• 제목/요약/키워드: Tetrahedral meshing

검색결과 15건 처리시간 0.021초

옥트리 기반의 적응적 부호거리장을 이용한 사면체 요소망 생성 (Tetrahedral Meshing with an Octree-based Adaptive Signed Distance Field)

  • 박석훈;최민규
    • 한국컴퓨터그래픽스학회논문지
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    • 제18권1호
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    • pp.29-34
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    • 2012
  • 양질의 사면체 요소망은 유한요소법 기반의 변형체 시뮬레이션이나 사면체 기반의 유체 시뮬레이션 등에서 필수적이다. 본 논문에서는 옥트리 기반의 적응적 부호거리장을 이용하여 다각형 표면을 가진 물체의 내부를 양질의 이면각을 가진 사면체로 채우는 볼륨 요소망 구성 방법을 제안한다. 옥트리를 이용하여 물체 내부에서 표면까지 다양한 크기의 사면체를 이용하여 생성된 요소의 개수를 줄이며, 옥트리의 인접 셀들 사이의 레벨 차이를 제한하여 양질의 이면각을 가진 요소망을 얻는다. 옥트리 기반의 요소망 생성에 있어서 물체 표면까지의 부호거리를 구하는 것은 매우 중요한 연산이다. 본 논문은 하향식으로 생성한 옥트리의 꼭짓점들에서 부호거리장을 빠르게 구하는데 중점을 두고 있다. 본 논문에서 제안한 사면체 요소망 구성 방법은 실행 시간이 빠르고 안정적이며 구현이 쉬운 장점을 가지고 있다.

Unstructured Tetrahedral Meshing by an Edge-Based Advancing Front Method

  • Kim, Young-Woong;Kwon, Gi-Whan;Chae, Soo-Won;Shim, Jae-Kyung
    • Journal of Mechanical Science and Technology
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    • 제16권2호
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    • pp.211-218
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    • 2002
  • This paper proposes an unstructured tetrahedral meshing algorithm for CAD models in the IGES format. The work presented is based on the advancing front method, which was proposed by the third author. Originally, the advancing front method uses three basic operators, namely, trimming, wedging, and digging. In this research, in addition to the basic operators, three new operators splitting, local finishing, and octahedral-are added to stabilize the meshing process. In addition, improved check processes are applied to obtain better-shaped elements. The algorithm is demonstrated and evaluated by four examples.

일반 단면으로부터 사면체 요소망의 자동생성 (Automatic Generation of Tetrahedral Meshes from General Sections)

  • 채수원;이규민;신상엽
    • 대한기계학회논문집A
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    • 제24권1호
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    • pp.196-205
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    • 2000
  • Computed Tomography (CT), Nuclear Magnetic Resonance Imaging (MR1) and some ultrasound techniques make it possible to obtain cross sections of human body or mechanical parts. In CAD system, a series of sectional surfaces can also be obtained from solid models of 3D objects. In this paper we introduce a tetrahedral meshing algorithm from these series of general sections using basic operators. In this scheme. general sections of three-dimensional object are triangulated first and side surfaces between two sections are triangulated by the use of tiling process. Finally tetrahedral meshing process is performed on each layer of 3D objects, which is composed of two general sections and one side surface.

절점 탐색이 적용된 전진경계법에 의한 사면체 요소망의 자동생성 (Automatic Tetrahedral Mesh Generation Using Advancing Front Technique with Node Searching)

  • 전성재;채수원
    • 한국정밀공학회지
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    • 제21권3호
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    • pp.91-99
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    • 2004
  • An unstructured tetrahedral mesh generation algorithm has been presented. In order to construct better meshes in interior region by using an advancing front technique, a connecting operator and a local finishing operator II have been developed in addition to the existing operators. Before applying digging operators that generate new nodes inside of a meshing region, a connecting operator is employed that uses existing nodes which satisfy certain conditions for producing well-conditioned elements. The local finishing operator II is introduced to terminate the meshing process more flexibly on remaining subregions. With these new operators, tetrahedral meshing process becomes more robust and good quality of meshes are constructed.

전진경계법에서 Delaunay 탐색조건을 이용한 사면체 요소망의 자동 생성 (Automatic Tetrahedral Mesh Generation using Advancing Front Technique with Delaunay Node Searching)

  • 전성재;채수원
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.1605-1608
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    • 2003
  • A unstructured tetrahedral mesh generation algorithm has been presented. To make better meshes in interior region using an advancing front technique, a connecting operator has been developed in addition to the existing operators. Before applying digging operators that generate new nodes inside of a meshing region, a connecting operator is employed that uses existing nodes which satisfy certain conditions for producing well-conditioned elements if possible. By introducing this new operator, tetrahedral meshing process becomes more robust and produces better quality of meshes.

