One of the concerned technical issues in the nuclear piping under operation is pipe wall thinning caused by flow accelerated corrosion. This paper focuses on influence of internal pressure on low cycle fatigue life of pipe bends with local wall thinning and evaluation of safety margin against seismic loading in order to apply the obtained knowledge to the nuclear piping. In-plane bending fatigue tests under several constant internal pressure magnitudes were carried out using carbon steel pipe bends with local wall thinning at the extrados. Also finite element analysis, code-based seismic evaluation and fatigue analysis based on calculated strain range were carried out. Obtained main conclusions are as follows: (1) the tested pipe bends with local wall thinning at the extrados have a strong resistance against fatigue failure based on nuclear seismic piping design in Japan at least up to 12 MPa. That is, the tested pipe bends with severe local wall thinning (eroded ratio = 0.5 and eroded angle = 180 deg) at the extrados have margins against fatigue failure, even though the wall thickness is less than the code-required minimum value based on the nuclear piping seismic design in Japan. (2) Combination of the conventional B2 index and the Ke factor provided in the JSME Design and Construction Code, which is referred by JEAC 4601-2008 overestimates fictitious stress amplitude, when sum of the primary and secondary stress is much greater than 3 Sm.

References

References
1.
Japan Atomic Energy Research Institute
,
1993
, “
Technical Report on the Piping Reliability Tests at the Japan Atomic Energy Research Institute
,” Report No. JAERI-M, 93-076, p.
104
.
2.
Nakamura
,
I.
,
Otani
,
A.
, and
Shiratori
,
M.
,
2007
, “
A Study on Fracture Mechanics of Eroded Pipes Under Seismic Loading
,” (Technical Note of the National Research Institute for Earth Science and Disaster Prevention) NIED, Japan, Vol. 306 (in Japanese).
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.
,
191
, pp.
195
204
.10.1016/S0029-5493(99)00141-7
4.
Ahn
,
S. H.
,
Nam
,
K. W.
,
Yoo
,
Y. S.
, and
Ando
,
K.
,
2002
, “
Fracture Behavior of Straight Pipe and Elbow With Local Wall Thinning
,”
Nucl. Eng. Des.
,
211
, pp.
91
103
.10.1016/S0029-5493(01)00447-2
5.
Takahashi
,
K.
,
Ando
,
K.
,
Watanabe
,
S.
,
Kawato
,
K.
,
Hisatsune
,
M.
, and
Hidaka
,
A.
,
2008
, “
Failure Behavior of Elbow Pipe With Local Wall Thinning
,”
J. High Press. Inst. Jpn.
,
46
(
5
), pp.
45
50
, (in Japanese).
6.
Takahashi
,
K.
,
Kato
,
A.
,
Ando
,
K.
,
Hisatsune
,
M.
, and
Hasegawa
,
K.
,
2005
, “
Fracture and Deformation Behaviors of Tee Pipe With Local Wall thinning
,”
Nucl. Eng. Des.
,
237
(
2
), pp.
137
142
.10.1016/j.nucengdes.2006.03.016
7.
Takahashi
,
K.
,
Ando
,
K.
,
Hisatsune
,
M.
, and
Hasegawa
,
K.
,
2005
, “
Failure Behavior of Carbon Steel Pipe With Local Wall Thinning near Orifice
,”
Nucl. Eng. Des.
,
237
(
4
), pp.
335
341
.10.1016/j.nucengdes.2006.04.033
8.
Miyazaki
,
K.
,
Nebu
,
A.
,
Ishiwata
,
M.
, and
Hasegawa
,
K.
,
2002
, “
Fracture Strength and Behavior of Carbon Steel Pipes With Local Wall Thinning Subjected to Cyclic Bending Load
,”
Nucl. Eng. Des.
,
214
, pp.
127
136
.10.1016/S0029-5493(02)00021-3
9.
Hasegawa
,
K.
,
Miyazaki
,
K.
, and
Nakamura
,
I.
,
2008
, “
Failure Mode and Failure Strength for Wall Thinning Straight Pipes and Elbows Subjected to Seismic Loading
,”
Trans. ASME J. Pressure Vessel Technol.
,
130
(
1
), p.
011404
.10.1115/1.2826425
10.
