Seismic behavior and life-cycle cost effectiveness of steel moment resisting frame structures with self-centering friction-viscous dampers

The self-centering friction-viscous damper (SCFVD) is a novel self-centering system that utilizes preloaded ring springs to offer self-centering and friction-based energy dissipation capacity, while a viscous damper provides viscous-based energy dissipation capacity. This study is to study the seismic behavior of steel moment-resisting frames (MRFs) with SCFVDs, considering cost effectiveness. The mechanical model of the SCFVD is first presented and validated through pseudo-static tests on a full-scale specimen. Simulation models of 3-story, 9-story, and 20-story steel MRFs with SCFVDs and viscous dampers are then built, and numerical analysis under 40 earthquake records is conducted on them to compare and evaluate the structural peak dynamic response and energy dissipation from an economic perspective. The results show that the SCFVD's hysteretic response can be reliably predicted by the mechanical model. When compared to the uncontrolled steel-MRFs and the steel-MRFs with FVDs, the SCFVD can significantly mitigate structural peak and residual drift, especially under high-intensity earthquakes, but may aggravate structural peak acceleration. Besides, the SCFVD can mitigate the structural hysteretic energy dissipation and damage to the 3-story and 9-story steel MRFs. The cost/average reduction ratio of peak drift for the steel-MRFs with SCFVDs is reduced by 6.3% when compared to that for the steel-MRFs with FVDs.