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

The Korean Society of Mechanical Engineers (대한기계학회)
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Fatigue Life Estimation of Cruciform Welded Joint Considering Multiple Collinear Surface Cracks

십자형 필렛용접 이음부의 복수균열 진전수명 평가

  • 한승호 (한국기계연구원 구조연구부) ;
  • 신병천 (한국기계연구원 구조연구부) ;
  • 김재훈 (충남대학교 기계설계공학과) ;
  • 한정우 (한국기계연구원 구조연구부)
  • Published : 2004.10.01
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Abstract

Fatigue life of welded joints is governed by the propagation of multiple collinear surface cracks distributed randomly along weld toe. These cracks propagate under the mechanisms of mutual interaction and coalescence of the adjacent two cracks. To estimate the fatigue life, its influences on the above two mechanisms should be taken into account, which appear through the stress intensity factors disturbed mutually. However, it is difficult to calculate the stress intensity factors of the multiple surface cracks located in vicinity of weld toe due to its geometrical complexity. They are calculated normally by using the Μk-factors, but such Mk-factors are very rare in literature. In this study, the Μ$textsc{k}$-factors were obtained from a parametric study on crack length and depth, for which a finite element method is used. A fatigue test for a cruciform welded Joint was conducted and the fatigue life of the tested specimen was estimated using the present method with the informations obtained from the test, such as the number, size, and locations of the cracks. The estimated and measured fatigue life showed a good agreement.

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References

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