Journal of the Korean Society of Manufacturing Technology Engineers (한국생산제조학회지)

The Korean Society of Manufacturing Technology Engineers (한국생산제조학회)
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Closed-Form Solutions for Stress Intensity Factor and Elastic Crack Opening Displacement for Circumferential Through-Wall Cracks in the Interface between an Elbow and a Straight Pipe under Internal Pressure

내압이 작용하는 직관과 엘보우의 경계면에 존재하는 원주방향 관통균열의 응력확대계수 및 탄성 균열열림변위 예측식

  • Jang, Youn-Young (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Jeong, Jae-Uk (School of Mechanical Engineering, Sungkyunkwan University) ;
  • Huh, Nam-Su (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Kim, Ki-Seok (Energy Infrastructure Research Group, Steel Solution Center, POSCO) ;
  • Cho, Woo-Yeon (Energy Infrastructure Research Group, Steel Solution Center, POSCO)
  • Received : 2015.08.27
  • Accepted : 2015.09.17
  • Published : 2015.10.15
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Abstract

Fracture mechanics analysis for cracked pipes is essential for applying the leak-before-break (LBB) concept to nuclear piping design. For LBB assessment, crack instability and leak rate should be predicted accurately for through-wall cracked pipes. In a nuclear piping system, elbows are connected with straight pipes by circumferential welding; this weld region is often considered a critical location. Hence, accurate crack assessment is necessary for cracks in the interface between elbows and straight pipes. In this study, the stress intensity factor (SIF) and elastic crack opening displacement (COD) were estimated through detailed 3D elastic finite element (FE) analyses. Based on the results, closed-form solutions of shape factors for calculating the SIFs and elastic CODs were proposed for circumferential through-wall cracks in the abovementioned interfaces under internal pressure. In addition, the effect of the elbow on shape factors was investigated by comparing the results with the existing solutions for a straight pipe.

Keywords

References

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  2. Prediction of fracture parameters of circumferential through-wall cracks in the interface between an elbow and a pipe under internal pressure vol.30, pp.9, 2016, https://doi.org/10.1007/s12206-016-0834-x