| Summary: | 碩士 === 國立暨南國際大學 === 土木工程學系 === 93 === The vibration mitigation performance of a conventional tuned mass damper system (TMD) is very sensitive to the detuning of the designed frequency. In view of the stochastic characteristics of external loading and the errors of identifying system parameters, a hybrid mass damper system (HMD) can guarantee the designed performance with the help of a supplementary active control force acted on the TMD system. However, the control performance degradation induced by the control force execution time delay should be considered together with the effect of detuning. The more generalized pseudo hybrid mass damper systems (PHMD and PHMD(xi_d)) are proposed in this study to investigate the interactive effects of detuning of parameters as well as control force time delay. The variation of modal properties with respect to delay time is discussed based on the analytical solutions. It is found that the delayed control force in a hybrid mass damper system with certain feedback sources can even enhance the reduction on responses. This advantage degrades for detuned PHMD systems with delayed control force. In order to provide the implementation guideline, the compensated optimal direct output feedback control forces are derived by using the discrete time control approach. The compensated PHMD systems provide good control performance as designed. Besides, this study also discusses the control robustness of the PHMD systems with respect to the false compensation of time-delay. The multiple-sampling-rate algorithm is applied to verify the above-mentioned control performance in time domain subjected to the earthquake excitation.
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