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Frontiers of Mechanical Engineering

Front Mech Eng    2013, Vol. 8 Issue (3) : 244-251     https://doi.org/10.1007/s11465-013-0264-8
RESEARCH ARTICLE
Dynamic analysis of a rig shafting vibration based on finite element
Van Thanh NGO, Danmei XIE(), Yangheng XIONG, Hengliang ZHANG, Yi YANG
School of Power and Mechanical Engineering Wuhan University, Wuhan 430072, China
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Abstract

In recently, finite elements method (FEM) has been used most popular for analysis of stress, vibration, heat flow and many other phenomena. Taking a rig shafting as an example, this paper studies the lateral vibration of the rig shafting with multi-degree-of-freedom by using FEM. The FEM model is created and the eigenvalues and eigenvectors are calculated and analyzed to find natural frequencies, critical speeds, mode shapes and unbalance responses. Then critical and mode shapes are determined. Finally, responses of unbalance force are analyzed in case of undamped and damped system, and peaks of response are compared.

Keywords Finite element method (FEM)      lateral vibration      rig shafting      rotor-bearing system      dynamic characteristics     
Corresponding Author(s): XIE Danmei,Email:dmxie@whu.edu.cn   
Issue Date: 05 September 2013
 Cite this article:   
Hengliang ZHANG,Yi YANG,Van Thanh NGO, et al. Dynamic analysis of a rig shafting vibration based on finite element[J]. Front Mech Eng, 2013, 8(3): 244-251.
 URL:  
http://journal.hep.com.cn/fme/EN/10.1007/s11465-013-0264-8
http://journal.hep.com.cn/fme/EN/Y2013/V8/I3/244
Fig.1  Shaft- line modeling of a rig rotor-bearing system
Fig.2  Coordinate used in analysis of rotor
Fig.3  Coordinate in plane
Fig.4  Journal bearing model
Speed/ (rev?min-1)Root s/(rad?s-1)ωn/Hzωd/Hzξ
0-23.21±126.53j-23.21±126.53j-37.97±163.37j-37.97±163.37j-25..40±220.39j-25.40±220.39j-26.75±449.60j-26.75±449.60j20.473320.473326.694626.694635.307635.307671.682971.682920.137220.137226.001626.001635.075535.075571.556471.55640.180.180.230.230.110.110.060.06
3500- 22.94±125.26j-23.48±127.77j-37.90±162.96j-38.03±163.81j-25.32±217.81j-25.47±223j-25.93±442.1j-27.56±457.24j20.266720.675826.628426.765134.899335.721670.475872.903919.935020.335325.936226.071834.665835.490970.354872.77180.1800.1840.2260.2260.1150.1130.0580.06
Tab.1  Eigenvalues (), natural frequencies (),damped natural frequencies () and damping ratio (ξ)
ΩIΩIIΩIIIΩIV
1212156221194384
Tab.2  First fourth critical speeds (rev/min)
Fig.5  Campbell diagram, FW (forward whirl), BW (backward whirl)
Fig.6  The first four critical speeds mode shapes of the rotor
Fig.7  3D view the first four critical mode shapes of the rotor
Fig.8  Unbalance response of the rotor at node 13, 31, 46 in case of undamped system
Fig.9  Forward- whirl orbits at node 13 (blue circle), 31 (green circle), 46 (red circle). The cross denotes the start of the orbit and the diamond denotes the end. The dimensions are μm
ResponseNode
Node 13Node 31Node 46
UndampedDampedUndampedDampedUndampedDamped
First peak12558.36833326152
Second peak636010829002191425480
Third peak840150606310591500260
Tab.3  Response magnitude at resonant in case of undamped and damped system (μm)
Fig.10  Unbalance response of the rotor at node 13, 31, 46 in case of damping system
Fig.11  Forward- whirl orbits at node 13 (blue circle), 31 (green circle), 46 (red circle). The cross denotes the start of the orbit and the diamond denotes the end. The dimensions are μm. (damping system)
1 Gash, R.Vibration of Large Turbo-Rotor in Fluid-Film bearing on Elastic Foundation. Journal of Sound and Vibration , 1976, 47(1): 53–73
2 Nelson H D, McVaugh J M . The dynamic of rotor-bearing systems using finite elements. Journal of Engineering for Industry , 1976, 98(2): 593-599
3 Hashish E, Sankar T S.Finite Element and Modal Analysis of Rotor-bearing system Under Stochastic Loading Condition. Journal of Vibration and Acoustics , 1984, 106 (1): 80–89
4 Jie Y. Lee C. Finite Element Modal of Asymmetrical Rotor-Bearing systems. KSME Journal , 1988, 2 (2),116–124
5 Ruhl R, Booker J F. A Finite Element Model for Distribute Parameter Turbo Rotor System. ASME journal of Engineering for Industry , 1972, 94,126–132
6 Friswell M I, Penny J E T, Garvey S D, Lees A W. Dynamics of Rotating Machines. New York, Cambridge University Press , 2010
7 Genta G, Dynamics of rotating systems, New York, Springer, 2005
8 Xie D, Liu Z, Zhang H, Yang Z, Dong C , Sensitivity analysis of torsional vibration behavior of the shafting of a turbo-generator set to changes of its mechanical parameters, Frontiers of Energy Power Engineering in China 2007, 1(4): 483–486
9 Genta G. Vibration Dynamics and Control. New York, Springer, 2009
10 Adam M L Jr. Rotating Machinery Vibration. Boca Raton, FL, CRC press, 2010
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