• Journal of KSNVE
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• v.6 no.3
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• pp.297-303
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• 1996

The general approach using sine series expansions was represented to evaluate the radiation loading from a vibrating surface on a simply supported cylinder. In this paper, the fluid-loading coefficients (radiation impedance) for a submerged finite cylindrical shell with an arbitrary end condition are defined and evaluated. The vibrations of cylindrical shell are expressed by using cosine series expansions to analyze the radiation impedance for a finite cylindrical shell. It is possible to represent the displacements at both ends of cylindrical shell in comparison with sine series. The direct and cross modal components of fluid-loading coefficients are shown and the validity of cosine series expansions are verified from the results of numerical computations. This approach and results are directly applicable in the analysis of sound radiation from subemerged finite cylindrical shell with arbitrary end conditions.

• Transactions of the Korean Society of Mechanical Engineers
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• v.3 no.4
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• pp.158-163
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• 1979

An approximate theory of circular chlindrical shells under arbitrary load is derived on the basis of Vlasov's semimembrane theory. With this approximate theory concrete cylindrical shells subjected to wind loading is analized and its accuracy is investigated with the results of Donnell's equation. In this study the foollowing results are abtained : (1) The expression of .kappa.$\_$2/=.part.$\^$2/.omega./.part. s$\^$2/ for the change of curvature gives much simplicated closed form colution. (2) This approximate theory is to be applicable with sufficient accuracy in the stress analysis of concrete cylindreical shells which the ratio L/D is equal or greater than three.

• Transactions of the Korean Society of Mechanical Engineers
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• v.2 no.2
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• pp.31-37
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• 1978

In order to specify the accuracy of the cylindrical shell theories, several cylindrical shell equations are studied. Cheng's equation is used as the exact theory for circular cylindrical shells. An error factor is defined and used for the measure of the accuracy in various cylindrical shell theories. The line load applied along generators of a thin-walled circular cylidrical shell of finite length is investigated as a numerical example. These numerical results show that Cheng's equation is used for the fundamental cylindrical shell equation and the difficulties in cumputation by a digital computer are same as the simplified equations, such as Donnell's Morley's, and Vlasov's equations.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.5
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• pp.789-799
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• 1987

The stress state and displacement for the orthotropic cylindrical shell subjected to line load along a generator is presented. It is assumed that the behavior of the material is specially-orthotropic. The governing equation for orthotropic cylindrical shell is derived on the basis of Novozhilov's shell theory. General solution is obtained by extending the Naghdi's method for the isotropic cylindrical shell under the line load. Numerical examples are presented for circular cylindrical shells having various othotropic material properties and geometries.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.348.2-348
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• 2002

ER mount is often used instead of rubber mount in cylindrical shell to improve the vibration and noise performanec. The noise radiated by cylindrical shell will be reduced by reducing the force transmitted to the cylindrical shell through ER mount. In this paper, LQ control theory is used to reduce the transmitted force to the cylindrical shell. The finite element method of cylindrical shell is formulated by NASTRAN and its vibrating shape is calculated in frequency domain. (omitted)

• Journal of KSNVE
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• v.6 no.6
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• pp.801-818
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• 1996

Free vibration analyses of circular cylindrical shells attached with plate structures for the symmetric boundary condition such as simply-simply supported shells by receptance method are found in literatures. However analyses of those shells with unsymmetric boundary condition as clamped free boundary are hardly found. Here frequency equation of the clamped free circular cylindrical shell with end plate is derived using receptance method and natural frequencies of the combined system were calculated. The frequencies and mode shapes obtained from present method are compared with those of ANSYS to show the validity of the method. Natural frequencies and mode component ratios of clamped-free cylindrical shell are obtained by employing Rayleigh-Ritz method on energy equations, and they are used in receptance calculation. Results show good agreement with those of ANSYS analyses.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.3
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• pp.261-267
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• 2014

The free vibration characteristics of cylindrical shells on inclined partial elastic foundations are investigated by an analytical method. The cylindrical shell is partially surrounded by the elastic foundations, these are represented by the Winkler or Pasternak model. The area of elastic foundation is not uniform and varies along the axial direction of the shell. The motion of shell is represented by first-order shear deformation theory(FSDT) to account for rotary inertia and transverse shear strains. The governing equation is obtained using the Rayleigh-Ritz method and a variation approach. To validate the present method, the numerical example is presented and compared with the present FEA results. The numerical results reveal that the elastic foundation has significant effect on vibration characteristics.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.11
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• pp.1119-1125
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• 2009

The coupled fluid-structure interaction problem is analyzed using the theoretical method to investigate the coupled vibration characteristics of functionally graded material(FGM) cylindrical shells conveying an incompressible, inviscid fluid. Material properties are assumed to vary continuously through the thickness according to a power law distribution in terms of the volume fraction of the constituents. The steady flow of fluid is described by the classical potential flow theory. The motion of shell represented by the first order shear deformation theory(FSDT) to account for rotary inertia and transverse shear strains. The effect of internal fluid can be taken into consideration by imposing a relation between the fluid pressure and the radial displacement of the structure at the interface. Numerical examples are presented and compared with exiting results.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.5
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• pp.422-429
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• 2011

The critical fluid velocity of cantilevered cylindrical shells subjected to internal fluid flow is investigated in this study. The fluid-structure interaction is considered in the analysis. The cantilevered cylindrical shell is supported intermediately at an arbitrary axial position. The intermediate support is simulated by two types of artificial springs: translational and rotational spring. It is assumed that the artificial springs are placed continuously and uniformly on the middle surface of an intermediate support along the circumferential direction. The steady flow of fluid is described by the classical potential flow theory. The motion of shell is represented by the first order shear deformation theory (FSDT) to account for rotary inertia and transverse shear strains. The effect of internal fluid can be considered by imposing a relation between the fluid pressure and the radial displacement of the structure at the interface. Numerical examples are presented and compared with existing results.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.883-888
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• 2001

The theoretical method is developed to investigate the effects of ring stiffeners on free vibration characteristics and transient response for the ring stiffened composite cylindrical shells subjected to the impulse pressure loading. In the theoretical procedure, the Love's thin shell theory combined with the discrete stiffener theory to consider the ring stiffening effect is adopted to formulate the theoretical model. The concentric or eccentric ring stiffeners are laminated with composite and have the uniform rectangular cross section. The modal analysis technique is used to develop the analytical solutions of the transient problem. The analysis is based on an expansion of the loads, displacements in the double Fourier series that satisfy the boundary conditions. The effect of stiffener's eccentricity, number, size, and position on transient response of the shells is examined. The theoretical results are verified by comparison with FEM results.