Hysteretic Behavior of Assembled Self-Centering Buckling-Restrained Brace with Replaceable Angle Steel Fuses

An innovative assembled self-centering buckling-restrained brace (ASCBRB) with replaceable angle steel fuses was developed, aiming to address the challenge of the high lateral restraining stiffness demands of flat energy dissipation cores on restraining members in traditional SCBRBs. First, the basic composition and theoretical hysteretic behavior of the ASCBRB were described, followed by quasi-static tests of ASCBRB specimens. Then, a three-dimensional refined numerical model of ASCBRB was established, allowing for an in-depth analysis of the mechanical behavior of each component. The experimental results indicate that the ASCBRB specimens exhibit stable hysteretic behavior throughout the loading process, and no strength degradation is observed in the hysteretic curves before the failure of angle steel fuses. Moreover, the hysteretic curves of the specimens display a typical flag-shaped pattern and apparent partial self-centering characteristics. Post-earthquake damage is confined to the replaceable angle steel fuses, while the other components remain elastic after repeated use. The proposed theoretical hysteretic model aligns well with the experimental results. Notably, the errors between the theoretical and experimental initial stiffness of the ASCBRB specimens are within 18%, demonstrating that the ASCBRB effectively reduces the sensitivity of initial stiffness to component manufacturing and assembly errors, which is a common issue in existing self-centering braces. The established numerical model can accurately predict the hysteretic behavior of ASCBRB. And the numerical results indicate that the proposed brace configuration significantly reduces the stiffness and strength demands on the restraining members imposed by the energy dissipation fuses, facilitating lightweight brace design and reducing production costs.