In this paper, a method for calibrating rotordynamic models of speed-dependent systems with anisotropic support is presented. The method is based on the comparison between the calculated eigenvalues and those extracted from the measured synchronous frequency response functions. An eigensensitivity analysis is conducted to calculate the sensitivity of the computed eigenvalues to the selected elements to be updated. This method is suitable for field application since it requires simple coastdown tests. The method is illustrated on a test rig with fluid film bearings and is shown to be effective in the calibration of rotordynamic models at the speeds of the modes excited within the operating speed range.

Issue Section:
Gas Turbines: Structures and Dynamics
Keywords:
calibration, dynamics, eigenvalues and eigenfunctions, rotors, velocity
Topics:
Anisotropy, Bearings, Calibration, Damping, Eigenvalues, Stiffness, Rotors
1.
Nelson
,
H. D.
, and
McVaugh
,
J. M.
, 1976, “
The Dynamics of Rotor Bearing Systems Using Finite Elements
,”
ASME J. Eng. Ind.
0022-0817,
98
, pp.
593
–
600
.
Crossref
Search ADS
 
2.
El-Shafei
,
A.
,
Bayoumi
,
H. N.
, and
Mansour
,
A. M. A
, 1998, “
Nonlinear Rotor Dynamic Analysis Using Finite Elements and Equivalent Linearization
,”
Fifth IFToMM International Conference on Rotor Dynamics
, Darmstadt, Germany, pp.
175
–
187
.
3.
Lund
,
J. W.
, 1975, “
Stability and Damped Critical Speeds of a Flexible Rotor in Fluid-Film Bearings
,”
ASME J. Eng. Ind.
0022-0817,
96
(
4
), pp.
1325
–
1332
.
4.
El-Shafei
,
A.
,
El-Kabbany
,
A. S.
, and
Younan
,
A. A.
, 2004, “
Rotor Balancing Without Trial Weight
,”
ASME J. Eng. Gas Turbines Power
0742-4795,
126
(
3
), pp.
445
–
683
.
5.
Eshleman
,
R. L.
, and
Guy
,
K.
, 1990, “
Validation of Rotor-Dynamics Models Using Dynamic Testing
,”
Proceedings of the Third IFToMM International Conference on Rotordynamics
, Lyon, France, pp.
27
–
31
.
6.
Irretier
,
H.
, and
Lindemann
,
S.
, 2002, “
Improvement of Damping Parameters of Flexible Rotors by Experimental Modal Analysis and Model Updating
,”
Proceedings of the Sixth IFToMM International Conference on Rotordynamics
, Sydney, Australia, pp.
388
–
395
.
7.
Smart
,
M. G.
,
Friswell
,
M. I.
, and
Lees
,
A. W.
, 2000, “
Estimating Turbogenerator Foundation Parameters: Model Selection and Regularization
,”
Proc. R. Soc. London, Ser. A
1364-5021,
456
, pp.
1583
–
1607
.
Crossref
Search ADS
 
8.
Ewins
,
D. J.
, 2000,
Modal Testing: Theory, Practice and Application
, 2nd ed.,
Research Studies Press Ltd.
,
Baldock, Hertfordshire, England
.
9.
Mottershead
,
J. E.
, and
Friswell
,
M. I.
, 1993, “
Model Updating in Structural Dynamics: A Survey
,”
J. Sound Vib.
0022-460X,
167
(
2
), pp.
347
–
375
.
Crossref
Search ADS
 
10.
Bayoumi
,
H. N
, 1995, “
Development of a Finite Element Program for Nonlinear Rotordynamics Analysis Using Equivalent Linearization
,” M.Sc. thesis, Faculty of Engineering, Cairo University.
11.
Lee
,
C. W.
, 1993,
Vibration Analysis of Rotors
,
Kluwer
, Dordrecht.
12.
Kessler
,
C.
, and
Kim
,
J.
, 2002, “
Vibration Analysis of Rotor Utilizing Implicit Directional Information of Complex Variable Descriptions
,”
ASME J. Vibr. Acoust.
0739-3717,
124
, pp.
340
–
349
.
Crossref
Search ADS
 
13.
Gutierrez-Wing
,
E. S.
, and
Ewins
,
D. J.
, 2002, “
Characterization of Rotating Machinery Dynamics Within Limited Frequency Intervals Using Modal Analysis
,”
Proceedings of the Sixth IFToMM International Conference on Rotordynamics
, Sydney, Australia, pp.
486
–
495
.
14.
Younan
,
A. A.
, 2004, “
Calibration of Rotor Dynamic Models
,” M.Sc. thesis, Faculty of Engineering, Cairo University.
Copyright © 2008
 by American Society of Mechanical Engineers
You do not currently have access to this content.