• Title, Summary, Keyword: large element

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Automatic Quadrilateral Mesh Generation for Large Deformation Finite Element Analysis (대변형 유한요소해석을 위한 요소망 자동 생성기법)

  • 김동준;최호준;장동환;임중연;이호용;황병복
    • Transactions of Materials Processing
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    • v.12 no.3
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    • pp.194-201
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    • 2003
  • An automatic quadrilateral mesh generator for large deformation finite element analysis such as metal forming simulation was developed. The NURBS interpolation method is used for modeling arbitrary 2-D free surface. This mesh generation technique is the modified paving algorithm, which is an advancing front technique with element-by-element resolving method for paving boundary intersection problem. The mesh density for higher analysis accuracy and less analysis time can be easily controlled with high-density points, maximum and minimum element size. A couple of application to large deformation finite element analysis is given as an example, which shows versatility and applicability of the proposed approach and the developed mesh generator for large deformation finite element analysis.

Development on a Vibration Reducing Element for the Large Transformers (대형 변압기 방진장치개발)

  • Lee, Jun-Shin;Lee, Wook-Ryun;Son, Seok-Man;Lee, Sang-Guk
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.259-262
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    • 2005
  • The large transformers used in the electric power company become targets of public complaints because of those characteristics generating high-level noise. Reducing vibration level is the basis of noise control for the large transformers. For this reason, a vibrating reducing element is developed for the large transformers with a sub-element enduring seismic movement. Large attenuation of vibration is achieved by applying the element to the large transformers in a substation.

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Large displacement geometrically nonlinear finite element analysis of 3D Timoshenko fiber beam element

  • Hu, Zhengzhou;Wu, Minger
    • Structural Engineering and Mechanics
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    • v.51 no.4
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    • pp.601-625
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    • 2014
  • Based on continuum mechanics and the principle of virtual displacements, incremental total Lagrangian formulation (T.L.) and incremental updated Lagrangian formulation (U.L.) were presented. Both T.L. and U.L. considered the large displacement stiffness matrix, which was modified to be symmetrical matrix. According to the incremental updated Lagrangian formulation, small strain, large displacement, finite rotation of three dimensional Timoshenko fiber beam element tangent stiffness matrix was developed. Considering large displacement and finite rotation, a new type of tangent stiffness matrix of the beam element was developed. According to the basic assumption of plane section, the displacement field of an arbitrary fiber was presented in terms of nodal displacement of centroid of cross-area. In addition, shear deformation effect was taken account. Furthermore, a nonlinear finite element method program has been developed and several examples were tested to demonstrate the accuracy and generality of the three dimensional beam element.

Stresses analyses of shell structure with large holes

  • Tian, Zongshu;Liu, Jinsong
    • Structural Engineering and Mechanics
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    • v.6 no.8
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    • pp.883-899
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    • 1998
  • The strength, deformation and buckling of a large engineering structure consisting of four ellipsoidal shells, two cylindrical shells with stiffening ribs and large holes, one conical shell and three pairs of large flanges under external pressure, self weight and heat sinks have been analysed by using two kinds of five different finite elements - four assumed displacement finite elements (shell element with curved surfaces, axisymmetric conical shell element with variable thickness, three dimensional eccentric beam element, axisymmetric solid revolutionary element) and an assumed stress hybrid element (a 3-dimensional special element developed by authors). The compatibility between different elements is enforced. The strength analyses of the top cover and the main vessel are described in the paper.

A Finite Element Nonlinear Formulation for Large Deformations of Plane Frames (평면 뼈대구조물의 큰 변형에 대한 비선형 유한요소의 정식화)

  • 윤영묵;박문호
    • Computational Structural Engineering
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    • v.7 no.4
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    • pp.69-83
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    • 1994
  • An explicit finite element nonlinear formulation for very large deformations of plane frame structures is developed. The formulation is based on an updated material reference frame and hence a true stress-strain relationship can be directly applied to characterize the properties of material which is subjected to very large deformations. In the formulation, a co-rotational approach is applied to deal with the large rotations but small strain problems. Straight beam element is considered when the strain of an element is large. The element formulation is based on the small deflection beam theory but with the inclusion of the effect of axial force. The element equations are constructed in an element local coordinate system which rotates and translates with the element, and then transformed to the global coordinate system. Several numerical examples are analyzed to validate the presented formulation.

