• 제목/요약/키워드: 3D Finite Element

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자동차용 모터케이스 성형용 멀티포머의 공정개선에 관한 유한요소해석 (Finite Element Analysis on Process Improvement of the Multi-Forming for the Motor-Case of an Automobile)

  • 김형진;배원병;조종래
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2005년도 춘계학술대회 논문집
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    • pp.467-470
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    • 2005
  • There are about 10 motors for tile actuator of the automation system in an auto-mobile recently. The performance of the motor-case is much related to the noise and the vibration of an auto-mobile Multi-Forming process is so much the better than existing deep-drawing or Multi-step forming by press by less cost, installation and staff. But there isn't the specific and general process design, so we aren't good at competition. So in the first step, I want to study about the core design for the multi-forming process. We can access by the elasto-plastic theory and the finite element method, and we use a commercial package of the Deform-2D and, Deform-3D which is based on three-dimensional elasto-plastic finite element, evaluated propriety oi the package. The evaluation of the package propriety was simulated by simple bending example. It was found the elasto-plastic theory was mostly in agreement with the simulation. We proposed that three type of section for the core and analyzed by finite element method (Deform-2D). We can get the best result with the ellipse type core. Then we apply the result of the preceding analysis to the finite element method (Deform-3D). In 3D-finite element analysis, we can get the result of 8/100mm-roundness. This result can help the improvement of the multi-forming process.

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3차원 적응 유한요소법을 위한 사면체 요소세분에 관한 연구 (A Study on Mesh Refinement for 3-D Adaptive Finite Element Method Using Tetrahedral Element)

  • 김형석;정현교;한송엽
    • 대한전기학회논문지
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    • 제39권9호
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    • pp.921-927
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    • 1990
  • This paper presents a mesh refinement scheme for 3-D adaptive finite element method. Firstly, the refinement of triangular meshes based on the bisection of triangles is discussed. And a new method to refine tetrahedral meshes employing the bisection method is presented. In two dimensional cases, it has been noted that all angles in the triangular meshes refined by the bisection method are greater than or equal to half the smallest angle in the original meshes. Through the examples where the newly proposed method is applied to three dimensional cases, it is shown that regarding the solid angles, the method gives nearly the same result as that in the two dimensional case. Accordingly, it can be concluded that the proposed method will be useful in the mesh refinements for 3-D adaptive finite element method.

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Advances in Simulation of Arbitrary 3D Crack Growth using FRANC3Dv5

  • Wawrzynek, P.A.;Carter, B.J.;Hwang, Chang-Yu;Ingraffea, A.R.
    • 한국전산구조공학회논문집
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    • 제23권6호
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    • pp.607-613
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    • 2010
  • FRANC3D is a program for simulating arbitrary three-dimensional crack growth. Recently, a completely new version of the program, FRANC3D/NG, has been created. Unlike previous versions, which relied largely on boundary element analysis, the new version of the program works with finite element analysis exclusively and is designed to work with general-purpose commercial finite element packages. This paper presents the theoretical underpinnings of the procedures to adaptively modify the geometry and mesh of a model to simulate crack growth.

Approximation Method for the Calculation of Stress Intensity Factors for the Semi-elliptical Surface Flaws on Thin-Walled Cylinder

  • Jang Chang-Heui
    • Journal of Mechanical Science and Technology
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    • 제20권3호
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    • pp.319-328
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    • 2006
  • A simple approximation method for the stress intensity factor at the tip of the axial semielliptical cracks on the cylindrical vessel is developed. The approximation methods, incorporated in VINTIN (Vessel INTegrity analysis-INner flaws), utilizes the influence coefficients to calculate the stress intensity factor at the crack tip. This method has been compared with other solution methods including 3-D finite element analysis for internal pressure, cooldown, and pressurized thermal shock loading conditions. For these, 3-D finite-element analyses are performed to obtain the stress intensity factors for various surface cracks with t/R=0.1. The approximation solutions are within $\pm2.5%$ of the those of finite element analysis using symmetric model of one-forth of a vessel under pressure loading, and 1-3% higher under pressurized thermal shock condition. The analysis results confirm that the approximation method provides sufficiently accurate stress intensity factor values for the axial semi-elliptical flaws on the surface of the reactor pressure vessel.

A continuum mechanics based 3-D beam finite element with warping displacements and its modeling capabilities

  • Yoon, Kyungho;Lee, Youngyu;Lee, Phill-Seung
    • Structural Engineering and Mechanics
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    • 제43권4호
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    • pp.411-437
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    • 2012
  • In this paper, we propose a continuum mechanics based 3-D beam finite element with cross-sectional discretization allowing for warping displacements. The beam element is directly derived from the assemblage of 3-D solid elements, and this approach results in inherently advanced modeling capabilities of the beam element. In the beam formulation, warping is fully coupled with bending, shearing, and stretching. Consequently, the proposed beam elements can consider free and constrained warping conditions, eccentricities, curved geometries, varying sections, as well as arbitrary cross-sections (including thin/thick-walled, open/closed, and single/multi-cell cross-sections). We then study the modeling and predictive capabilities of the beam elements in twisting beam problems according to geometries, boundary conditions, and cross-sectional meshes. The results are compared with reference solutions obtained by analytical methods and solid and shell finite element models. Excellent modeling capabilities and solution accuracy of the proposed beam element are observed.

