Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Estimates of Elastic Fracture Mechanics Parameters for Thick-Walled Pipes with Slanted Axial Through-Wall Cracks

두꺼운 배관에 존재하는 축방향 경사관통균열의 탄성파괴역학 매개변수 계산

  • Han, Tae-Song (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Huh, Nam-Su (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Science and Technology)
  • 한태송 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 허남수 (서울과학기술대학교 기계시스템디자인공학과)
  • Received : 2012.05.25
  • Accepted : 2012.09.12
  • Published : 2012.12.01
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Abstract

The present paper provides the elastic stress intensity factors (SIFs) and the crack opening displacements (CODs) of a thick-walled pipe with a slanted axial through-wall crack. For estimating these elastic fracture mechanics parameters, systematic three-dimensional elastic finite element (FE) analyses were performed by considering geometric variables, i.e., thickness of pipe, reference crack length, and crack length ratio, affecting the SIFs and CODs. As for loading condition, the internal pressure was considered. Based on the FE results, the SIFs and CODs of slanted axial through-wall cracks in a thickwalled pipe along the crack front and the wall thickness were calculated. In particular, to calculate the SIFs of a thick-walled pipe with a slanted axial through-wall crack from those of a thick-walled pipe with an idealized axial through-wall crack, a slant correction factor representing the effect of the slant crack on the SIFs was proposed.

본 논문에서는 두꺼운 배관에 존재하는 축방향 경사관통균열의 탄성응력확대계수 및 탄성 균열열림변위 해를 제시하였다. 이를 위해 배관의 두께, 기준균열길이, 경사관통균열 길이비를 체계적으로 변화시키며 3차원 탄성 유한요소해석을 수행하였다. 하중조건으로는 균열 성장에 영향을 미치는 내압을 고려하였다. 유한요소해석 결과를 바탕으로 두꺼운 배관에 존재하는 이상적인 축방향 관통균열과 경사관통균열에 대한 탄성응력확대계수와 탄성 균열열림변위를 균열선단 및 두께를 따라 제시하였다. 특히 응력확대 계수의 경우에는 이상적인 축방향 관통균열 결과로부터 쉽게 경사관통균열의 응력확대계수를 구할 수 있는 경사관통균열 보정계수를 제시하였다.

Keywords

References

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