Analytical investigation of mixed BRBF and SCBF braced steel frames

In this paper the nonlinear Einelastic behavior of two kinds of braced frame systems, i.e., special concentric steel braced frame, SCBF, and buckling restrained braced frame system, BRBF, have been investigated. Several structural models have been analyzed and designed by current standards and their push-over and cyclic analysis has been performed using Opensees software. As the results showed, the inelastic behavior of BRBF was mostly localized in the lower stories. Therefore; it is possible to replace the BRBF for SCBF in upper stories without any adverse effect on the ductility and energy absorption of the whole system. The number of stories where the substitution of BRBF for SCBF seems to be feasible has been determined though it must be further examined.