0
Research Papers: Gas Turbines: Structures and Dynamics

Structural Change Quantification in Rotor Systems Based on Measured Resonance and Antiresonance Frequencies

[+] Author and Article Information
Adam C. Wroblewski

e-mail: a.wroblewski@csuohio.edu

Alexander H. Pesch

e-mail: a.pesch@csuohio.edu

Jerzy T. Sawicki

e-mail: j.sawicki@csuohio.edu
Center for Rotating Machinery Dynamics
and Control (RoMaDyC),
Cleveland State University,
Cleveland, OH 44115-2214

Contributed by the Structures and Dynamics Committee of ASME for publication in the Journal of Engineering for Gas Turbines and Power. Manuscript received August 19, 2013; final manuscript received September 6, 2013; published online November 1, 2013. Editor: David Wisler.

J. Eng. Gas Turbines Power 136(2), 022506 (Nov 01, 2013) (6 pages) Paper No: GTP-13-1314; doi: 10.1115/1.4025484 History: Received August 19, 2013; Revised September 06, 2013

A structural change quantification methodology is proposed in which the magnitude and location of a structural alteration is identified experimentally in a rotor system. The resonance and antiresonance frequencies are captured from multiple frequency response functions and are compared with baseline data to extract frequency shifts due to these features. The resulting expression contains sufficient information to identify the dynamic characteristics of the rotor in both the frequency and spatial domains. A finite element model with carefully selected tunable parameters is iteratively adjusted using a numerical optimization algorithm to determine the source of the structural change. The methodology is experimentally demonstrated on a test rig with a laterally damaged rotor and the frequency response functions are acquired through utilization of magnetic actuators positioned near the ball bearings.

FIGURES IN THIS ARTICLE
<>
Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Meruane, V., and HeylenW., 2011, “Structural Damage Assessment With Antiresonances Versus Mode Shapes Using Parallel Genetic Algorithms,” Struct. Control Health Monit., 18(8), pp. 825–839. [CrossRef]
Jones, K., and Turcotte, J., 2002, “Finite Element Model Updating Using Antiresonant Frequencies,” J. Sound Vib., 252(4), pp. 717–727. [CrossRef]
Ewins, D. J., 2001, Modal Testing: Theory, Practice and Application, Research Studies Press Ltd., Hertfordshire, UK.
Wroblewski, A. C., 2011, “Model Identification, Updating and Validation of an Active Magnetic Bearing High-Speed Machining Spindle for Precision Machining Operation,” Ph.D. thesis, Cleveland State University, Cleveland, OH.
Wroblewski, A. C., Sawicki, J. T., and Pesch, A. H., 2012, “Rotor Model Updating and Validation for an Active Magnetic Bearing Based High-Speed Machining Spindle,” ASME J. Eng. Gas Turbines Power, 134(12), p. 122509. [CrossRef]
Meruane, V., and Heylen, W., 2011, “An Hybrid Real Genetic Algorithm to Detect Structural Damage Using Modal Properties,” Mech. Syst. Signal Process., 25(5), pp. 1559–1573. [CrossRef]
Friswell, M., and Mottershead, J. E., 1995, Finite Element Model Updating in Structural Dynamics, Kluwer, Dordrecht, The Netherlands.
Marwala, T., 2010, Finite Element Model Updating Using Computational Intelligence Techniques: Applications to Structural Dynamics, Springer, New York.
Xiong, Y., Chen, W., TsuiK.-L., and Apley, D. W., 2009, “A Better Understanding of Model Updating Strategies in Validating Engineering Models,” Comput. Methods Appl. Mech. Eng., 198(15–16), pp. 1327–1337. [CrossRef]
Wu, Y.-X., 1999, “Sensitivity-Based Finite Element Model Updating Methods With Application to Electronic Equipments,” Ph.D. thesis, Polytechnique de Mons, Mons, Belgium.
Madden, R. J., and Sawicki, J. T., 2012, “Rotor Model Validation for an Active Magnetic Bearing Machining Spindle Using μ-Synthesis Approach,” ASME J. Eng. Gas Turbines Power, 134(9), pp. 092501–092506. [CrossRef]
Sawicki, J. T., Storozhev, D. L., and Lekki, J. D., 2011, “Exploration of NDE Properties of AMB Supported Rotors for Structural Damage Detection,” ASME J. Eng. Gas Turbines Power, 133(10), p. 102501. [CrossRef]
Sawicki, J. T., Friswell, M. I., Kulesza, Z., Wroblewski, A. C., and Lekki, J. D., 2011, “Detecting Cracked Rotors Using Auxiliary Harmonic Excitation,” J. Sound Vib., 330(7), pp. 1365–1381. [CrossRef]
Sawicki, J. T., and Maslen, E. H., 2008, “Accurate Identification of Plant Model for Robust Control of an AMB Machine Tool Spindle,” 9th Int. Conference on Motion and Vibration Control (MOVIC2008), Munich, Germany, September 15–18.
Sawicki, J. T., and Maslen, E. H., 2007, “Rotordynamic Response and Identification of AMB Machining Spindle,” ASME Turbo Expo Conference Proceedings, Montreal, Canada, May 14–17, ASME Paper No. GT2007-28018, pp. 977–982. [CrossRef]
Nelder, J. A., and Mead, R., 1965, “A Simplex Method for Function Minimization,” The Comput. Journal, 7(4), pp. 308–313. [CrossRef]
Yang, W. Y., Cao, W., Chung, T.-S., and Morris, J., 2005, Applied Numerical Methods Using MATLAB, Wiley, New York.

Figures

Grahic Jump Location
Fig. 1

The rotor test rig photo is pictured (top) with the description of the layout (bottom)

Grahic Jump Location
Fig. 2

Rotor model cross section illustrating components as well as I/OS for the TF calculations and measurements

Grahic Jump Location
Fig. 3

The updated baseline model is plotted against baseline experimental data showing good agreement

Grahic Jump Location
Fig. 4

Photo of the circumferential cut inducing a stiffness reduction of the shaft. Three cut depth cases are progressively implemented, 1.8 mm, 2.8 mm, and 4.0 mm.

Grahic Jump Location
Fig. 5

The stiffness of a single element from the FE rotor model was investigated as a function of cut depth. (a) A side view of element; (b) A FE model of selected rotor element.

Grahic Jump Location
Fig. 6

The predicted stiffness reduction of a single finite element of the rotor model as a function of cut depth

Grahic Jump Location
Fig. 7

The element sensitivity study illustrates which elements are sensitive to the objective function in the model updating routine. Element number 28 was chosen to host the stiffness reduction in the test rig.

Grahic Jump Location
Fig. 8

Experimental FRFS for use in the model updating routines for the baseline and three stiffness reduction cases

Grahic Jump Location
Fig. 9

The updated FE rotor models illustrating normalized detected structural change

Grahic Jump Location
Fig. 10

Graphical representation of stiffness reduction prediction values are present in other finite elements

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In