Seismic response of steel frames with self-centeringbuckling-restrained braces

Self-centering buckling-restrained braces(SCBRB) have demonstrated favorable self-centering capacity and energy dissipating capacity. The seismic performance of a steel frame buildings with SCBRBs (SCBRBF）should be investigated through relevant study. The proper relationship between the stiffness of the main structure and that of the braces should be investigated, and the proper relationship between the energy dissipating system and the self-centering system of the SCBRBF is also worth studying, both through structural parametrical study. All the steel structures are designed according to Chinese codes. Then the hysteretic model of the SCBRBF is proposed and the prototype model of the SCBRBFs is realized in FEA software ANSYS. The seismic performance of BRB frame (BRBF) and SCBRBF has been compared. The effects of the stiffness ratio of braces to main structures (αB/M), the stiffness ratio of self-centering system to energy dissipating system (αc) and the strength ratio of the self-centering system to the energy dissipating system (β) on the overall seismic response have been studied. It shows that SCBRBF can minimize both the residual and maximum displacement compared with the BRBF. It can be concluded that residual deformation can be reduced withαB/M; less deformation can be expected with larger β or larger αc. In the initial design, αB/M, βand αc are recommended to be 3, 0.5-0.9 and 0.5, respectively.