During pipeline construction, the pipeline may be impacted by sharp rocks or excavators. To study the failure mechanism of the pipeline, the damage degree and springback rate of the pipelines with two typical dents (transverse and longitudinal) were analyzed in terms of various factors (indenter size, pipeline size and internal pressure, and dent depth). The results reveal the following: (1) when pipeline size and internal pressure are unchanged and indenter size is changed, the integral value I used to measure the damage degree of the dented pipeline increases with increasing dent depth. When the dent depth reaches a certain value, at the same dent depth, the smaller the indenter size, the larger the damage integral value; (2) when other parameters remain unchanged, the larger the pipeline size is, the larger is the damage integral value, and the larger the internal pressure is, the smaller is the damage integral value. (3) The curves for damage and springback for the two kinds of dents are basically similar. Generally, the maximum damage of the longitudinal dent is larger than that of the transverse dent. (4) By a combination of an orthogonal experimental design and a gray correlation degree calculation, for the damage integral value of the two typical dented pipelines, the order of importance of the influential factors was obtained. (5) Formulas for the damage integral value and influence factors were fit using a nonlinear regression method, which provides a reference for calculation of pipeline damage.

References

1.
Wierzbicki
,
T.
, and
Suh
,
M. S.
,
1988
, “
Indentation of Tubes Under Combined Loading
,”
Int. J. Mech. Sci.
,
30
(
3–4
), pp.
229
248
.
2.
Allouti
,
M.
,
Schmitt
,
C.
,
Pluvinage
,
G.
,
Gilgert
,
J.
, and
Hariri
,
S.
,
2012
, “
Study of the Influence of Dent Depth on the Critical Pressure of Pipeline
,”
Eng. Failure Anal.
,
21
(
1
), pp.
40
51
.
3.
Cosham
,
A.
, and
Hopkins
,
P.
,
2004
, “
The Effect of Dents in Pipelines—Guidance in the Pipeline Defect Assessment Manual
,”
Int. J. Pressure Vessels Piping
,
81
(
2
), pp.
127
139
.
4.
Yang
,
Q.
,
Shuai
,
J.
, and
Zuo
,
S.
,
2009
, “
Research Status of Pipeline Dents
,”
Gas Storage Transp.
,
28
(
6
), pp.
10
15
.
5.
Ying
,
W.
,
Xiao
,
J.
, and
Peng
,
Z.
,
2016
, “
The Analysis of Damage Degree of Oil and Gas Pipeline With Type II Plain Dent
,”
Eng. Failure Anal.
,
66
, pp.
212
222
.
6.
Allouti
,
M.
,
Schmitt
,
C.
, and
Pluvinage
,
G.
,
2014
, “
Assessment of a Gouge and Dent Defect in a Pipeline by a Combined Criterion
,”
Eng. Failure Anal.
,
36
(
1
), pp.
1
13
.
7.
Pluvinage
,
G.
,
Capelle
,
J.
, and
Schmitt
,
C.
,
2016
, “
Chapter 3—Methods for Assessing Defects Leading to Gas Pipe Failure
,” Handbook of Materials Failure Analysis With Case Studies From the Oil and Gas Industry,
Butterworth-Heinemann
,
Oxford, UK
.
8.
Firouzsalari
,
S. E.
, and
Showkati
,
H.
,
2013
, “
Investigation of Free-Spanned Pipeline Behavior Due to Axial Forces and Local Loads
,”
J. Constr. Steel Res.
,
86
(
9
), pp.
128
139
.
9.
Ghaednia
,
H.
, and
Das
,
S.
,
2014
, “
Behavior of NPS30 Pipe Subject to Denting Load
,”
ASME
Paper No. IMECE2014-37598.
10.
Han
,
C.
,
Tan
,
S.
,
Zhang
,
J.
, and
Zhang
,
C.
,
2018
, “
Simulation Investigation of Dent Behavior of Steel Pipe Under External Load
,”
Eng. Failure Anal.
,
90
, pp.
341
354
.
11.
EGIG
,
2011
, “
8th Report of the European Gas Pipeline Incident Data Group
,” Groningen, The Netherlands. Report No. EGIG 11.R.0402.
12.
Chengzhi
,
Q.
, and
Ying
,
W.
,
2014
, “
Study on Damage Degree of Oil and Gas Pipeline With Simple Dent Defect
,” M.S. thesis, SWPU, Chengdu, China.
13.
Zhang
,
P.
,
Huang
,
Y.
, and
Wu
,
Y.
,
2018
, “
Springback Coefficient Research of API X60 Pipe With Dent Defect
,”
Energies
,
11
(
11
), p.
3213
.
14.
Oyane
,
M.
,
Sato
,
T.
,
Okimoto
,
K.
, and
Shima
,
S.
,
1980
, “
Criteria for Ductile Fracture and Their Applications
,”
J. Mech. Work. Technol.
,
4
(
1
), pp.
65
81
.
15.
Li
,
C.
, and
Dang
,
S.
,
2017
, “
Plastic Damage Analysis of Oil and Gas Pipelines With Unconstrained and Constrained Dents
,”
Eng. Failure Anal.
,
77
, pp.
39
49
.
16.
Seberry
,
J.
,
Finlayson
,
K.
,
Adams
,
S. S.
,
Wysocki
,
T. A.
,
Xia
,
T.
, and
Wysocki
,
B. J.
,
2008
, “
The Theory of Quaternion Orthogonal Designs
,”
IEEE Trans. Signal Process.
,
56
(
1
), pp.
256
265
.
17.
Chen
,
Y. M.
, and
Zhang
,
M.
,
2015
, “
Cubic Spline Based Grey Absolute Relational Grade Model
,”
Syst. Eng.-Theory Pract.
,
35
(
5
), pp.
1304
1310
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