Self-centering friction spring dampers for seismic resilience

摘要

This paper presents a comprehensive study on self-centering dampers equipped with friction springs. The basic mechanical behavior of individual friction springs is first understood via analytical descriptions that are verified by a preliminary experimental study. The working principle, fabrication process, and mechanical performance of the proposed dampers are subsequently described, where the design details related to seismic applications are highlighted. This is followed by physical tests on three damper specimens, where the influence of the treatment of the taper surfaces of the friction springs on the overall damper behavior is examined, and the reliability of the dampers under repeated rounds of cyclic loading is evaluated. The damper specimens show reliable flag-shaped load-deformation hysteretic curves with excellent self-centering capability. Satisfactory energy dissipation with an equivalent viscous damping (EVD) of up to 20% is shown, and the EVD is stabilized throughout the entire loading process. The dampers are capable of withstanding multiple rounds of cyclic loading with stable hysteretic behavior, indicating that they are fully reusable after multiple strong earthquakes. A larger friction coefficient on the taper surfaces leads to increased yield load and energy dissipation. Following the experimental study, some practical design recommendations are provided. Based on the available analytical model, an additional parametric study is performed to highlight the influences of precompression and friction condition of the friction springs on the damper behavior. Finally, the seismic performance of a building which adopts the friction spring dampers is evaluated via numerical simulation.