Investigation of failure modes and load-deflection of cold-formed steel connections using sub-assemblage frame tests

Cold-formed steel (CFS) is a type of steel manufactured at ambient temperature using bending and rolling methods, enabling enhanced precision in shape and sizing. Its adaptability, resilience, and environmental sustainability render it very beneficial for building. Furthermore, its manufacturing method is more energy-efficient than conventional steel production and decreases emissions. Nonetheless, CFS has several limitations, including vulnerability to buckling owing to its slender profile. This research especially examines beam-column constructions with cold-formed steel connections. The paper discusses an experiment utilizing the sub-assemblage frame test method to improve the connection’s resistance by emphasizing haunched gusset plates, rectangular gusset plates, and a combination of rectangular gusset plates with the top-seat angle. The results demonstrated that the lateral-torsional buckling occurred on the beam. The connection’s bolt hole exhibited a bearing failure, and the flange cleat also experienced buckling. Graphs were employed to examine the load and deflection data, with maximum load and deflection values documented for each specimen. The result shows that the type of gusset plate, the height of the beam, and the utilization of flange cleats have an impact on the performance of the connection.