• Title/Summary/Keyword: 손상발전 방정식

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

  • 노인식
    • Journal of Ocean Engineering and Technology
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    • v.14 no.2
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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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Development of Temperature and Strain-Rate Dependent Unified Constitutive Equation for Ships and Offshore Structures (선박 및 해양구조물용 극저온 재료의 온도 및 변형률 속도 의존 통합 구성방정식 개발)

  • Park, Woong-Sup;Kim, Jeong-Hyeon;Chun, Min-Sung;Lee, Jae-Myung
    • Journal of the Society of Naval Architects of Korea
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    • v.48 no.3
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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.

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

  • Lee, Kyoung-Joon;Kim, Tae-Woo;Yoo, Jea-Sin;Yoo, Seong-Won;Chun, Min-Sung;Lee, Jae-Myung
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.5
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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.

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

  • Lee, Jae-Min;Jung, In-Hwan;Lee, Jae-Wook;Lee, Young-Seung;Kwon, Jong-Hwa
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.3
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    • pp.284-290
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    • 2016
  • As the recently advanced scientific developments result in high lever of the usability and the needs for the electrical equipment and devices in various situations, the safety technologies protecting malfunction and electrical critical damages including soft and hardware from the unexpectedly radiated electromagnetic interferences are required gradually. In addition, the numerical analysis for the miniaturized electrical components and equipments as well as the conventional electrical devices installed inside the electrically large enclosures and structures requires the memory requirement and time consumption too big to be handled in a realistic situation, which will result in a limitation in solving the complete set of maxwell's equations. In this paper, PWB method based on statistical theory and topological modeling with appropriate zoning concepts are introduced for the EM analysis of an electrically large complex structures.