Effect of Shape Imperfections on Thin-Walled Pipe Bends under Out-Of-Plane Moment and Internal Pressure

Abstract:

This paper quantifies the effect of ovality and thinning/thickening of thin-wall pipe bend modeled using the geometric parameters of r/t=15 and 20 and λ=0.1 to 0.3. For each model the ovality and thinning is varied from 5% to 20 % in steps of 5 % .The collapse loads were obtained from twice-elastic-slope method of pipe bends subjected to out-of-plane moment with and without internal pressure. Large displacement analysis was performed on elastic-perfectly plastic material using the nonlinear FE package of ABAQUS. The analyzed shows that the thinning effect is insignificant and ovality produce the significant effect of upto 27.7% decrease in collapse load for pipe bend subjected to combined moment and internal pressure.

• Periodical: Applied Mechanics and Materials (Volumes 592-594)
• Pages: 1050-1054
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.592-594.1050
• Online since: July 2014
• Authors: A. Buckshumiyan*, A.R. Veerappan, Subramaniam Shanmugam
• Keywords: Collapse Load, Ovality, Pipe Bend, Thinning, Twice-Elastic Slope

References

[1] Buckshumiyan A, Veerappan AR, Shanmugam S. Plastic collapse loads in shape-imperfect pipe bends under in-plane opening bending moment. Int. J Press Vess Piping (2013), 111-112: 21-26.

DOI: 10.1016/j.ijpvp.2013.04.034

[2] Christo Michael T, Veerappan AR, Shanmugam S. Effect of ovality and variable wall thickness on collapse loads bends subjected to in-plane bending closing moment. Eng. Fract Mech. (2012), 79: 138-48.

DOI: 10.1016/j.engfracmech.2011.10.009

[3] Christo Michael T, Veerappan AR, Shanmugam S. Comparison of plastic limit and collapse loads in pipe bends with shape imperfections under in-plane bending and an internal pressure. J Press Vess Piping (2012), 99-100: 23-33.

DOI: 10.1016/j.ijpvp.2012.07.013

[4] Findlay, G. E. and J. Spence, Flexibility of smooth circular curved tubes with flanged end constraints, Int. J Press Vess and Piping (1979b), 7(1), 13-29.

DOI: 10.1016/0308-0161(79)90003-6

[5] Chattopadhyay, J, Pavankumar T. V, Dutta B. K, Kushwaha H. S. Fracture experiments on throughwall cracked elbows under in-plane bending moment: test results and theoretical/numerical analyses. Eng. Fract. Mechanics (2005), 72, 1461–1497.

DOI: 10.1016/j.engfracmech.2004.11.005

[6] Kim YJ, Oh CS. Limit loads for elbows under combined pressure and in-plane bending based on finite element limit analysis, Int. J Press Vess Piping (2006), vol. 83, pp.85-90.

DOI: 10.1016/j.ijpvp.2005.11.001

[7] Dan V. The influence of the initial ovality tolerance on the nonlinear cycling analysis of piping bends, Journal of Press Vess Technology (2009), vol. 131(041203), pp.1-7.

DOI: 10.1115/1.3147983

[8] Mourad, H M, Younan M Y A. The effect of modeling parameters on the predicted limit loads for pipe bends subjected to out-of-plane moment loading and internal pressure, Journal of Pressure Vessel Technology (2000), 122(4), 450-456.

DOI: 10.1115/1.1310334

[9] Mourad HM, Younan MYA. Nonlinear analysis of pipe bends subjected to out–of-plane moment loading and internal pressure. J Press Vess Technol (2001) 123: 253-258.

DOI: 10.1115/1.1310335

[10] Mourad, H M, Younan MYA. Limit-load analysis of pipe bends under out-of-plane moment loading and internal pressure, Journal of Press Vess Technology (2002), 124(1), 32-37.

DOI: 10.1115/1.1425807

[11] Lee KH, Kim YJ, Park CY. Plastic loads of pipe bends under combined pressure and out-of-plane bending, Int. J. Fract (2008), 149: 31-45.

DOI: 10.1007/s10704-008-9217-3

[12] ABAQUS Version 6. 9. User's manual. Simulia, RI: USA(2009).