scholarly journals Elastic Response of Acoustic Coating on Fluid-Loaded Rib-Stiffened Cylindrical Shells

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Christopher Gilles Doherty ◽  
Steve C. Southward ◽  
Andrew J. Hull
Keyword(s):  
Cylindrical Shell ◽  
Cylindrical Shells ◽  
Coupled System ◽  
Elastic Response ◽  
System Response ◽  
Elastic Cylindrical Shell ◽  
Fluid Environment ◽  
Reinforcing Ribs ◽  
Double Index ◽  
Stress Boundary Conditions

Reinforced cylindrical shells are used in numerous industries; common examples include undersea vehicles, aircraft, and industrial piping. Current models typically incorporate approximation theories to determine shell behavior, which are limited by both thickness and frequency. In addition, many applications feature coatings on the shell interior or exterior that normally have thicknesses which must also be considered. To increase the fidelity of such systems, this work develops an analytic model of an elastic cylindrical shell featuring periodically spaced ring stiffeners with a coating applied to the outer surface. There is an external fluid environment. Beginning with the equations of elasticity for a solid, spatial-domain displacement field solutions are developed incorporating unknown wave propagation coefficients. These fields are used to determine stresses at the boundaries of the shell and coating, which are then coupled with stresses from the stiffeners and fluid. The stress boundary conditions contain double-index infinite summations, which are decoupled, truncated, and recombined into a global matrix equation. The solution to this global equation results in the displacement responses of the system as well as the exterior scattered pressure field. An incident acoustic wave excitation is considered. Thin-shell reference models are used for validation, and the predicted system response to an example simulation is examined. It is shown that the reinforcing ribs and coating add significant complexity to the overall cylindrical shell model; however, the proposed approach enables the study of structural and acoustic responses of the coupled system.

Dynamic thermo-elastic response of a discrete multi-layered cylindrical shell subjected to transient thermal loading

2008 ◽  
Vol 222 (4) ◽  
pp. 549-561 ◽  
Author(s):  
J Y Zheng ◽  
X D Wu ◽  
Y J Chen ◽  
G D Deng ◽  
Q M Li ◽  
...  
Keyword(s):  
Cylindrical Shell ◽  
Boundary Conditions ◽  
Thermal Loading ◽  
Elastic Response ◽  
Elastic Part ◽  
Dynamic Part ◽  
Layered Cylindrical Shell ◽  
Stress Boundary Conditions ◽  
Transient Thermal ◽  
Stress Boundary

Explosion containment vessels (ECVs) are used to fully contain the effects of explosion events. A discrete multi-layered cylindrical shell (DMC) consisting of a thin inner cylindrical shell and helically cross-winding flat steel ribbons has been proposed, which has obvious advantages of fabrication convenience and low costs. The applications of ECVs are closely associated with blast and thermal loads, and thus, it is important to understand the response of a DMC under transient thermal load in order to develop a design code and operation procedures for the use of DMC as ECV. In this paper, a mathematical model for the elastic response of a DMC subjected to thermal loading due to rapid heating is proposed. Based on the axisymmetric plane strain assumption, the displacement solution of the dynamic equilibrium equations of both inner shell and outer ribbon layer are decomposed into two parts, i.e. a thermo-elastic part satisfying inhomogeneous stress boundary conditions and a dynamic part for homogeneous stress boundary conditions. The thermo-elastic part is solved by a linear method and the dynamic part is determined by means of finite Hankel transform and Laplace transform. The thermo-elastic solution of a DMC is compared with the solution of a monobloc cylindrical shell, and numerical results are presented and discussed in terms of winding angle and material parameters.