Varelis
,
G. E.
,
Karamanos
,
S. A.
, and
Gresnigt
,
A. M.
,
2013
, “
Pipe Elbows Under Strong Cyclic Loading
,”
Trans. ASME J. Pressure Vessel Technol.
,
135
(
1
), p.
011207
.10.1115/1.4007293
11.
Shiratori
,
M.
,
Yakura
,
M.
,
Ogasawara
,
N.
,
Nakamura
,
I.
, and
Otani
,
A.
,
2001
, “
Failure Analysis of Degraded Piping against Seismic Loading
,”
Trans. Jpn. Soc. Mech. Eng., Ser. A
,
67
(
654
), pp.
209
215
(in Japanese).10.1299/kikaia.67.209
12.
Urabe
,
Y.
,
Takahashi
,
K.
, and
Ando
,
K.
,
2012
, “
Low Cycle Fatigue Behavior and Seismic Assessment for Elbow Pipe with Local Wall Thinning
,”
Trans. ASME J. Pressure Vessel Technol.
,
134
(
4
), p.
041801
.10.1115/1.4005870
13.
Japan Welding Society
,
1972
, “
Research on Stress Indices and Flexible Factors
,” Report No. SIP-47, pp.
185
196
(in Japanese).
14.
Takahashi
,
K.
,
Watanabe
,
S.
,
Ando
,
K.
,
Urabe
,
Y.
,
Hidaka
,
A.
,
Hisatsune
,
M.
, and
Miyazaki
,
K.
,
2009
, “
Low Cycle Fatigue Behaviors of Elbows Subjected to Seismic Loading
,”
Nucl. Eng. Des.
,
239
, pp.
2719
2727
.10.1016/j.nucengdes.2009.09.011
15.
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 J. Pressure Vessels Piping
,
407
, pp.
139
146
.
16.
Suzuki
,
K.
,
Namita
,
H.
,
Abe
,
I.
,
Ichihashi
,
I.
,
Suzuku
,
K.
,
Ishiwata
,
T.
,
Fujiwaka
,
T.
, and
Tai
,
K.
,
2003
, “
Seismic Proving Test of Ultimate Piping Strength (Simulation Analysis of Simplified Piping System Test)
,”
ASME J. Pressure Vessels Piping
,
466
, pp.
23
30
.
17.
Namita
,
Y.
,
Suzuki
,
H.
,
Abe
,
I.
,
Ichihashi
,
M.
,
Shiratori
,
K.
,
Tai
,
K.
,
Iwata
,
K.
, and
Nebu
,
A.
,
2003
, “
Seismic Proving Test of Eroded Piping (Status of Eroded Piping Component and System Test)
,”
ASME J. Pressure Vessels Piping
,
466
, pp.
15
21
.
18.
ASME Boiler and Pressure Vessel Code Section III
, Mandatory Appendix I,
2010
.
19.
ASME Boiler and Pressure Vessel Code Section III
, NB-3656,
2010
.
20.
Kobayashi
,
H.
, and
Urabe
,
Y.
,
2009
, “
Study on Strain Rate Effect on Dynamic Strain Aging and Safety Margin of Pipe Elbow at Seismic Event
,”
2009 ASME Pressure Vessels and Piping Division Conference
, July 26–30,
Prague, Czech Republic
.
21.
Tagart
,
S. W.
,
Tang
,
Y. K.
,
Guzy
,
D. J.
, and
Ranganath
,
S.
,
1990
, “
Piping Dynamic Reliability and Code Rule Change Recommendations
,”
Nucl. Eng. Des.
,
125
, pp.
373
385
.10.1016/0029-5493(90)90258-Y
22.
JEAC 4601-2008
,
2008
, “
Technical Code for Seismic Design of Nuclear Power Plants
,” The Japan Electric Association, p.
310
(in Japanese).
23.
JSME S NC1-2008
,
2008
, “
Code for Pressure Vessel Design PPB-3411
,” The Japanese Society of Mechanical Engineers, pp.
I-5-8
I-5-9
(in Japanese).
24.
JSME S NC1-2008
,
2008
, “
Code for Simplified Elastic-Plastic Analysis PVB-3351.1
,” The Japanese Society of Mechanical Engineers, pp.
I-4-36
I-4-39
(in Japanese).
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