FREE AND FORCED WHIRLING ANALYSES OF A SINGLE-DISK ROTOR SUBJECT TO AXIAL FORCE

Mohammad Reza Zeınolabedını; Mansour Rafeeyan

FREE AND FORCED WHIRLING ANALYSES OF A SINGLE-DISK ROTOR SUBJECT TO AXIAL FORCE

Abstract

Rotor vibrations and its control is an important subject in many industries such as power plants and gas stations. When lateral vibrations of rotors during operation exceed allowable level, a huge damage will be occurred. Surge and stall may be some common reasons of these vibrations. This paper aims to present a simple model for surge and stall and assumes that its effect as a distributed force acting on a rotor-disk system. This is a basic and conceptual model for future investigations in this area. Therefore, the effect of a distributed axial force exerted on an assembled disk on a rotating shaft is investigated theoretically. The set of equations for free and forced whirling analyses of a rotor- disc is derived. Also, transverse load composed of unbalanced mass and total weight of the system is considered. For forced whirling analysis, static deflection of the rotor is considered as the initial conditions and rotational speed of the rotor is considered as a time variable parameter which increases from zero to its nominal value in a limited period of time. For a simply supported rotor, the free whirling analysis is investigated using Galerkin method and using Galerkin and Newmark-beta methods, the forced whirling analysis is studied numerically. Forward and backward frequencies and Campbell diagrams are presented in free whirling analysis and variation of deflection, and shear force in any point of the rotor are depicted versus time in forced whirling analysis. The most advantages of the presented paper are consideration of time-dependency of rotating speed in forced whirling analysis. Results indicate that the axial load has a considerable effect on the forward and backward frequencies and lateral vibration amplitude of the rotor.

Keywords

References

[1] Musznynska A., (2005). Rotor dynamics. Crc press, Taylor Francis Group, LLC.
[2] Grybos R., (1991). Effect and rotary inertia of a rotor at its critical speeds, Archive of Applied Mechanics, 61(2), 104-109.
[3] Jei Y G., Lee C W., (1992). Modal analysis of continues asymmetrical rotor-bearing systems, Journal of Sound and Vibration, 152(2), 245 -262.
[4] Sturla F A., Argento A., (1996). Free and forced vibrations of a spinning viscoelastic beam. Journal of Vibration and acoustics, 118(3), 463 -468.
[5] Jun O S., Kim J A., (1999). Free bending vibration of a multi-step rotor. Journal of Sound and Vibration,224(4), 625-642.
[6] Tiwari S., Bhsduri S., (2017). Danamic analysis of rotor-bearing system for flexible bearing support condition. International journal of mechanical engineering and technology, vol.8, 1785-1792.
[7] Nelson H D., (1980). A finite rotating shaft element using Timoshenko beam theory. Journal of Mechanical Design, 102(4), 703-803.
[8] Edney S L.,Fox C H J., Williams E j., (1990). Tapered Timoshenko finite elements for rotor dynamics analysis, Journal of Sound and Vibration, 137(3), 463-481.

[9] Chen S., Geradin M., (1994). Exact and direct modeling earing system technique for rotor with arbitrary selected degress-of-freedom. Shock and Vibration, vol.1, No.6, 497-506.
[10] Choi S H., Pierre C., Ulsoy A G., (1992). Consistent modeling of rotating Timoshenko shafts subjected to axial loads. Journal of Vibration and Acoustics, 114(2), 249-259.
[11] Ouyang M., Wang M., (2007). A dynamic model for a rotating beam subjected to axially moving forces. Journal of Sound and Vibration 308. 674-682.
[12] Askarian A., Hashemi S M R., (2007). Effect of axial force, unbalance and coupling misalignment on vibration of a rotor gas turbine. 14 th International Congress on Sound Vibration.
[13] Nawal M., Raheimg AL., (2012). Free vibration of simply supported beam subjected to axial force. Journal of Babylon University.No .1 ,Vol -20.
[14] Motallebi A A., Poorjamshidian , M., Shekhi j., (2014). Vibration analysis of a nonlinear beam under axial force by homotopy analysis method. Journal of Solid Mechanics.Vol.6, No.3. 289-298.
[15] Torabi k., afshari H., (2015). Exact solution for whirling analysis of axial–loaded Timoshenko rotor using basic functions. Engineering Solid Mechanics. 4, 97-108.
[16] Genta G .,(2007). Dynamics of rotating systems. Springer Science & Business Media.
[17] Hutchinson J R.,(2001). Shear coefficients for Timoshenko beam theory, Journal of Applied Mechanics, 68(1), 87-92.
[18] Bassin G b., Brodsky S M., Wolkaff H., (1979). Statics and Strength of Materials. McGRAW-Hill Book Company.

