Seismic resilience enhancement of MDOF systems utilizing a hybrid TMD-TLD

This paper proposes a novel hybrid tuned mass damper (TMD) and tuned liquid damper (TLD) system (TMD + TLD) for vibration control of multi-degree of freedom structures under seismic excitations. The proposed system is introduced using equations of motions of a five-degree of freedom structure which is modeled as a shear-type with a lateral degree of freedom at each floor under harmonic and earthquake excitations. The proposed hybrid TMD + TLD system is introduced to the building structure in the model. Several case studies are investigated to evaluate the performance of the proposed system. In the first case, both TMD and TLD are tuned to the first frequency of the structure, and the TMD is fixed to the top floor, and the TLD is fitted to the fourth floor of the primary structure. In the second case, the TMD is tuned to the first frequency of the structure, whereas the TLD is tuned to the second frequency of the structure. All the cases are investigated under harmonic force and real earthquake ground motions. The earthquakes selected in this study are classified as low, intermediate, and high-frequency content earthquakes. Results indicated that with comparatively less mass ratio, the earthquake-induced structural vibration is successfully suppressed when the TMD is tuned to the 1st frequency, and the TLD is tuned to the 2nd frequency of the structure. The focus of the investigation is to develop a practical framework to demonstrate the efficiency of such a hybrid damper.