Plane-Strain Dynamic Response of a Cylindrical Shell—A Comparison Study of Three Different Shell Theories

1968 ◽  
Vol 35 (2) ◽  
pp. 297-305 ◽  
Author(s):  
H. Reismann ◽  
P. S. Pawlik

An analytical study of the plane-strain dynamic response of a circular, cylindrical shell is presented. The shell is subjected to a radially directed concentrated impulse acting on its surface. Solutions are presented within the framework of (a) membrane theory, (b) Flu¨gge theory, and (c) improved theory (including shear deformation and rotatory inertia). A quantitative study of the initial motion of the shell indicates major differences in response prediction of the three theories. An explanation of these differences is offered.

1979 ◽  
Vol 46 (4) ◽  
pp. 772-778 ◽  
Author(s):  
G. E. Cummings ◽  
H. Brandt

A numerical solution technique is presented for determining the dynamic response of a thin, elastic, circular, cylindrical shell of constant wall thickness and density, in a potential fluid. The shell may be excited by any radial forcing function with a specified time history and spatial distribution. In addition, a pressure history may be specified over a segment of the fluid outer boundary. Any of the natural shell end conditions may be prescribed. The numerical results are compared to experimental results for a 1/12-scale model of a nuclear-reactor core-support barrel. Natural frequencies and modes are determined for this model in air, water, and oil. The computed frequencies are within 15 percent of experimental results. A sample application compares the numerical technique to an analytical solution for shell beam modes. The comparison resolves an uncertainty concerning the proper effective mass to use in the analytical technique.


Author(s):  
J. Kaplunov ◽  
L. I. Manevitch ◽  
V. V. Smirnov

A new asymptotic approximation of the dynamic equations in the two-dimensional classical theory of thin-elastic shells is established for a circular cylindrical shell. It governs long wave vibrations in the vicinity of the lowest cut-off frequency. At a fixed circumferential wavenumber, the latter corresponds to the eigenfrequency of in-plane vibrations of a thin almost inextensible ring. It is stressed that the well-known semi-membrane theory of cylindrical shells is not suitable for tackling a near-cut-off behaviour. The dispersion relation within the framework of the developed formulation coincides with the asymptotic expansion of the dispersion relation originating from full two-dimensional shell equations. Asymptotic analysis also enables refining the geometric hypotheses underlying various ad hoc set-ups, including the assumption on vanishing of shear and circumferential mid-surface deformations used in the semi-membrane theory. The obtained results may be of interest for dynamic modelling of elongated cylindrical thin-walled structures, such as carbon nanotubes.


1973 ◽  
Vol 40 (3) ◽  
pp. 725-730 ◽  
Author(s):  
P. S. Pawlik ◽  
H. Reismann

A radially directed load is suddenly applied to a portion of the outer surface of a circular cylindrical shell which responds in a state of plane strain. An analytical solution for the resulting dynamic response is obtained within the context of linear elasticity theory, Flu¨gge shell theory, and an “improved” shell theory. A comparison of results for specific loading conditions indicates that the improved theory is far superior to the Flu¨gge theory in terms of predicting both the magnitude and characteristics of the response. However, as expected, neither shell theory satisfactorily predicts the wave character of the initial response.


2007 ◽  
Vol 51 (02) ◽  
pp. 94-103
Author(s):  
Li Xuebin

Following Flu¨ gge's exact derivation for the buckling of cylindrical shells, the equations of motion for dynamic loading of a circular cylindrical shell under external hydrostatic pressure have been formulated. The normal mode theory is used to provide transient dynamic response for the equations of motion. The responses of displacements, strain, and stress are obtained for the area of impact, while those outside the area of impact are also calculated. The accuracy of normal mode theory and Timoshenko shell theory are examined in this paper.


2009 ◽  
Vol 25 (3) ◽  
pp. 299-306 ◽  
Author(s):  
K. Daneshjou ◽  
R. Talebitooti ◽  
A. Nouri

AbstractAnalytical study is conducted in this paper to understand the characteristics of sound transmission through cylindrical shell with free layer damping (FLD) treatment. It is assumed an infinitely long circular cylindrical shell subjected to a plane wave with uniform airflow in the external fluid medium. The damping layer applied on the surface of the shell is represented by HN model with frequency-dependent specifications. An exact solution is obtained by solving the Markus equations of FLD shells and acoustic wave equations simultaneously. As the pressure and displacement terms are expressed in series form, an iterative procedure is founded to cut them with an appropriatenumber of modes. Transmission losses obtained from the solution are compared with “modal-impedance method” for an especial case of untreated shell. Eventually, the numerical results show the effects of stiffness, loss factor and thickness of damping material, and also incident wave angles on TL curves.


1996 ◽  
Vol 3 (3) ◽  
pp. 159-167 ◽  
Author(s):  
Marco Amabili

The receptance method is applied to the analytical study of the free vibrations of a simply supported circular cylindrical shell that is either empty or filled with an in viscid, incompressible fluid and with lumped masses attached at arbitrary positions. The receptance of the fluid-filled shell is obtained using the added virtual mass approach to model the fluid–structure interaction. The starting data for the computations is the modal properties of the cylinder that can be obtained using any theory of shells. Numerical results are obtained as roots of the frequency equation and also by considering the trivial solution. They are compared to data obtained by experimental modal analysis performed on a stainless steel tank, empty, or filled with water, with a lead mass attached.


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