Assesing the Impact of the Tuned Mass Damper on the Seismic Performance of Isolated Steel Structures using Endurance Time Analysis.

Isolators and dampers are devices that dissipate energy and reduce the seismic response of structures during strong earthquakes. Lead Rubber Bearings (LRBs) and Tuned Mass Dampers (TMDs) are two common types of these devices. Studying non-linear behavior and seismic properties of structural systems equipped with this type of isolators and dampers can significantly enhance understanding of their behavior against lateral forces caused by strong earthquakes. In this study, a 9-story steel structure was analyzed using the Endurance Time Analysis (ETA) method in SAP2000 software with fixed and isolated bases, along with a tuned mass damper with different mass ratios and without a tuned mass damper. The analysis results indicate that the tuned mass damper is highly effective in reducing the displacement of the isolator level, drift ratio, and story shear forces. This effect is more significant with higher mass ratios of the TMD. This effect is more pronounced with higher mass ratios of the TMD. However, reducing the absolute acceleration response of the structure has not been effective, and increasing the mass ratio of the TMD only reduces the performance of the control system in improving the absolute acceleration response compared to the isolated state. [ABSTRACT FROM AUTHOR]