An experimental and numerical study on the innovative metallic box-section damper for improving the behavior of CBF systems

Abstract

The susceptibility of the diagonal member of the Concentrically Braced Frames (CBFs) to buckling reduces
the energy-dissipating capacity of the CBFs. Despite of high ultimate strength and stiffness of the CBFs as considerable advantages, its shortcoming (low dissipating energy capacity) is accounted as an important dilemma for this system. Although using metallic energy dampers, the seismic behavior of CBFs is enhanced, they impose more cost to structure and more constructional complicity. To address the issue, in this study, an innovative damper with a shear mechanism constructed as a box section was considered experimentally and numerically as well as parametrically. Results revealed that the proposed damper pertains to a suitable performance with stable hysteresis curves without degradation in stiffness, strength, and dissipating energy. The results also indicated that the overstrength of the damper reaches more than 1.5 (recommended by AISC). Moreover, a limitation as of ρ > 0.55, ψ > 10, and 67 < λw < 113 was recommended to design the damper. Correspondingly, the required equations to design the damper were presented and were in good agreement with FE results.