Effect of TLD Frequency Detuning on the Seismic Performance of Steel Moment Frames

Building vibration has become one of the major concerns to civil engineering structures. Use of a Tuned Liquid Damper (TLD) as a vibration control mechanism is an interesting approach that is now widely accepted and frequently applied in civil engineering. A TLD is a passive control system, which utilizes fluid sloshing motion to dissipate the lateral excitation energy. Basically, TLD is a frequency dependent device. In this study, the TLD is modelled as anequivalent Tuned Mass Damper according to Yu`s model. Even though the natural frequency of the TLD is always chosen to match the natural frequency of the structure, change in the frequency of the primary structure or amplitude dependent frequency of the TLD results indetuned TLD system. Therefore, this paper aims at evaluating the efficiency of detuned TLD system for some tuning ratios (0.8~1.2). The seismic performance of existing intermediate steel moment resisting frames equipped with TLD are investigated based on nonlinear response dynamic history analysis. Result shows tuning ratio in the range 0.9 to 1.1 has slight influence on the seismic response of the structure.

Keywords:

Tuned Liquid Damper , frequency detuning , Seismic Performance , Steel Moment Resisting Frame