Natural Frequencies And Modes Of A Circular Plate Welded To A Circular Cylindrical Shell At Arbitrary Axial Positions

This study is concerned with the “Free Asymmetric Vibrations of Composite Full Circular Cylindrical Shells Stiffened by a Bonded Central Shell Segment.” The base shell is made of an orthotropic “full” circular cylindrical shell reinforced and/or stiffened by an adhesively bonded dissimilar, orthotropic “full” circular cylindrical shell segment. The stiffening shell segment is located at the mid-center of the composite system. The theoretical analysis is based on the “Timoshenko-Mindlin-(and Reissner) Shell Theory” which is a “First Order Shear Deformation Shell Theory (FSDST).” Thus, in both “base (or lower) shell” and in the “upper shell” segment, the transverse shear deformations and the extensional, translational and the rotary moments of inertia are taken into account in the formulation. In the very thin and linearly elastic adhesive layer, the transverse normal and shear stresses are accounted for. The sets of the dynamic equations, stress-resultant-displacement equations for both shells and the in-between adhesive layer are combined and manipulated and are finally reduced into a ”Governing System of the First Order Ordinary Differential Equations” in the “state-vector” form. This system is integrated by the “Modified Transfer Matrix Method (with Chebyshev Polynomials).” Some asymmetric mode shapes and the corresponding natural frequencies showing the effect of the “hard” and the “soft” adhesive cases are presented. Also, the parametric study of the “overlap length” (or the bonded joint length) on the natural frequencies in several modes is considered and plotted.

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Vibration Analysis of a Railway Carbody Model as a Non-Circular Cylindrical Shell

Volume 1: 21st Biennial Conference on Mechanical Vibration and Noise, Parts A, B, and C ◽

10.1115/detc2007-35195 ◽

2007 ◽

Author(s):

Yukinori Kobayashi ◽

Kotaro Ishiguri ◽

Takahiro Tomioka ◽

Yohei Hoshino

Keyword(s):

Cylindrical Shell ◽

Natural Frequencies ◽

Circular Cylindrical Shell ◽

Experimental Studies ◽

Three Dimensional ◽

Elastic Vibration ◽

Mode Shapes ◽

Simply Supported ◽

Vibration Problems ◽

Good Agreement

Railway carbody is modeled as a non-circular cylindrical shell with simply-supported ends in this paper. The shell model doesn’t have end plates of the carbody and other equipments attached to actual carbody are neglected. We have applied the transfer matrix method (TMM) to the analysis of three-dimensional elastic vibration problems on the carbody. We also made a 1/12 size carbody model for experimental studies to verify the validity of the numerical simulation. The model has end plates and was placed on soft sponge at both ends of the model to emulate the freely-support. The modal analysis was applied to the experimental model, and natural frequencies and mode shapes of vibration were measured. Comparing the results by TMM and the experiment, natural frequencies and mode shapes of vibration for lower modes show good agreement each other in spite of differences of boundary conditions.

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Numerical Determination of Natural Frequencies and Modes of the Vibrations of a Thick-Walled Cylindrical Shell

International Applied Mechanics ◽

10.1007/s10778-018-0861-7 ◽

2018 ◽

Vol 54 (1) ◽

pp. 75-84 ◽

Cited By ~ 4

Author(s):

A. Ya. Grigorenko ◽

M. Yu. Borisenko ◽

E. V. Boichuk ◽

A. P. Prigoda

Keyword(s):

Cylindrical Shell ◽

Natural Frequencies ◽

Numerical Determination ◽

Natural Frequencies And Modes

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Analysis of Fiberglass Winding Angle on Natural Frequency of Free Vibration of Cylindrical Shell with Asymmetric Boundary Conditions

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.274.65 ◽

2013 ◽

Vol 274 ◽

pp. 65-69 ◽

Cited By ~ 1

Author(s):

Zhi Wei Wang ◽

Bo Wu ◽

Yan Fu Wang ◽

S.M. Bosiakov

Keyword(s):

Cylindrical Shell ◽

Free Vibration ◽

Boundary Conditions ◽

Natural Frequency ◽

Natural Frequencies ◽

Circular Cylindrical Shell ◽

Geometrical Parameters ◽

Glass Fiber Reinforced Plastic ◽

Glass Fiber Reinforced ◽

Winding Angle

In order to obtain approximate solution of natural frequencies for the free vibration of anisotropic circular cylindrical shells made of GFRP (glass fiber-reinforced plastic) with asymmetric boundary conditions, Love’s theory and energy method are used. Computation results show that the fundamental natural frequency comes from different vibration modes while the winding angle varies, the effect of number of axial half waves is stronger than number of circumferential waves on natural frequency of free vibration of anisotropic circular cylindrical shell. The effect of shell’s geometrical parameters is also investigated on natural frequencies.

