Acoustic scattering from fluid-loaded stiffened cylindrical shell: Analysis using elasticity theory

2000 ◽  
Vol 107 (6) ◽  
pp. 3208-3216 ◽  
Author(s):  
André Baillard ◽  
Jean-Marc Conoir ◽  
Dominique Décultot ◽  
Gérard Maze ◽  
Aleksander Klauson ◽  
...  
Keyword(s):  
Cylindrical Shell ◽  
Elasticity Theory ◽  
Acoustic Scattering ◽  
Stiffened Cylindrical Shell ◽  
Shell Analysis

scholarly journals Acoustic scattering from a stiffened finite cylindrical shell with external rings

2019 ◽  
Vol 283 ◽  
pp. 03002
Author(s):  
Fulin Zhou ◽  
Jun Fan ◽  
Bin Wang
Keyword(s):  
Cylindrical Shell ◽  
Acoustic Waves ◽  
Cylindrical Shells ◽  
Acoustic Scattering ◽  
Approximate Analytical Expression ◽  
Low Frequencies ◽  
Stiffened Cylindrical Shell ◽  
Layered Shells ◽  
Underwater Target ◽  
Finite Cylindrical Shell

Studying the interaction of sound with cylindrical shells immersed in water is essential and helpful to improving underwater target detection and classification algorithms. Elastic cylindrical shells often occur as part of double-layered shell and have been widely used in marine and aerospace area. Acoustic waves are easy to be transmitted through the outer shell to the interior especially at low frequencies, thus directly being scattered by the inner shell and the rings in water between double-layered shells. Therefore, the externally ring-stiffened cylindrical shell is investigated in this paper. An experiment was conducted that measured the acoustic scattering. A hybrid 2-D/3-D finite-element modelling technique is employed to numerically calculate the scattering characteristics. Good qualitative agreement is found between numerical calculations and experimental measurement. An approximate analytical expression is given explicitly to identify the Bragg wave trajectories in the frequency-angle spectrum. It also has been shown that the rings not only affect the dynamic response of shell and indirectly influence the exterior scattered field, but also become direct acoustic scatterers in water and increase the target cross section especially at oblique incidence.

Sound scattering by a stiffened cylindrical shell using elasticity theory

1998 ◽  
Vol 104 (3) ◽  
pp. 1754-1754
Author(s):  
A. Baillard ◽  
J.‐M. Conoir ◽  
D. Décultot ◽  
G. Maze ◽  
A. Klauson ◽  
...  
Keyword(s):  
Cylindrical Shell ◽  
Elasticity Theory ◽  
Sound Scattering ◽  
Stiffened Cylindrical Shell

Laminated Composite Stiffened Cylindrical Shell Panels with Cutouts under Free Vibration

2015 ◽  
Vol 5 (3) ◽  
pp. 37-63 ◽  
Author(s):  
Sarmila Sahoo
Keyword(s):  
Cylindrical Shell ◽  
Free Vibration ◽  
Laminated Composite ◽  
Beam Element ◽  
Benchmark Problems ◽  
Finite Element Code ◽  
Optimum Size ◽  
Isoparametric Element ◽  
Stiffened Cylindrical Shell ◽  
Practical Constraints

The free vibration of laminated composite stiffened cylindrical shell panels in the presence of cutout is investigated. A finite element code is developed using eight-noded curved quadratic isoparametric element for shell with a three noded beam element for stiffener and the formulation is validated through solution of benchmark problems which were earlier solved by other researchers. Parametric study is carried out varying the size of the cutouts and their positions with respect to the shell centre for different edge constraints. The results are presented in the form of figures and tables. The results are further analyzed to suggest guidelines to select optimum size and position of the cutout with respect to shell centre considering the different practical constraints.

Vibrational and acoustic radiation from a submerged periodic cylindrical shell with axial stiffening

2009 ◽  
Vol 223 (5) ◽  
pp. 1083-1089 ◽  
Author(s):  
C-J Liao ◽  
W-K Jiang ◽  
H Duan ◽  
Y Wang
Keyword(s):  
Cylindrical Shell ◽  
Analytical Study ◽  
Acoustic Radiation ◽  
Sound Radiation ◽  
Mechanical Impedance ◽  
Stiffened Cylindrical Shell ◽  
Reaction Forces ◽  
Radial Forces ◽  
Vibration And Sound Radiation ◽  
Finite Cylindrical Shell

An analytical study on the vibration and acoustic radiation from an axially stiffened cylindrical shell in water is presented. Supposing that the axial stiffeners interact with the cylindrical shell only through radial forces, the reaction forces on the shell from stiffeners can be expressed by additional impedance. The coupled vibration equation of the finite cylindrical shell with axial stiffening is derived; in this equation additional impedance caused by the axial stiffeners is added. As a result, the vibration and sound radiation of the shell are dependent on the mechanical impedance of the shell, the radiation sound impedance, and the additional impedance of the axial stiffeners. Based on the numerical simulation, it is found that the existence of axial stiffeners decreases the sound radiation and surface average velocity, whereas it increases the radiation factor. The characteristics of the acoustic radiation can be understood from the simulation with good results, which show that the presented methodology can be used to study the mechanism of the acoustic radiation of the complicated cylindrical shell and to optimize its design.

CYLINDRICAL SHELL ANALYSIS BY DYNAMIC RELAXATION.

1968 ◽  
Vol 39 (1) ◽  
pp. 75-84 ◽  
Author(s):  
A C CASSELL ◽  
P J KINSEY ◽  
D J SEFTON
Keyword(s):  
Cylindrical Shell ◽  
Dynamic Relaxation ◽  
Shell Analysis
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