade, though no major variations in the initial stiffness are observed. The failure modes involved weld failure in two test specimens, nut stripping in four tests and bolt fracture in the remaining, always after significant yielding of the end plate and bolt bending. Comparisons of the joint ductility and the corresponding equivalent T-stub for the end plate side are drawn.