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Elasto-plastic Analysis of Reinforced Concrete Precast Large Panel Connections by Rigid Element Method (강체요소법에 의한 철근 콘크리트 프리캐스트 대형판 접합부의 탄소성해석)

  • Park, Kang-Geun;Kim, Yong-Tae;Kwun, Taek-Jin
    • Journal of the Korean Association for Spatial Structures
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    • v.1 no.2
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    • pp.111-116
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    • 2001
  • This paper is a study on the elasto-plastic analysis of reinforced concrete precast large panel connections by rigid element spring model. In the analysis of rigid element spring model, each collapsed part or piece of structures at limiting state of loading is assumed to behave like rigid bodies. The present author propose new elements for the improement and expansion of the rigid element spring model. In this study, it is proposed how the rigid element method can be applied to the elesto-plastic analysis of precat large panel connections. Some numerical results of analytical modeling and load displacement curves are shown.

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Finite Element Analysis of Elasto-Plastic Large Deformation considering the Isotropic Damage(the 2nd Report) (등방성손상을 고려한 탄소성 대변형 무제의 유한요소해석(제2보))

  • 이종원
    • Journal of Ocean Engineering and Technology
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    • v.14 no.2
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    • pp.76-83
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    • 2000
  • this paper was concentrated on the finite element formulation to solve boundary value problems by using the isotropic elasto-plastic damage constitutive model proposed previously(Noh, 2000) The plastic damage of ductile materials is generally accompanied by large plasticdeformation and strain. So nonlinearity problems induced by large deformation large rotation and large strain behaviors were dealt with using the nonlinear kinematics of elasto-plastic deformations based on the continuum mechanics. The elasto-plastic damage constitutive model was applied to the nonlinear finite element formulation process of Shin et al(1997) and an improved analysis model considering the all nonlinearities of structural behaviors is proposed. Finally to investigate the applicability and validity of the numerical model some numerial examples were considered.

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Beam finite element model of a vibrate wind blade in large elastic deformation

  • Hamdi, Hedi;Farah, Khaled
    • Wind and Structures
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    • v.26 no.1
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    • pp.25-34
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    • 2018
  • This paper presents a beam finite element model of a vibrate wind blade in large elastic deformation subjected to the aerodynamic, centrifugal, gyroscopic and gravity loads. The gyroscopic loads applied to the blade are induced by her simultaneous vibration and rotation. The proposed beam finite element model is based on a simplex interpolation method and it is mainly intended to the numerical analysis of wind blades vibration in large elastic deformation. For this purpose, the theory of the sheared beams and the finite element method are combined to develop the algebraic equations system governing the three-dimensional motion of blade vibration. The applicability of the theoretical approach is elucidated through an original case study. Also, the static deformation of the used wind blade is assessed by appropriate software using a solid finite element model in order to show the effectiveness of the obtained results. To simulate the nonlinear dynamic response of wind blade, the predictor-corrector Newmark scheme is applied and the stability of numerical process is approved during a large time of blade functioning. Finally, the influence of the modified geometrical stiffness on the amplitudes and frequencies of the wind blade vibration induced by the sinusoidal excitation of gravity is analyzed.

LARGE TIME-STEPPING METHOD BASED ON THE FINITE ELEMENT DISCRETIZATION FOR THE CAHN-HILLIARD EQUATION

  • Yang, Yanfang;Feng, Xinlong;He, Yinnian
    • Journal of applied mathematics & informatics
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    • v.29 no.5_6
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    • pp.1129-1141
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    • 2011
  • In this paper, a class of large time-stepping method based on the finite element discretization for the Cahn-Hilliard equation with the Neumann boundary conditions is developed. The equation is discretized by finite element method in space and semi-implicit schemes in time. For the first order fully discrete scheme, convergence property is investigated by using finite element analysis. Numerical experiment is presented, which demonstrates the effectiveness of the large time-stepping approaches.

Study on the Frame Structure Modeling of the Beam Element Formulated by Absolute Nodal Coordinate Approach

  • Takahashi Yoshitaka;Shimizu Nobuyuki;Suzuki Kohei
    • Journal of Mechanical Science and Technology
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    • v.19 no.spc1
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    • pp.283-291
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    • 2005
  • Accurate seismic analyses of large deformable moving structures are still unsolved problems in the field of earthquake engineering. In order to analyze these problems, the nonlinear finite element method formulated by the absolute nodal coordinate approach is noticed. Because, this formulation has several advantages over the standard procedures on mass matrix, elastic forces and damping forces in the case of large displacement problems. But, it has not been fully studied to build frame structure models by using beam elements in the absolute nodal coordinate formulation. In this paper, we propose the connecting method of the beam elements formulated by the absolute nodal coordinate. The coordinate transformation matrix of this element is introduced into the frame structure. This beam element has the characteristic that the mass matrix and bending stiffiness matrix are constant even if in the case of large displacement problems, and this characteristic is being kept after the transformation. In order to verify the proposed method, we show the numerical simulation results of frame structures for a vibration problem and a large displacement problem.