0
Research Papers: Materials and Fabrication

Low Cycle Fatigue Evaluation of Pipe Bends With Local Wall Thinning Considering Multi-Axial Stress State

[+] Author and Article Information
Yoshio Urabe

Japan Nuclear Safety Institute,
5-36-7, Shiba, Minato-ku,
Tokyo 108-0014, Japan
e-mail: urabe.yoshio@genanshin.jp

Koji Takahashi

Professor
Division of Materials Science and
Chemical Engineering,
Faculty of Engineering,
Yokohama National University,
79-5, Tokiwadai, Hodogaya,
Yokohama 240-8501, Japan
e-mail: ktaka@ynu.ac.jp

Hisanori Abe

Yokohama National University,
79-5, Tokiwadai, Hodogaya,
Yokohama 240-8501, Japan
e-mail: abe-hisanori-br@ynu.jp

1Corresponding author.

Contributed by the Pressure Vessel and Piping Division of ASME for publication in the JOURNAL OF PRESSURE VESSEL TECHNOLOGY. Manuscript received February 18, 2014; final manuscript received October 21, 2014; published online February 20, 2015. Assoc. Editor: David L. Rudland.

J. Pressure Vessel Technol 137(4), 041404 (Aug 01, 2015) (9 pages) Paper No: PVT-14-1028; doi: 10.1115/1.4028889 History: Received February 18, 2014; Revised October 21, 2014; Online February 20, 2015

Low cycle fatigue tests and finite element (FEM) analysis were conducted using 100A pipe bend specimens made of STPT410 carbon steel with and without local wall thinning local wall thinning was machined on the inside of the elbow and was prepared at extrados, crown, and intrados. The parameters of the wall thinning were same (the wall thinning ratio = 0.5, the wall thinning angle = 180 deg, and the wall thinning length = 100 mm) in the all test cases. The pipe bend specimens were subjected to the prescribed cyclic in-plane bending displacement with constant internal pressure of 0–12 MPa. Also, low cycle fatigue tests using sound pipe bend specimens were carried out for comparison. According to the test results, low cycle fatigue strength of wall thinned pipe bend specimens was not so different, regardless of location of wall thinning. Low cycle fatigue strength of the pipe bend specimens was beneath the best fit fatigue curve and its reason can be explained quantitatively by a proposed cumulated damage rule introducing ductility exhaustion considering multi-axial stress state. The validity of the new proposed cumulative damage rule was also confirmed by the another sample analysis using other reference data obtained by pre-overloaded in-plane cyclic bending tests.

FIGURES IN THIS ARTICLE
<>
Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Sakakida, T., Endou, R., Kawabata, M., Yokota, H., Fujiwaka, T., Asada, Y., and Suzuki, K., 2000, “Study on Seismic Design of Nuclear Power Plant Piping in Japan, Part 4: Analytical Evaluation of Piping Component Tests,” ASME PVP, 407, pp. 139–146.
Namita, H., Suzuki, K., Abe, H., Ichihashi, I., Shiratori, M., Tai, K., Iwata, K., and Neb, A., 2003, “Seismic Proving Test of Eroded Piping (Status of Eroded Component and System Test),” ASME Paper No. PVP2003-2097. [CrossRef]
Urabe, Y., Takahashi, K., and Ando, K., 2012, “Low Cycle Fatigue Behavior and Seismic Assessment for Elbow Pipe With Local Wall Thinning,” ASME J. Pressure Vessel Technol., 134(4), p. 041801. [CrossRef]
Takahashi, K., Matsuo, K., Sato, K., Ando, K., Urabe, Y., and Kasai, N., 2011, “Low Cycle Fatigue Behaviors Elbows With Local Wall Thinning Under Combined Bending and Internal Pressure,” ASME Paper No. PVP2011-57322. [CrossRef]
Urabe, Y., Takahashi, K., Sato, K., and Ando, K., 2013, “Low Cycle Fatigue Behavior and Seismic Assessment for Pipe Bends Having Local Wall Thinning—Influence of Internal Pressure,” ASME J. Pressure Vessel Technol., 135(4), p. 041802. [CrossRef]
Takahashi, K., Matsuo, K., Ando, K., and Urabe, Y., 2014, “Estimation of Low Cycle Fatigue Life of Elbow Pipes Considering the Multi-Axial Stress Effect,” ASME J. Pressure Vessel Technol., 136(4), p. 041405. [CrossRef]
Ando, K., Takahashi, K., Matsuo, K., and Urabe, Y., 2012, “Evaluation of Low Cycle Fatigue Life of Elbow Pipes Considering the Bi-Axial Stress Effect,” J. High Pressure Inst. Jpn., 50(4), pp. 184–193 (in Japanese).
ASME Boiler and Pressure Vessel Code Section III, Mandatory Appendices, Mandatory Appendix I, Design Fatigue Curves, 2013.
Manson, S. S., 1965, “Fatigue: A Complex Subject—Some Simple Approximations,” Exp. Mech., 5(7), pp. 193–226. [CrossRef]
Nakamura, I., Ota, A., and Shiratori, M., 2001, “Research on Seismic Safety Margin Evaluation Method Considering Degradation of Aged Equipments and Piping,” Technical Note of the National Research Institute for Earth Science and Disaster Prevention, Vol. 220 (in Japanese).
Miyazaki, K., Nebu, K., Kanno, S., Ishiwata, M., and Hasegawa, K., 2002, “Fracture Criterion of Carbon Steel Piping Containing Local Wall Thinning,” J. High Pressure Inst. Jpn., 40(2), pp. 62–71 (in Japanese).
Sato, K., Ogino, K., Takahashi, K., Ando, K., and Urabe, Y., 2010, “Influences of Internal Pressure and Overload on Low Cycle Fatigue Behaviors of Elbow Pipe With Local Wall Thinning,” ASME Paper No. PVP2010-25571. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Shape and geometry of pipe bend with local wall thinning. (a) Pipe bend specimen, (b) wall thinning at extrados (t: nominal wall thickness), (c) wall thinning at intrados, and (d) wall thinning at crown

Grahic Jump Location
Fig. 2

Typical example of failure behavior of pipe bend (E-P6-D20, Nf = 123 cycles)

Grahic Jump Location
Fig. 3

True stress versus true strain curve of carbon steel STPT410

Grahic Jump Location
Fig. 4

FEM model of pipe bend specimen. (a) 1/2 model of sound elbow pipe, (b) 1/2 model of elbow pipe with local wall thinning at extrados, (c) 1/2 model of elbow pipe with local wall thinning at crown, and (d) 1/2 model of elbow pipe with local wall thinning at intrados.

Grahic Jump Location
Fig. 5

Analysis condition

Grahic Jump Location
Fig. 6

An example of load versus load point displacement relationship (E-P12-D20)

Grahic Jump Location
Fig. 7

Hoop strain history at outer surface of crown, E-P9-D20 (Nf = 119)

Grahic Jump Location
Fig. 8

Relationship between hoop strain range and fatigue life

Grahic Jump Location
Fig. 9

Relationship between equivalent strain range and fatigue life

Grahic Jump Location
Fig. 10

Dd versus Df diagram using εθa

Grahic Jump Location
Fig. 11

Modified Dd versus Df diagram using correction factor (εeq,5/εθa,5)

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In