0
Research Papers: Materials and Fabrication

Alignment Rule for Non-Aligned Flaws for Fitness-for-Service Evaluations Based on LEFM

[+] Author and Article Information
Kunio Hasegawa

Safety Standard Division, Japan Nuclear Energy Safety Organization (JNES), Toranomon 3-17-1, Minato-ku, Tokyo 105-0001, Japanhasegawa-kunio@jnes.go.jp

Koichi Saito

Power Systems Hitachi Works, Hitachi, Ltd., Saiwai-cho 3-1-1, Hitachi-shi 317-8511, Ibaraki-ken, Japankoichi.saito.qe@hitachi.com

Katsumasa Miyazaki

Hitachi Research Laboratory, Hitachi, Ltd., Saiwai-cho 3-1-1, Hitachi-shi 317-8511, Ibaraki-ken, Japankatsumasa.miyazaki.xs@hitachi.com

J. Pressure Vessel Technol 131(4), 041403 (Jun 26, 2009) (6 pages) doi:10.1115/1.3152229 History: Received June 20, 2007; Revised March 02, 2008; Published June 26, 2009

If multiple discrete flaws are detected that are in close proximity to one another, alignment rules are used to determine whether the flaws should be treated as nonaligned or as coplanar. Alignment rules are defined in many fitness-for-service codes and standards in the world. However, the criteria of the alignment rules are different in these codes and standards. This paper introduces the current alignment rules and, in addition, interaction of stress intensity factors for nonaligned through-wall flaws was calculated by finite element analysis. Also, brittle fracture experiments were performed on carbon steel plates with two nonaligned flaws. From these calculations and experiments, authors studied the effect of stress intensity factor interaction on fracture behavior and proposed a new alignment rule for linear elastic fracture mechanics evaluation.

Copyright © 2009 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Two nonaligned flaws

Grahic Jump Location
Figure 2

Stress intensity factor interaction at the inside position of flaw tip for semicircular cracks

Grahic Jump Location
Figure 3

Stress intensity factors at the inner tip of the through-wall flaws

Grahic Jump Location
Figure 4

Mesh breakdown of a flat plate with two nonaligned through-wall flaws

Grahic Jump Location
Figure 5

Stress intensity factor distribution for similar through-wall flaws (2a1=2a2=30 mm)

Grahic Jump Location
Figure 6

Stress intensity factor distribution for dissimilar through-wall flaws (2a1=20 mm,2a2=10 mm)

Grahic Jump Location
Figure 7

Stress intensity factor distribution for dissimilar through-wall flaws (2a1=30 mm,2a2=5 mm)

Grahic Jump Location
Figure 8

Stress intensity factor interaction area for two nonaligned similar flaws (2a1=2a2=30 mm)

Grahic Jump Location
Figure 9

Stress intensity factor interaction area for two nonaligned dissimilar flaws (2a1=20 mm,2a2=10 mm)

Grahic Jump Location
Figure 10

Stress intensity factor interaction area for two nonaligned dissimilar flaws (2a1=30 mm,2a2=10 mm)

Grahic Jump Location
Figure 11

Stress intensity factor interaction area for two nonaligned dissimilar flaws (2a1=20 mm,2a2=5 mm)

Grahic Jump Location
Figure 12

Stress intensity factor interaction area for two nonaligned dissimilar flaws (2a1=30 mm,2a2=5 mm)

Grahic Jump Location
Figure 13

Experiments on flat plate specimens with two nonaligned through-wall flaws (2a1=20 mm, 2a2=20 mm, 10 mm, and 5 mm)

Grahic Jump Location
Figure 14

Brittle crack propagation paths for specimens (BW-01 and BW-02) with two nonaligned similar flaws

Grahic Jump Location
Figure 15

Brittle crack propagation paths for specimens (BD-04 and BD-01) with two nonaligned dissimilar flaws

Grahic Jump Location
Figure 16

Brittle crack propagation paths for specimens (BDS-01 and BDS-02) with two nonaligned dissimilar flaws

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.

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