Optimization of position, size and thickness of viscoelastic damping patch for vibration reduction of a cylindrical shell structure

Model updating techniques are used to modify structural model for more accurate predictions of dynamics behavior. A simple survey on the model updating methods and correlation criteria is presented. Based on the inverse eigensensitivity method (IESM) and modal assurance criterion (MAC), a scheme of model updating for structures is presented and realized by user defined subroutine combined with APDL in commercial software ANSYS®. A four-DOF spring-mass system is assumed and updated, from which the predicted frequencies and MAC values are satisfied compared to the actual dynamics characteristics. This gives evidence that the presented model updating scheme is feasible and efficient. Furthermore, a cylindrical shell structure containing global and local modal information is established to research the updating ability of the scheme on some focused local modal information. The results due to the updated model of cylindrical shell structure show that not only the global modal data but also the local modal data have a good agreement with that of the actual structure.

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Experimental Study on Influence of Edge Constraint and Mass Distribution Upon Elastic Vibration of Rectangular Cylindrical Shell Structure

The Proceedings of the Dynamics & Design Conference ◽

10.1299/jsmedmc.2019.114 ◽

2019 ◽

Vol 2019 (0) ◽

pp. 114

Author(s):

Makoto SASAKI ◽

Takahiro TOMIOKA

Keyword(s):

Experimental Study ◽

Cylindrical Shell ◽

Mass Distribution ◽

Shell Structure ◽

Elastic Vibration

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Influence of Acoustic Coating on the Underwater Sound Radiation of a Double Hull Cylindrical Shell Structure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.338.406 ◽

2011 ◽

Vol 338 ◽

pp. 406-410

Author(s):

Fu Zhen Pang ◽

Fu Bin Pang ◽

Xu Chao Yin ◽

Shuai Lv

Keyword(s):

Cylindrical Shell ◽

Noise Reduction ◽

Shell Structure ◽

Sound Radiation ◽

Radiation Characteristic ◽

Underwater Sound ◽

Surrounding Water ◽

Covering Density ◽

Hull Structure ◽

Double Hull

This paper studies the influence of acoustic coating to the underwater sound radiation characteristic of a double hull cylindrical shell by the Statistical Energy Analysis (SEA) method. Influence of covering density and laying location of acoustic coating to the underwater sound radiation characteristic of the double hull cylindrical shell structure are discussed. Study shows that low covering density of acoustic coating will cause “sound leaking” phenomena, sound will leak out from the uncovered area of the double hull cylindrical hull structure and radiate into the surrounding water, which harms the underwater noise reduction performance of the acoustic coating; however, the noise reduction capacity of the acoustic coating improves gradually as the covering density increases. Besides, laying location of acoustic coating also impact the underwater sound radiation performance of the double hull cylindrical shell structure; inner hull covered with acoustic coating is better than the outer hull covered from the noise treatment point of view

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