Optimum Design Of Tuned Liquid Damper For Vibration Control Of Frame Structures Under Seismic Excitation.

Abstract

Current trends in construction industry demands taller and lighter structures, which are also more flexible and having quite low damping value. This increases failure possibilities and also problems from serviceability point of view due to the vibration of structure. There are some effective techniques available to minimize the vibration of structures; Tuned Liquid Damper (TLD) is one of the techniques available to minimize the vibration of the structure. Tuned Liquid Damper is the most economically and environmentally sustainable system, because no power source is required for its operation, free of maintenance, ease of frequency tuning and reduction of motion in two directions simultaneously. The objective of this research was to prepare optimum design of TLD for vibration control of frame structures under seismic excitation. Analytical analysis was made to investigate the response of the frame structure models fitted with a TLD. Time history analysis was carried out in SAP2000 using the nonlinear transient dynamic analysis. A standard multi-degree of freedom system was investigated to evaluate TLD protection efficiency in case of excitation by using rectangular tanker as liquid damper. To prepare optimum design for TLD it was needed to optimize analytically the passive parameters of the TLD. A total of five loading conditions were applied at the base of the structure. For optimization design of the damper parametric studies were done using dynamic parameters such as depth ratio and mass ratio. The effectiveness of the TLD was calculated in terms of percentage of reduction of displacements and peak acceleration of the structure. The results of the study show that TLDs are effective in reducing structural vibrations and the highest structural response reduction has been found from optimum design of the damper which is 48.72% reduction of the structural response. The optimum water depth ratio and mass ratio have found to be 0.122 and 3.5% respectively. From this study, it can be concluded that properly designed TLD with optimum design parameters are considered to be very effective device to reduce the structural response. Further works are required to achieve optimum design of the damper to better protect building structures.