Online condition monitoring of axial-flow turbomachinery blades using rotor-axial Eulerian laser Doppler vibrometry

• Published in: Mechanical systems and signal processing Vol. 23; no. 5; pp. 1634 - 1643
• Main Authors: Oberholster, A.J., Heyns, P.S.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2009; Elsevier
• Subjects: Applied sciences; Eulerian laser Doppler vibrometry; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Industrial metrology. Testing; Measurement and testing methods; Mechanical engineering. Machine design; Non-harmonic Fourier analysis; Online blade condition monitoring; Phase angle trends; Physics; Solid mechanics; Structural and continuum mechanics; Tracking laser Doppler vibrometry; Tracking laser Doppler vibrometry; Eulerian laser Doppler vibrometry; Online blade condition monitoring; Non-harmonic Fourier analysis; Phase angle trends; Measurement; Tracking; Turbomachine; Blades; Euler coordinate; Structure integrity; Harmonic analysis; Modeling; Vibrometer; Finite element method; Laser dopplerometry; Shaft; Turbine blade; Axial flow; Monitoring; Turbomachinery rotor; Vibration; Fourier analysis; Experimental study; Tracking(movable target)
• ISSN: 0888-3270; 1096-1216
• DOI: 10.1016/j.ymssp.2009.01.001

The ability to monitor the vibration of blades online is of great importance to the structural health of turbomachinery. This paper focuses on the fixed reference frame or Eulerian implementation of laser Doppler vibrometry to perform this function. The way in which this measurement technique works is studied analytically and then a numerical simulation approach is proposed. Through experimental testing and finite element modeling, it is shown that this measurement approach is in principle viable for online blade condition monitoring when phase angles at reference frequencies are monitored, using non-harmonic Fourier analysis.