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Plastic Limit Loads of 90° Elbows with Local Wall-Thinning Using Small Strain FE Limit Analyses (II)- Bending Moment -

소변형 이론에 입각한 감육이 존재하는 90 도 곡관의 소성 한계 하중 (II)- 굽힘 -

  • 김종현 (고려대학교 대학원 기계공학과) ;
  • 안중혁 (고려대학교 대학원 기계공학과) ;
  • 홍석표 (고려대학교 대학원 기계공학과) ;
  • 박치용 (한전 전력연구원 원자력 연구실) ;
  • 김윤재 (고려대학교 기계공학과)
  • Published : 2007.04.01

Abstract

This paper proposes closed-form plastic limit load solutions for elbows under in-plane bending, via three-dimensional (3-D), small strain FE limit analyses using elastic-perfectly plastic materials. A wide range of elbow and thinning geometries are considered. For systematic analyses of the effect of the axial thinning length on limit loads, two limiting cases are considered; a sufficiently long wall thinning, and the circumferential part-through surface crack. Closed-form plastic limit load solutions for wall thinning with intermediate longitudinal extents are then obtained from these two limiting cases. The effect of the axial extent of wall thinning on plastic limit loads for elbows is highlighted by comparing that for straight pipes. Although the proposed solutions are developed for the case when wall thinning exists in the center of elbows, it is also shown that they can be applied to the case when wall thinning exists anywhere within the elbow.

Keywords

FE Analysis;Wall Thinning;Elbow;Plastic Limit Load;Bending Moment

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