Experimental investigation of header end-plate beam-to-column composite connections with single-corner gusset plates

• Published in: Journal of constructional steel research 2023-02, Vol.201, p.107722, Article 107722
• Main Authors: Zhang, Wenyuan, Zhao, Zengyang, Liu, Yazhi
• Format: Article
• Language: English
• Subjects: Concrete slab; Header end-plate connection; Reserve capacity; Single-corner gusset plate; Slab opening
• ISSN: 0143-974X; 1873-5983
• DOI: 10.1016/j.jcsr.2022.107722

Experiments on 6 full-scale header end-plate beam-to-column connections with concrete slabs and single-corner gusset plates of bracing members were conducted to study the contribution of concrete slabs and gusset plates to the hysteretic behavior of this type of connection. The main failure mode of the connections was the out-of-plane distortion instability of the steel beam caused by the bottom-up beam web crack near the connecting weld between the header end-plate and beam web. The experimental results showed that the connection had a certain energy dissipation capacity. Considering the concrete slab and the gusset plate, the connection behaved as a partially restrained connection and had flexural strength equivalent to 80% and 64% of the plastic moment of the beam under positive and negative moments, respectively. At a connection rotation of 0.02 rad, the connection still had a flexural capacity equivalent to 65% and 30% of the plastic moment of the beam under positive and negative moments, respectively, which provided a reserve capacity to resist seismic collapse of concentrically braced frame structures after brace failure. To make the gusset plate rotate out of the plane freely during brace buckling, some specimens were opened in the slab around the gusset plate. The existence of openings reduced the energy dissipation capacity and the flexural strength of the connection by 6% and 5%, respectively. The beam bottom flange comes into contact and extrudes with the column flange to regain stiffness and strength under negative loads in the later stage. •Experimentally investigated the header end-plate beam-to-column composite connections with gusset plates.•The connection behaved as a partially restrained connection when considering the concrete slab and gusset plate.•The connection still had flexural capacity at a rotation of 0.02 rad and provided reserve capacity for CBF structures.•The existence of slab openings reduced the energy dissipation capacity and the flexural strength of the connection.