# 내압과 굽힘하중을 받는 곡관의 소성 하중에 굽힘 각도가 미치는 영향

• 이국희 (고려대학교 대학원 기계공학과) ;
• 오창식 (고려대학교 대학원 기계공학과) ;
• 유봉 (고려대학교 기계공학과) ;
• 박치용 (한국전력연구원) ;
• 김윤재 (고려대학교 기계공학과)
• Published : 2007.03.01
• 68 21

#### Abstract

This paper quantifies the effect of a bend angle of a pipe bend on plastic loads, via small strain and large strain FE limit analyses using elastic-perfectly plastic materials. To consider the effect of the attached straight pipe, two limiting cases are considered. One case corresponds to the pipe bend without the attached straight pipe, and the other to that with a sufficiently long attached straight pipe. For the former case, the FE results suggest that the limit load is not affected by the bend angle for both in-plane bending and internal pressure. For the latter case, however, the bend angle affects plastic loads. An interesting finding is that the plastic load smoothly changes from the limit load of the straight pipe when the bend angle approaches zero to the plastic load of the $90^{\circ}$ pipe bend when the bend angle approaches 90 degree. Based on such observations, closed-form plastic load solutions are proposed for the pipe bend with an arbitrary bend angle under in-plane bending and internal pressure.

#### Keywords

Bend Angle;Finite Element Limit Analysis;Large Geometry Change;Pipe Bend;Plastic Load;Small Geometry Change

#### References

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