• 한국해안해양공학회지
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• 제3권3호
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• pp.117-125
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• 1991

유체 중에서 진동하고 있는 얇은 원통형 탄성쉘의 고유진동수를 계산할 수 있는 두 가지 방법을 제시하였다. 두 방법 모두 고유진동수를 해석적인 형태로 나타내었다. 하나는 간단한 형태로서 쉘의 고차변형모드에 적합하고 다른 하나는 정확하며 유체중에 부분 잠수된 쉘의 경우에 사용된다. 쉘이 유체중에 완전 잠수된 경우로서, 저차변형모드에 대해서는 주위유체가 고유진동수에 상당한 영향을 미침을, 그리고 고차변형모드에 대해서는 그 영향이 작음을 알 수 있었다. 그러나 쉘이 유체중에 부분잠수된 경우에는 최저변형모드에서 항상 위 영향이 최대가 되는 것은 아니었다.

• 대한기계학회논문집
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• 제12권4호
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• pp.670-674
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• 1988

본 연구에서는 저자들에 의해 제시된 직교이방성 적층 원통셸의 진동해법을 이용하여, 국내외적으로 많은 분야에서 이용되고 있는 CFRP 적층 원통셸에 대한 진동 해석을 수행하였다. 본 연구에서는 원통셸의 경계조건, 기하학적 매개변수 및 적층 방법에 따른 CFRP원통셸의 진동특성을 고찰하였다.

• 대한기계학회논문집
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• 제17권11호
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• pp.2684-2693
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• 1993

The free vibration and dynamic response of cross-ply for CFRP and GFRP laminated circular cylindrical shells under dynamic loadings are investigated by using the first-order shear deformation shell theory. The modal analysis technique is used to develop the analytical solutions of simply supported cylindrical shells under dynamic load. The analysis is based on an expansion of the loads, displacements and rotations in a double Fourier series which satisfies the and boundary conditions of simply support. Analytical solution is assumed to be separable into a function of time and a function of position. In this paper, the considered load forces are step pulse, sine pulse, triangular(1, 2, 3) pulse and exponential pulse. The solution for a given loading pulse can be found by involving the convolution integral. The results show that the dynamic response are governed primarily by the natural period of the structure.

• Structural Engineering and Mechanics
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• 제57권1호
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• pp.45-63
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• 2016

Fiber metal laminates (FMLs) represent a high-performance family of hybrid materials which consist of thin metal sheets bonded together with alternating unidirectional fiber layers. In this study, the buckling behavior of a FML circular cylindrical shell under axial compression is investigated via both analytical and finite element approaches. The governing equations are derived based on the first-order shear deformation theory and solved by the Navier solution method. Also, the buckling load of a FML cylindrical shell is calculated using linear eigenvalue analysis in commercial finite element software, ABAQUS. Due to lack of experimental and analytical data for buckling behavior of FML cylindrical shells in the literature, the proposed model is simplified to the full-composite and full-metal cylindrical shells and buckling loads are compared with the available results. Afterwards, the effects of FML parameters such as metal volume fraction (MVF), composite fiber orientation, stacking sequence of layers and geometric parameters are studied on the buckling loads. Results show that the FML layup has the significant effect on the buckling loads of FML cylindrical shells in comparison to the full-composite and full-metal shells. Results of this paper hopefully provide a useful guideline for engineers to design an efficient and economical structure.

• Journal of Mechanical Science and Technology
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• 제14권1호
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• pp.39-47
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• 2000

Bifurcation intability modes of axially compressed circular cylindrical shell are investigated in the limit of zero thickness (i.e., h (thickness) ${\rightarrow}$ 0) analytically, adopting the general stability theory developed by Triantafyllidis and Kwon (1987) and Kwon (1992). The primary state of the shell is obtained in a closed form using the asymptotic technique, and then the straight-forward bifurcation analysis is followed according to the general stability theory to obtain the bifurcation modes in the limit of zero thickness in a full analytical manner. Hence, the closed form bifurcation solution is obtained. Finally, the result is compared with the classical one.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.568-574
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• 2000

This paper presents the vibration characteristics of a continuous circular cylindrical shell multi-simply supported at arbitrary axial positions for searching design parameters. In this modal test the impulse test method is applied to the excitation of experimental model. Natural frequencies are obtained from the peak points of frequency response function(FRF) through frequency analyzer and vibration behaviors are investigated. FE analysis is performed with ANSYS 5.5 to improve the reliability of experimental results. Their results are compared with experimental results. The effect of dynamic characteristics is analyzed for the number of support point on the shell.

• 한국소음진동공학회논문집
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• 제26권2호
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• pp.203-209
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• 2016

According to the wear detection history for the steam generator tubes in the nuclear power plant, the outer tubes inside the steam generator have more problems on the flow-induced vibration than inner tubes. Many researchers and engineers have used a specified added mass coefficient for a given tube array during the design stage of the steam generator even though the coefficient is not constant for entire tube in cylindrical shell. The aim of this study is to find out the distribution of added mass coefficients for each tube along the radial location. When numbers of tubes inside a cylindrical shell are increased, values of added mass coefficients are also increased. Added mass coefficients at outer tubes are less than those of inner tubes and they are decreased with increasing the gap between the outermost tube and the cylindrical shell. It also turns out when the gap between the outermost tube and the cylindrical shell approaches infinite value, the added mass coefficient converges to an asymptotic value of given tube array in a free fluid field.

• 한국강구조학회 논문집
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• 제12권6호
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• pp.639-648
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• 2000

충격하중을 받는 단순지지된 2층 원통쉘의 탄성 충격응답해석에 대한 모델해석을 실시하였다. 2층 원통쉘에 대한 지배방정식은 전단변형과 회전관성을 고려한 단층 수정쉘 이론을 적용하여 충격하중을 받는 철-콘크리트 원통쉘에 대해서 해석하였다. 수치결과에서 알 수 있듯이 응답의 기본적 특성 이해 및 유한요소법 등의 수치해법에 대한 정도 확립에 유효하게 이용될 수 있다고 생각한다.

• Structural Engineering and Mechanics
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• 제10권5호
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• pp.451-462
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• 2000

Buckling loads are determined for thin isotropic circular cylindrical shell panels subject to radial pressure using the new differential quadrature method. The Budiansky stability theory serves as the basis of the analysis. For this problem involving four boundary lines a two-dimensional approach is used, and a detailed convergence study is carried out to determine the appropriate analysis parameters for the method. Numerical results are determined for a total of twelve cylindrical shell panel cases for a number of different boundary support conditions. The results are compared with analytical and finite element method results. Conclusions are drawn about the technical significance of the results and the solution process.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.529-534
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• 2002

The receptance method was applied for the analysis of a cylindrical shell with a curvaturated plate attached at the top of the shell. The boundary conditions of the shell considered here were clamped at the bottom and free at the top of the shell. Before the analysis of the shell/plate combined structure, the natural frequencies of the plate and the shell were calculated separately and then they were used in the calculation of the frequencies of the combined structure by the receptance method. The frequency equation of the combined structure was derived from the continuity condition at the junction of the shell and the plate. The frequencies for various curvature factors of the plate were presented and compared with those from ANSYS to show its validity of the present method.