Shafting Coupled Vibration Research Based on Wave Approach

doi:10.1007/s12204-014-1506-6

摘要/Abstract

摘要： Because of propeller hydrodynamic influence, the shafting vibration is a coupled vibration which includes torsional, longitudinal and whirling vibrations. It is unsuitable to analyze different vibrations of propulsive shafting systems with development of shipbuilding technologies. To overcome the shortages of traditional marine standards, we establish a new numerical model of the shafting coupled vibration. And we put forward shafting coupled vibration calculation to ensure better reliability of main propulsion system. The shafting system is modeled into two sub-systems, a continuous one and a discrete one. Wave approach and transit matrix method are used to investigate displacement and stress fields in continuous and discrete sub-systems, respectively. And vibrations of different modes in both sub-systems are coupled by using dynamic equilibrium and continuity condition to deduce the global equations governing the motion of shafting. The coupling calculation is then used to research the reason of a very large crude carrier (VLCC) stern hull vibration. It is shown by the comparison of the results from both coupling and dependent vibration calculations that vibration in deferent directions will cause deformation in the same mode, which leads to extra stress and displacements on shafting, especially as the resonant frequencies of different vibration modes match each other. This is helpful to prevent ship stern vibration due to poor shafting vibration calculation.

关键词: shafting, coupled vibration, wave approach, resonance

Abstract: Because of propeller hydrodynamic influence, the shafting vibration is a coupled vibration which includes torsional, longitudinal and whirling vibrations. It is unsuitable to analyze different vibrations of propulsive shafting systems with development of shipbuilding technologies. To overcome the shortages of traditional marine standards, we establish a new numerical model of the shafting coupled vibration. And we put forward shafting coupled vibration calculation to ensure better reliability of main propulsion system. The shafting system is modeled into two sub-systems, a continuous one and a discrete one. Wave approach and transit matrix method are used to investigate displacement and stress fields in continuous and discrete sub-systems, respectively. And vibrations of different modes in both sub-systems are coupled by using dynamic equilibrium and continuity condition to deduce the global equations governing the motion of shafting. The coupling calculation is then used to research the reason of a very large crude carrier (VLCC) stern hull vibration. It is shown by the comparison of the results from both coupling and dependent vibration calculations that vibration in deferent directions will cause deformation in the same mode, which leads to extra stress and displacements on shafting, especially as the resonant frequencies of different vibration modes match each other. This is helpful to prevent ship stern vibration due to poor shafting vibration calculation.

Key words: shafting, coupled vibration, wave approach, resonance

中图分类号:

U 664.21

YANG Yong1,2 (杨勇), CHE Chi-dong1* (车驰东), TANG Wen-yong1 (唐文勇). Shafting Coupled Vibration Research Based on Wave Approach[J]. 上海交通大学学报（英文版）, 2014, 19(3): 325-336.

YANG Yong1,2 (杨勇), CHE Chi-dong1* (车驰东), TANG Wen-yong1 (唐文勇). Shafting Coupled Vibration Research Based on Wave Approach[J]. Journal of shanghai Jiaotong University (Science), 2014, 19(3): 325-336.

参考文献

[1] Jin Xian-ding, Chen Xue-ming. Naval stern vibration and its decreasing by dynamic absorber [J]. Journal of Shanghai Jiaotong University, 1997, 31(2): 38-44 (in Chinese).
[2] Jin Xian-ding, Fu Jing-hua, Hu Chang-yun. Stern vibration response prediction of a high-speed craft due to change of the main engine [J]. Journal of Shanghai Jiaotong University, 1997, 31(11): 75-77 (in Chinese).
[3] Yin Yu-mei, Zhao De-you. Study on FE modeling method of the ship superstructure’s overall vibration [J]. Shipbuilding of China, 2009, 50(3): 49-53 (in Chinese).
[4] Xia Li-juan, Wu Wei-guo, Weng Chang-jian, et al.Analysis of fluid-structure-coupled vertical vibration for high-speed ships [J]. Journal of Shanghai Jiaotong University, 2000, 34(12): 1713-1716 (in Chinese).
[5] Li Zhi-qiang, Zhao De-you. Study on ship hull vibration model building [D]. Dalian, China: Department of Naval Architecture Engineering, Dalian University of Technology, 2006.
[6] Wei Hai-jun. Modification of some formulas for calculating shaft torsional vibration [J]. Journal of Vibration and Shock, 2006, 25(2): 166-167 (in Chinese).
[7] Wang Hong-zhi, Wei Hai-jun, Guan De-lin, et al. Numerical simulation on ship shafting mechanics condition of intermediate bearing [J]. Journal of Ship Mechanics,2006, 10(1): 98-105 (in Chinese).
[8] Zhu Han-hua, Yan Xin-ping, Liu Zheng-lin, et al. Research on impact response relationship between the rotating speed and lateral vibration [J]. Journal of Wuhan University of Technology: Transportation Science & Engineering, 2008, 32(6): 983-985 (in Chinese).
[9] Li Hui, Zhou Rui-ping. Research on the key points of torsional vibration of ship propulsion shafting [D].Wuhan, China: School of Energy and Power Engineering,Wuhan University of Technology, 2007 (in Chinese).
[10] Zhang Suo-huai, Guo Jun. Nonlinear model of the propeller and crankshaft system coupled in torsional and axial direction [J]. Chinese Journal of Mechanical Engineering, 2010, 46(11): 121-128 (in Chinese).
[11] Huang Jian-liang, Chen Shu-hui. Study on nonlinear vibration of an axially moving beam with coupled transverse and longitudinal motions [J]. Journal of Vibration and Shock, 2011, 30(8): 24-27 (in Chinese).
[12] Hosseini S A A, Khadem S E. Combination resonaces in a rotating shaft [J]. Mechanism and Machine Theory, 2009, 44: 1536-1547.
[13] Tang Bin, Song Xi-geng. Study on the coupled torsional,axial and bending three-dimensional vibrations of internal engine shafting basing on exact dynamic stiffness matrix methods [D]. Dalian, China: School of Energy and Power Engineering, Dalian University of Technology, 2006 (in Chinese).
[14] Tang Bin, Xue Dong-xin, Song Xi-geng. Study on dynamic matrix method for torsional vibration calculation of complex shafting [J]. Ship Engineering, 2003,25(3): 24-27 (in Chinese).
[15] Hsieh S C, Chen J H, Lee A C. A modified transfer matrix method for the coupling lateral and torsional vibrations of symmetric rotor-bearing systems [J]. Journal of Sound and Vibration, 2006, 289: 294-333.
[16] Firth J, Black J. Vibration interaction in a multiple flywheel system [J]. Journal of Sound and Vibration,2012, 331: 1701-1714.
[17] Vatta F, Vigliani A. Internal damping in rotating shafts [J]. Mechanism and Machine Theory, 2008, 43:1376-1384.