Mechanical damage in transportation pipelines is a threat to its structural integrity. There are many parameters that affect the severity of the mechanical damage which are related to the pipe geometry and material properties, the defect geometry and boundary conditions, the loading cycle, and the pipe state of stress. To understand those effects, the utilization of numerical finite element analysis (FEA) has been used extensively to supplement the expensive; and thus, limited full-scale tests. The actual pipe material exhibits a number of special features including nonlinear elasticity, anisotropy, and cyclic softening which need advanced material modeling techniques. However, the success of the numerical material model to actually simulate the pipe material behavior could not be studied in detail previously due to the insufficient experimental data especially in cyclic pressure loading. The objective of this paper is to investigate the effect of material modeling using FEA on the integrity assessment of dented pipe under static and cyclic loading by simulating pipe denting followed by subsequent pressure cycles. Several material models are tested and calibrated against the measurements of full-scale tests to find the effects of material modeling assumptions (e.g. isotropy, yield point, hardening rule). The results show that a combined material model simulating all special features of nonlinear elasticity, anisotropy, and cyclic softening gives a very close representation of experimental data in terms of strain values and fatigue cycles to failure. Therefore, detailed material properties are needed to conduct accurate integrity assessments of dented pipes especially under cyclic conditions.

References

References
1.
Kiefner
,
J. F.
,
Melosh
,
R. E.
, and
Kiefner
,
B. A.
,
2000
, “
Analysis of DOT Reportable Incidents for Gas Transmission and Gathering System Pipelines, Incident Data—1985 to 1997
,” Final Report to Pipeline Research Council International, Report No. PR-218-9801, Catalogue No. L51830.
2.
Advantica Ltd.
,
2004
, “
Risk Assessment of Selected Saudi Aramco Pipelines
,” Report No. 6725, Advantica, United Kingdom.
3.
Fowler
,
J. R.
,
Katsounas
,
A. T.
, and
Boubenider
,
R.
,
1992
, “
Criteria for Dent Acceptability of Offshore Pipelines,” Final Report Prepared to Pipeline Research Council International
, Report No. PR-201-927, Catalogue No. L51671, Stress Engineering Services, Inc.
4.
Fowler
,
J. R.
,
Alexander
,
C. R.
,
Kovach
,
P. J.
, and
Connelly
,
L. M.
,
1994
, “
Cyclic Pressure Fatigue Life of Pipelines With Plain Dents, Dents With Gouges, and Dents With Welds
,” Final Report Prepared to Pipeline Research Council International, Report No. PR-201-927/201-9324, Catalogue No. L51705, Stress Engineering Services, Inc.
5.
API 1156
,
1999
,
Effects of Smooth and Rock Dents on Liquid Petroleum Pipelines (Phase II)
,
American Petroleum Institute
, Washington, DC.
6.
Leis
,
B. N.
,
Forte
,
T. P.
, and
Zhu
,
X.
,
2004
Integrity Analysis for Dents in Pipelines
,”
Proceedings of the International Pipeline Conference
, Paper No.
ASME
, IPC04-0061,
Calgary, Alberta, Canada
.
7.
Le Bastard
,
A.
,
2006
, “
Influence of Internal Pressure for Depth Measurement on Dent
,”
Proceedings of the International Pipeline Conference
,
ASME
, Paper No. IPC2006-10103,
Calgary, Alberta, Canada
.
8.
Pinheiro
,
B.
,
Pasqualino
,
I.
, and
da Cunha
,
S.
,
2006
Stress Concentration Factors of Dented Pipelines
,”
Proceedings of the International Pipeline Conference
,
ASME
, Paper NO. IPC2006-10598,
Calgary, Alberta, Canada
.
9.
Pinheiro
,
B.
,
Pasqualino
,
I.
, and
da Cunha
,
S.
,
2008
Fatigue Life Analysis of Steel Pipelines With Plain Dents Under Cyclic Internal Pressure
,”
Proceedings of the International Pipeline Conference
,
ASME
, Paper No. IPC2008-64690,
Calgary, Alberta, Canada
.
10.
Dawson
,
S. J.
,
Russel
,
A.
, and
Patterson
,
A.
,
2006
, “
Emerging Techniques for Enhanced Assessment and Analysis of Dents
,”
Proceedings of the International Pipeline Conference
, Paper No.
ASME
, IPC2006-10264,
Calgary, Alberta, Canada
.
11.
Jandu
,
C.
,
Francini
,
B.
,
Taylor
,
M.
, and
Francis
,
A.
,
2008
Towards a New Limit State Function for Determining the Failure Pressure of a Pipeline Containing Mechanical Damage
,”
Proceedings of the International Pipeline Conference
,
ASME
, Paper No. IPC2008-64304,
Calgary, Alberta, Canada
.
12.
Dinovitzer
,
A.
,
Fredj
,
A.
,
Carroll
,
B.
,
Semiga
,
V.
,
Asavare
M.
, and
Tiku
,
S.
