Abstract
In some circumstances, it is impossible to exploit resonance crossings to identify the modal properties of rotor disks. In these cases, the identification process must rely on nonsynchronous vibrations and becomes challenging for two reasons. First, the signals are weak (compared to the levels measured during resonance crossings) and random, thus an averaging procedure is necessary. Second, the dynamical system is time-variant due to the variation of the rotor speed. This paper presents a modal identification procedure formulated in the framework of the time–frequency analysis. A region of the time–frequency plane is stretched to map the system into a fictitious linear time-invariant (LTI) system. Then, the power spectral density function (PSD) of the response is computed by an averaging procedure. Finally, the modal properties are estimated through an output-only modal identification algorithm. The procedure is applied to simulated and experimental data regarding a bladed disk of a steam turbine.
Issue Section:
Research Papers
References
1.
Maywald
,
T.
,
Beirow
,
B.
,
Heinrich
,
C. R.
, and
Kühhorn
,
A.
, 2015
, “
Vacuum Spin Test Series of a Turbine Impeller With Focus on Mistuning and Damping by Comparing Tip Timing and Strain Gauge Results
,” ASME
Paper No. GT2015-42649.10.1115/GT2015-426492.
Zhang
,
J.
,
Shan
,
P.
,
Cheng
,
K.
, and
Ye
,
D.
, 2018
, “
Comparison of Blade Tip Timing With Strain Gauge Data for Evaluation of Dynamic Characterization of Last Stage Blade With Interlocked Shroud for Steam Turbine
,” ASME
Paper No. GT2018-76264.10.1115/GT2018-762643.
Hackenberg
,
H.
, and
Hartung
,
A.
, 2016
, “
An Approach for Estimating the Effect of Transient Sweep Through a Resonance
,” ASME J. Eng. Gas Turbines Power
,
138
(8
), p. 082502
.10.1115/1.40326644.
Carassale
,
L.
,
Marrè-Brunenghi
,
M.
, and
Patrone
,
S.
, 2018
, “
Wavelet-Based Identification of Rotor Blades in Passage-Through-Resonance Tests
,” Mech. Syst. Signal Process.
,
98
, pp. 124
–138
.10.1016/j.ymssp.2017.04.0235.
Carassale
,
L.
,
Marrè-Brunenghi
,
M.
, and
Patrone
,
S.
, 2016
, “
Modal Identification of Dynamically Coupled Bladed Disks in Run-Up Tests
,” ASME
Paper No. GT2016-57251.10.1115/GT2016-572516.
Mallat
,
S.
, 1998
, A Wavelet Tour of Signal Processing
,
Academic Press
, San Diego, CA.7.
Priestley
,
M. B.
, 1981
, Spectral Analysis and Time Series
,
Academic Press
,
London, UK
.8.
Loève
,
M.
, 1955
, Probability Theory
,
Van Nostrand
,
New York
.9.
Staszewski
,
W. J.
, 1997
, “
Identification of Damping in MDOF Systems Using Time-Scale Decomposition
,” J. Sound Vib.
,
203
(2
), pp. 283
–305
.10.1006/jsvi.1996.086410.
Ruzzene
,
M.
,
Fasana
,
A.
,
Garibaldi
,
L.
, and
Piombo
,
B.
, 1997
, “
Natural Frequencies and Dampings Identification Using Wavelet Transform: Application to Real Data
,” Mech. Syst. Signal Process.
,
11
(2
), pp. 207
–218
.10.1006/mssp.1996.007811.
Kijewski
,
T.
, and
Kareem
,
A.
, 2003
, “
Wavelet Transforms for System Identification in Civil Engineering
,” Comput.-Aided Civ. Infrastruct. Eng.
,
18
(5
), pp. 339
–355
.10.1111/1467-8667.t01-1-0031212.
Slavič
,
J.
,
Simonovski
,
I.
, and
Boltežar
,
M.
, 2003
, “
Damping Identification Using a Continuous Wavelet Transform: Application to Real Data
,” J. Sound Vib.
