Experimental and numerical studies on the cyclic behavior of a new metallic-friction hybrid damper

This paper develops a novel metallic-friction hybrid damper (MFHD) for seismic protection of buildings considering multiple seismic levels, which is composed of a metal component (MC) and a friction component (FC) in series. The configuration and working mechanism of the MFHD was detailed. The MC yields under small earthquake and the initial stiffness, yield strength and yield displacement can be obtained through theoretical analysis. Then under strong earthquake, the FC is activated and converts seismic energy into thermal energy to dissipate energy and protect the MC from severe damage. To evaluate the cyclic behavior of the hybrid damper, the hysteretic performance, energy dissipation capacity and deformation behavior were investigated by performing cyclic loading tests. Subsequently, a reliable 3D numerical model was built for deeply understanding the hysteresis response and analyzing the influence of critical parameters on the mechanical characteristics of the MFHD. The results demonstrated that the hysteretic curve of the MFHD specimens depended on the strength of the MC and the friction force of the FC. The specimens exhibited stable phased energy dissipation, enabling control over multiple seismic levels. The good correlation between experimental responses, theoretical formulas, and numerical simulations validated the adequacy of the finite element modelling strategy and the accuracy of the theoretical analysis.