| Summary: | 碩士 === 國立臺灣大學 === 造船工程學系 === 85 === Abstract
In this paper we develop an identification system of dynamical
parameters, which are determined by the measured data from
multiple I/O channels of structures. The modal
parameters, natural frequency, damping ratio, mode shape and
frequency response function (FRF) can be estimated by a Vector
Auto-Regressive model (VAR model). The VAR simultaneous
equations are set up in a time discrete state equations,
which are consisted of measured points with q-time steps,
in which q is the order of AR model. The classical modal
testing approach based on fast Fourier transformation is used to
compare the working procedure and the difference of results
from both approaches. Finally we selected the
identification of modal parameters for analysis of a
numerical 3 dof numerical dynamic system and experiment of a
cantilever beam as study cases. Results show that the VAR
model has following advantages: (1)VAR model has better
ability to filter out the noise. (2)The
FRF curves from VAR model are more smooth.
(3)The modal parameters determined from VAR model are in a more
convenient way. (4)The calculated results from VAR model are
more accurate.
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