## 9 Seismic Isolation and Energy Dissipation Devices for Composite Structures
### Seismic Isolation and Energy Dissipation Devices for Composite Structures: State-of-the-Art
They investigated the effectiveness and design parameters of these devices by employing the fragility function method. The results showed that the hybrid-damped frame (HDF) is effective in withstanding multiple hazards, and that the energy dissipation contributions of VDs and BRBs vary based on the hazard intensities. [PERSON] et al. (2022) [147] experimentally studied the seismic behavior of eccentrically braced composite frames with vertical shear links. The use of low-yield-point steel in the shear links was found to enhance seismic performance. The eccentric bracing system increased the stiffness, strength, and energy dissipation capacity of the composite frame without affecting force conditions on primary beams and columns. However, strain hardening of the low-yield-point steel resulted in severe damage to the concrete slab in the middle segment of the primary beam. Similarly, [PERSON] and [PERSON] (2023) [148] evaluated the impact of buckling-restrained braces and viscous dampers on the seismic performance of asymmetrical composite frames. Both devices effectively reduced seismic response, with viscous dampers being more efficient in reducing period and base shear by 65-73% and 80-90%, respectively. Buckling-restrained braces performed better in reducing maximum overturning moments. Implementing both devices reduced inter-story drift ratio and horizontal displacement, but increased compression force on columns by 20-25% for buckling-restrained braces and 15-22% for viscous dampers. Viscous dampers were found to be more effective. [PERSON] and [PERSON] (2023) [149] examined a dual system consisting of a double-skin CFT frame and metallic dampers. The energy distribution along the height was analyzed using nonlinear models validated by test results. They found that the metallic damper absorbed significant energy under seismic loads, whereas a semi-rigid connection harmed the column. A method to estimate energy distribution in the dual system was developed, providing valuable insights for future applications. [PERSON] and [PERSON] (2022) [150] analyzed the seismic performance of an eccentrically braced composite frame with a low-yield-point steel shear link. A theoretical and finite element model is used to understand the structural mechanics and energy dissipation mechanisms. Various design parameters were investigated to determine their impact on the system's mechanical properties. Additionally, recommended design parameter values were provided. Furthermore, [PERSON] and [PERSON] (2023) [151] examined the seismic response of composite structures integrated with fluid viscous dampers and base isolation. They evaluated the seismic performance of composite structures using finite element analysis. The results showed that integrating fluid viscous dampers and base isolation reduces the structural response to seismic events. A synergistic combination of fluid viscous dampers and base isolation outperforms their individual use. A new type of shear panel dampers with bent web panels, installed in composite frames to enhance stiffness and strength was examined by [PERSON] et al. (2022) [152]. Unlike traditional dampers, BSPDs minimize bending moments on the primary beam, reducing damage to the concrete slab. Experimental and numerical investigations confirmed their ductile behavior and energy dissipation capacities. Design recommendations included using low-yield-point steel and link flanges to increase deformation capacity and efficiency. [PERSON] et al. (2020) [153] presented analytical studies and experiments on blind-bolted end plate CFT composite frames with buckling-restrained braces. Pseudo-dynamic tests on two 2/3-scaled two-story composite frames with buckling-restrained braces showedgood hysteretic behavior and high ductility. The moment capacity, rotation capacity, and mathematical model of a composite joint were analyzed and modified. The shear force-deformation relation of a CFT panel zone was checked.