• 제목/요약/키워드: SOLID element

검색결과 983건 처리시간 0.03초

표준 8절점 고체요소를 이용한 원전 격납건물 벽체요소의 비선형해석 (Nonlinear Analysis of Nuclear Containment Wall Element using Standard 8-node Solid Element)

  • 이홍표;전영선
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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    • pp.151-158
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    • 2005
  • For the safety analysis of large structures such as nuclear containment buildings, we conventionally prefer to use analytical approach using finite element method rather than empirical test. Therefor, this paper is mainly focused to develop low-order solid finite element model with the elasto-plastic material model for the safety analysis of nuclear containment building. Drucker-Prager failure criteria in uncracked concrete and maximum tensile stress criteria in cracked concrete are used to model the constitutive behavior of concrete. The concrete material model takes into account the aspects of tensile strain, compression strength reduction of concrete and shear transfer to improve the accuracy of the finite element analysis. Finally, numerical simulation to compare the performance of the developed model with experimental results is employed. The numerical results in this study agree very well with the experimental data.

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삼차원 유한요소의 자동생성 (2) -사면체 옥트리로부터의 유한요소 생성- (Automatic Generation of 3-D Finite Element Meshes: Part(II) -Mesh Generation from Tetrahedron-based Octree-)

  • 정융호;이건우
    • 대한기계학회논문집
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    • 제19권3호
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    • pp.647-660
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    • 1995
  • Given the tetrahedron-based octree approximation of a solid as described in part(I) of this thesis, in this part(II) a systematic procedure of 'boundary moving' is developed for the fully automatic generation of 3D finite element meshes. The algorithm moves some vertices of the octants near the boundary onto the exact surface of a solid without transforming the topology of octree leaf elements. As a result, the inner octree leaf elements can be used as exact tetrahedral finite element meshes. In addition, as a quality measure of a tetrahedral element, 'shape value' is propopsed and used for the generation of better finite elements during the boundary moving process.

Investigation of the behavior of reinforced concrete hollow-core thick slabs

  • Al-Azzawi, Adel A.;Abed, Sadeq A.
    • Computers and Concrete
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    • 제19권5호
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    • pp.567-577
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    • 2017
  • This study presents investigation of the behavior of moderately thick reinforced concrete slabs having hollow cores with different parameters. The experimental part of this investigation includes testing eight specimens of solid and hollow-core slab models having (2.05 m) length, (0.6 m) width and (25 cm) thickness under two monotonic line loads. Load versus deflection was recorded during test at mid span and under load. Numerically, the finite element method is used to study the behavior of these reinforced concrete slabs by using ANSYS computer program. The specimens of slab models are modeled by using (SOLID65) element to represent concrete slabs and (LINK180) element to represent the steel bars as discrete axial members between concrete nodes. The finite element analysis has showed good agreement with the experimental results with difference of (4.71%-8.68%) in ultimate loads. A parametric study have been carried out by using ANSYS program to investigate the effects of concrete compressive strength, size and shape of core, type of applied load and effect of removing top steel reinforcement.

SIMP 기반 절점밀도법에 의한 3 차원 위상최적화 (3-D Topology Optimization by a Nodal Density Method Based on a SIMP Algorithm)

  • 김철;팡난
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.412-417
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    • 2008
  • In a traditional topology optimization method, material properties are usually distributed by finite element density and visualized by a gray level image. The distribution method based on element density is adequate for a great mass of 2-D topology optimization problems. However, when it is used for 3-D topology optimization, it is always difficult to obtain a smooth model representation, and easily appears a virtualconnect phenomenon especially in a low-density domain. The 3-D structural topology optimization method has been developed using the node density instead of the element density that is based on SIMP (solid isotropic microstructure with penalization) algorithm. A computer code based on Matlab was written to validate the proposed method. When it was compared to the element density as design variable, this method could get a more uniform density distribution. To show the usefulness of this method, several typical examples of structure topology optimization are presented.

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PARALLEL COMPUTATIONAL APPROACH FOR THREE-DIMENSIONAL SOLID ELEMENT USING EXTRA SHAPE FUNCTION BASED ON DOMAIN DECOMPOSITION APPROACH

  • JOO, HYUNSHIG;GONG, DUHYUN;KANG, SEUNG-HOON;CHUN, TAEYOUNG;SHIN, SANG-JOON
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제24권2호
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    • pp.199-214
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    • 2020
  • This paper describes the development of a parallel computational algorithm based on the finite element tearing and interconnecting (FETI) method that uses a local Lagrange multiplier. In this approach, structural computational domain is decomposed into non-overlapping sub-domains using local Lagrange multiplier. The local Lagrange multipliers are imposed at interconnecting nodes. 8-node solid element using extra shape function is adopted by using the representative volume element (RVE). The parallel computational algorithm is further established based on message passing interface (MPI). Finally, the present FETI-local approach is implemented on parallel hardware and shows improved performance.

