• 제목/요약/키워드: Finite Deformation

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탄소성 대변형 거동에서의 손상의 운동학 (The Kinematics of Damage for Elasto-Plastic Large Deformation)

  • 박대효;김기두
    • 한국강구조학회 논문집
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    • 제9권3호통권32호
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    • pp.401-419
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    • 1997
  • 탄소성 대변형에서의 손상의 운동학을 연속체 역학적 구도 안에서 유효 응력의 개념을 통하여 4차 유효 손상 텐사를 이용하여 소개하였다. 손상 변형의 운동학적인 기술의 부재로 인하여 소변형 문제에서는 고체의 손상의 특성을 기술하기 위해서는 다음의 두 가지 가정 (변형률 등가의 가정 또는 에너지 등가의 가정)중의 하나가 일반적으로 채택되어진다. 본 연구에서 제안된 방법은 대변형에 적용될 수 있는 손상 거동의 운동학적인 일반화된 방법을 제공한다. 이 방법은 소 변형률에 국한되는 변형률 등가의 가정이나 에너지 등가의 가정 방식이 아닌 변형장의 운동학을 직접 고려하여 손상 거동의 운동학을 2차 손상 텐사의 함수인 4차 유효 손상 텐사를 이용하여 탄성 및 소성 영역에서 표현하였다.

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외연 유한요소 프로그램을 이용한 고체-액체 조합 구조물의 변형해석 (Deformation Analysis of Solid-Liquid Coupled Structure using Explicit Finite Element Program)

  • 최형연
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2000년도 봄 학술발표회논문집
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    • pp.150-155
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    • 2000
  • In this study, deformation analysis for solid-liquid coupled structure has been performed using explicit finite element program In order to model the behavior of liquid, SPH (Smooth Particle Hydrodynamics) algorithm was adopted. Crash test and simulation for the hydro-type impact energy absorber were given as an example of industrial application. The obtained good correlation between the test results and simulation reveals that the proposed method could be used effectively for the structural analysis of solid-liquid coupled problems

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철근콘크리트 골조의 연성화 해석 (Softening Analysis of Reinforced Concrete Frames)

  • 나유성;홍성걸
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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    • pp.438-443
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    • 1998
  • Softening os the name used for decreasing bending moment at advanced flexural deformation. To accommodate softening deformation in analysis, it is assumed that a hinge has finite length. The softening analysis of R/C frames relies on the primary assumption that softening occurs over a finite hinge length and that the moment-curvature relationship for any section may be closely described by a trilinear approximation. A stiffness matrix for elastic element with softening regions are derived and the stiffness matrix allows extension of the capability of an existing computer program for elastic-plastic analysis to the softening situation. The effect of softening on the collapse load of R/C frame is evaluated.

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온간 ECAP 공정에서 Zr-702 합금의 변형거동해석 (Deformation Behavior Analysis of Zr-702 Alloy during ECAP at Elevated Temperature)

  • 이강무;권기환;채수원;권숙인;김명호;황선근
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.877-881
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    • 2002
  • Much research efforts have been made on the equal channel angular pressing(ECAP) which produces ultra-fine grains. In this paper the ECAP processes with Zr-702 alloy at elevated temperature and at room temperature are considered. Both two-dimensional and three-dimensional finite element analyses have been employed to investigate the deformation behaviors of specimen during ECAP process.

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열간분말단조 공정의 열탄소성 유한요소해석 (Thermo-Elasto-Plastic Finite Element Analysis of Powder Hot Forging)

  • 김형섭
    • 한국분말재료학회지
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    • 제4권2호
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    • pp.83-89
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    • 1997
  • A finite element analysis to solve the coupled thermomechanical problem in the plane strain upsetting of the porous metals was performed. The analysis was formulated using the yield function advanced by Lee and kim and developed using the thermo-elasto-plastic time integration procedure. The density and temperature dependent thermal and mechanical properties of porous metals were considered. The internal heat generation by the plastic deformation and the changing thermal boundary conditions corresponding to the geometry were incorporated in the program. The distributions of the stress, strain, pressure, density and temperature were predicted during the free resting period, deformation period and dwelling period of the forging process.

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Finite Element Analysis of Temperature Distribution and Thermally Caused Deformation in Ventilated Disk Brakes

  • Kim, Chung-Kyun
    • Tribology and Lubricants
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    • 제11권5호
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    • pp.150-155
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    • 1995
  • In order to analyze the thermal effects of the rotor models, the finite element technique was used in this study. The length of the hat was investigated as a design parameter. At the start of each brake application the disk surface temperature rapidly increases to a maximum value and then decays due to external cooling and thermal conduction to the hat. The calculated results indicate that the long length of the hat shows the minimum deformation in axial direction, which is related to the thermal problems, coned wear, vibration and noise.

집합조직의 발전을 반영하는 다결정재의 정상상태성형공정해석 (Finite Element Analysis for Steady State Forming Process of Polycrystalline Metal Including Texture Development)

  • 김응주;이용신
    • 소성∙가공
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    • 제5권4호
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    • pp.297-304
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    • 1996
  • A process model is formulated considering the effect of crystallographic texture developed in forming process. The deformation induced plastic anisotropy can be predicted by capturing the evolution of texture during large deformation in the polycrystalline aggregate. The anisotropic stiffness matrix for the aggregate is derived and implemented in Eulerian finite element code using a Consistent Penalty method. As an application the evolution of texture in rolling drawing and extrusion processes are simulated. The numerical results show good agreements with report-ed experimental textures.

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