Hamed Ebrahimian - Ph.D. Candidate, Civil Engineering Department, Shiraz University, Shiraz, Iran
Mohammad-Reza Banan - Associate Professor, Civil Engineering Department, Shiraz University, Shiraz, Iran
Mahmoud-Reza Banan - Assistant Professor, Civil Engineering Department, Shiraz University, Shiraz, Iran

Buckling-Restrained Braced Frames (BRBF) become popular as Earthquake-Resisting systems. This study investigates the seismic behavior of BRBF using probabilistic performance–based modeling. Through nonlinear time history analyses for a family of ground motions, damage indices and fragility curves for an eight-story BRBF are determined for the whole structure, primary beams and columns, and secondary buckling-restrained braces. The results show highly ductile performance of BRBFs. The developed fragility-design curves can be used as a basis to design and evaluate BRBF for a given risk and performance level.