Development and experimental study of a novel rotational metallic damper

Abstract

As passive control technology advances and building forms become increasingly diversified, traditional axial and shear dampers may no longer meet diverse structural application requirements. This paper introduces a novel rotational metallic damper, i.e. rotational steel rod damper (RSRD), as an alternative engineering solution. The RSRD comprises three steel plates rotating around a central pin and four low yield point steel rods as energy dissipators. The input seismic energy can be dissipated in the form of plastic rotation of the RSRD. Initially, the structural form, working mechanism, and design approach of the RSRD are presented. Subsequent cyclic quasi-static tests on two RSRD specimens under varied loading protocols demonstrated satisfactory energy dissipation capacity, with an equivalent viscous damping ratio exceeding 0.47. The cyclic behavior, rotational strength, and cumulative plastic deformation capacity are discussed following the tests. A finite element (FE) analysis on the RSRD using ABAQUS is conducted to further investigate its performance. A comparison between the hysteretic behavior and failure mode of tested and simulated results is presented to validate the FE model. Additionally, two new structural forms, with linear and arc-shaped weakening on the steel rod, are simulated and compared with the original. FE results indicate that the arc-shaped weakening of the steel rod effectively avoids plastic strain concentration, showcasing superior low-cycle-fatigue performance. Finally, nonlinear time history analyses on two RC frames, with and without RSRD, reveal that structural and non-structural damage can be controlled under the maximum considered earthquake (MCE) by utilizing RSRDs.