Evaluation of Plastic Collapse Bending Load of Elbows with Thinning Area of Various Shapes

여러 형상의 감육부를 가진 엘보우의 소성붕괴 굽힘 하중의 평가

  • Shin, Kyu-In (Energy.Safety Research Institute, Chung Ang University) ;
  • Lee, Sung-Ho (Korea Electric Power Research Institute) ;
  • Yoon, Kee-Bong (Department of Mechanical Engineering, Chung Ang University)
  • 신규인 (중앙대학교 차세대에너지.안전연구소) ;
  • 이성호 (한국전력 전력연구원) ;
  • 윤기봉 (중앙대학교 기계공학부)
  • Published : 2008.06.30

Abstract

Elbows with various shapes of local wall thinning were numerically analyzed by finite element method to get load-displacement curves and the maximum loads. Results were compared with the experimental data obtained by another study. Elastic-plastic analysis were carried out under the combined loading conditions of internal pressure and in-plane bending loads. Two types of bending loads were considered such as elbow opening mode and elbow closing mode. Also, two different wall thinning geometries were modeled. Wall thinning area located extrados or intrados of elbow inner surface was considered. Longitudinal and circumferential lengths of the thinning area and the thinned thickness were varied for analysis. The results showed that the maximum load of the wall-thinned elbow decreased with increasing of the circumferential thinning length and the thinned thickness in both of extrados and intrados thinning locations in both loading types. The maximum load obtained by the analysis were in good agreement with the experimentally measured maximum load with the same wall thinning type and dimensions. This supports accuracy of the analysis results obtained in this study.

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