Analysis of Wave Propagation in Elastic Cylindrical Shells by the Perturbation Method

1972 ◽  
Vol 39 (2) ◽  
pp. 385-389 ◽  
Author(s):  
T. L. Geers
Keyword(s):  
Cylindrical Shell ◽  
Wave Propagation ◽  
Perturbation Method ◽  
Cylindrical Shells ◽  
Stress Waves ◽  
Elastic Cylindrical Shell ◽  
Series Solutions ◽  
Perturbation Solutions

Simple perturbation solutions are given for the propagation of stress waves in an elastic cylindrical shell subjected to transient, axisymmetric, longitudinal excitations. The solutions are shown to be accurate even at rather large distances from the boundary at which the excitation is applied. Convergence of the series solutions is examined and application of the technique to related problems is discussed.

Response of an Elastic Cylindrical Shell to a Transverse, Step Shock Wave

1953 ◽  
Vol 20 (2) ◽  
pp. 189-195
Author(s):  
R. D. Mindlin ◽  
H. H. Bleich
Keyword(s):  
Shock Wave ◽  
Cylindrical Shell ◽  
Wave Front ◽  
Plane Shock Wave ◽  
Elastic Response ◽  
Acoustic Medium ◽  
Elastic Cylindrical Shell ◽  
Plane Shock ◽  
Mathematical Solution ◽  
Long Cylindrical Shell

Abstract A plane shock wave in an acoustic medium encounters a long cylindrical shell whose axis is parallel to the wave front. An approximate mathematical solution is obtained for the elastic response of the shell.

Acoustic Radiation From Thick Laminated Cylindrical Shells With Sparse Cross Stiffeners

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Xiongtao Cao ◽  
Chao Ma ◽  
Hongxing Hua
Keyword(s):  
Cylindrical Shell ◽  
Radial Displacement ◽  
Acoustic Radiation ◽  
Periodic Structures ◽  
Cylindrical Shells ◽  
Acoustic Power ◽  
Acoustic Energy ◽  
Parallel Plates ◽  
Wavenumber Domain ◽  
Laminated Cylindrical Shells

A general method for predicting acoustic radiation from multiple periodic structures is presented and a numerical solution is proposed to find the radial displacement of thick laminated cylindrical shells with sparse cross stiffeners in the wavenumber domain. Although this method aims at the sound radiation from a single stiffened cylindrical shell, it can be easily adapted to analyze the vibrational and sound characteristics of two concentric cylindrical shells or two parallel plates with complicated periodic stiffeners, such as submarine and ship hulls. The sparse cross stiffeners are composed of two sets of parallel rings and one set of longitudinal stringers. The acoustic power of large cylindrical shells above the ring frequency is derived in the wavenumber domain on the basis of the fact that sound power is focused on the acoustic ellipse. It transpires that a great many band gaps of wave propagation in the helical wave spectra of the radial displacement for stiffened cylindrical shells are generated by the rings and stringers. The acoustic power and input power of stiffened antisymmetric laminated cylindrical shells are computed and compared. The acoustic energy conversion efficiency of the cylindrical shells is less than 10%. The axial and circumferential point forces can also produce distinct acoustic power. The radial displacement patterns of the antisymmetric cylindrical shell with fluid loadings are illustrated in the space domain. This study would help to better understand the main mechanism of acoustic radiation from stiffened laminated composite shells, which has not been adequately addressed in its companion paper (Cao et al., 2012, “Acoustic Radiation From Shear Deformable Stiffened Laminated Cylindrical Shells,” J. Sound Vib., 331(3), pp. 651-670).

Acoustic wave diffraction by an elastic cylindrical shell with viscous filling

1989 ◽  
Vol 25 (7) ◽  
pp. 662-667 ◽  
Author(s):  
O. B. Kachaenko ◽  
L. S. Pal'ko ◽  
N. A. Shul'ga
Keyword(s):  
Cylindrical Shell ◽  
Acoustic Wave ◽  
Wave Diffraction ◽  
Elastic Cylindrical Shell

scholarly journals An Evaluation of Active Noise Control in a Cylindrical Shell

1989 ◽  
Vol 111 (3) ◽  
pp. 337-342 ◽  
Author(s):  
R. J. Silcox ◽  
H. C. Lester ◽  
S. B. Abler
Keyword(s):  
Cylindrical Shell ◽  
Analytical Model ◽  
Noise Control ◽  
Active Noise Control ◽  
Effective Control ◽  
Elastic Cylindrical Shell ◽  
Noise Sources ◽  
Active Noise ◽  
Fixed Array ◽  
Forced Responses

