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Structural Integrity Evaluation of SG Tube with Surface Wear-type Defects

표면 마모결함을 고려한 증기발생기 세관의 구조건전성 평가

  • 김종민 (성균관대학교 기계공학부) ;
  • 허남수 (성균관대학교 기계공학부) ;
  • 장윤석 (성균관대학교 기계공학부) ;
  • 황성식 (한국원자력연구소) ;
  • 김정수 (한국원자력연구소) ;
  • 김영진 (성균관대학교 기계공학부)
  • Published : 2006.12.01

Abstract

During the last two decades, several guidelines have been developed and used for assessing the integrity of a defective steam generator (SG) tube that is generally caused by stress corrosion cracking or wall-thinning phenomenon. However, as some of SG tubes are also failed due to fretting and so on, alternative failure estimation schemes are required for relevant defects. In this paper, parametric three-dimensional finite element (FE) analyses are carried out under internal pressure condition to simulate the failure behavior of SG tubes with different defect configurations; elliptical wear, tapered and flat wear type defects. Maximum pressures based on material strengths are obtained from more than a hundred FE results to predict the failure of SG tube. After investigating the effect of key parameters such as defect depth, defect length and wrap angle, simplified failure estimation equations are proposed in relation to the equivalent stress at the deepest point in wear region. Comparison of failure pressures predicted by the proposed estimation scheme with corresponding burst test data showed a good agreement.

Keywords

Burst Test;Finite Element Analysis;Steam Generator Tube;Plugging Criteria;Wear Type Defects

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