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Comparison of Vibration Characteristics of Stiffened Composite Shallow Circular Cylindrical Shell Panels

Recent Advances in Solids and Structures ◽

10.1115/imece2002-32298 ◽

2002 ◽

Cited By ~ 1

Author(s):

V. O¨zerciyes ◽

U. Yuceoglu

Keyword(s):

Cylindrical Shell ◽

Natural Frequencies ◽

Circular Cylindrical Shell ◽

Free Vibrations ◽

Vibration Characteristics ◽

Mode Shapes ◽

Shallow Cylindrical Shell ◽

Parametric Studies ◽

Complete Set ◽

Hit And Run

The problem of “Free Vibrations Centrally and Non Centrally Stiffened Composite Shallow Cylindrical Shell Panels” are briefly considered and their vibration characteristics are compared, in detail, in terms of their natural frequencies and the corresponding mode shapes. First, the complete set of composite shallow cylindrical shell equations are reduced to a system of first order ordinary differential equations in “state-vector” form. Then, by making use of the “Modified Transfer Matrix Method”, the effects of the position and the width of the stiffening shell strip in the natural frequencies and the mode shapes of the panel system are plotted and compared. Some significant results of parametric studies and also the possibility of some kind of hit-and-run type of optimization are presented.

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Natural frequencies of a circular cylindrical shell reinforced by ring corrugations

Strength of Materials ◽

10.1007/bf01523909 ◽

1978 ◽

Vol 10 (6) ◽

pp. 710-713

Author(s):

V. I. Kosse ◽

B. A. Obodovskii

Keyword(s):

Cylindrical Shell ◽

Natural Frequencies ◽

Circular Cylindrical Shell

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ANALYTICAL AND NUMERICAL STUDIES OF FREE VIBRATIONS OF CYLINDRICAL SHELL WITH ACOUSTIC MEDIUM

Problems of Strength and Plasticity ◽

10.32326/1814-9146-2021-83-1-35-48 ◽

2021 ◽

Vol 83 (1) ◽

pp. 35-48

Author(s):

I.A. Dyachenko ◽

A.A. Mironov

Keyword(s):

Finite Element ◽

Cylindrical Shell ◽

Natural Frequencies ◽

Mutual Influence ◽

Circular Cylindrical Shell ◽

Middle Layer ◽

Free Vibrations ◽

Acoustic Medium ◽

Compressible Medium ◽

Full Spectrum

The research materials are related to the problem of ensuring vibration resistance of pipelines exposed to dynamic loads, for which increased vibration is the main cause of damage. The solution to this problem involves studying the parameters of free vibrations of the structure. The paper solves the problem of determining the natural frequencies and forms of vibrations of a section of a circular cylindrical shell filled with an medium considered in the acoustic approximation. The results of studies of the parameters of free vibrations were obtained both by the analytical method of shell theory based on the Kirchhoff-Love hypotheses, and using the finite element complex of engineering analysis ANSYS. It is shown that the influence of the medium density on the parameters of free vibrations of the shell depends on the ratio of the shell thickness to its radius it turns out to be significant only for the shape of vibrations associated with bending deformation, and insignificant for forms associated with deformations of the middle layer. A comparative analysis of the results of calculations obtained for models of compressible and incompressible medium shows that when solving the problem of determining the parameters of free vibrations of the shell, the compressibility of the medium can be neglected. At the same time, to solve practical problems that require taking into account the full spectrum of natural frequencies of the shell–medium system, a compressible medium model should be used, in which the results on the effect of shell stiffness on the frequency spectrum of the medium volume are obtained. When solving practical problems of pipeline systems vibration, the use of the finite element method in a coupled formulation is an effective tool that allows us to consider all physical processes taking into account their mutual influence on each other.

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