Performance-based plastic design method for buckling-restrained braced frames

This paper presents a performance-based plastic design (PBPD) methodology for the design of buckling-restrained braced frames (BRBFs). The design base shear is obtained based on energy–work balance using pre-selected target drift and yield mechanism. Three low-to-medium rise BRBFs (3-story, 6-story and 9-story) were designed by the proposed methodology and their seismic performance was evaluated through extensive nonlinear time-history analyses using forty ground motions representing the DBE and the MCE hazard levels. Both isotropic and kinematic hardening characteristics of buckling-restrained braces were considered in the modeling of their force–deformation behaviors. All BRBFs considered in this study reached the intended performance objectives in terms of yield mechanisms and target drift levels. Since PBPD is a direct design method, no iterations were carried out to achieve the performance objectives of BRBFs.