• Journal of Power System Engineering
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• v.17 no.2
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• pp.46-55
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• 2013

In this paper, the computational algorithm for free vibration analysis of an axisymmetric cylindrical shell is formulated by the Sylvester-transfer stiffness coefficient method (S-TSCM) which combines the Sylvester's inertia theorem and the transfer stiffness coefficient method. After the computational programs for obtaining the natural frequencies and natural modes of the axisymmetric cylindrical shell are made by the S-TSCM and the finite element method (FEM), the computational results which are natural frequencies, natural modes, and computational times by both methods are compared. From the computational results, we can confirm that S-TSCM has the reliability in the free vibration analysis of the axisymmetric cylindrical shell and is superior to FEM in the viewpoint of computational times.

• Journal of Power System Engineering
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• v.17 no.6
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• pp.33-39
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• 2013

It is very important to analyze the dynamic responses of the shell structures from the viewpoint of the design of shell structures with a variety of axisymmetric loadings. In this paper, the computational algorithm for the dynamic response analysis of an cylindrical shell with axisymmetric loading is formulated by the transfer mass coefficient method based on the transfer of mass coefficient. After the computational programs for obtaining the dynamic responses of cylindrical shells with axisymmetric loading are made by the transfer mass coefficient method and the finite element method, the computational results by both methods are compared. From the computational results, we can confirm that the transfer mass coefficient method has the effectiveness in the dynamic response analyses of cylindrical shells with a variety of axisymmetric loadings.

• Structural Engineering and Mechanics
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• v.8 no.1
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• pp.39-51
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• 1999

The dynamic response of buried pipelines has gained considerable importance because these pipelines perform vital role in conducting energy, water, communication and transportation. After realizing the magnitude of damage, and hence, the human uncomfort and the economical losses, researchers have paid sincere attention to this problem. A number of papers have appeared in the past which discuss the different aspects of the problem. This paper presents a theoretical analysis of non-axisymmetric dynamic response of buried orthotropic cylindrical shell subjected to a moving load along the axis of the shell. The orthotropic shell has been buried in a homogeneous, isotropic and elastic medium of infinite extent. A thick shell theory including the effects of rotary inertia and shear deformation has been used. A perfect bond between the shell and the surrounding medium has been assumed. Results have been obtained for very hard (rocky), medium hard and soft soil surrounding the shell. The effects of shell orthotropy have been brought out by varying the non-dimensional orthotropic parameters over a long range. Under these conditions the shell response is studied in axisymmetric mode as well as in the flexural mode. It is observed that the shell response is significantly affected by change in orthotropic parameters and also due to change of response mode. It is observed that axial deformation is large in axisymmetric mode as compared to that in flexural mode.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.160-165
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• 2008

Fluid loading of a vibrating cylindrical shell can change natural frequencies and vibration magnitudes of the shell and a vibrating cylindrical shell can also change acoustic pressure of fluid. The vibroacoustics of fluid-filled cylindrical shells need the coupled solution of Helmholtz equation and governing equation of a cylindrical shell with boundary conditions. This paper proposed the wall impedance of fluid-filled axisymmetric cylindrical shells, focusing on the inner fluid/shell interaction. To propose the impedance, shell displacements used the linear combination of in vacuo shell modes. Acoustic pressure prediction of fluid used Kirchchoff-Helmholtz Integral equation with Green function of the plane mode. For the demonstration of the proposed results, numerical applications on mufflers were conducted.

