Analysis of structural dynamic characteristics of a high speed light special catamaran

Abstract

In this paper, structural dynamic characteristics of a high-speed light special catamaran-wave piercing catamaran are analyzed using the FEA software MSC-NASTRAN. The dynamic reduction method is introduced to eliminate the local vibration modes in order to obtain the whole ship’s mode shapes. In the post-processor, a lot of accessorial methods are adopted to eliminate the local vibrations, so that the whole ship’s mode shapes can be identified. The modal analysis indicates that the dynamic reduction method fits for mode shapes identifying. In the end, the test results of a catamaran named Frederick G. Greed are used for reference to validate the obtained results. The comparison process shows that the results are credible. A special mode shape, which is quite different with that of conventional monohull ship, is also pointed out. The obtained results provide a valuable reference for the coming computation of catamaran’s vibration characteristics.

Keywords

catamaran / dynamic characteristics / finite element method / dynamic reduction method

References

[1] Jin Xianding. Ship hull vibration[M]. 1988, Shanghai: Shanghai Jiaotong University Publishing Company, (in Chinese)

[2] WENG Changjian. Characteristic and numerical analysis of high speed ship[A]. Proceedings of 5^th National Inland Ship and Shipping Conference[C]. Harbin, 1996 (in Chinese).

[3] Weng Changjian. Vibration prediction of high speed ship [J]. Ship Inspect Technology, 1997, 2: 21-24 (in Chinese)

[4] Pegg N G, Gilroy L E, Kumar R. Full scale verification of finite element modelling of a 75 tonne SWATH vessel [J]. Marine Structures, 1995, 8: 211-228

[5] Zhang Ruqing, Yin Xuegang, Dong Ming. Computational structure mechanics [M]. 1987, Chongqing: Chongqing University Publishing Company, (in Chinese)