Development and application of replaceable self-centering energy dissipative braces

Aiming to enhance seismic resilience of steel frames, this paper proposes a novel replaceable self-centering energy dissipative brace (RSCEDB), in which the combined disc springs act as self-centering (SC) system and the replaceable slit dampers act as energy dissipating (ED) system. Initially, the configuration details, assembly process of RSCEDB are introduced. Based on the numerical simulations, the working mechanism and hysteretic model of RSCEDB are discussed in depth. After that, a steel frame equipped with RSCEDB (SF-RSCEDB) is presented, and the effect of RSCEDB with various parameters on the performance of the SF-RSCEDB is investigated by numerical simulation. The results indicate that the damage is concentrated in the ED system, while the remaining parts of the RSCEDB remain elastic. The self-centering and energy dissipation capacity of RSCEDB can be flexibly modified by pre-pressure and stiffness of combined disc springs, as well as yield strength of dampers, which is consistent with the prediction of the hysteretic model. Benefiting from the contribution of RSCEDB, the SF-RSCEDB has satisfactory self-centering capacity. Before activation, the RSCEDB serves as a structural component, providing larger lateral stiffness. After activation, the RSCEDB serves as a structural fuse, dissipating most of the seismic energy. With favorable self-centering performance, the damaged dampers can be easily identified and replaced, demonstrating that the SF-RSCEDB possesses excellent seismic resilience. Finally, a resilient design method is proposed for SF-RSCEDB.