Laser-cut I-beam-to-CHS column moment-resisting steel joints

Abstract

Although open-to-circular hollow section (CHS) connections are highly encouraged in the current structural steelwork industry thanks to the extensive range of advantages provided by the CHS columns, a complicated and expensive fabrication procedure has limited their application in practice. The additional gusset plates or stiffeners needed to strengthen a conventional open-to-CHS connection lead to excessive welding quantities and localized CHS distortion, thus causing an economic as well as structural disadvantage. However, if designed efficiently, the CHS connections can offer an extensive range of solutions for modern multi-storey structures. To that end, different types of nominally pinned and moment-resisting "passing-through" open-to-CHS connections have been developed using laser cutting technology (LCT) and proposed by the European research project LASTEICON. This current article concentrates on the LASTEICON two-way moment-resisting connections. The non-linear behaviour of the connections is discussed by way of an appropriate understanding of the force transfer mechanism. Furthermore, these innovative connections are compared with directly welded conventional open-to-CHS connections in order to highlight the advantages offered by the "passing-through" approach.