• Steel and Composite Structures
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• v.53 no.2
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• pp.195-208
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• 2024

This study focused on the cyclic behavior of Triangular-plate Added Damping and Stiffness (TADAS) and the impact of axial force on its performance. First, the numerical model was verified, and the impact of damper dimensions on elastic and effective stiffness, ultimate strength, energy dissipation, and equivalent viscous damping ratio (EVDR) was studied. The numerical results were then used to propose approximate equations to estimate these findings. In the second section, the buckling load of TADAS was calculated analytically, and an approximate equation was presented to facilitate estimation. The effects of axial force on elastic stiffness, ductility, and ultimate strength were then investigated. This study found that decreasing the height, increasing the width, and increasing the middle width of TADAS improved its energy absorption, effective stiffness, and ultimate strength. The EVDR results improved with decreasing height, increasing width, and middle width. Approximate equations provided results that were close to numerical results, indicating that they are reliable for calculating seismic parameters. The damper's ultimate strength was most affected by the axial force. In the most affected model, an increase in axial force of 0.025 Pcr (Buckling load of the damper) reduced ultimate strength, ductility, and elastic stiffness by 26%, 22%, and 16%, respectively.

• Structural Engineering and Mechanics
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• v.89 no.5
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• pp.507-524
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• 2024

Since the cost of reconstruction is very high and the structure may have been damaged by an earthquake, we must retrofit the structure. Therefore, the importance of studying this issue is very high in order to achieve the desired resistance against the regulations. The present study involved the numerical and experimental analysis of nine concrete frames, consisting of three concrete frames, three concrete frames with bracing, and three concrete frames with a TADAS damper. The purpose of this study is to strengthen the damaged concrete frame using braces and TADAS dampers. Observations were made of the frames as they were subjected to controlled displacement. Also, ABAQUS software was used to compare numerical and experimental results. According to the results, the software was sufficiently capable of modeling the studied frames. Additionally, a parametric study was conducted on the thickness and number of bending plates. Thickness increases from 8 mm to 12 mm, 8 mm to 15 mm, and 8 mm to 20 mm, increasing the base shear by about 6.7%, 11.1%, and 25%, respectively. Furthermore, increasing the number of plates from 4 to 5, 4 to 6, and 4 to 7 increased base shears by about 4.5%, 8.4%, and 14%, respectively.