• 한국농공학회지
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• 제45권4호
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• pp.115-125
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• 2003

Shell structures are widely used in a variety of engineering application, and mathematical solution of shell structures are available only for a few special cases. The solution of shell structure is more complicated when it has such condition as winkler foundation, other problems. In this study many simplified methods (analogy of beam on elastic foudation, finite element method and transfer matrix method) are applied to analyze a hemisphere-cylindrical shell structures on elastic foundation. And the transfer matrix method is extensively used for the structural analysis because of its merit in the theoretical backgroud and applicability. Therefore, this paper presents the analysis of hemisphere-cylindrical shell structure base on the transfer matrix method. The technique is attractive for implementation on a numerical solution by means of a computer program coded in FORTRAN language with a few elements. To demonstrate this fact, it gives good results which compare well with finite element method.

• 한국농공학회지
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• 제45권2호
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• pp.68-77
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• 2003

Shell structure are widely used in a variety of engineering application and mathematical solution of shell structures are available only for a few special cases. The solution of shell structure is more complicated when it has such condition as winker foundation, variable thickness and other problem. In this paper, a simple finite element method is presented for the analysis of axisymmetric several types of shell structure subjected to axisymmetric loads and having uniform and varying wall thickness on elastic foundation. The method is based on the analogy with a beam on elastic foundation (BEF), foundation stiffness matrix where the foundation modulus and beam flexural rigidity are replaced by appropriate parameters pertaining to the shell under considerations. The technique is attractive for implementation on a numerical solution by means of a computer program coded in FORTRAN language with a few elements. To demonstrate this fact, it gives good results which compare well with SAP2000.

• Structural Engineering and Mechanics
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• 제32권3호
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• pp.447-457
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• 2009

A general analytical method for computing the joint stiffness from the sectional properties of the members that form the joint is derived using Vlasov's thin-walled beam theory. The analytical model of box T-joint under out-of-plane loading is investigated and validated using shell finite element results and experimental data. The analytical model of the T-joint is implemented in a beam finite element model using a revolute joint element. The out-of-plane displacement computed using the beam-joint model is compared with the corresponding shell element model. The results show close correlation between the beam revolute joint model and shell element model.

• 동력기계공학회지
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• 제16권6호
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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.

• 대한기계학회논문집A
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• 제31권1호
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• pp.105-112
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• 2007

The linkage framework of geometric modeling based on NURBS(Non-Uniform Rational B-Spline) surface and shell finite analysis is developed in the present study. For this purpose, geometrically exact shell finite element is implemented. NURBS technology is employed to obtain the exact geometric quantities for the analysis. Especially, because NURBS is the most powerful and wide-spread method to represent general surfaces in the field of computer graphics and CAD(Computer Aided Design) industry, the direct computation of surface geometric quantities from the NURBS surface equation without approximation shows great potential for the integration between geometrically exact shell finite element and geometric modeling in the CAD systems. Some numerical examples are given to verify the performance and accuracy of the developed linkage framework. In additions, trimmed surfaces with some cutouts are considered for more practical applications.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.229-236
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• 2004

A new three-node triangular shell element based on higher order zig-zag theory is developed for laminated composite shells with multiple delaminations. The present higher order zig-zag shell theory is described in a general curvilinear coordinate system and in general tensor notation. All the complicated curvatures of surface including twisting curvatures can be described in an exact manner in the present shell element because this element is based on geometrically exact surface representation. The displacement field of the proposed finite element includes slope of deflection. which requires continuity between element interfaces. Thus the nonconforming shape function of Specht's three-node triangular plate bending element is employed to interpolate out-of-plane displacement. The present element passes the bending and twisting patch tests in flat surface configurations. The developed element is evaluated through the buckling problems of composite cylindrical shells with multiple delaminations. Through the numerical examples it is demonstrated that the proposed shell element is efficient because it has minimal degrees of freedom per node. The accuracy of the present element is demonstrated in the prediction of buckling loads and buckling modes of shells with multiple delaminations. The present shell element should serve as a powerful tool in the prediction of buckling loads and modes of multi-layered thick laminated shell structures with arbitrary-shaped multiple delaminations.

• 한국공간구조학회:학술대회논문집
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• 한국공간구조학회 2006년도 춘계 학술발표회 논문집 제3권1호(통권3호)
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• pp.256-264
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• 2006

This paper describes the formulation of rectangular flat shell element that is modeled with the six degree of freedoms including a rotational degree of freedom. The rectangular finite element matrix with a rotational degree of freedom is developed using a beam stiffness matrix and compared with other methods. The outputs of the quantity of vertical deflection of cantilever beam show us the improving evidence of the Frame-Shell finite element matrix in a calculation of vertical deflections of cantilever beam.

• 소성∙가공
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• 제12권1호
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• pp.49-59
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• 2003

To reduce the cost of finite element analyses for sheet forming, a 3D hybrid membrane/shell method has been developed to study the springback of anisotropic sheet metals. In the hybrid method, the bending strains and stresses were analytically calculated as post-processing, using incremental shapes of the sheet obtained previously from the membrane finite element analysis. To calculate springback, a shell finite element model was used to unload the final shape of the sheet obtained from the membrane code and the stresses and strains that were calculated analytically. For verification, the hybrid method was applied to predict the springback of a 2036-T4 aluminum square blank formed into a cylindrical cup. The springback predictions obtained with the hybrid method was in good agreement with results obtained using a full shell model to simulate both loading and unloading and the experimentally measured data. The CPU time saving with the hybrid method, over the full shell model, was 75% for the punch stretching problem.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.516-523
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• 1998

Radiation efficiency of a cylindrical shell whose surface vibrates under harmonic distribution is investigated by theoretical solutions and Boundary Element Method. The vibration modes of a cylindrical shell is determined from experiment and is compared with the result of Finite Element Method. Harmonic vibration response of the cylindrical shell under the point excitation and the radiation phenomena from its response is analyzed by Finite Element Method and Boundary Element Method.

• 한국지반공학회논문집
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• 제36권12호
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• pp.27-34
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• 2020

구조물에 대한 축대칭 쉘요소는 지반과 구조물의 상호작용에 대한 유한요소해석에서 효율성과 정확성을 높이게 된다. 본 논문에서는 Kirchhoff 이론에 근거한 축대칭 쉘요소의 힘평형 방정식과 모멘트 평형 방정식을 유도하였다. 축방향 변형에 대한 지배방정식은 등매개변수 형상함수를 이용한 Galerkin 수식화를 수행하고, 휨에 대한 지배방정식은 고차의 형상함수를 이용하였다. 개발된 축대칭 쉘요소는 지반과의 연계해석을 위하여 지반해석 유한요소 프로그램인 Geo-COUS에 결합하였다. 원형판과 액체 저장 탱크에 대한 예제해석을 통하여 개발된 요소의 정확성을 확인하였다. 그리고 축대칭 쉘요소에 대한 에너지 평형방정식을 제시하였다.