Computer Simulation of Cylindrical Shell Penetrated by Rigid Projectile

2012 ◽  
Vol 152-154 ◽  
pp. 594-598
Author(s):  
Xue Hui Yu ◽  
Zhi Jun Han ◽  
Zuo Yi Kang ◽  
Guo Yun Lu ◽  
Zhi Fang Liu
Keyword(s):  
Computer Simulation ◽  
Cylindrical Shell ◽  
Energy Distribution ◽  
Critical Speed ◽  
Cylindrical Shells ◽  
Great Influence ◽  
Geometric Parameters ◽  
Lateral Impact ◽  
Rigid Projectile ◽  
Different Thickness

Computer simulation of cylindrical shell subject to lateral impact by rigid projectile is carried out. The effects of three kinds of typical rigid projectiles, geometric parameters of cylindrical shell and constraint conditions on critical speed are analyzed. The results indicate that the shape of projectile and size of cylindrical shell have a great influence on penetration, and the tapered projectile has a minimum critical speed. The influence of constraint conditions on penetration has a great relationship with thickness of cylindrical shells; energy distribution varies with different thickness of cylindrical shells.

Influence of Geometry on the Non-Linear Vibrations of Cylindrical Shells With Internal Flowing Fluid

2010 ◽  
Author(s):  
Zenon J. del Prado ◽  
Paulo B. Gonc¸alves ◽  
Michael P. Pai¨doussis
Keyword(s):  
Cylindrical Shell ◽  
Degrees Of Freedom ◽  
Lateral Displacement ◽  
Equations Of Motion ◽  
Cylindrical Shells ◽  
Dynamic Environment ◽  
Geometric Parameters ◽  
Flowing Fluid ◽  
Non Linear ◽  
Linear Vibrations

In this work, the influence of the characteristic geometric parameters of a cylindrical shell, such as radius-to-thickness and radius-to-length ratios, on both the linear and non-linear vibrations of a fluid-filled cylindrical shell with internal flowing fluid is studied. The Donnell non-linear shallow shell equations are used to study a simply supported cylindrical shell subjected to both lateral and axial time-dependent loads with internal flowing fluid. The fluid is assumed to be inviscid and incompressible and the flow isentropic and irrotational. An expansion with eight degrees of freedom, containing the fundamental, companion, gyroscopic and five axisymmetric modes is used to describe the lateral displacement of the shell. The Galerkin method is used to obtain the nonlinear equations of motion which are, in turn, solved by the Runge-Kutta method. First, the parametric linear equations are used to study the influence of geometry and physical properties on the natural frequencies, critical flow and critical circumferential wavenumber. Secondly, numerical methods are used to describe the influence of geometric characteristics on the non-linear frequency-amplitude relations of the shell. The results obtained show the influence of the geometric parameters on the vibration characteristics of the shell and can be used as a basic tool for design of cylindrical shells in a dynamic environment.

scholarly journals Simulation Analysis of Cylindrical Shell Cavity Noise with Melamine Foam Lining

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Menghui Qi ◽  
Bin Li ◽  
Shilin Yan ◽  
Qinghua Yan ◽  
Qiyu He
Keyword(s):  
Cylindrical Shell ◽  
Noise Reduction ◽  
Simulation Analysis ◽  
Cylindrical Shells ◽  
Element Model ◽  
Measured Data ◽  
Frequency Noise ◽  
Precision Instrument ◽  
Different Thickness ◽  
Melamine Foam

To solve the problem of the harsh midlow frequency noise of rocket fairing, the cylindrical section of the protective precision instrument fairing is simplified as cylindrical shells, and different lining strategies of melamine foam (MF) are studied experimentally and numerically. Based on Virtual.Lab Acoustic software, a finite element model of the cylindrical cavity is established, and the correctness is verified by comparison with the measured data. On that basis, the influences of the lining position of different thickness MF on the noise reduction of cylindrical shells are investigated. It is shown that the thickness and location of the laying material have a significant effect on the noise reduction at the same specific gravity.

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).

Acoustical Design Study on Application of Absorption Materials

2014 ◽  
Vol 711 ◽  
pp. 546-549
Author(s):  
Wei Lin ◽  
Wei Hwa Chiang
Keyword(s):  
Computer Simulation ◽  
Energy Distribution ◽  
Ray Tracing ◽  
Impulse Response ◽  
Background Noise ◽  
Three Dimensional ◽  
Design Phase ◽  
Design Study ◽  
Sound Energy ◽  
Reinforcement System

Taipei Top Church Auditorium is a hall primarily intended for praise and worship. A three dimensional ray tracing computer simulation was used to provide sound energy distribution on the audience area of the hall, realistic design have been performed. The volume of the hall is 24600m3, which is occupied for 2200 people and equipped the hall with acoustical curtains by modifying its acoustical characteristics. Objective measurements of impulse response are reported, and background noise control and noise isolation are also be considered in the design phase. Reinforcement system is conducted to meet all the activity for the acoustical environments.

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.

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.

Numerical Simulation on Failure Process of Internally Pressured Cylindrical Shell Subjected to Wedge Impact

2006 ◽  
Vol 324-325 ◽  
pp. 523-526 ◽  
Author(s):  
Gang Chen ◽  
Qing Ping Zhang ◽  
Zhong Fu Chen ◽  
Si Zhong Li ◽  
Yu Ze Chen
Keyword(s):  
Numerical Simulation ◽  
Cylindrical Shell ◽  
Experimental Observation ◽  
Impact Loading ◽  
Cylindrical Shells ◽  
Failure Process ◽  
Dynamic Failure ◽  
Local Impact ◽  
Wedge Impact ◽  
Numeral Simulation

Cylindrical shell is a kind of common used structure in engineering. Interest in the response of cylindrical shells to local impact loading has increased over the last few years. A structure always endures working load more or less. For a cylindrical shell, the working load commonly is internally pressure. In this paper, a numeral simulation of wedge block impact internally Pressured cylindrical shell was carried out. The dynamic failure process of the structure was obtained. The consistency between experimental observation and numerical simulation is satisfactory.

Cylindrical Shells: Energy, Equilibrium, Addenda, and Erratum

1955 ◽  
Vol 22 (1) ◽  
pp. 111-116
Author(s):  
E. H. Kennard
Keyword(s):  
Cylindrical Shell ◽  
Strain Energy ◽  
Cylindrical Shells ◽  
Uniform Thickness ◽  
Energy Equilibrium

Abstract The strain energy in a homogeneous cylindrical shell of uniform thickness is calculated from equations obtained by Epstein’s method. The indeterminateness of the equations of equilibrium is further discussed and simplified forms of these equations and of the expressions for the stress resultants are given. Addenda and an erratum to a prior paper are included.

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