Details

Primary Language

English

Subjects

Engineering

Journal Section

Research Article

Authors

Mohammad Reza Zeınolabedını This is me
0000-0002-1975-449X
Iran

Mansour Rafeeyan This is me
0000-0002-2175-5969
Iran

Publication Date

March 1, 2018

Submission Date

July 17, 2017

Acceptance Date

November 27, 2017

Published in Issue

Year 2018 Volume: 36 Number: 1

IZ

https://izlik.org/JA94FF96EH

Cite

RIS / Bibtex

APA

Zeınolabedını, M. R., & Rafeeyan, M. (2018). FREE AND FORCED WHIRLING ANALYSES OF A SINGLE-DISK ROTOR SUBJECT TO AXIAL FORCE. Sigma Journal of Engineering and Natural Sciences, 36(1), 21-31. https://izlik.org/JA94FF96EH

AMA

1.Zeınolabedını MR, Rafeeyan M. FREE AND FORCED WHIRLING ANALYSES OF A SINGLE-DISK ROTOR SUBJECT TO AXIAL FORCE. SIGMA. 2018;36(1):21-31. https://izlik.org/JA94FF96EH

Chicago

Zeınolabedını, Mohammad Reza, and Mansour Rafeeyan. 2018. “FREE AND FORCED WHIRLING ANALYSES OF A SINGLE-DISK ROTOR SUBJECT TO AXIAL FORCE”. Sigma Journal of Engineering and Natural Sciences 36 (1): 21-31. https://izlik.org/JA94FF96EH.

EndNote

Zeınolabedını MR, Rafeeyan M (March 1, 2018) FREE AND FORCED WHIRLING ANALYSES OF A SINGLE-DISK ROTOR SUBJECT TO AXIAL FORCE. Sigma Journal of Engineering and Natural Sciences 36 1 21–31.

IEEE

[1]M. R. Zeınolabedını and M. Rafeeyan, “FREE AND FORCED WHIRLING ANALYSES OF A SINGLE-DISK ROTOR SUBJECT TO AXIAL FORCE”, SIGMA, vol. 36, no. 1, pp. 21–31, Mar. 2018, [Online]. Available: https://izlik.org/JA94FF96EH

ISNAD

Zeınolabedını, Mohammad Reza - Rafeeyan, Mansour. “FREE AND FORCED WHIRLING ANALYSES OF A SINGLE-DISK ROTOR SUBJECT TO AXIAL FORCE”. Sigma Journal of Engineering and Natural Sciences 36/1 (March 1, 2018): 21-31. https://izlik.org/JA94FF96EH.

JAMA

1.Zeınolabedını MR, Rafeeyan M. FREE AND FORCED WHIRLING ANALYSES OF A SINGLE-DISK ROTOR SUBJECT TO AXIAL FORCE. SIGMA. 2018;36:21–31.

MLA

Zeınolabedını, Mohammad Reza, and Mansour Rafeeyan. “FREE AND FORCED WHIRLING ANALYSES OF A SINGLE-DISK ROTOR SUBJECT TO AXIAL FORCE”. Sigma Journal of Engineering and Natural Sciences, vol. 36, no. 1, Mar. 2018, pp. 21-31, https://izlik.org/JA94FF96EH.

Vancouver

1.Mohammad Reza Zeınolabedını, Mansour Rafeeyan. FREE AND FORCED WHIRLING ANALYSES OF A SINGLE-DISK ROTOR SUBJECT TO AXIAL FORCE. SIGMA [Internet]. 2018 Mar. 1;36(1):21-3. Available from: https://izlik.org/JA94FF96EH