,
2007
, “
Evaluation of the Interaction of Mechanical Damage on Welds
,” Final Report Prepared to Pipeline Research Council International, Report No. PR-214-0326, Catalogue No. L52048, BMT Fleet Technology Limited.
13.
Carroll
,
L. B.
,
Tiku
,
S.
, and
Dinovitzer
,
A.
,
2006
,
Full Scale “Demonstration of the Interaction of Dents With Localized Effects- State of the Knowledge Review
,” Quarterly Progress Report to Pipeline Research Council International, Project No. MD 4-2B Task 1, BMT Fleet Technology Limited.
14.
Semiga
,
V.
,
2007
, “
Full Scale Demonstration of the Interaction of Dents With Localized Effects
,” Task 4 Interim Report to Pipeline Research Council International, No. Project MD 4-2, BMT Fleet Technology, Ltd.
15.
Bolton
,
B.
,
Semiga
,
V.
,
Dinovitzer
,
A.
,
Tiku
,
S.
, and
Alexander
,
C.
,
2008
Towards a Validated Pipeline Dent Integrity Assessment Model
,”
Proceedings of the International Pipeline Conference
,
ASME
, Paper No. IPC2008-64621,
Calgary, Alberta, Canada
.
16.
Carroll
,
L. B.
,
2007
, “
Full Scale Demonstration of the Interaction of Dents With Localized Effects—Task 3 Material Characterization
,” Updated Report to Pipeline Research Council International, Project No. MD-4B Task 3, BMT Fleet Technology Limited.
17.
Karamanos
,
S. A.
, and
Andredakis
,
K. P.
,
2006
, “
Denting of Internally Pressurized Tubes Under Lateral Loads
,”
Int. J. Mech. Sci.
,
48
(
10
), pp
1080
1094
.10.1016/j.ijmecsci.2006.03.018
18.
Gresnigt
,
A. M.
,
Karamanos
,
S. A.
, and
Andreadakis
,
K. P.
,
2007
Lateral Loading of Internally Pressurized Steel Pipes
,”
J. Pressure Vessel Technol.
,
129
(
4
), pp
630
638
.10.1115/1.2767345
19.
ASME B31.4
,
2009
,
Gas Transmission and Distribution Piping Systems
,
American Society of Mechanical Engineers
,
New York
.
20.
ASME B31.8
,
2007
,
Gas Transmission and Distribution Piping Systems
,
American Society of Mechanical Engineers
,
New York
.
21.
CSA Z662-11
,
2011
,
Oil and Gas Pipeline Systems
,
Canadian Standards Association
,
Toronto, CAN
.
22.
CSA Z245.1-02
,
2002
,
Steel Pipe
,
Canadian Standards Association
,
Toronto, CAN
.
23.
Das
,
S.
,
1993
, “
Fracture of Wrinkled Energy Pipelines
,” Ph.D. thesis, University of Alberta, Edmonton, Alberta, CAN.
24.
ANSYS, Inc.
,
2007
, Structural Analysis Guide 11.0.
25.
Lourenco
,
M. I.
, and
Netto
,
T. A.
,
2010
, “
Low Cycle Fatigue of Corroded Pipes Under Cyclic Bending and Internal Pressure
Proceedings of the International Pipeline Conference
,
ASME
Paper No. IPC2010-31570,
Calgary, Alberta, Canada
.
26.
Bolton
,
B.
,
Semiga
,
V.
,
Tiku
,
S.
,
Dinovitzer
,
A.
, and
Zhou
,
J.
,
2010
, “
Full Scale Fatigue Testing of Dented Pipelines and Development of a Validated Pipe Finite Element Model
,”
Proceedings of the International Pipeline Conference
,
ASME
, Paper No. IPC2010-31579,
Calgary, Alberta, Canada
.
27.
ANSYS, Inc.
,
2007
, Theory Reference for ANSYS and ANSYS Workbench 11.0.
28.
Chaboche
,
J. L.
,
2008
A Review of Some Plasticity and Viscoplasticity Constitutive Theories
,”
Int. J. Plast.
,
24
, pp
1642
1693
.10.1016/j.ijplas.2008.03.009
29.
Broggiato
,
G. B.
,
Campana
,
F.
, and
Cortese
,
L.
,
2008
, “
The Chaboche Nonlinear Kinematic Hardening Model: Calibration Methodology and Validation
,”
Meccanica
,
43
, pp.
115
124
.10.1007/s11012-008-9115-9
30.
Dama
,
E.
,
Karamanos
,
S. A.
, and
Gresnight
,
A. M.
,
2007
, “
Failure of Locally Buckled Pipelines
,”
J. Pressure Vessel Technol.
,
129
(
2
), pp.
272
279
.10.1115/1.2716431
31.
Shigley
,
J. E.
, and
Mischke
,
C. R.
,
1989
,
Mechanical Engineering Design
, International Edition,
5th ed.
,
Mc-Graw Hill Book Co.
,
Singapore
, pp.
276
299
.
You do not currently have access to this content.