This paper examines the physical mechanisms governing the use of active noise control in an extended volume of a cylindrical shell. Measured data were compared with computed results from a previously derived analytical model based on infinite shell theory. For both the analytical model and experiment, the radiation of external monopoles is coupled to the internal acoustic field through the radial displacement of the thin, elastic, cylindrical shell. An active noise control system was implemented inside the cylinder using a fixed array of discrete monopole sources, all of which lie in the plane of the exterior noise sources. Good agreement between measurement and prediction was obtained for both internal pressure response and overall noise reduction. Attenuations in the source plane greater than 15 dB were recorded along with a uniformly quieted noise environment over an indicative length inside the experimental model. Results indicate that for forced responses with extended axial distributions, axial arrays of control sources may be required. Finally, the Nyquist criteria for the number of azimuthal control sources is shown to provide for effective control over the full cylinder cross section.

scholarly journals Strain Growth in a Finite-Length Cylindrical Shell Under Internal Pressure Pulse

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Qi Dong ◽  
Q. M. Li ◽  
Jinyang Zheng
Keyword(s):  
Cylindrical Shell ◽  
Boundary Conditions ◽  
Internal Pressure ◽  
Finite Length ◽  
Pressure Pulse ◽  
Elastic Response ◽  
Local Dynamic ◽  
Growth Phenomenon ◽  
Modal Coupling ◽  
Elastic Responses

Strain growth is a phenomenon observed in the elastic response of containment vessels subjected to internal blast loading. The local dynamic response of a containment vessel may become larger in a later stage than its response in the earlier stage. In order to understand the possible mechanisms of the strain growth phenomenon in a cylindrical vessel, dynamic elastic responses of a finite-length cylindrical shell with different boundary conditions subjected to internal pressure pulse are studied by finite-element simulation using LS-DYNA. It is found that the strain growth in a finite-length cylindrical shell with sliding–sliding boundary conditions is caused by nonlinear modal coupling. Strain growth in a finite-length cylindrical shell with free–free or simply supported boundary conditions is primarily caused by the linear modal superposition, possibly enhanced by the nonlinear modal coupling. The understanding of these strain growth mechanisms can guide the design of cylindrical containment vessels.

Buckling of Stiffened Curved Panels and Cylindrical Shells: A Study of Comparison Among Various Theories

2012 ◽  
Author(s):  
S. Harutyunyan ◽  
D. J. Hasanyan ◽  
R. B. Davis
Keyword(s):  
Cylindrical Shell ◽  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Laminated Composite ◽  
Physical Parameters ◽  
Buckling Loads ◽  
Isotropic Cylindrical Shell ◽  
Analytical Formulas ◽  
Laminated Composite Shells ◽  
Curved Panels

Formulation is derived for buckling of the circular cylindrical shell with multiple orthotropic layers and eccentric stiffeners acting under axial compression, lateral pressure, and/or combinations thereof, based on Sanders-Koiter theory. Buckling loads of circular cylindrical laminated composite shells are obtained using Sanders-Koiter, Love, and Donnell shell theories. These theories are compared for the variations in the stiffened cylindrical shells. To further demonstrate the shell theories for buckling load, the following particular case has been discussed: Cross-Ply with N odd (symmetric) laminated orthotropic layers. For certain cases the analytical buckling loads formula is derived for the stiffened isotropic cylindrical shell, when the ratio of the principal lamina stiffness is F = E2/E1 = 1. Due to the variations in geometrical and physical parameters in theory, meaningful general results are complicated to present. Accordingly, specific numerical examples are given to illustrate application of the proposed theory and derived analytical formulas for the buckling loads. The results derived herein are then compared to similar published work.

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