Experimental validation and numerical simulation of a dual-self-centering variable friction braced frame under strong ground motions

Abstract

The dual self-centering variable friction brace (DSC-VFB) is a novel resilient system with a loading stiffness higher than the unloading stiffness and an enhanced energy dissipation capability. This study presents experimental and numerical analyses of a 1/3-scaled dual-self-centering variable friction braced frame (DVBF). The pinned beam–column, column–base connections in the DVBF ensured that the DSC-VFBs were a standalone lateral seismic resisting system. Three ground motions scaled to six shaking intensities were conducted to evaluate the seismic responses of the DVBF. The ground motions were subjected to far- and near-field earthquakes. Owing to the high seismic resistance of the DVBF, the stiffness degradation could be omitted after several strong earthquakes. The frame returned to its initial position with nearly zero residual drift, although the maximum drift exceeded 2.5%. The grooved friction plates and self-centering system, which could be disassembled and replaced conveniently, had no observable damage after the tests. A 3D simulation model was developed based on practical constructions. The nonlinear analysis results were compared with the experimental results. The two exhibited good agreement. The results showed that the DVBF under near-field pulse earthquakes resulted in larger displacement and acceleration responses than those under far-field and near-field no-pulse earthquakes. The present study verified the effective working mechanism and good resilience of the DSC-VFB and DVBF even under strong seismic shaking intensities.