A new buckling-restrained brace with gap-supported tendon protection: Experiment and application

Abstract

For the Buckling-Restrained Braced Frame (BRBF), the reserve strength is critical to reduce maximum and residual drifts, and improve the collapse prevention margin. In this paper, a newly proposed brace is named TP-BRB, which is composed of a Buckling-Restrained Brace (BRB) and a gap-supported Tendon Protection in parallel. Instead of the conventional BRB, the TP-BRB is designed to provide additional stiffness and strength for steel frames after the axial deformation of TP-BRB reaches a threshold value. A quasi-static test of the TP-BRB was conducted to confirm the excellent performance of the new configuration and calibrate the numerical model in OpenSees. Nonlinear time-history analyses were performed to compare the responses of the TP-BRB frame and BRB frame models. The results show that replacing BRB with TP-BRB is an effective means to reduce the maximum and residual story drifts, and increase the collapse prevention margin under strong earthquake; moreover, it reduces the BRB deformation demands without reducing of the energy dissipation capacity of steel frames.