{"title":"In situ Modelling of Lateral-Torsional Vibration of a Rotor-Stator with Multiple Parametric Excitations","authors":"B. X. Tchomeni, A. A. Alugongo, L. M. Masu","volume":95,"journal":"International Journal of Mechanical and Mechatronics Engineering","pagesStart":1855,"pagesEnd":1862,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/9999772","abstract":"
This paper presents a 4-DOF nonlinear model of a
\r\ncracked de Laval rotor-stator system derived based on Energy
\r\nPrinciples. The model has been used to simulate coupled torsionallateral
\r\nresponse of the faulty system with multiple parametric
\r\nexcitations; rotor-stator-rub, a breathing transverse crack, eccentric
\r\nmass and an axial force. Nonlinearity of a “breathing” crack is
\r\nincorporated in the model using a simple hinge mechanism suitable
\r\nfor a shallow crack. Response of the system while passing via its
\r\ncritical speed with intermittent rotor-stator rub is analyzed. Effects of
\r\neccentricity with phase and acceleration are investigated. Features of
\r\ncrack, rub and eccentricity in vibration response are explored for
\r\ncondition monitoring. The presence of a crack and rub are observable
\r\nin the power spectrum despite excitations by an axial force and rotor
\r\nunbalance. Obtained results are consistent with existing literature and
\r\ncould be adopted into rotor condition monitoring strategies.<\/p>\r\n","references":"[1] T.H. Patel, and A.K. Darpe, Coupled bending torsional vibration analysis\r\nof rotor with rub and crack, Journal of Sound and Vibration Vol.326,\r\n2009, pp 740\u2013752.\r\n[2] F. CHU, and W. LU, Determination of the rubbing location in a multidisc\r\nrotor system by means of dynamic stiffness identification. Journal of\r\nsound and vibration, 2001. 235-246.\r\n[3] G. Litak, and J. T. Sawicki, Intermittent behaviour of a cracked rotor in\r\nthe resonance region, Chaos, Solutions and Fractals, 2009, 42, 1495-\r\n1501.\r\n[4] R. Gasch, A Survey of the Dynamic Behaviour of a Simple Rotating\r\nShaft with Transverse Crack, Journal of Sound and Vibration, 1993,\r\n160(2): 313-332\r\n[5] J.T. Sawicki, A. K. Sen, and L. Grzegorz, Multiresolution Wavelet\r\nAnalysis of the Dynamics of a Cracked Rotor International Journal of\r\nRotating Machinery, 2009.\r\n[6] R.F. Beatty, Differentiating Rotor response due to radial rubbing, Journal\r\nof Vibration, Acoustics, Stress ,and Reliability in Design Vol107, 1985,\r\npp151\u2013160.\r\n[7] B. O. Al-bedoor, Transient torsional and lateral vibrations of unbalanced\r\nrotors with rotor-to-stator rubbing. Journal of Sound and vibration\r\n229(3), 2000, 627-645.\r\n[8] J.T. Sawicki, J. Padovan, and R. Al-Khatib, The Dynamics of Rotor with\r\nRubbing. International Journal of Rotating Machinery 1999, Vol. 5, No.\r\n4, 1998, pp. 295-304.\r\n[9] J.T. Sawicki, X. Wu, G. Y. Baaklini, and A. L. Gyekenyesi, \u201cVibrationbased\r\ncrack diagnosis in rotating shafts during acceleration through\r\nresonance,\u201d in Nondestructive Evaluation and Health Monitoring of\r\nAerospace Materials and Composites II, vol. 5046 of Proceedings of\r\nSPIE, 2003, pp. 1\u201310, San Diego, Calif, USA.\r\n[10] Y. B. Kim, and S.T. Noah, Bifurcation analysis for modified Jeffcott\r\nrotor with bearing clearances, Nonlinear Dynamics Vol. 1, 1990, pp 221-\r\n241.\r\n[11] F. CHU, and W. LU, Stiffening effect of the rotor during the rotor-tostator\r\nrub in a rotating machine, Journal of Sound and Vibration\r\nVol.308, 2007, pp 758\u2013766.\r\n[12] R. Sukkar, and A.S. Yigit, Analysis of fully coupled torsional and lateral\r\nvibrations of unbalanced rotors subject to axial loads. Kuwait\r\nJ.Sci.Eng.35 (2B), 2008, pp. 143-170.\r\n[13] I. Mayes, W. Davies, The vibration behavior of a rotating shaft system\r\ncontaining a transverse crack. Vibration in rotating machinery, Inst.\r\nMech, E, 1976, p.53-65.\r\n[14] A.S. Sekhar, Crack identification in a rotor system: a model- based\r\napproach. Journal of sound and vibration 270, 2004, 887-920.\r\n[15] A.S. Yigit, and A.P. Christoforou, Coupled Torsional and Bending\r\nVibrations of Actively Controlled Drillstings. Journal of Sound and\r\nVibration, 2000, 234: 67-83.\r\n[16] A.K.Darpe, Dynamics of cracked rotor. PhD Thesis, IIT Delhi, 2000.","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 95, 2014"}