• 제목/요약/키워드: 손상발전 방정식

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등방성 손상을 고려한 탄소성 대변형 문제의 유한요소해석(제1보) -탄소성 손상 구성방정식 개발- (Finite Element Analysis of Elasto-Plastic Large Deformation considering the Isotropic Damage (the 1st Report) -Development of Elasto-Plastic Damage Constitutive Model-)

  • 노인식
    • 한국해양공학회지
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    • 제14권2호
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    • pp.70-75
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    • 2000
  • In this paper a new constitutive model for ductile materials was proposed. This model can describe the material degradation due to the evolution of isotropic damage during elasto-platic deformation. The plastic flow rule was derived under the framework of thermodynamic approach of continuum damage mechanics(CDM) in which plastic strain hardening parameters and isotropic damage were taken as thermodynamic state variables. And the process to determine material constants for constitutive model using an experimental data was presented.

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선박 및 해양구조물용 극저온 재료의 온도 및 변형률 속도 의존 통합 구성방정식 개발 (Development of Temperature and Strain-Rate Dependent Unified Constitutive Equation for Ships and Offshore Structures)

  • 박웅섭;김정현;전민성;이제명
    • 대한조선학회논문집
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    • 제48권3호
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    • pp.200-206
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    • 2011
  • The mechanical properties of the most widely used cryogenic materials, i.e. austenitic stainless steel (ASS), aluminum alloy and invar steel, strongly depend on temperatures and strain rates. These phenomena show very complicated non-linear behaviors and cannot be expressed by general constitutive equation. In this study, an unified constitutive equation was proposed to represent the effect of temperature and strain rate on the materials. The proposed constitutive equation has been based on Tomita/Iwamoto and Bodner/Partom model for the expression of 2nd hardening due to martensite phase transformation of ASS. To simulate ductile fracture, modified Bodner/Chan damage model was additionally applied to the model and the model validity was verified by comparison of experimental and simulation results.

극저온 재료 성능분석을 위한 온도의존 손상모델 개발 (Development of Temperature Dependent Damage Model for Evaluating Material Performance under Cryogenic Environment)

  • 이경준;김태우;유재신;유성원;전민성;이제명
    • 대한조선학회논문집
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    • 제45권5호
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    • pp.538-546
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    • 2008
  • In this paper, the constitutive equation is developed to analyze the characteristics of strain-induced plasticity in the range of low temperature of 316 stainless steel. The practical usefulness of the developed equations is evaluated by the comparison between experimental and numerical results. For 316 stainless steel, constitutive equations, which represent the characteristics of nonlinear material behavior under the cryogenic temperature environment, are developed using the Bodner's plasticity model. In order to predict the material behaviour such as damage accumulation, Bodner-Chan's damage model is implemented to the developed constitutive equations. Based on the developed constitutive equations, 3-D finite element analysis program is developed, and verified using experimental results.

위상학적 모델링과 PWB Method를 이용한 대형 구조물 내부의 전자파 영향 해석 (Electromagnatic Effect Analysis inside Electrically Large Structures Using Topological Modeling and PWB Method)

  • 이재민;정인환;이재욱;이영승;권종화
    • 한국전자파학회논문지
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    • 제27권3호
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    • pp.284-290
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    • 2016
  • 최근 과학의 발전으로 인해 여러 장소에서 전자기기의 활용도가 높아졌기 때문에 예기치 못한 전자기파로 인한 오작동과 하드웨어와 소프트웨어의 치명적인 손상을 확인할 수 있는 안전 기술들이 요구되었다. 기존의 전자 제품뿐만 아니라 소형화 전자기기들이 복잡도가 높은 대형구조물 안에 비치가 되면서 그에 대한 전자파 영향을 맥스웰 방정식(Maxwell Equation)으로 모두 해석하기에는 여러 한계점을 갖고 있다. 본 논문에서는 대형 구조물에서의 복잡한 전자파 해석을 위해 확률론에 바탕을 둔 PWB(PoWer Balance) Method와 위상학적 모델링을 적용하여 내부의 전파 영향을 해석하고자 한다.