| Summary: | 碩士 === 國立臺灣大學 === 土木工程學研究所 === 102 === A Tuned Liquid Damper (TLD) is a passive control device on the top of a structure so that dissipates the input excitation energy rely on the liquid sloshing in the container as well as through the liquid boundary layer friction, the free surface contamination and wave breaking. In order to design an efficient TLD, using Fujino’s model to illustrate the liquid behavior as well as knowing optimum TLD parameters are crucial importance.
Numerical simulations of a single-degree-of-freedom (SDOF) structure, rigidly supporting a tuned liquid damper (TLD) and subjected to both wind and earthquake ground motions, show that a properly designed TLD can significantly reduce the structure''s response to these motions.
The TLD is a rigid, square tank with shallow water in it. Its fundamental linear sloshing frequency is tuned to the structure''s natural frequency. The TLD is more effective in reducing structural response as the ground excitation level increases. This is because it then dissipates more energy due to sloshing and wave breaking.
A larger water-depth to tank-length ratio than previous studies (0.1) suggested, which still falls within the constraint of shallow water theory, is shown to be more suitable for excitation levels expected in strong earthquake motions.
A larger water-mass to structure-mass ratio is shown to be required for a TLD to remain effectiveness and ensure structural safety.
Furthermore, the reduction in response is seen to be fairly insensitive to the bandwidth of the ground motion but is dependent on the structure''s natural frequency relative to the significant ground frequencies. By numerical method, therefore, observing that maximum response of system with TLD is in resonance condition.
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