ضریب رفتارقابهای بتن مسلح تقویت شده با بادبندهای کمانش تاب

Steel bracing has proven to be one of the most effective systems in resisting lateral loads. Disadvantages of seismic behavior of common braces such as ductility, buckling and also unsymmetrical hysteresis performance in tension and compression induced researchers to suggest new generation of braces that are buckling restrained braces. Buckling restrained brace (BRB) is a type of energy dissipating members which the buckling of the bracing is prevented by plastic deformation under tension – compression cycles, with stable hysteresis. The focus of this article is on determination of response modification factors of RC frames was strengthening with buckling restrained braces. Response modification factor represents ration of maximum seismic force on a structure during specified ground motion if it was remain elastic to the design seismic force. The actual seismic forces reduced by response modification factors to obtain design forces. To do so four, eight, twelve and sixteen stories buildings with three and five bays were considered and designed in accordance with Iranian Earthquake Resistance Design Codes and Iranian National Building Code (part 9) for structural concrete design and nonlinear static pushover analysis have been performed using Opensees software. Finally response modification factor for all of models obtained from this study has been determined separately for ultimate limit state