Development and validation of a versatile hysteretic model for pre-compressed self-centering buckling-restrained brace

Abstract

Due to the preferable self-centering and energy dissipation capabilities, self-centering energy dissipation (SCED) braces have become an emerging structural component in earthquake engineering. In this paper, an innovative self-centering steel buckling-restrained brace (SC-SBRB) consisting of two independent and complementary systems, i.e., a buckling-restrained energy-dissipation system and a pre-compressed disc spring self-centering system, is proposed. The working mechanism and mechanics of the SC-SBRB are investigated under one cycle of cyclic loading. A versatile self-centering hysteretic model (SCHM) is developed based on the working principle of the SC-SBRB to accurately characterize the energy dissipation and self-centering properties of the SC-SBRB under repeated cyclic loading. The SCHM is a path-dependent model that allows for straightforward parameter interpretation of the mechanics of the SC-SBRB. Numerical simulations are conducted on four SC-SBRBs with different self-centering ratios to validate the prediction results obtained from the SCHM. A good agreement between the simulation results and the prediction results confirm the validity of the proposed SCHM. Simulation results also demonstrate that the SC-SBRB can provide a stable and repeatable flag-shaped hysteretic response, as well as substantial energy dissipation and self-centering ability. Additionally, the SCHM is reasonably extended to other SCED braces with similar hysteretic rules. Further validation of the SCHM is performed by comparing the experimental results of the SCED braces with the SCHM results. It is concluded that the proposed SCHM has excellent applicability and can describe the responses of other SCED braces.