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옥트리 기반의 적응적 사면체 요소망구성 (Octree-Based Adaptive Tetrahedral Meshing)

  • 김철원;박석훈;최민규
    • 한국컴퓨터그래픽스학회논문지
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    • 제17권2호
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    • pp.45-53
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    • 2011
  • 본 논문에서는 양질의 이면각을 가진 사면체로 물체 내부를 채우는 볼륨 요소망 구성 방법을 제안한다. 본 논문에서 제안한 방법은 실행시간이 빠르고 안정적이며 구현이 쉬운 장점을 가지고 있다. 효율적인 공간 활용을 위해 옥트리를 사용함으로써 물체 내부에서 표면에 이르기까지 다양한 크기의 사면체를 활용할 수 있다. 최소 이면각을 최대화하고 최대 이면각을 최소화하는 양질의 요소망을 얻기 위하여 옥트리의 인접 셀들 사이의 레벨 차이를 제한하며, 옥트리 및 요소망 생성 속도를 높이기 위하여 정규 격자에서의 부호거리장을 사용한다. 본 논문에서 제안한 요소망 구성 방법은 유한요소법 기반의 변형체 시뮬레이션이나 사면체 기반의 유체 시뮬레이션 등에서 유용하게 활용될 수 있다.

흉추 CT 영상으로부터 사면체 요소망의 자동생성 (Tetrahedral Mesh Generation from CT Images of Thoracic Vertebra)

  • 박정민;권기환;전성재;채수원;이관행;이태수;서중근;박정율
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.150-153
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    • 2002
  • The use of the finite element method for biomechanical analysis is increasing rapidly in recent years. Since biomechanical models are usually in very complex shapes, it takes a lot of time and efforts to build reasonable finite element models. In this paper, a new tetrahedral meshing algorithm from the series of 2-D computed tomography(CT) images has been proposed. In this scheme, the planar sections of three-dimensional objects and the side surfaces between two planar sections are triangulated first, and then an advancing front algorithm is employed to construct tetrahedral elements by using basic operators. A sample finite element model for thoracic vertebra is presented.

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셀 구조물에서 중립면에 대한 유한요소망의 자동생성 (Automatic Generation of Finite Element Meshes on Midsurfaces in Shell Structures)

  • 손준희;채수원
    • 대한기계학회논문집A
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    • 제28권10호
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    • pp.1517-1525
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    • 2004
  • Shell finite elements are widely used for the analysis of thin section objects such as sheet metal parts, automobile bodies and et al. due to their computational efficiency. Since many of input data for finite element analysis are given as solid models or triangulated surface models, one should extract midsurface information from these input data initially and then construct shell meshes on the extracted midsurfaces. In this paper, a method of generating shell elements on midsurfaces directly from input models has been proposed, in which midsurface generating process can be omitted. In order to construct shell meshes, the input models should be triangulated on surfaces first, and then tetrahedral elements are generated by using an advancing front method, and finally mid shell surfaces are obtained from tetrahedral meshes. Some examples are given to demonstrate the efficiency of the proposed method.

3 차원 구조물에서 Chordal Axis Transform 을 이용한 쉘 요소망의 자동생성 (Automatic Generation of Shell Elements by Using Chordal Axis Transform in 3D Structures)

  • 손준희;채수원
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.700-705
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    • 2004
  • Shell finite elements are widely used for the analysis of thin section objects such as sheet metal parts, automobile bodies and et al. due to their computational efficiency. Since many of input data for finite element analysis are given as solid models or triangulated surface models, one should extract midsurface information from these input data initially and then construct shell meshes on the extracted midsurfaces. In this paper, a method of generating shell elements on midsurfaces directly from input models have been proposed. In order to construct shell meshes, the input models should be triangulated on surfaces first, and then tetrahedral elements are generated by using an advancing front method, and finally mid shell surfaces are obtained from tetrahedral meshes. Some examples are given to demonstrate the efficiency of the proposed method.

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THE EFFECTS OF MESH STYLE ON THE FINITE ELEMENT ANALYSIS FOR ARTIFICIAL HIP JOINTS

  • Shin, Jae-Min;Lee, Dong-Sun;Kim, Sung-Ki;Jeong, Da-Rae;Lee, Hyun-Geun;Kim, Jun-Seok
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제15권1호
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    • pp.57-65
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    • 2011
  • In this paper, a good quality mesh generation for the finite element method is investigated for artificial hip joint simulations. In general, bad meshes with a large aspect ratio or mixed elements can give rise to excessively long computational running times and extremely high errors. Typically, hexahedral elements outperform tetrahedral elements during three-dimensional contact analysis using the finite element method. Therefore, it is essential to mesh biologic structures with hexahedral elements. Four meshing schemes for the finite element analysis of an artificial hip joint are presented and compared: (1) tetrahedral elements, (2) wedge and hexahedral elements, (3) open cubic box hexahedral elements, and (4) proposed hexahedral elements. The proposed meshing scheme is to partition a part before seeding so that we have a high quality three-dimensional mesh which consists of only hexahedral elements. The von Mises stress distributions were obtained and analyzed. We also performed mesh refinement convergence tests for all four cases.