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Applicability of the mα-tangent Method to Estimate Plastic Limit Loads of Elbows and Branch Junctions

선형탄성해석과 mα-tangent방법을 이용한 배관 한계하중 평가 적용성

  • 김재민 (고려대학교 기계공학부) ;
  • 김상현 (고려대학교 기계공학부) ;
  • 배경동 (고려대학교 기계공학부) ;
  • 김윤재 (고려대학교 기계공학부) ;
  • 김종성 (세종대학교 원자력공학과)
  • Received : 2016.10.27
  • Accepted : 2017.02.14
  • Published : 2017.06.01

Abstract

In this study, the limit loads calculated by the $m_{\alpha}-tangent$ method based on the linear finite element analysis are compared with the closed form solutions that are proposed by various authors. The objects of the analysis is to select the elbow and the branch pipe which are representative structure of piping system. The applicability of the $m_{\alpha}-tangent$ method are investigated by applying it to cases with various geometries. The internal pressure and the in-plane bending moment are considered and the $m_{\alpha}-tangent$ method is in good agreement with the existing solutions in case of elbows. However, the limit loads calculated by the $m_{\alpha}-tangent$ method for branch junctions do not agree well with the existing solutions and do not show any tendency. The reason is a biased result due to the stress concentration of the discontinuous parts.

Acknowledgement

Supported by : 한국연구재단

References

  1. Hill, R. and Siebel, M. P. L., 1951, "On Combined Bending and Twisting of Thin Tubes in the Plastic Range," Phil. Mag., 42, p. 722. https://doi.org/10.1080/14786445108561300
  2. Mura, T., Rimawi, W.H. and Lee, S.L., 1965, "Extended Theorems of Limit Analysis," Quarterly of applied mathematics, Vol. 23, No. 2, pp. 171-179. https://doi.org/10.1090/qam/99943
  3. Goodall, I. W., 1978b, "Lower Bound Limit Analysis of Curved Tubes Loaded by Combined Internal Pressure and In-plane Bending Moment," Research Division Report RD/B/N4360, Central Electricity Generating Board, UK.
  4. Ainsworth, R.A., 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. Seshardri, R. and Mangalaramanan, S.P., 1997, "Lower Bound Limit Loads using Variational Concepts: the $m_{\alpha}$-method," Int, J Pressure Vessels Piping, Vol. 71, pp. 93-106. https://doi.org/10.1016/S0308-0161(96)00071-3
  6. Xuan, F.Z., Li, P.N. and Tu, S.T., 2003, "Limit Load Analysis for the Piping Branch Junctions under Internal Pressure," Nucl Eng Design., Vol. 224, pp. 1-9. https://doi.org/10.1016/S0029-5493(03)00075-X
  7. Kim, Y.J., Lee, K.H. and Park, C.H., 2006, "Limit Loads for Thin-walled Piping Branch Junctions under Internal Pressure and In-plane Bending," Int J. of Pres. Ves. and pip., Vol. 83, pp. 645-653. https://doi.org/10.1016/j.ijpvp.2006.07.002
  8. Xuan, F.Z., Li, P.N. and Tu, S.T., 2006, "Limit Load Analysis for the Piping Branch Junctions under Inplane Moment," Int J. Mech. Sci., Vol 48, pp. 460-467. https://doi.org/10.1016/j.ijmecsci.2005.07.013
  9. Kim, Y.J. and Oh, C.S., 2007, "Effect of Attached Straight Pipes on Finite Element Limit Analysis of Pipe Bends," Int, J Pressure Vessels Piping, Vol. 84, pp. 177-184. https://doi.org/10.1016/j.ijpvp.2006.09.017
  10. Seshadri, R. and Hossain, M.M., 2009, "Simplified Limit Load Determination using the $m_{\alpha}$-tangent Method," ASME j. Pressure Vessel Technol., Vol. 131, pp. 021213-1-7. https://doi.org/10.1115/1.3067001
  11. Hossain, M.M., Reinhardt, W.D. and Seshadri, R., 2009, "Simplified Stress Categorization using a Single Linear Elastic Analysis," J. of Pressure Vessel Technology, Vol. 131, 061204-1-10. https://doi.org/10.1115/1.4000199
  12. Lee, K.H., Kim, Y.J. Budden, P.J. and Nikbin, K., 2009, "Plastic Limit Loads for Thick-walled Branch Junctions," J. Strain analysis, Vol. 44, pp. 143-148. https://doi.org/10.1243/03093247JSA455
  13. Kim, Y.J. and Budden, P.J., 2009, "Plastic Loads for $90^{\circ}$ Thick-walled Elbows under Combined Pressure and Bending," Journal of Strain Analysis., Vol. 45, pp. 115-127.
  14. Kim, N.H., Oh, C.S., Kim, Y.J., Kim, J.S., Jerng, D.W. and Budden, P.J., 2011, "Limit Loads and Fracture Mechanics Parameters for Thick-walled Pipes," Int J. of Pres. Ves. and pip., Vol. 88, pp. 403-414. https://doi.org/10.1016/j.ijpvp.2011.07.005