Cyclic Behavior Evaluation of Multi-Stage Yielding Buckling-Restrained Braces

Buckling-restrained braces (BRBs) are energy-dissipating members increasingly used to achieve minimum seismic design requirements. However, BRBs experience large permanent deformations under severe earthquake due to the high plasticity of their core and low post-yield stiffness. This paper presents a practical and cost-effective alternative, where a conventional BRB is modified to achieve staged yielding in its core. The proposed multi-stage BRB (MSBRB) consists of isolated parallel cores with differing yield strengths. A low-yield-point (LYP) core utilizes a material with a lower yield strength, while a high-strength steel (HSS) core employs a material with a higher yield strength. This research investigated the effect of different steel combinations on the re-centering behavior and energy dissipation of MSBRB using ABAQUS finite element software. The results demonstrated that the strain hardening and yield point of the steels significantly impact achieving a system with superior seismic performance.

کلیدواژه ها:

High-strength steel ، Low yield-point steel ، Multi-stage buckling-restrained braces ، Strain hardening