The similitude research on underwater complex shell-structure based on SEA

Abstract

In this paper, the vibration and sound radiation of the underwater complex shell-structure which is the cylindrical shell with hemi-spherical shell on the ends are studied by statistical energy analysis (SEA). The whole shell-structure is divided into the four subsystems, and the SEA physical model and power flow balance equations among these subsystems are established. The similitude relations of input power, coupling loss factor and modal density of the subsystems between the complex shell-structure and its scaled-down model are analyzed. According to the similitude theory and power flow balance equations, when the immerged shell-structures are excited, the similar relations of spatially averaged vibration response and underwater radiating sound power are established for the complex shell-structure and its scaled-down model.

Keywords

SEA / similar relation / sound radiation / structural vibration

References

[1] Soedel W. Similitude approximations for vibrating thin shell [J]. The Journal of the Acoustical Society of America, 1971, 49: 1535-1541

[2] Rezaeepazhand J, Simises G J. Design of scaled-down models for predicting shell vibration response [J]. Journal of Sound and Vibration, 1996, 195: 301-311

[3] Mengsa Yu, Xiaojun Shi. Study on acoustic similitude of elastic stiffened cylindrical shells by FEM and BEM [J]. Shipbuilding of China, 1999, 40: 65-71 (in Chinese)

[4] WANG Sande, YANG Desen, WANG Huili. Prediction of the vibration response and sound radiation of the finite cylindrical shell by the similitude method [A]. 5^th International Symposium on Test and Measurement [C]. Shenzhen, China, 2003.

[5] Deyuan Yao, Qizheng Wang. Theory and application of statistical energy analysis [M]. 1995, Beijing: Publishing House of Beijing, (in Chinese)

[6] Lyon R H. Statistical energy analysis of dynamical system: theory and applications [M]. 1996, Cambridge: The MIT Press

[7] Mengsa Yu, Xiaojun Shi, Yong Wu. Similitude analysis of vibration and acoustic radiation for elastic structure [J]. Journal of Ship Mechanics, 1998, 2: 55-61 (in Chinese)

[8] Langley R S. A derivation of the coupling loss factors used in statistical energy analysis [J]. Journal of Sound and Vibration, 1990, 141: 207-219

[9] White R G, Walker J G. Noise and vibration [M]. 1982, New York: Halsted Press