Coupled vibro-acoustic analysis of submerged double cylindrical shells with stringers, rings, and annular plates in a symplectic duality system

2022 ◽  
Vol 171 ◽  
pp. 108671
Author(s):  
Chenge Pan ◽  
Yahui Zhang
Keyword(s):  
Acoustic Analysis ◽  
Cylindrical Shells ◽  
Annular Plates ◽  
Symplectic Duality

Simulation of Vibration and Acoustic Radiation of Finite Underwater Cylindrical Shells

2000 ◽  
Author(s):  
X. M. Zhang ◽  
G. R. Liu ◽  
K. Y. Lam
Keyword(s):  
Acoustic Analysis ◽  
Acoustic Radiation ◽  
Cylindrical Shells ◽  
Sound Radiation ◽  
Coupled Vibration ◽  
Response Curves ◽  
Vibration And Sound Radiation ◽  
Acoustic Domain ◽  
High Sound ◽  
Element Method

Abstract A coupled structural-acoustic analysis of vibration and sound radiation of underwater finite cylindrical shells is investigated in this paper. The coupled vibration and radiation problem is formulated using Finite Element Method (FEM) for the structure and Boundary Element Method (BEM) for the acoustic domain. Vibration and sound radiation under symmetrical and unsymmetrical point force excitations are examined. It is shown that the coupled modals are the causes of large vibration of the shell and high sound pressure radiation of the acoustic fields. The shapes of frequency response curves of pressure are quite similar in the far fields but change greatly in the near fields.

Free vibration analysis of embedded functionally graded carbon nanotube-reinforced composite conical/cylindrical shells and annular plates using a numerical approach

2016 ◽  
Vol 24 (6) ◽  
pp. 1123-1144 ◽  
Author(s):  
R Ansari ◽  
J Torabi ◽  
M Faghih Shojaei
Keyword(s):  
Carbon Nanotube ◽  
Free Vibration ◽  
Vibration Analysis ◽  
Cylindrical Shells ◽  
Free Vibration Analysis ◽  
Energy Functional ◽  
Functionally Graded ◽  
Differential Quadrature ◽  
Annular Plates ◽  
Reinforced Composite

Free vibration analysis of embedded functionally graded carbon nanotube-reinforced composite (FG-CNTRC) conical, cylindrical shells and annular plates is carried out using the variational differential quadrature (VDQ) method. Pasternak-type elastic foundation is taken into consideration. It is assumed that the functionally graded nanocomposite materials have the continuous material properties defined according to extended rule of mixture. Based on the first-order shear deformation theory, the energy functional of the structure is calculated. Applying the generalized differential quadrature method and periodic differential operators in axial and circumferential directions, respectively, the discretized form of the energy functional is derived. Based on Hamilton’s principle and using the VDQ method, the reduced forms of mass and stiffness matrices are obtained. The comparison and convergence studies of the present numerical method are first performed and then various numerical results are presented. It is found that the volume fractions and functionally grading of carbon nanotubes play important roles in the vibrational characteristics of FG-CNTRC cylindrical, conical shells and annular plates.

Effect of Drive Location on Vibro-Acoustic Characteristics of Submerged Double Cylindrical Shells with Damping Layers

2013 ◽  
Vol 387 ◽  
pp. 59-63
Author(s):  
Chao Zhang ◽  
De Jiang Shang ◽  
Qi Li
Keyword(s):  
Annular Plate ◽  
Cylindrical Shells ◽  
Three Dimensional ◽  
Plane Motion ◽  
Superposition Method ◽  
Annular Plates ◽  
Radiated Power ◽  
Modal Superposition Method ◽  
Viscoelastic Theory ◽  
Vibration And Sound Radiation

Based on the modal superposition method, the analytical model of vibration and sound radiation from submerged double cylindrical shells with damping layers was presented. The shells were described by the classical thin shell theory. The damping layers were described by three-dimensional viscoelastic theory. The annular plates, connecting the double shells, were analyzed with in-plane motion theory. For different drive locations of radial point force on the inner shell, the sound radiated power and the radial quadratic velocity of the model were calculated and analyzed. The results show that making the drive location near the annular plate helps to reduce the sound radiated power and radial quadratic velocity of model, and making the drive location far from the middle of model also helps to reduce the sound radiated power. The drive applied on the location of annular plate causes high similarity of vibrations from inner shell and outer shell.

CONTINUOUS ELEMENT FORMULATIONS FOR COMPOSITE RING-STIFFENED CYLINDRICAL SHELLS

2018 ◽  
Vol 56 (4) ◽  
pp. 515 ◽  
Author(s):  
Nam Bich Le ◽  
Cuong Manh Nguyen ◽  
Thinh Ich Tran
Keyword(s):  
Dynamic Stiffness ◽  
Equations Of Motion ◽  
Cylindrical Shells ◽  
Governing Equations ◽  
Composite Ring ◽  
Annular Plates ◽  
Proposed Model ◽  
Assembly Procedure ◽  
Stiffened Cylindrical Shells ◽  
Ring Stiffener

This research studies the free vibration of composite ring-stiffened cylindrical shells by the continuous element method (CEM). The dynamic stiffness matrix (DSM) of the investigated structure has been constructed based on the analytical solutions of the governing equations of motion for composite cylindrical shells and annular plates. By applying the powerful assembly procedure of continuous elements method, natural frequencies and harmonic responses of composite ring-stiffened cylindrical shells have been obtained. In addition, the proposed model allows extracting exactly ring-stiffener vibration modes by choosing appropriate points of response. Numerical examples have confirmed many advantages of the developed model.

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