|
NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR) >
NISCAIR PUBLICATIONS >
Research Journals >
Indian Journal of Engineering and Materials Sciences (IJEMS) >
IJEMS Vol.19 [2012] >
IJEMS Vol.19(5) [October 2012] >
| Title: | Operational modal analysis of a scaled bridge model using EFDD and SSI methods |
| Authors: | Altunişik, Ahmet Can
Bayraktar, Alemdar
Sevim, Barış |
| Keywords: | Bridge model
Dynamic characteristic
Enhanced frequency domain decomposition
Highway bridge
Operational modal analysis
Stochastic subspace identification |
| Issue Date: | Oct-2012 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | In this
study, dynamic characteristics of a laboratory bridge model are determined by
operational modal analysis using frequency and time domain methods. For this
purpose, a reinforced box girder concrete bridge model is constructed in
laboratory conditions. The bridge deck consists of a main span of 3 m and two side span of 1.5 m each. The structural
system of the model bridge consists of deck, piers and foundation. The total
length of bridge deck is 6 m
and width of bridge deck is 60
cm. Ambient vibration tests are conducted to the model
bridge to identify its natural frequencies, mode shapes and damping ratios.
Natural excitations such as wind and impact hammer are used to vibrate the
model bridge. Vibration data is gathered from bridge
deck. Measurement time, frequency span and effective mode number are determined
by consider similar studies in literature. Sensitivity accelerometers are placed to collect
signals from the measurements. The signals collected from the tests are
processed by operational modal analysis; and the dynamic characteristics of the
bridge model are estimated using enhanced frequency domain decomposition (EFDD)
method in the frequency domain and stochastic subspace identification (SSI)
method in the time domain. The dynamic characteristics obtained from both
methods are found to be close to each other. Maximum 2.68% differences are
obtained between natural frequencies for the first mode. Modal assurance
criteria values are between 0.85-1.00. This shows that EFDD and SSI results are
almost overlapped. It can be concluded that the both of enhanced frequency
domain decomposition and stochastic subspace identification methods are very useful
to identify the dynamic characteristics of the bridge model.
|
| Page(s): | 320-330 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-1017 (Online); 0971-4588 (Print) |
| Source: | IJEMS Vol.19(5) [October 2012]
|
|
