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《Influence of Mechanical Filter with Periodic Structure on Vibration Transmission Properties of Raft Isolation System》

HUANG Xiu-chang;FENG Guo-ping;ZHANG Zhi-yi;HUA Hong-Xing

2010, 30 (2): 9-12. DOI: 10.3969/j.issn.1006-1355.2010.02.009

Abstract （2299）

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A medium with periodic heterogeneity has special frequency ranges in which waves may be either effectively attenuated or allowed to propagate in space. These frequency ranges are referred to as stop bands (or band gaps) and pass bands (or bands). Such unique characteristics can be employed to design a kind of virtual mechanical filters with periodic structures. The mechanical filter can be inserted between the lower isolator and the base of the raft isolation system to alter the transmission properties from the machine to the base, so that the frequency of the raft isolation system can approach its excitation frequency, and differ from the shells intrinsic frequency and excitation frequency of the cabin. The transmission matrix method is used to analyze the transmission property and the dynamic response of the raft system. Result shows that the responses of displacement, force and power flow of the base can be greatly reduced when the excitation frequency is within the stop bend of the periodic structure.

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《Analysis of Transmission Paths of Ship Stern VibrationBased on Power Flow Theory》

FENG Guo-ping;HUANG Xiu-chang;LIU Xing-tian;ZHANG Zhi-yi;HUA Hong-xing

2010, 30 (2): 5-8. DOI: 10.3969/j.issn.1006-1355.2010.02.005

Abstract （2673）

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Vibration of ship sterns is a key point in ship vibration control. Study of the characteristic of vibration transmission paths of ship stern will be helpful for vibration reduction of the ship stern. Based on the modal shape analysis methods and power flow theory, the transmission path of the stern system vibration is deducted and analyzed numerically. The results show that the stern bearing is the main path for lower frequency vibration, while the thrust bearing base is the main path for medium frequency vibration.

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《Study on Transmission Paths in Submarine Stern Excited Longitudinally》

FENG Guo-ping;CHEN Yong;HUANG Xiuchang;HUA Hong-xing

2009, 29 (6): 132-135. DOI: 10.3969/j.issn.1006-1355.2009.06.132

Abstract （2281）

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It is effective to reduce vibration of a ship stern that vibration isolation on the dominant transmission path. The transmission paths model of a ship stern was built based on the ship stern structure. When excited longitudinally at the propeller, the transmission paths of stern is analyzed and sequenced by the transmission paths analysis method. The results show that the palace at bearing basement is a dominant path when excited longitudinally. Thus, when the dominant transmission path is identified, passive control or structural modifications on the path can attenuate vibration levels effectively. The numerical results explain that the acoustic radiations of the structure can reduced by modification of the bearings rigidities and of bearing basement configuration.