• Title/Summary/Keyword: 재료 전이

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Leak-Before-Break (LBB) Assessment Method Considering Crack Nonlinearity Using Effective Elastic Modulus and Material Nonlinearity (유효탄성계수를 이용한 균열 비선형 및 재료 비선형을 고려한 파단전누설(LBB) 평가 방법)

  • Kim, Maan-Won;Kim, Sung-Hwan;Lee, Eui-Jong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.6
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    • pp.651-659
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    • 2011
  • With the increase in the thermal power output of recently developed nuclear power plants, the applied forces and moments are increased in some piping systems, so that the leak-before-break (LBB) application criteria would not be satisfied in those pipes. In this paper, we present a method for obtaining the additive LBB margin in the pipes by considering the nonlinearity of the crack and material properties. Finite element analysis and the moment-rotation equation of beam theory were used to calculate the nonlinearity of the crack and material properties. Moreover crack stability analysis was performed using the method proposed in this study. The LBB margin was increased effectively through consideration of the nonlinearity of the crack and material properties in the pipe.