Experimental and analytical studies on a novel double-stage coupling damper

Abstract

A series of experimental and numerical studies on the novel double-stage coupling damper (DSCD) are presented in this paper. The effects of the damper configuration, friction-yield ratio (Rfy), and loading protocol on the hysteresis performance of the DSCD are investigated via quasi-static tests on seven specimens, and the variation in the failure mode, compression-strength adjustment factor, energy dissipation capacity, and equivalent viscous damping ratio of the DSCD is discussed. The test results demonstrate that the arrangement of ribs in the DSCD increased the average energy dissipation per loading cycle, compared to the device without these elements. The damper exhibits double-stage energy dissipation characteristics for several friction-yield ratios, however, relatively low values of this parameter (Rfy = 0.5) leads to reduced energy dissipation capacity, due to significant variations in the friction force associated with creep, ploughing, and preload effect. Furthermore, a detailed finite element model of the DSCD is conducted based on the experimental data, focusing on exploring the effectiveness of the device. Numerical analysis revealed that the cumulative energy dissipation and peak force of the DSCD reduced with increasing the length of the friction mechanism (Lf). A large clearance between the yield segment and the restraining system (Cb) reduces the stability of the equivalent viscous damping ratio of the damper under compression, but Cb has no effect in the cumulation energy dissipation of the damper, which has important implications in the design of these devices for the seismic control of structures. Based on these results design recommendations for the DSCD are provided.