A novel inerter-enhanced self-centering damper (ISCD) for improving seismic resilience of self-centering RC building frames

The residual inter-story drift can be reduced or even eliminated owing to the success of the various self-centering devices. Nevertheless, the structural acceleration response of the self-centering frames can be amplified due to their unique flag-shaped hysteretic behavior, which may cause severe damage of acceleration-sensitive nonstructural components. Hence, this paper proposes a novel inerter-enhanced self-centering damper (ISCD) that friction spring-based self-centering device and the inerter are arranged in parallel, to overcome the above shortcoming by providing balanced control on the drift and acceleration responses. The conceptual design and ideal mechanical model of the proposed ISCD are elaborated. Then, a 6-story reinforced concrete frame building is designed and equipped with the devices (e.g., the friction spring-based self-centering damper, the inerter, and the proposed ISCD). Nonlinear dynamic analysis and incremental dynamic analysis are conducted to evaluate the effectiveness and advantages of the proposed ISCD. Finally, seismic resilience assessment is conducted to assess the influence of the ISCD on the post-earthquake functionality. The results indicate that the ISCD demonstrates a satisfactory capacity for reducing acceleration response, while maintaining desirable performance on the maximum inter-story drift and residual inter-story drift responses. Furthermore, the ISCDs provide an optimal balance between structural safety and nonstructural protection by reducing up to 20.46 % of seismic loss and up to 19.46 % of recovery time.