Development of a self-centering buckling restrained brace using cross-anchored pre-stressed steel strands

Abstract

A refined self-centering buckling restrained brace (SC-BRB), which provides good energy dissipation and self-centering ability for structures, is proposed. The SC-BRB system is made of two tubes and core plates. To improve the energy dissipation performance under earthquake excitation, the low-yield-point steel core plates are restrained by the middle and outer tubes. The self-centering capacity is provided by a group of pre-stressed steel strands coupled with two cover plates and the middle and outer tubes. Cross-anchored technology is used to improve the deformability of the pre-stressed strands, which also improves the deformability of the SC-BRB. To study the energy dissipation performance and self-centering ability of the proposed SC-BRB, two specimens using cross-anchored pre-stressed strands were fabricated and tested. Finite element analysis using ABAQUS was carried out to simulate the behavior of the SC-BRB. Based on the finite element analyses, a parametric study was conducted by using the initial pre-stress value and cross-section area of the steel core plates as design parameters to obtain the optimal values of these two parameters. The SC-BRBs with the appropriate parameters exhibited good energy dissipation and self-centering capacity up to a deformation that equals 1% of the brace length. The finite element analysis results agree well with the physical test results, and the two design parameters are interrelated and both have significant effects on the energy dissipation and self-centering ability of the SC-BRB.