On-line rotor crack detection

Details On-line rotor crack detection On-line rotor crack detection

1981-02-19

1983-04-19

Birmiel, Howard A.

Measuring and testing

Vibration

Sensing apparatus

73587, 73660, G01H 100, G01N 2900

Patent

active

043801722

ABSTRACT:
A method is disclosed by which incipient cracks are detected in the rotor of a fluid powered turbine while the turbine is on-line and running under substantially normal load. In a preferred form of the invention, vibrations are monitored in the rotor and signature analysis of the normal background vibration pattern is obtained to establish the spectral content of the normal vibration signal. The turbine rotor is then transitorily perturbed, preferably by changing the temperature of the motive fluid (steam temperature is changed for example in a steam driven turbine), and the signature analysis is again performed to determine changes in the vibration pattern. An increase in the amplitude of the fundamental frequency and the appearance and increase in amplitude of higher harmonics following rotor perturbation is indicative of the presence and size of a crack in the rotor.

REFERENCES:
patent: 3292425 (1966-12-01), Conn
patent: 3315522 (1967-04-01), Frarey et al.
patent: 3705516 (1972-12-01), Reis
patent: 4184205 (1980-01-01), Morrow
patent: 4213346 (1980-07-01), Polovnikov et al.
patent: 4229796 (1980-10-01), Garrett
patent: 4274288 (1981-06-01), Tittmann et al.
patent: 4283956 (1981-08-01), Lechner et al.
"The Vibrational Behavior of a Turbine Rotor Containing a Transverse Crack", Grabowski, Transactions of the ASME, vol. 102, pp. 140-146.
"Vibrational Behavior of a Rotating System Containing a Transverse Crack", Mayes et al, 1976, paper No. C168/76, Conference on Vibrations in Rotating Machinery, I. Mech. E., Sep. 15-17, 1976.
"Dynamic Behavior of a Simple Rotor with a Cross-Sectional Crack", Gasch, 1976, paper No. C178-76, Conference as above.
"Vibrations in Cracked Shafts", Henry et al, paper No. 162/76, 1976, Conference as above.
Computerized Signal Processing for Detecting Cracks under Installed Fasteners-J. Couchman, J. Bell and P. Noronha.
Crack Propagation Testing Machine Using Shimadzu Servopulser Dynatec-Fujimoto et al., Shimadzu Corporation, Japan.

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