,
262
(2
), pp. 291
–307
.10.1016/S0022-460X(02)01032-513.
Le
,
T.-P.
, and
Argoul
,
P.
, 2004
, “
Continuous Wavelet Transform for Modal Identification Using Free Decay Response
,” J. Sound Vib.
,
277
(1–2
), pp. 73
–100
.10.1016/j.jsv.2003.08.04914.
Chen
,
S.-L.
,
Liu
,
J.-J.
, and
Lai
,
H.-C.
, 2009
, “
Wavelet Analysis for Identification of Damping Ratios and Natural Frequencies
,” J. Sound Vib.
,
323
(1–2
), pp. 130
–147
.10.1016/j.jsv.2009.01.02915.
Kougioumtzoglou
,
I. A.
, and
Spanos
,
P. D.
, 2013
, “
An Identification Approach for Linear and Nonlinear Time-Variant Structural Systems Via Harmonic Wavelets
,” Mech. Syst. Signal Process.
,
37
(1–2
), pp. 338
–352
.10.1016/j.ymssp.2013.01.01116.
Staszewski
,
W. J.
, and
Wallace
, D.
M.
, 2014
, “
Wavelet-Based Frequency Response Function for Time-Variant Systems—An Exploratory Study
,” Mech. Syst. Signal Process.
,
47
(1–2
), pp. 35
–49
.10.1016/j.ymssp.2013.03.01117.
Spanos
,
P. D.
, and
Failla
,
G.
, 2004
, “
Evolutionary Spectra Estimation Using Wavelets
,” ASCE J. Eng. Mech.
,
130
(8
), pp. 952
–960
.10.1061/(ASCE)0733-9399(2004)130:8(952)18.
Reynders
,
E.
, 2012
, “
System Identification Methods for (Operational) Modal Analysis: Review and Comparison
,” Arch. Comput. Methods Eng.
,
19
(1
), pp. 51
–124
.10.1007/s11831-012-9069-x19.
Shih
,
C. Y.
,
Tsuei
,
Y. G.
,
Allemang
,
R. J.
, and
Brown
,
D.
, 1988
, “
Complex Mode Indicator Function and Its Applications to Spatial Domain Parameter Estimation
,” Mech. Syst. Signal Process.
,
2
(4
), pp. 367
–377
.10.1016/0888-3270(88)90060-X20.
Aoki
,
M.
, 1987
, State Space Modelling of Time Series
,
Springer
,
Berlin, Germany
.21.
Peeters
,
B.
, and
de Roeck
,
G.
, 1999
, “
Reference-Based Stochastic Sub-Space Identification for Output-Only Modal Analysis
,” Mech. Syst. Signal Process.
,
13
(6
), pp. 855
–878
.10.1006/mssp.1999.124922.
Ewins
,
D. J.
, 2000
, Modal Testing
, 2nd ed.,
Research Studies Press
,
Baldock, UK
.23.
Bessone
,
A.
,
Guida
,
R.
,
Marre-Brunenghi
,
M.
,
Patrone
,
S.
,
Carassale
,
L.
,
Kubin
,
Z.
,
Arnone
,
A.
, and
Pinelli
,
L.
, 2020
, “
Aeromechanical Characterization of a Last Stage Steam Blade at Low Load Operation: Part 1—Experimental Measurements and Data Processing
,” ASME
Paper No. GT2020-15450.10.1115/GT2020-1545024.
Pinelli
,
L.
,
Vanti
,
F.
,
Peruzzi
,
L.
,
Arnone
,
A.
,
Bessone
,
A.
,
Bettini
,
C.
,
Guida
,
R.
,
Marré-Brunenghi
,
M.
, and
Slama
,
V.
, 2020
, “
Aeromechanical Characterization of a Last Stage Steam Blade at Low Load Operation: Part 2—Computational Modelling and Comparison
,” ASME
Paper No. GT2020-15409.10.1115/GT2020-15409Copyright © 2023 by ASME
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