Self-centering BRBs with composite tendons in series:Tests and structural analyses

The self-centering system and yielding energy dissipation system are two main parts of self-centering buckling-restrained braces (SC-BRBs), which have important influences on brace performance. To improve the performance of the two parts, an SC-BRB with composite tendons in series (SC-BRB-CTS) is proposed by introducing a self-centering system in series that can improve the deformation capability of the brace, and the yielding energy dissipation system made of low-yield steel LYP160 with a strong energy dissipation capacity is adopted. The performance of the braces is studied by quasi-static tests, and the influence of the self-centering system in series and low-yield steel on the seismic performance of the structure is determined by nonlinear dynamic analyses and fragility analyses. The results show that the deformation capacity of the SC-BRB-CTS is approximately 44% higher than that of a traditional SC-BRB, and the collapse resistance of the structure is improved by avoiding or delaying tendon fracture. The use of LYP160 steel core plates can substantially improve the energy dissipation capacity and post-yielding bearing capacity of the brace, which is beneficial for reducing the seismic response of the structure.