Material optimization of tuned liquid column ball damper (TLCBD) for the vibration control of multi-storey structure using various liquid and ball densities

In this study, a modified form of tuned liquid column damper (TLCD) for multi-degree of freedom (MDOF) structure is presented, which is termed as tuned liquid column ball damper (TLCBD). TLCBD is a passive vibration control device used for the reduction of response induced from earthquake or wind loads. Instead of orifice, a spherical ball is used in the TLCBD for increase in the damping effect by resisting the water motion. TLCBD is placed on the top storey of a 4-storey steel frame, and its effect on vibration response is investigated experimentally. For performance optimization, a combination of varying densities of ball and liquid are used in the TLCBD. The optimal performance of TLCBD is studied under different excitations including harmonic and seismic loadings, through a series of shake table tests. Root mean square (RMS) acceleration is calculated against each loading and for each storey, for all combinations of balls and liquids. In order to better understand the response, percentage reduction of RMS acceleration is also determined, for all combinations. The results confirm that the response reduction for TLCBD controlled structure with liquid and ball having high densities is significantly better as compared to other combinations of liquids and ball having low densities. Moreover, the response reduction for TLCBD is more effective in the seismic excitations as compared to harmonic excitations.