Mechanical performance of pre-engineered closed section beam-column connections in CFS frames: Experimental investigation

The mechanical performance of connector types is essential for promoting the application of pre-engineered lightweight cold-formed steel structures with closed sections. In this paper, two types of pre-engineered fabricated beam-column connections with popular connectors were innovatively proposed, and full-scale static experiments were implemented. The mechanical performance and the component parameter variations of the pre-engineered fabricated connections were systematically investigated and quantificationally compared. It's worth noting from experimental results that the ultimate capacity and initial stiffness of the proposed beam-column connections with the core-pulling rivets increased by 79.3% and 34.3%, respectively compared to those of self-tapping screws. The ultimate moment and initial stiffness of connections with self-tapping screws can be promoted with the diameter dimension increase of self-tapping screws. The ultimate moment and initial stiffness of the connection with lateral angle steels decreased by 29.9% and 40.6%, respectively than those with beam supports up and down. The proper connection types and connectors can be comprehensively determined based on the mechanical performance and engineering construction requests.