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Abstract
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The major concerns of buckling-restrained braced frames (BRBFs) are the low post-yield stiffness and excessive residualdisplacement, which can delay the post-earthquake recovery procedure and enhance the repair cost. The current numericalwork presents an innovative buckling-restrained brace (BRB) including a reduced-length hybrid core that is attached to arobust steel pipe. The core is laterally supported and consists of a shape memory alloy (SMA) rod inserted into a steel pipe.The paper represents a detailed description of the proposed device. The performance of the proposed BRB is numericallyinvestigated at the component level using the ABAQUS finite element package. Subsequently, the system-level responseof the proposed device is investigated by nonlinear static pushover and dynamic time history analyses in the OpenSEESenvironment. The results demonstrate that the proposed device shows a two-stage yielding mechanism, benefits the combinedhysteretic responses of the SMA and the steel cores, and exhibits a stable and symmetric cyclic behavior with a nearly flag-shaped hysteresis. Furthermore, compared with conventional BRBs, the proposed device reduces the maximum inter-storyand particularly the problematic residual drift responses of the BRBFs. Additionally, by an increase in the total area of theSMA core, though the maximum inter-story drift response is slightly increased due to the low elastic modulus of the SMAmaterial, the residual drift response of the BRBFs is further decreased
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