Abstract
Purpose
During their lifetime, rotating machines experience various problems. Among others, rotor–stator rubbing is one of the most common problems encountered. Therefore, this paper proposes a two-step procedure for rotor–stator partial rub detection.
Methods
The first step applies the instantaneous angular speed (IAS) measurement. In this paper, the IAS signal is measured at low to moderate sampling rates as an analog signal from the zebra tape encoder. The correction of encoder segment non-uniformity is also briefly presented in the paper. As a means of coping with the nonlinear signal of the partial rub, the variational mode decomposition (VMD) is proposed in the paper, as the second step of the detection procedure. The VMD is a relatively new method with promising results for machinery fault detection.
Results
The partial rub detection tool was tested on the laboratory test rig under three different rotor operating conditions; firstly, for constant rotor speed without rubbing, secondly for rotor running at near critical constant speed with light rotor–stator rubbing, and finally under the condition which describes capabilities of the proposed rubbing detection procedure during variable rotor speed operation. The measurements were taken with an optical phase sensor pointed at the zebra tape encoder. The results are presented in the shape of rotor orbits, IAS signals, FFT spectra of IAS signals and VMD spectrograms of IAS signals.
Conclusions
It can be concluded that VMD spectrogram of IAS signal yields a clear detection criterion for light partial rotor–stator rubbing by the presence of 1/2×, 3/2× and 5/2× fractional harmonics. Depending on the analyzed conditions of partial rubbing, at least one of the mentioned fractional harmonics should appear.
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References
Choy FK, Padovan J (1987) Non-linear transient analysis of rotor-casing rub events. J Sound Vib 113(3):529–545
Bartha AR (2000) Dry friction backward whirl of rotors. PhD Thesis Swiss Federal Institute of Technology
Von Groll G, Ewins DJ (2002) A mechanism of low subharmonic response in rotor/stator contact—measurement and simulation. J Vib Acoust 124:350–358
Ahrens J, Jiang J, Ulbrich H, Ahaus G (2001) Experimentelle Untersuchungen zum Schaufelanstreifen. Schwingungen in rotierenden maschinen. SIRM V Tagung, Vienna, pp 97–108
Fumagalli M, Schweitzer G (1994) Impact dynamics of high speed rotors in retainer bearings and measurement concepts. In: 4th international symposium on magnetic bearings
Orth M, Nordmann R (2002) A modeling tool for nonlinear analysis of active magnetic bearing systems. In: 2nd IFAC conference on mechatronic systems, pp 357–362
Sinha JK (2007) Higher order spectra for crack and misalignment identification in shaft of a rotating machine. Struct Health Monit 6(4):325–334
Braut S (2006) Analysis of the rotor–stator contact dynamics. PhD thesis, University of Rijeka
Braut S, Žigulić R, Butković M (2008) Numerical and experimental analysis of a shaft bow influence on a rotor to stator contact dynamics. Stroj Vest J Mech Eng 54(10):693–706
Sinha JK, Elbhbah K (2013) A future possibility of vibration based condition monitoring of rotating machines. Mech Syst Signal Process 34:231–240
Li Y, Gu F, Harris G, Ball A, Bennett N, Travis K (2005) The measurement of instantaneous angular speed. Mech Syst Signal Process 19:786–805
Renaudin L, Bonnardot F, Musy O, Doray JB, Remond D (2010) Naturall rollerbearing fault detection by angular measurement of true instantaneous angular speed. Mech Syst Signal Process 24:1998–2011
Gu F, Yesilyurt I, Li Y, Harris G, Ball A (2006) An investigation of the effects of measurement noise in the use of instantaneous angular speed for machine diagnosis. Mech Syst Signal Process 20:1444–1460
Braut S, Žigulić R, Štimac G, Skoblar A, (2014) Light rotor–stator partial rub characterization using instantaneous angular speed measurement. VETOMAC-X, 673-682
Braut S, Žigulić R, Sladić S (2016) Analysis of low sampling rate time interval torsional vibration measurement system with encoder non-uniformity problem. J Vib Eng Technol 4(4):349–359
Huang NE, Shen Z, Long SR et al (1998) The empirical mode decomposition and the Hilbert spectrum for nonlinear and nonstationary time series analysis. P R Soc Lond 1998:903–995
Rilling G, Flandrin P, Gonçalves P, Lilly JM (2007) Bivariate empirical mode decomposition. IEEE Signal Process Lett 14(12):936–939
Rilling G, Flandrin P (2008) One or two frequencies? The empirical mode decomposition answers. IEEE Trans Signal Process 56(1):85–95
Braut S, Žigulić R, Štimac G, Skoblar A (2014) Rotor–stator partial rub diagnosis using Hilbert Huang transform. 9th IFToMM ICORD 1945–1953. https://doi.org/10.1007/978-3-319-06590-8_161
Dragomiretskiy K, Zosso D (2014) Variational mode decomposition. IEEE Trans Signal Process 62(3):531–564
Braut S, Žigulić R, Štimac Rončević G, Skoblar A, (2015) Diagnosis of partial rotor–stator rubbing using variational mode decomposition. IFToMM.14TH.WC
Braut S, Žigulić R, Skoblar A, Štimac Rončević G (2018) Fault detection based on instantaneous angular speed measurement and variational mode decomposition. MATEC WEB CONF. https://doi.org/10.1051/matecconf/201821118006
Muszynska A (2005) Rotordynamics. Taylor & Francis, Boca Raton
Peng ZK, Tse PW, Chu FL (2005) An improved Hilbert–Huang transform and its application in vibration signal analysis. J Sound Vib 286:187–205
Acknowledgments
This work has been fully supported by the University of Rijeka under the project number uniri-tehnic-18-225.
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Braut, S., Žigulić, R., Skoblar, A. et al. Partial Rub Detection Based on Instantaneous Angular Speed Measurement and Variational Mode Decomposition. J. Vib. Eng. Technol. 8, 351–364 (2020). https://doi.org/10.1007/s42417-019-00177-2
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DOI: https://doi.org/10.1007/s42417-019-00177-2