Fabrication of laser cut I-beam-to-CHS-column steel joints with minimized welding

The available connection methods of I-beam-to-CHS-columns are complex and costly. They commonly need local stiffeners and gusset plates to allow an efficient load transfer between the beam and the column, resulting in excessive welding quantities, since directly welding the beams to the column surface increases the vulnerability of the joint to the local distortions. These problems prevent the widespread use of CHS profiles as columns in the construction sector, although they have excellent structural and architectural properties. Researchers worldwide have been investigating the possibilities to simplify the fabrication and increase the structural performance of such joints. This article proposes “LASTEICON” solution to achieve this objective: joints with “passing through” beams, obtained by using laser cutting technology (LCT). Thanks to LCT, welding quantity and fabrication time of such tubular connections can be reduced significantly, obtaining better precision with higher quality in the joint assembly, and improving the workplace safety with less manual work and more computer-programmed automation. For the development of this new joint type, the first step was to investigate the fabrication details including the tolerances required for the slots, laser cutting parameters, and welding aspects. This paper presents the whole fabrication process applied to the joints assembled with different column and beam sizes and welding types, quantifying the time and resources spent during the process. Furthermore, a detailed description of laser cutting procedure has been provided, to show its potential in the steel construction sector.