A friction-strip hybrid damper with multi-phase energy dissipation mechanism: Cyclic test and numerical verification

Abstract

By combining the frictional and plastic energy dissipation modules (FEDM and PEDM), a novel multi-phase friction-strip hybrid damper (MFSHD) is proposed in the current study. The theoretical analyses demonstrate that, when applied in a self-centering structure, the MFSHD is able to provide higher strength, secondary stiffness and energy dissipation and maintain the self-centering capacity compared with conventional friction dampers. A series of quasi-static tests was conducted on the MFSHD to evaluate the effects of different parameters on the hysteresis performance of the MFSHD. The results showed that increasing the strip number or the bolt pre-tension force could both improve the mechanical performance of the MFSHD. The MFSHD with sandglass-shaped strips had a better performance than that with I-shaped strips. In the MFSHD with lower slipping displacement, the PEDM was activated earlier and provided higher strength, stiffness and energy dissipation, whereas its low-cycle fatigue life was reduced. The numerical analyses based on the model validated by the test results showed that the self-centering braced frame substructure equipped with the MFSHD exhibited hysteresis behavior in consistency with the theoretical model. The superior performance of the MFSHD compared with conventional friction dampers was verified numerically.