Geometrically nonlinear analysis of planar beam and frame structures made of functionally graded material

  • Nguyen, Dinh-Kien;Gan, Buntara S.;Trinh, Thanh-Huong
    • Structural Engineering and Mechanics
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    • 제49권6호
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    • pp.727-743
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    • 2014
  • Geometrically nonlinear analysis of planar beam and frame structures made of functionally graded material (FGM) by using the finite element method is presented. The material property of the structures is assumed to be graded in the thickness direction by a power law distribution. A nonlinear beam element based on Bernoulli beam theory, taking the shift of the neutral axis position into account, is formulated in the context of the co-rotational formulation. The nonlinear equilibrium equations are solved by using the incremental/iterative procedure in a combination with the arc-length control method. Numerical examples show that the formulated element is capable to give accurate results by using just several elements. The influence of the material inhomogeneity in the geometrically nonlinear behavior of the FGM beam and frame structures is examined and highlighted.

가정 변형률 요소를 이용한 복합재 압전작동기의 작동특성해석 (Performance analysis of composite piezoceramic actuator by assumed strain elements)

  • 김영성;이상기;박훈철;윤광준
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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    • pp.461-469
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    • 2002
  • This paper deals with a fully coupled piezoelectric-mechanical assumed strain solid element that can be used for geometric and material nonlinear modeling of thin piezoelectric actuators. Since the assumed strain solid element can alleviate locking, the element is suitable for performance analysis of very thin actuators without locking. A finite element code is developed based on the finite element formulation and validated by solving typical numerical examples such as bimorph and unimorph beams. Using thecode, we have conducted performance analysis for LIPCA actuator. The estimated actuation displacement of LIPCA agrees well with experimental data under low prescribed voltage.

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강화변형률 솔리드 요소를 사용한 사각형태 층간분리를 갖는 복합적층판의 탄성좌굴해석 (Elastic Buckling Analysis of Laminated Composite Plates with Embedded Square Delamination Using an Enhanced Assumed Strain Solid Element)

  • 박대용;장석윤
    • 복합신소재구조학회 논문집
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    • 제1권2호
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    • pp.1-13
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    • 2010
  • 복합적층구조의 층간분리현상은 탄성좌굴하중을 감소시키며 설계값보다 낮은 수준에서 전체구조물의 파괴를 유발한다. 따라서 복합적층구조의 층간분리 현상은 매우 중요한 문제이며 많은 이론과 실험적인 연구가 진행되어왔다. 본 연구에서는 3차원 이론을 사용한 효과적인 유한요소법에 기초하여 임베디드된 사각형 층간분리 현상을 갖는 복합적층판의 탄성좌굴 거동을 분석하였다. 해석을 위해 개발된 3차원 유한요소는 EAS-SOLID8이라고 이름 붙여졌으며 강화된 대체 변형률 방법을 사용하였다. 임베디드된 사각형 층간분리를 갖는 복합적층판의 탄성좌굴거동 분석을 위해 경계조건, 폭-두께비 변화에 대하여 매개변수 해석을 수행하였다. 본 연구의 그래프와 좌굴모드는 임베디드된 사각형 층간분리를 갖는 복합적층판의 설계에 매우 유용한 자료가 될 것으로 사료된다.

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3차원 10절점-상당요소에 의한 굽힘문제의 정적.동적해석 (Static and Dynamic Analyses of Bending Problems Using 3-Dimensional 10-Node Equivalent Element)

  • 권영두;윤태혁
    • 전산구조공학
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    • 제10권4호
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    • pp.117-130
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    • 1997
  • 본 논문에서는 등방성판의 인장이나 전단변형은 물론 굽힘문제에도 적용할 수 있는 3차원 고체요소들 중에서 최소의 자유도를 갖는 수정 10절점 상당요소를 제안하였다. 제안된 수정 10절점 상당요소는 Q11요소나 20절점요소로부터 자유도가 줄어듬에 기인한 과대한 굽힘강성을 나타낸다. 이러한 상대적 강성과잉 현상을 수정하기 위한 효과적인 방법으로 가우스 적분점 수정 방법을 제안하였다. 수정량은 포아송 비의 함수이다. 수정 10절점 상당요소의 효과를 여러 가지 예에 적용하여 검증하였다. 제안된 수정 10절점 상당요소에 의한 등방성판의 정적해석과 자유진동 해석의 결과들은 20절점요소를 사용한 결과들과 잘 일치하였다.

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고유진동수 시험을 통한 복합재 격자구조체의 유한요소모델 검증 (Verification of Finite Element Model for Composite Lattice Structures through Natural Frequency Test)

  • 임재문;신광복;이상우
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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    • pp.832-834
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    • 2017
  • 본 논문에서는 고유진동수 시험을 통해 복합재 격자구조체의 유한요소모델을 검증하였다. 복합재 격자구조체의 유한요소모델은 빔, 쉘 그리고 솔리드 요소를 사용하여 생성하였다. 고유진동수는 자유 경계조건 하에서 충격시험법을 사용하여 측정하였다. 쉘과 솔리드 요소의 유한요소해석 결과, 고유진동수 시험과 잘 일치하는 것을 확인하였다. 빔 요소는 섬유 비교차부의 물성저하를 고려하지 못하여 오차가 발생된 것으로 판단된다.

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