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Materials and Fabrication

Fabrication Uncertainty in B2 for Nuclear Pipe Bends Subjected to In-Plane Opening Moment

[+] Author and Article Information
Pronab Roy

e-mail: pronabroy07@gmail.com

Siddhartha Ghosh

e-mail: sghosh@civil.iitb.ac.in
Department of Civil Engineering,
Indian Institute of Technology Bombay,
Mumbai 400076, India

1Corresponding author.

Contributed by the Pressure Vessel and Piping Division of ASME for publication in the JOURNAL OF PRESSURE VESSEL TECHNOLOGY. Manuscript received May 24, 2011; final manuscript received August 7, 2012; published online December 5, 2012. Assoc. Editor: Somnath Chattopadhyay.

J. Pressure Vessel Technol 135(1), 011402 (Dec 05, 2012) (6 pages) Paper No: PVT-11-1129; doi: 10.1115/1.4007470 History: Received May 24, 2011; Revised August 07, 2012

For reliability-based design of pipe bends and elbows, a probabilistic characterization of the primary stress indices (B1 and B2) is essential. This paper aims at the characterization of the fabrication/geometric uncertainty in B2, for thin stainless steel long radius pipe bends, subjected to in-plane opening moment. This characterization is performed in a framework based on Monte Carlo simulation and nonlinear finite element analysis. A revision of the code-based expression for B2 is proposed where a random variable K replaces the constant numerator in this expression. The statistics for K are provided for different pipe nominal dimensions, which indicates that the existing provision gives a very conservative estimate of the plastic collapse moment for pipe bends subjected to in-plane opening flexure.

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References

Gupta, A., and Choi, B., 2003, “Reliability-Based Load and Resistance Factor Design for Piping: An Exploratory Case Study,” Nucl. Eng. Des., 224(2), pp. 161–178. [CrossRef]
American Society of Mechanical Engineers, 2004, Rules for Construction of Nuclear Facility Components, ASME Boiler and Pressure Vessel Code Committee, American Society of Mechanical Engineers, New York.
American Society of Mechanical Engineers, 2007, Development of Reliability-Based Load and Resistance Factor Design (LRFD) Methods for Piping (CRTD-86), ASME Boiler and Pressure Vessel Code Committee, American Society of Mechanical Engineers, New York.
Avrithi, K., and Ayyub, B. M., 2009, “A Reliability-Based Approach for the Design of Nuclear Piping for Internal Pressure,” Trans. ASME J. Pressure Vessel Technol., 131(4), p. 0412011. [CrossRef]
Avrithi, K., and Ayyub, B. M., 2009, “Strength Model Uncertainties of Burst, Yielding, and Excessive Bending of Piping,” Trans. ASME J. Pressure Vessel Technol., 131(3), p. 0312071. [CrossRef]
Avrithi, K., and Ayyub, B. M., 2010, “Load and Resistance Factor Design (LRFD) of Nuclear Straight Pipes for Loads That Cause Primary Stress,” Trans. ASME J. Pressure Vessel Technol., 132(2), p. 0211011. [CrossRef]
Avrithi, K., and Ayyub, B. M., 2010, “A Reliability-Based Approach for Low-Cycle Fatigue Design of Class 2 and 3 Nuclear Piping,” Trans. ASME J. Pressure Vessel Technol., 132(5), p. 0512021. [CrossRef]
Avrithi, K., and Ayyub, B. M., 2010, “A Reliability-Based Expression of ASME B&PV Code Equation (11) for Class 2 and 3 Nuclear Pipes,” Trans. ASME J. Pressure Vessel Technol., 132(5), p. 0545021 [CrossRef].
Roy, P., and Ghosh, S., 2012, “Statistical Characterisation of B2 for Nuclear Pipe Bends: In-Plane Closing Moment,” Nucl. Eng. Des., 249, pp. 268–274. [CrossRef]
Ghosh, S., and Roy, P., 2012, “Quantification of the Uncertainty in Stress Index B2 for Pipe Bends Subjected to Out-of-Plane Bending,” Int. J. Pressure Vessels Piping, 95, pp. 24–30. [CrossRef]
Chattopadhyay, J., 2002, “The Effect of Internal Pressure on In-Plane Collapse Moment of Elbows,” Nucl. Eng. Des., 212(1–3), pp. 133–144. [CrossRef]
Digiteo, 2009, scilab User's Manual, version 5.1, The Scilab Consortium (Digiteo), Le Chesnay Cedex, France.
Matzen, V. C., and Yu, L., 1998, “Elbow Stress Indices Using Finite Element Analysis,” Nucl. Eng. Des., 181(1–3), pp. 257–265. [CrossRef]
Shalaby, M. A., and Younan, M. Y. A., 1998, “Nonlinear Analysis and Plastic Deformation of Pipe Elbows Subjected to In-Plane Bending,” Int. J. Pressure Vessels Piping, 75(8), pp. 603–611. [CrossRef]
Shalaby, M. A., and Younan, M. Y. A., 1999, “Limit Loads for Pipe Elbows Subjected to In-Plane Opening Moments and Internal Pressure,” Trans. ASME J. Pressure Vessel Technol., 121(1), pp. 17–23. [CrossRef]
Simulia, 2008, abaqus FEA User’s Manual, version 6.8, Dassault Systèmes, Vélizy-Villacoublay, France.
Tan, Y., Wilkins, K., and Matzen, V., 2002, “Correlation of Test and FEA Results for Elbows Subjected to Out-of-Plane Loading,” Nucl. Eng. Des., 217(3), pp. 213–224. [CrossRef]
Mourad, H. M., 1999, “Elastic-Plastic Behavior and Limit Load Analysis of Pipe Bends Under Out-of-Plane Moment Loading and Internal Pressure,” M.S. thesis, School of Sciences and Engineering Department, The American University in Cairo, Egypt.

Figures

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Fig. 1

Schematic diagram of the pipe specimen and its cross-section geometry

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Fig. 2

Determination of the plastic collapse moment

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Fig. 3

Sample moment-end rotation plot for nominal Do = 0.4064 m

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Fig. 4

Sample moment-end rotation plot for nominal Do = 0.2032 m

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Fig. 5

Sample moment-end rotation plot for nominal Do = 0.1524 m

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Fig. 6

Sample moment-end rotation plot for nominal Do = 0.1016 m

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Fig. 7

Effect of number of simulations on μK for different cases

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