چكيده به لاتين
Nowadays, most lateral resisting systems, such as moment-resisting frames dissipate earthquake energy by using the nonlinear capacity of members. These systems cause a lot of structural and non-structural damage due to their high residual displacements, which in some cases necessitate structural destruction. Therefore, the development of methods that can reduce the residual displacement of the structure in addition to absorbing the appropriate energy seems necessary.
In this study, one of the newest self-centering systems called self-centering buckling restrained brace (SC-BRB) with prestressed steel cable is studied, which has proper energy absorption in addition to reduced residual displacement. In the present study, three factors affecting the behavior of this brace, including core yield stress (fy), fPrestressed-strand/fy-strand ratio, and cable/core area ratio (AStrand/ABRB), have been investigated. In this study, the optimum state of this brace was determined using 62 numerical models, and then this brace was used in a moment-resisting frame system and its optimal state was determined with 62 other models. The results showed that in optimum brace 91% and in optimum brace used in moment resisting frame system 60% reduction of residual displacement occurred compared to buckling restrained brace. It was also found that as the AStrand/ABRB ratio increases, in brace alone, the self-centering property improves, but for the buckling restrained brace used in moment resisting frame structure AStrand/ABRB=1 has the least residual displacement. Modeling and relationships showed that increasing the fPrestressed-strand/fy-strand ratio decreased residual displacement in both modes, but the effect of core yield stress was dependent on the AStrand/ABRB ratio.
