When the external sheath of flexible pipes experiences damage, seawater floods the annulus. Then, the external pressure is applied directly on the internal polymeric layer, and the load is transferred to the interlocked carcass, the innermost layer. In this situation, the so-called wet collapse failure of the interlocked carcass can occur. Simplified methodologies to address such a scenario, using restricted three-dimensional (3D) finite element models, are presented in this work. They are compared with full 3D models, studying both straight and curved flexible pipes scenarios. The curvature of the flexible pipe is shown to be important for wet collapse pressure predictions.

References

1.
Gay Neto
,
A.
,
Martins
,
C. A.
,
Malta
,
E. R.
,
Tanaka
,
R. L.
, and
Godinho
,
C. A. F.
,
2016
, “
Simplified Finite Element Models to Study the Dry Collapse of Straight and Curved Flexible Pipes
,”
ASME J. Offshore Mech. Arct. Eng.
,
138
(
2
), p.
021701
.
2.
Timoshenko
,
S. P.
, and
Gere
,
J. M.
,
1961
,
Theory of Elastic Stability
,
McGraw-Hill
,
New York
, Chap. 7.
3.
Martins
,
C. A.
,
Pesce
,
C. P.
, and
Aranha
,
J. A. P.
,
2003
, “
Structural Behavior of Flexible Pipe Carcass During Launching
,”
ASME
Paper No. OMAE2003-37053.
4.
Gay Neto
,
A.
, and
Martins
,
C. A.
,
2012
, “
A Comparative Wet Collapse Buckling Study for the Carcass Layer of Flexible Pipes
,”
ASME J. Offshore Mech. Arct. Eng.
,
134
(
3
), p.
031701
.
5.
de Sousa
,
J. R. M.
,
Ellwanger
,
G. B.
,
Lima
,
E. C. P.
, and
Papaleo
,
A.
,
2001
, “
Local Mechanical Behavior of Flexible Pipes Subjected to Installation Loads
,”
ASME
Paper No. OMAE2001/PIPE-4102.
6.
Lu
,
J.
,
Ma
,
F.
,
Tan
,
Z.
, and
Sheldrake
,
T.
,
2008
, “
Bent Collapse of an Unbonded Rough Bore Flexible Pipe
,”
ASME
Paper No. OMAE2008-57063.
7.
Gay Neto
,
A.
, and
Martins
,
C. A.
,
2014
, “
Flexible Pipes: Influence of the Pressure Armor in the Wet Collapse Resistance
,”
ASME J. Offshore Mech. Arct. Eng.
,
136
(
3
), p.
031401
.
8.
Paumier
,
L.
,
Averbuch
,
D.
, and
Felix-Henry
,
A.
,
2009
, “
Flexible Pipe Curved Collapse Resistance Calculation
,”
ASME
Paper No. OMAE2009-79117.
9.
Malta
,
E. R.
,
Martins
,
C. A.
,
Gay Neto
,
A.
, and
Toni
,
F. G.
,
2012
, “
An Investigation About the Shape of the Collapse Mode of Flexible Pipes
,”
Twenty-Second International Offshore and Polar Engineering Conference
, Rhodes, Greece, June 17–22, Vol.
II
, SPE Paper No.
ISOPE-I-12-280
.https://www.onepetro.org/conference-paper/ISOPE-I-12-280
10.
Gay Neto
,
A.
,
Martins
,
C. A.
,
Malta
,
E. R.
,
Godinho
,
C. A. F.
,
Barbosa Neto
,
T. F.
, and
de Lima
,
E. A.
,
2012
, “
Wet and Dry Collapse of Straight and Curved Flexible Pipes: A 3D FEM Modeling
,”
Twenty-Second International Offshore and Polar Engineering Conference
, Rhodes, Greece, June 17–22, Vol.
II
, SPE Paper No.
ISOPE-I-12-309
.https://www.onepetro.org/conference-paper/ISOPE-I-12-309
11.
Li
,
F. S.
, and
Kyriakides
,
S.
,
1991
, “
On the Response and Stability of Two Concentric, Contacting Rings Under External Pressure
,”
Int. J. Solids Struct.
,
27
(
1
), pp.
1
14
.
12.
ANSYS
,
2011
, “
ANSYS 13 Help
,”
ANSYS, Inc.
,
Canonsburg, PA
.
13.
API
,
2002
, “
API Recommended Practice 17B
,” Information Handling Services, American Petroleum Institute, Washington, DC.
14.
Gay Neto
,
A.
,
Pimenta
,
P. M.
, and
Martins
,
C. A.
,
2017
, “
Hydrostatic Pressure Load in Pipes Modeled Using Beam Finite Elements: Theoretical Discussions and Applications
,”
J. Eng. Mech.
,
143
(
4
), p.
04017003
.
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