3차원 결정소성 유한요소해석을 통한 변형 집합조직 예측 (Prediction of Deformation Texture Based on a Three-Dimensional Crystal Plasticity Finite Element Method)

  • 정경환;김동규;임용택;이용신
    • 소성∙가공
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    • 제21권4호
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    • pp.252-257
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    • 2012
  • Crystallographic texture evolution during forming processes has a significant effect on the anisotropic flow behavior of crystalline material. In this study, a crystal plasticity finite element method (CPFEM), which incorporates the crystal plasticity constitutive law into a three-dimensional finite element method, was used to investigate texture evolution of a face-centered-cubic material - an aluminum alloy. A rate-dependent polycrystalline theory was fully implemented within an in-house program, CAMPform3D. Each integration point in the element was considered to be a polycrystalline aggregate consisting of a large number of grains, and the deformation of each grain in the aggregate was assumed to be the same as the macroscopic deformation of the aggregate. The texture evolution during three different deformation modes - uniaxial tension, uniaxial compression, and plane strain compression - was investigated in terms of pole figures and compared to experimental data available in the literature.

3차원 유한요소해석을 이용한 줄눈콘크리트 포장의 다웰바 최적배치에 대한 연구 (Study on Dowel-Bar Optimum Position of Jointed Concrete Pavement Using 3-D FEM Analysis)

  • 전범준;홍성재;이승우
    • 대한토목학회논문집
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    • 제30권2D호
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    • pp.135-141
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    • 2010
  • 국내 줄눈콘크리트 포장 다웰바의 경우 합리적 근거가 없이 경험에 의하거나 국외의 기준에 의해 설계시공되고 있다. 다웰바를 합리적으로 설계하기 위해서는 다웰바 거동에 대한 고찰이 요구되며 이에 3차원 유한요소해석을 이용하여 분석하였다. 다웰바의 거동을 평가하기 위해서 다웰바의 3차원 유한요소해석과 다웰바 거동에 대한 대표적인 모델인 Timoshenko 이론을 비교분석하였다. 본 연구에서는 다웰바의 사이즈 및 배치에 대한 합리적인 설계를 하기 위해서 3차원 유한요소해석을 사용하여 다웰바의 그룹작용(Dowel Group Action) 범위와 차량바퀴의 주행경로(Wheel Path)분포를 고려하여 슬래브 처짐을 감소시킬 수 있는 다웰바 최적배치를 제시하였다.

Finite element modeling of multiplyconnected three-dimensional areas

  • Polatov, Askhad M.;Ikramov, Akhmat M.;Razmukhamedov, Daniyarbek D.
    • Advances in Computational Design
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    • 제5권3호
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    • pp.277-289
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    • 2020
  • This article describes the technology for constructing of a multiply-connected three-dimensional area's finite element representation. Representation of finite-element configuration of an area is described by a discrete set that consist of the number of nodes and elements of the finite-element grid, that are orderly set of nodes' coordinates and numbers of finite elements. Corresponding theorems are given, to prove the correctness of the solution method. The adequacy of multiply-connected area topology's finite element model is shown. The merging of subareas is based on the criterion of boundary nodes' coincidence by establishing a simple hierarchy of volumes, surfaces, lines and points. Renumbering nodes is carried out by the frontal method, where nodes located on the outer edges of the structure are used as the initial front.

환상압연 공정의 실용적 모델링 방법에 관한 연구 (A Study on the Practical Finite Element Modeling Method for Ring Rolling)

  • 이두규;김응주;이용신
    • 소성∙가공
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    • 제24권3호
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    • pp.161-166
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    • 2015
  • The finite element method has been widely used in the analysis of ring rolling. For ring rolling it requires a high computational expense due to the non-steady state material flow characteristics of the process. The high computational expense causes the finite element analysis to be impractical for industrial applications. In the current study, we aim to develop a practical implicit finite element modeling method for ring rolling. This method uses a step-wise steady state assumption and is called the “Stepped method”. The stepped method divides the whole process time of unsteady-state flow model into a finite number of steady-state models. It then solves the process at several specific time steps until convergence is reached. In order to confirm the performance and validity of the newly proposed stepped method, the result from the stepped method were compared to the results from a Lagrangian finite element method and to results from experiments reported in the literature.

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

  • 김동준;최호준;장동환;임중연;이호용;황병복
    • 소성∙가공
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    • 제12권3호
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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.