Development of an innovative metallic damper for concentrically braced frame systems based on experimental and analytical studies

초록

Although concentrically braced frames (CBFs) possess high lateral stiffness and strength, the buckling of compressive members indicates that a system does not have appropriate ductility. Therefore, CBF is not a successful system for high seismic regions. Comprehensive studies have been performed on this drawback concerning CBF systems. The use of a metallic damper is considered an appropriate method to enhance the behavior of CBFs. While metallic dampers improve the hysteretic behavior of the CBF, they impose additional costs on the structures. Therefore, in this study, a steel damper, which is economical and straightforward to construct and replace after a severe earthquake, was developed. The proposed damper was investigated experimentally and numerically. In addition, a parametric study was performed to evaluate the effect of the three types of damper mechanisms (shear, shear-flexural, and flexural) with three types of buckling (elastic, inelastic, and plastic) on the behavior of the proposed damper. The experimental results, as well as the numerical results, indicate that the shear damper exhibits better performance than the other dampers in terms of strength and stiffness. Except in the case where the shear damper is accompanied by plastic buckling, it has a higher energy dissipation capability. In addition, a flexural damper with elastic buckling cannot be considered as an energy-dissipating device because of the fracturing of the damper due to displacement near the elastic zone. Fundamental relationships were used to predict the behavior of these dampers, and these predictions showed good agreement with the finite element results.

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