Seismic performance of novel SC-FEDB and its application in RC frames

To enhance the energy dissipation capacity of traditional self-centering braces, a novel friction self-centering brace (SC-FEDB) with response amplification mechanism has been proposed. This paper delineates the fundamental structure and operational principles of the brace, while deriving both the theoretical restoring force model and amplification calculation formulas for deformation and load responses. Furthermore, low-cycle repeated loading tests were conducted to investigate its bearing capacity, residual deformation, energy dissipation, and stiffness variations at each stage; these experimental results were subsequently compared with the theoretical restoring force model. A simplified model of the SC-FEDB was developed using Abaqus software, followed by dynamic time history analysis of a RC frame structure incorporating the SC-FEDB to assess its seismic control efficacy. The findings indicate that the hysteretic curve of SC-FEDB is smooth and robust, exhibiting distinct flag-shaped characteristics alongside stable energy dissipation performance. By decreasing the initial amplification angle, significant improvements in both bearing capacity and energy dissipation capability were observed. Compared with traditional buckling-restrained braced (BRB) frame structures, the proposed brace structural system demonstrates superior performance in reducing key seismic response parameters, including inter-story drift angle, residual inter-story drift angle, and base shear force of the structure. As the initial amplification angle decreases, the SC-FEDB shows a significant force amplification phenomenon, with its output displacement significantly reduced, but the energy dissipation efficiency significantly improved. The seismic control effect of the SC-FEDB on the structure is more remarkable.