• Title/Summary/Keyword: Flugge shell theory

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Analysis of a cantilever cylindrical shell by an approximate thory (근사이론에 의한 Cantilever원통쉘의 해석)

  • ;;Lee, Young Shine
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.5 no.3
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    • pp.183-192
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    • 1981
  • The present study gives an apprximate equation of circular cylindrical shell on the basis of Flugges's exact theory. The longitudinal bending moment .MU.$\_$x/ and circumferential strain .epsilon.$\_$.theta. are assumed to be small to be small and have been neglected. The governing equation of the cylindrical shell, which is generaly presented as 8th order partial differential equation, is reduced into a 4th order partial differential equation for axial coordinate. To verify the validity and accuracy of this approximate theory, the cantilever cylindrical shell subjected to a concentrated load is analyzed. The maximum errors of longitudinal stress and deflection are about 10 percent compared with the analysis by flugge's theory and are about 15 percent with experimental results.

Free Vibration Analysis of the Scroll Compressor Housing by Shell Theory (셸이론을 이용한 스크롤 압축기 하우징의 자유진동해석)

  • Kim, H.S.;Lee, Y.S.;Yang, M.S.;Choi, M.H.;Ryu, C.H.
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.242-247
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    • 2000
  • In this study, the Rayleigh's energy method and the Rayleigh-Ritz method on the basis of Flugge's shell theory was used to analyze the dynamic characteristics of the scroll compressor housing with clamped boundary condition. The frequencies and mode shapes from theoretical calculation were compared with those of commercial finite element code, ANSYS. In order to validate the theory, modal test was also performed by impact test and FFT analysis.

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Buckling and Vibration of Laminated Composite Non-Circular Cylindrical Shells (비원형 단면을 가진 적층복합재료원통셸의 좌굴 및 진동해석)

  • 이영신;안상균;이우식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.5
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    • pp.807-819
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    • 1989
  • Buckling and vibration of laminated non-circular cylindrical shells with constant thickness and simply supported boundary condition is considered. Governing equations are derived based on the Donnell and Flugge shell theory and Galerkin method is applied for the numerical analysis. Comparisons are made between present results and others. Variations of frequency parameter and buckling load parameter on the change of stacking angle, eccentricity parameter and shell theories are investigated. Conclusion of this study is as follows: (1) General solutions of buckling and vibration of laminated non-circular cylindrical shell are obtained. (2) Frequency parameter is decreased as the initial axial load is increased. (3) In general, frequency and buckling load parameter of laminated non-circular cylindrical shells are decreased as increasing of eccentricity parameter and stacking angle.

Vibration Characteristics of Conical Shells with Linearly Varying Thickness (선형적으로 두께가 변하는 원추형 셸의 진동특성)

  • Yeo, D.J.;Cho, I.S.
    • Journal of Power System Engineering
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    • v.12 no.2
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    • pp.35-40
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    • 2008
  • This paper deals with the free vibrations of conical shells with linearly variable thickness by the transfer influence coefficient method. The classical thin shell theory based upon the Flugge theory is assumed and the governing equations of a conical shell are written as a coupled set of first order matrix differential equations using the transfer matrix. The Runge-Kutta-Gill integration method is used to solve the governing differential equation. The natural frequencies and corresponding mode shapes are calculated numerically for the conical shells with linearly variable thickness and various boundary conditions at the edges. The present method is applied to conical shells with linearly varying thickness, and the effects of the semi-vertex angle, the number of circumferential waves and thickness ratio on vibration are studied.

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Free Vibration of Orthotropic Laminated Composite Conical Shells (직교이방성 적층 복합재료 원추셸의 자유진동)

  • 이영신;강인식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.4
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    • pp.595-603
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    • 1989
  • Free vibration of orthotropic laminated composite conical shells with constant thickness are considered. Governing frequency equations are derived based on the Flugge theory and Galerkin method is applied for the numerical analysis. Comparisons are made between present results and others for the isotropic conical shells and numerical results are obtained based on these results for the specially orthotropic laminated composite conical shells with simply supported edges. Variations of frequency parameter on the change of material properties, stacking sequences, stacking number, geometrical parameters and orthotropic parameters are considered in the analysis.

Composite action in connection of single-walled carbon nanotubes: Modeled as Flügge shell theory

  • Mohamed A. Khadimallah;Imene Harbaoui;Sofiene Helaili;Abdelhakim Benslimane;Humaira Sharif;Muzamal Hussain;Muhammad Nawaz Naeem;Mohamed R. Ali;Aqib Majeed;Abdelouahed Tounsi
    • Computers and Concrete
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    • v.32 no.4
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    • pp.365-371
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    • 2023
  • On the basis of Flügge shell theory, the vibrations of single walled carbon nanotubes (SWCNTs) are investigated. The structure of armchair single walled carbon nanotubes are used here. Influences of length-to-diameter ratios and the two boundary conditions on the natural frequencies of armchair SWCNTs are examined. The Rayleigh-Ritz method is employed to determine eigen frequencies for single walled carbon nanotubes. The solution is obtained using the geometric characteristics and boundary conditions for natural frequencies of SWCNTs. The natural frequencies decrease as ratio of length to diameter increase and the effect of frequencies is less significant and more prominent for long tube. To assess the frequency confirmation carried out in this paper are compared with the earlier computations.

Stress analysis near a circular hole in a flat plate reinforced by a cylinder (원통으로 보강된 평판의 응력해석)

  • 정인승;이대희;이완익;윤갑영
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.11 no.5
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    • pp.800-809
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    • 1987
  • For precise stress analysis of pressure vessel nozzle junction area, it should be modelized as a cylindrical shell with a cylindrical outlet attached on it, but because of its geometrical complexity, exact analysis and solution is very difficult to obtain. So, when the nozzle diameter is small compared to that of vessel, it is general to simplify the model as a flat plate with a cylinder. As the current nozzle shape is manufactured as "Through Type" to reduce the stress concentration around the nozzle junction part of pressure vessel, a theoretical analysis on the cylinder with finite length should be performed to accomodate this fact. In this paper, the general solutions which were obtained by applying Fulgge's theory to the finite length cylinder, membrane and bending theory to the flat plate were superposed to analyze the model. Each theoretical optimal values were obtained through the analysis of stress concentration caused by the variation of cylinder length and thickness, and these results were estimated by performing model experimentation.mentation.

Service ability design of vibrating chiral SWCNTs: Validation and parametric study

  • Muzamal Hussain;Mohamed R. Ali;Abdelhakim Benslimane;Humaira Sharif;Mohamed A. Khadimallah;Muhammad Nawaz Naeem;Imene Harbaoui;Sofiene Helaili;Aqib Majeed;Abdelouahed Tounsi
    • Computers and Concrete
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    • v.32 no.4
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    • pp.393-398
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    • 2023
  • This paper provides the free vibrations of chiral carbon nanotubes. The governing equations of Flügge theory is considered for vibration frequencies of chiral single walled carbon nanotubes. The solution of frequency equation is obtained from a novel model for better representation of stubby and short vibration characteristics of chiral tubes with clamped-clamped and clamped-simply supported end conditions. For the harmonic response of this tube, the model displacement function is adopted. The variational approach Rayleigh-Ritz method with kinetic and strain energies are used. The Lagragian function is differentiated with respect to unknown functions. The frequency equation is written in compact form to solve with MATLAB software. The frequencies of chiral SWCNTs for first ten aspect ratios as small level are investigated. The results shown as for decreasing the aspect rations, the frequencies are increases. The presented results of this model are verified with experimental and numerical results, which found as an excellent agreement.