Seismic performance assessment of steel strip dampers equipped in high-rise steel frame

Abstract

This paper aims to utilize a novel steel strip damper to enhance seismic resilience of high-rise steel frame in high seismic intensity regions. The developed damper is composed of external casing, internal casing and steel strip fuses dissipating seismic energy via bending-dominated deformation throughout the entire section, which is convenient for post-earthquake replacement. A series of cyclic loading tests have shown the damper's good energy dissipation capacity with features of stable and full hysteretic loops. A numerical model for the damper is proposed and validated by the experimental results. Then a 20-story steel frame is adopted as the representative building and retrofitted using a design procedure based on the stiffness and displacement demands. Nonlinear dynamic analysis considering damper failure is performed to evaluate seismic responses of the steel frames. And incremental dynamic analysis is employed to discuss the seismic fragility. Finally, seismic losses of the steel frames are assessed through the story-based loss estimation method in which the demolition-related economic losses are included. The analyses indicate that the presented damper can obviously mitigate the roof displacement, inter-story drift, plastic damage and soft story deformation mechanism; the damper-fused frame has much lower probability to collapse; the expected total losses, expected annual losses and expected life-cycle losses are significantly decreased by retrofitting with the novel dampers.