Fatigue Life Estimation of Welding Details by Using a Notch Strain Approach

노치변형률법을 적용한 용접구조상세의 피로수명평가

  • 한정우 (한국기계연구원 구조연구부) ;
  • 한승호 (한국기계연구원 구조연구부) ;
  • 신병천 (한국기계연구원 구조연구) ;
  • 김재훈 (충남대학교 기계설계공학)
  • Published : 2004.07.01


An evaluation of fatigue life of welded components is complicated due to various geometrically complex welding details and stress raisers in vicinity of weld beads, ego under cuts, overlaps and blow holes. These factors have a considerable influence on the fatigue strength of welded joints, as well as the welding residual stress which is relaxed depending on the distribution of local stress at the front of the stress raisers. To reasonably evaluate fatigue life, the effect of geometries and welding residual stress should be taken into account. The several methods based on the notch strain approach have been proposed in order to accomplish this. These methods, however, result in differences between analytical and experimental results due to discrepancies in estimated amount of relaxed welding residual stress present. In this paper, an approach that involves the use of a modified notch strain approach considering geometrical effects and a residual stress relaxation model based on experimental results was proposed. The fatigue life for five types of representative welding details, ego cruciform, cover plate, longitudinal stiffener, gusset and side attachment joint, are evaluated using this method.


Fatigue Life;Welding Details;Stress Raiser;Welding Residual Stress;Notch Strain Approach


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