Experimental study on self-centering steel connections based on phased energy dissipation mechanism

Traditional steel beam-column connections and column bases often experience yield or buckling, which makes repair difficult. The recent development of resilient seismic structures has addressed this issue. Resilient seismic structures can achieve self-centering functionality through prestressed steel strands and dissipate energy through energy dissipation elements, while protecting the main components such as beams and columns from damage. This paper presents an experimental study on connections that combine friction and plastic deformation of T-stub to achieve energy dissipation. Four specimens were designed by varying the cross-sectional form of the T-stub flanges and the material of the friction plates. Quasi-static tests were conducted under low-cycle reversed loading to observe the test phenomena. The test results including moment-rotation response, deformation, stiffness, energy dissipation capacity, force of high strength strands and strain were analyzed to investigate the seismic performance of the connections. It was found that weakening the cross-section of the T-stub enabled uniform yielding and energy dissipation. Reducing the friction force between the friction plates and the T-stub web enhanced the self-centering capability while decreased the energy dissipation capacity. Overall, the connections exhibited good seismic performance.