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Limit Loads for Pipe Bends under Combined Pressure and in-Plane Bending Based on Finite Element Limit Analysis

압력과 모멘트의 복합하중을 받는 곡관에 대한 유한요소 한계하중 해석

  • 오창식 (고려대학교 대학원 기계공학과) ;
  • 김윤재 (고려대학교 기계공학과)
  • Published : 2006.05.01

Abstract

In the present paper, approximate plastic limit load solutions fur pipe bends under combined internal pressure and bending are obtained from detailed three-dimensional (3-D) FE limit analyses based on elastic-perfectly plastic materials with the small geometry change option. The present FE results show that existing limit load solutions for pipe bends are lower bounds but can be very different from the present FE results in some cases, particularly for bending. Accordingly closed-form approximations are proposed for pipe bends under combined pressure and in-plane bending based on the present FE results. The proposed limit load solutions would be a basis of defective pipe bends and be useful to estimate non-linear fracture mechanics parameters based on the reference stress approach.

Keywords

References

  1. R6, 2001, 'Assessment of the Integrity of Structures Containing Defects,' Revision 4, British Energy
  2. R5, 1999, 'An Assessment Procedure for the High Temperature Response of Structures,' Revision 2, British Energy
  3. Webster GA., Ainsworth RA., 1994, 'High Temperature Component Life Assessment,' Chapman & Hall
  4. Ainsworth RA., 1984, 'The Assessment of Defects in Structures of Strain Hardening Materials,' Engineering Fracture Mechanics, Vol. 19, pp. 633-642 https://doi.org/10.1016/0013-7944(84)90096-1
  5. Miller AG., 1988, 'Review of Limit Loads of Structures Containing Defects,' International Journal of Pressure Vessels and Piping, Vol. 32, pp. 191-327 https://doi.org/10.1016/0308-0161(88)90073-7
  6. Kim Y-J, Shim D-J, Huh N-S, Kim Y-J., 2002, 'Plastic Limit Pressures for Cracked Pipes Using Finite Element Limit Analyses,' International Journal of Pressure Vessels and Piping, Vol. 79, pp. 321-330 https://doi.org/10.1016/S0308-0161(02)00031-5
  7. Kim Y-J, Shim D-J, Nikbin K, Kim Y-J, Hwang S-S, Kim J-S., 2003, 'Finite Element Based Plastic Limit Loads for Pipes with Part-Through Surface Cracks Under Combined Loading,' International Journal of Pressure Vessels and Piping, Vol. 80, pp. 527-540 https://doi.org/10.1016/S0308-0161(03)00106-6
  8. Roberston A. Li H. and Mackenzie D., 2005, 'Plastic Collapse of Pipe Bends Under Combined Internal Pressure and In-Plane Bending,' International Journal of Pressure Vessels and Piping, Vol. 82, pp. 407-416 https://doi.org/10.1016/j.ijpvp.2004.09.005
  9. Miller AG., 1986, 'The Plastic Collapse of Cracked Pipe Bends Under Internal Pressure or In-Plane Bending,' CEGB Report, TPRD/B/0806/R86 Central Electrical Generating Board
  10. Yahiaoui K. Moffat DG. and Moreton DN., 2000, 'Piping Elbows with Cracks-a Parametric Study of the Influence of Crack Size on Limit Loads Due to Pressure and Opening Bending,' Journal of Strain Analysis, Vol. 35, pp. 35-46 https://doi.org/10.1243/0309324001513991
  11. Yahiaoui K. Moffat DG. and Moreton DN., 2000, 'Piping Elbows with Cracks-Global Finite Element and Experimental Plastic Loads Under Opening Bending,' Journal of Strain Analysis, Vol. 35, pp. 47-57 https://doi.org/10.1243/0309324001514008
  12. Chattopadhyay J. Natahani DK. Dutta BK. and Kushwaha HS., 2000, 'Closed-Form Collapse Moment Equations of Elbows Under Internal Pressure and In-Plane Bending Moment,' Journal of Pressure Vessel Technology, Vol. 122, pp. 431-436 https://doi.org/10.1115/1.1285988
  13. Yahiaoui K. Moreton DN. and Moffat DG., 2002, 'Evaluation of Limit Load Data for Cracked Pipe Bends Under Opening Bending and Comparisons with Existing Solutions,' International Journal of Pressure Vessels and Piping, Vol. 79, pp. 27-36 https://doi.org/10.1016/S0308-0161(01)00131-4
  14. Chattopadhyay J. Tomar AKS. Dutta BK. and Kushwaha HS., 2004, 'Closed-Form Collapse Moment Equations of Throughwall Circumferentially Cracked Elbows Subject to In-Plane Bending Moment,' Journal of Pressure Vessel Technology, Vol. 126, pp.307-317 https://doi.org/10.1115/1.1767177
  15. Goodall I.W., 1978, 'Lower Bound Limit Analysis of Curved Tubes Loaded by Combined Internal Pressure and In-Plane Bending Moment,' CEGB report RD/B/N4360 Central Electrical Generating Board
  16. Spence J. and Findlay GE., 1973, 'Limit Load for Pipe Bends Under In-Plane Bending,' Proc. 2nd Int. Conf. On Pressure Vessel Technology, San Antonio, Vol. 1-28, pp. 393-399
  17. Calladine CR., 1974, 'Limit Analysis of Curved Tubes.,' Journal of Mechanical Engineering Science, Vol. 16, pp. 85-87 https://doi.org/10.1243/JMES_JOUR_1974_016_016_02
  18. ABAQUS Version 6.4., 2003, 'User's Manual,' Hibbitt, Karlsson and Sorensen, Inc.