| Summary: | 碩士 === 國立中興大學 === 土木工程研究所 === 82 === In this study, an optimum design guideline and system
identification technique are developed to evaluate the modal
parameters for a structure with TMD based only on partial
response measurements (without the measurement of input
excitation). First, a random decrement method is employed to
reduce the measured response data to extract free vibration
responses at each measured location due to initial
displacement. Then, Ibrahim time domain technique is applied to
calculate the modal frequencies, damping ratios and mode
shapes. To obtain the complete mode shapes, an interpolation
and iteration scheme are developed to calculate the mode
shape value for the locations without measurement. All mode
shapes obtained are mutually orthogonal and the structural
seismic responses are also estimated.Based on the identified
modal parameters, an optimum TMD is determined. Numerical
examples of one-story, three-story, and five-story buildings
with and without TMD are used to verify that the proposed
system identification technique is able to identify
structural dominant modal parameters and responses
accurately even with small number of measurements and the
noise-to-signal ratio up to 20%. Furthermore, the optimal
design TMD is proved to be a useful control device.
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