Transient Response of a Periodically Supported Cylindrical Shell Immersed in a Fluid Medium

1965 ◽  
Vol 32 (3) ◽  
pp. 562-568 ◽  
Author(s):  
Harry Herman ◽  
J. M. Klosner
Keyword(s):  
Cylindrical Shell ◽  
Integral Transform ◽  
Circular Cylindrical Shell ◽  
Fourier Integral ◽  
Cylindrical Wave ◽  
Acoustic Medium ◽  
Steel Shell ◽  
Fluid Medium ◽  
Wave Approximation ◽  
Fourier Integral Transform

The dynamic response of a periodically simply supported, infinitely long, circular cylindrical shell to a pressure suddenly applied through the surrounding acoustic medium is investigated. The incident particle velocity is zero, and the pressure is assumed to have a harmonic spatial variation parallel to the shell axis. The exact solution is obtained by use of a Fourier integral transform, and the resulting inversion integral is evaluated by numerical and asymptotic integration. Two solutions to the same problem are obtained by using a plane and cylindrical wave approximation for the radiated field. The range of their applicability is investigated. For a steel shell in water ccs2=0.08815 it is found that, when the supports are placed three shell diameters apart, the use of the cylindrical wave approximation results in a 5-percent underestimation of the maximum deflection, while when the supports are placed one sixth of a shell diameter apart, the approximations are invalid.

scholarly journals Interaction of a Ring-Reinforced Shell and a Fluid Medium

1968 ◽  
Vol 35 (1) ◽  
pp. 139-147 ◽  
Author(s):  
Jerry W. Berglund ◽  
Jerome M. Klosner
Keyword(s):  
Circular Cylindrical Shell ◽  
Salt Water ◽  
Power Series Expansion ◽  
Cylindrical Wave ◽  
Acoustic Medium ◽  
Steel Shell ◽  
Fluid Medium ◽  
Transient Dynamic ◽  
Wave Approximation ◽  
Fluid Field

This work is concerned with the transient dynamic response of a periodically ring-reinforced, infinitely long, circular cylindrical shell to a uniform pressure suddenly applied through the surrounding acoustic medium. The incident particle velocity is zero, and the rings are assumed to be slightly flexible. A classical theory of the Donnell type is used to analyze the shell while the fluid is described by the linear acoustic field equation. The solution is obtained by assuming a power series expansion in the ring stiffness parameter and utilizing a technique which reduces the transient dynamic problem to an equivalent steady-state formulation. Numerical results are presented for a steel shell immersed in salt water for different ring spacings. For the case of rigid rings, a cylindrical and plane wave approximation was also used to represent the fluid field. It is shown that the cylindrical wave approximation yields reasonably accurate results. Flexible ring results, although limited, indicate that undamped or nonradiating components of the shell vibration are activated.

Nonlinear Response of an Elastic Cylindrical Shell to a Transient Acoustic Wave

1981 ◽  
Vol 48 (1) ◽  
pp. 15-24 ◽  
Author(s):  
T. L. Geers ◽  
C.-L. Yen
Keyword(s):  
Cylindrical Shell ◽  
Acoustic Wave ◽  
Nonlinear Response ◽  
Circular Cylindrical Shell ◽  
Elastic Cylindrical Shell ◽  
Fluid Medium ◽  
Energy Functionals ◽  
Potential Formulation ◽  
Rigorous Treatment ◽  
Residual Potential

Governing equations are developed for the nonlinear response of an infinite, elastic, circular cylindrical shell submerged in an infinite fluid medium and excited by a transverse, transient acoustic wave. These equations derive from circumferential Fourier-series decomposition of the field quantities appearing in appropriate energy functionals, and from application of the “residual potential formulation” for rigorous treatment of the fluid-structure interaction. Extensive numerical results are presented that provide understanding of the phenomenology involved.

Effects of Interleaves on Fracture of Laminated Composites: Part I—Analysis

1990 ◽  
Vol 57 (1) ◽  
pp. 168-174 ◽  
Author(s):  
A. K. Kaw ◽  
J. G. Goree
Keyword(s):  
Composite Laminates ◽  
Integral Transform ◽  
Singular Integral Equations ◽  
Fourier Integral ◽  
Elastic Media ◽  
Two Dimensional ◽  
Shear Moduli ◽  
Fourier Integral Transform ◽  
Shaped Crack ◽  
Symmetric Crack

The influence of placing interleaves between fiber-reinforced plies in multilayered composite laminates is investigated. The geometry of the composite is idealized as a two-dimensional, isotropic, linearly elastic media consisting of a damaged layer bonded between two half-planes and separated by thin interleaves of low extensional and shear moduli. The damage in the layer is taken in the form of a symmetric crack perpendicular to the interface. The case of an H-shaped crack in the form of a broken layer with delamination along the interface is also analyzed. Fourier integral transform techniques are used to develop the solutions in terms of singular integral equations.

Stresses Emanating From the Supports of a Cylindrical Shell Produced by a Lateral Pressure Pulse

1972 ◽  
Vol 39 (1) ◽  
pp. 124-128 ◽  
Author(s):  
M. J. Forrestal ◽  
G. E. Sliter ◽  
M. J. Sagartz
Keyword(s):  
Cylindrical Shell ◽  
Shell Theory ◽  
Pressure Pulse ◽  
Integral Transform ◽  
Circular Cylindrical Shell ◽  
Radial Pressure ◽  
Rectangular Pulse ◽  
Wave Fronts ◽  
Timoshenko Type ◽  
Stress Resultant

A semi-infinite, elastic, circular cylindrical shell is subjected to two uniform, radial pressure pulses, one a step pulse and the other a short-duration, rectangular pulse. Solutions for the stresses emanating from both a clamped support and a simple support are presented for a Timoshenko-type shell theory and a shell bending theory. Results from the Timoshenko-type theory are obtained using the method of characteristics, and results from the shell bending theory are obtained using integral transform techniques. Numerical results from both shell theories are presented for the bending stress and the shear stress resultant. Results show that the effects of rotary inertia and shear deformation are important only in the vicinity of the wave fronts. However, if the duration of the pressure pulse is short, maximum stresses can occur in the vicinity of the wave fronts where a Timoshenko-type shell theory is required for realistic response predictions.

Excitation of an Elastic Cylindrical Shell by a Transient Acoustic Wave

1969 ◽  
Vol 36 (3) ◽  
pp. 459-469 ◽  
Author(s):  
T. L. Geers
Keyword(s):  
Cylindrical Shell ◽  
Acoustic Wave ◽  
Circular Cylindrical Shell ◽  
Elastic Cylindrical Shell ◽  
Sandwich Shell ◽  
Governing Equations ◽  
Fluid Medium ◽  
Method Of Solution ◽  
Plane Step ◽  
Strain Responses

An infinite, elastic, circular cylindrical shell submerged in an infinite fluid medium is engulfed by a transverse, transient acoustic wave. The governing equations for modal shell response are reduced through the application of a new method of solution to two simultaneous equations in time; these equations are particularly amenable to solution by machine computation. Numerical results are presented for the first six modes of a uniform sandwich shell submerged in water and excited by a plane step-wave. These results are then used to evaluate the accuracy of a number of approximations which have been employed previously to treat this and similar problems. The results are also used to compute displacement, velocity, and flexural strain responses at certain points in the sandwich shell.

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