| Summary: | 碩士 === 國立中興大學 === 土木工程研究所 === 83 === The use of active and passive control devices such as Tuned
Mass Damper (TMD) has become an area of considerable research
interest recently. It is gaining more acceptance not only for
the design of new structures but also for the retrofit of
existing structures to improve structural safety. Designing an
optimum TMD requires the prior knowledge of modal properties of
the controlled structure. For a real building structure, the
lateral and torsional motions are coupled if the centers of
mass and resistance do not coincide. Therefore,it is of great
importance that system identification of torsionally-coupled
buildings using real response measurements be carried out in
conjunction with the design of optimal TMDs. In this study, an
optimum design procedure and system identification technique
are developed to evaluate the modal parameters of a torsionally-
coupled structure with TMD based only on partial response
measurements. First, a random decrement method is employed to
reduce the measured response data to extract free vibration
responses at each measured location. Then, the Ibrahim time
domain technique is applied to calculate the modal parameters.
To obtain the complete mode shapes, an interpolation method is
also developed to calculate the mode shape value for the
locations without measurement. Based on the identified modal
parameters, an optimum TMD is determined. Numerical example of
a five-story torsionally-coupled building shows that the
proposed system identification technique is able to identify
structural dominant modal parameters and responses accurately
even with small number of measurements. In addition, a single
story torsionally-coupled building with one or two optimal TMDs
is used to verify that the proposed optimum TMD can reduce the
building responses significantly.
|
|---|