• Journal of Power System Engineering
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• v.16 no.6
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• pp.45-51
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• 2012

In this paper, the algorithm for the static analysis of an axisymmetric cylindrical shell by using the finite element-transfer stiffness coefficient method (FE-TSCM) is suggested. TE-TSCM combining both the modeling procedure of the finite element method (FEM) and the transfer procedure of the transfer stiffness coefficient method (TSCM) has the advantages of FEM and TSCM. After computational programs are made by both FE-TSCM and FEM for the stress analysis of the axisymmetric cylindrical shell, we compare the numerical results by FE-TSCM with those of FEM for two computational models in order to confirm the trust of FE-TSCM.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.9
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• pp.930-936
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• 2008

Fluid loading of a vibrating cylindrical shell has influence on natural frequencies and vibration magnitudes of the shell and the acoustic pressure of fluid. The vibroacoustics of fluid-filled cylindrical shells need the coupled solution of Helmholtz equation and governing equation of a cylindrical shell with boundary conditions. This paper proposed the wall impedance of fluid-filled axisymmetric cylindrical shells, focusing on the inner fluid/shell interaction. To propose the impedance, shell displacements used the linear combination of in vacuo shell modes. Acoustic pressure prediction of fluid used Kirchhoff-Helmholtz integral equation with Green's function of the plane mode. For the demonstration of the proposed results, numerical applications on mufflers were conducted.

• Structural Engineering and Mechanics
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• v.6 no.3
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• pp.291-304
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• 1998

This paper deals with the non-axisymmetric dynamic response of an imperfectly bonded buried orthotropic pipeline subjected to longitudinal wave (P-wave) excitation. An infinite cylindrical shell model, including the rotary inertia and shear deformation effects, has been used for the pipeline. For some cases comparison of axisymmetric and non-axisymmetric responses have also been furnished.

• Journal of KSNVE
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• v.7 no.3
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• pp.411-418
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• 1997

A method to analyze the axisymmetric vibration and the internal pressure of the fluid filled, strength member embedded infinite cylindrical shell under the condition of axial static tension load applied is presented. As an example, the hose wall vibration and the internal pressure variation characteristics of a fluid filled infinite polyurethane hose are analyzed and dicussed, under the effects of the variation of the embedded strength members and the response positions.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.2
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• pp.179-187
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• 2000

When one considers the property of the axisymmetry, an analysis of an axisymmetric shell subjected to unaxisymmetric loading can be employed to save time and computer memory space. If one considers the Fourier series of the circumference direction of loads and displacements, an axisymmetric tank subjected to a nonaxisymmetric load can be treated as a frame element. Using the Fourier series, the authors derived the stiffness matrix of the cylindrical shell subjected to unaxisymmetric loading by the usual finite element method, and converted the stiffness matrix of a frame element into a transfer matrix by rearranging the stiffness matrix to apply the transfer matrix method. Here the most significant purpose of this paper is to achieve the fewest number of simultaneous equations for analysing an axisymmetric shell subjected to a nonaxisymmetric load. The results of the proposed method of the analysis of the cylindrical shell subjected to a wind load and a water load show no differences when compared to the other methods.

• Advances in nano research
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• v.15 no.4
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• pp.367-384
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• 2023

Natural frequency behavior of graphene platelets reinforced composite (GPL-RC) joined truncated conical-cylindrical- conical shells resting on Winkler-type elastic foundation is presented in this paper for the first time. The rule of mixture and the modified Halpin-Tsai approach are applied to achieve the mechanical properties of the structure. Four different graphene platelets patterns are considered along the thickness of the structure such as GPLA, GPLO, GPLX, GPLUD. Finite element procedure according to Rayleigh-Ritz formulation has been used to solve 2D-axisymmetric elasticity equations. Application of 2D axisymmetric elasticity theory allows thickness stretching unlike simple shell theories, and this gives more accurate results, especially for thick shells. An efficient parametric investigation is also presented to show the effects of various geometric variables, three different boundary conditions, stiffness of elastic foundation, dispersion pattern and weight fraction of GPLs nanofillers on the natural frequencies of the joined shell. Results show that GPLO and BC3 provide the most rigidity that cause the most natural frequencies among different BCs and GPL patterns. Also, by increasing the weigh fraction of nanofillers, the natural frequencies will increase up to 200%.