It is important to assess the failure strengths for pipes with wall thinning to maintain the integrity of the piping systems and to make codification of allowable wall thinning. Full-scale fracture experiments on cyclic loading under constant internal pressure were performed for 4in. diameter straight pipes and 8in. diameter elbow pipes at ambient temperature. The experiments were low cycle fatigue under displacement controlled conditions. It is shown that a dominant failure mode under cyclic loading for straight pipes and elbows is crack initiation∕growth accompanying swelling by ratchet or buckling with crack initiation. When the thinning depth is deep, the failure mode is burst and crack growth with ratchet swelling. In addition, failure strengths were compared with the design fatigue curve of the ASME Code Sec. III. It is shown that pipes with wall thinning less than 50% of wall thickness have sufficient margins against a seismic event of the safety shutdown earthquake.

1.
The Japan Society of Mechanical Engineers
, “
Codes for Power Generation Facilities, Rules on Pipe Wall Thinning Management
,” JSME S CA1-2005, March 2005 (in Japanese).
2.
Isozaki
,
T.
,
Shibata
,
K.
,
Ueda
,
S.
,
Kurihara
,
R.
,
Onizawa
,
K.
, and
Kohsaka
,
A.
, 1993, “
Technical Report on the Piping Reliability Proving Tests at the Japan Atomic Energy Research Institute
,” Report No. JAERI-M 93-076.
3.
Miyazaki
,
K.
,
Kanno
,
S.
,
Ishiwata
,
M.
,
Hasegawa
,
K.
,
Ahn
,
S. H.
, and
Ando
,
K.
, 1999, “
Fracture Behavior of Carbon Steel Pipe With Local Wall Thinning Subjected to Bending Load
,”
Nucl. Eng. Des.
0029-5493,
191
, pp.
195
204
.
4.
Ahn
,
S. H.
,
Nam
,
K. W.
,
Yoo
,
Y. S.
,
Ando
,
K.
,
Ji
,
S. H.
,
Ishiwata
,
M.
, and
Hasegawa
,
K.
, 2002, “
Fracture Behavior of Straight Pipe and Elbow With Local Wall Thinning
,”
Nucl. Eng. Des.
0029-5493,
211
, pp.
91
103
.
5.
Hasegawa
,
K.
,
Sakata
,
K.
,
Miyazaki
,
K.
, and
Kanno
,
S.
, 2002, “
Fatigue Strength for Pipes With Allowable Flaws and Design Fatigue Curve
,”
Int. J. Pressure Vessels Piping
0308-0161,
79
, pp.
37
44
.
6.
Shin
,
D. J.
,
Choi
,
J. B.
, and
Kim
,
Y. J.
, 2004, “
Failure Strength Assessment of Pipes With Local Wall Thinning Under Combined Loading Based on Finite Element Analyses
,”
ASME J. Pressure Vessel Technol.
0094-9930,
126
, pp.
179
183
.
7.
Kim
,
Y. J.
,
Shim
,
D. J.
,
Lim
,
H.
, and
Kin
,
Y. J.
, 2004, “
Reference Stress Based on Approach to Predict Failure Strength of Pipes With Local Wall Thinning Under Single Loading
,”
ASME J. Pressure Vessel Technol.
0094-9930,
126
, pp.
194
201
.
8.
Hasegawa
,
K.
,
Wilkowski
,
G.
,
Goyette
,
L.
, and
Scarth
,
D.
, 2004, “
Development of Analytical Evaluation Procedures and Acceptance Criteria for Pipe Wall Thinning in ASME Code Section XI
,”
Proceedings of 2004 ASME Pressure Vessels and Piping Conference
,
San Diego
, Vol.
474
, pp.
83
88
.
9.
Nakamura
,
I.
, 2004, “
Study on Damage Behavior and Evaluation at Seismic Events for Degraded Piping (in Japanese)
,” Ph.D. thesis, Yokohama National University.
10.
2004, ASME P&PV Code Sec. III, Div. I, Appendix 1.
11.
ASME
, 1969,
Criteria of the ASME Boiler and Pressure Vessel Code for Design by Analysis in Section III and VIII, Division 2
,
ASME
,
New York
.
12.
ASME
, 1972,
Pressure Vessels and Piping: Design and Analysis: A Decade of Progress
,
ASME
,
New York
, Vol.
1
.
13.
The Japan Society of Mechanical Engineers
, 2005, “
Codes for Nuclear Power Generation Facilities, Rules on Design and Construction for Nuclear Power Plants
,” Report No. JSME S NC1-2005.
You do not currently have access to this content.