Extended Stiffened End-Plate Steel Joints with Octagonal Bolt Arrangement Under Column Loss Scenario

Extended stiffened end-plate bolted connections represent one of the most utilised steel connection types in seismic-prone regions, and several studies have been dedicated to the improvement of their performance. Recently, a new stiffened joint configuration, with a non-symmetric octagonal bolt arrangement, was proposed, highlighting its excellent performance in seismic scenarios. Therefore, two new design procedures according to both the European and North American codes were developed. Within this framework, the present work aims to investigate the performance of this innovative joint under column loss scenarios. A total of sixteen beam-to-column steel assemblies, defined by varying the beam depth and the design procedure, were numerically investigated using advanced FE models validated against experimental results. The numerical results show that the innovative joints exhibit a ductile behaviour, even better than traditional joints designed according to the current versions of EU and US codes. Indeed, the new bolt arrangement allows us to reduce the damage in the connection thanks to a better stress distribution among the bolts.