MRFs with Laser-Cut I-Beam-to-CHS-Column Joints: Seismic Performance and Repairability Potential

Traditionally, connecting steel I-beams to tubular cross section columns for seismic resistance involves extensive welding and additional plates, making it expensive and visually unappealing. The LASTEICON project addressed this by developing innovative beam-to-column connections using laser-cutting technology. The laser-cutting technology creates precise slots in circular hollow section columns, allowing short I-beams or plates to be inserted and welded for direct bending moment transfer. This not only improves joint continuity, stiffness and strength, but also simplifies on-site construction through prefabricated cross-joint assemblies and bolted simple, partial or full-strength connections. Building on this alternative approach to connecting I-beams to tubular columns, the ongoing LASTTS project is investigating the behavior of individual components under both monotonic and cyclic loading. The aim of the research project is to provide a strong foundation for further exploration of the potential of the laser-cutting technology in the construction sector, including for seismic-resistant structures. Prior to conducting experimental tests, a 3D multi-story building with perimeter MRFs (i.e., frames with two moment bays and one bay with replaceable dissipative fuses) was investigated to assess its seismic response and potential for repair after a Significant Damage seismic event. Nonlinear static and dynamic analyses were employed for the current study.