Evaluation of building code provisions for buckling restrained braced frames using non-linear time history analysis

One of the primary challenges of structural engineers in high seismic regions is to design buildings with both adequate ductility and stiffness. Special moment resisting frame (SMRF) lateral force resisting systems when properly detailed are sufficiently ductile, but require heavy and therefore expensive steel sections for stiffness. Braced frame systems are often chosen because they are typically less expensive than SMRFs. Recent testing has demonstrated that the braces and connections in braced frames are susceptible to unacceptable non-ductile failure mechanisms. The buckling restrained braced frame (BRBF) is a recently developed lateral-force resisting system that combines the economy and stiffness of a braced frame and the ductility of a SMRF. This thesis summarizes current state of BRBF research and presents the results of a series of time history analyses that validate the current trend in seismic building codes to assume that BRBFs have ductility similar to SMRFs.