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Summary: The most important issues that researchers are faced with are extensive damages and permanent deformations in the structures after earthquakes. This study proposes new hybrid smart dampers combined with shape memory alloy (SMA) plates, friction devices, and polyurethane springs (e.g., ASFP damper) with an aim to decrease structural damage as well as to mitigate residual deformation in the concentrically braced frames (CBFs). These dampers are simply fabricated, and the other parts are low cost except for the nitinol SMA plates. In addition, they can be employed for not only new construction but also rehabilitation of existing structures. In order to investigate the behavior of each key component (e.g., SMA plates, friction devices, and polyurethane springs), eight different cases are experimentally investigated under quasi‐static cyclic loading, and the effects of all components are evaluated in this study. In four cases, the SMA plates are replaced by the steel plates to better understand the effect of SMA plates on recentering capability. The details of experimental tests are described with more details. The final results demonstrate that the SMA dampers can restore more than half of residual displacement. In addition, these SMA dampers exhibit stable energy dissipation and adequately operates under both compressive and tensile loading. [ABSTRACT FROM AUTHOR]

Shear recentering polyurethane friction damper is a type of passive control device, including the shape memory alloy plates, polyurethane springs, and friction devices. This damper can be employed in the shear link of an inverted Y-shaped braced frame. As the failure mode is a shear failure, in this study, the shear recentering polyurethane friction damper is proposed to remove the residual deformation of the structure that remains after a strong earthquake and causes considerable damage to the structure. The shear recentering polyurethane friction damper can help the structure to return to the initial position. Furthermore, as compared to many other dampers, this new damper is of low cost, and its assembling requires a simple technology. In order to evaluate the performance of the damper, four different cases are considered. Furthermore, the effect of each component is investigated in each case, and a finite element analysis is performed under cyclic loading using the ABAQUS platform. In addition, for the sake of comparison, the shape memory alloy plates are replaced by steel ones, and a comparison for the results demonstrates that the recentering shear dampers can significantly decrease residual deformation, while there is a large amount of residual deformation in the steel damper. Due to using the polyurethane springs, the ultimate capacity of the shear shape memory alloy polyurethane friction damper is 500 kN; however, in the shear steel polyurethane friction damper, it is only about 300 kN. Furthermore, the energy dissipation by the shear shape memory alloy polyurethane friction damper is larger than the shear steel polyurethane friction damper. The results show that the steel plates cannot effectively increase energy dissipation. [ABSTRACT FROM AUTHOR]