Threaded pipe couplings are used to join pipelines when they have to be uncoupled frequently or as an easy to assemble alternative to welding. A large variety of patented coupling modifications are available, but little is known about their influence on the connection’s behavior. In this study, the finite element model of an API line pipe threaded pipe connection is presented and its nonlinearities in material properties and contact behavior are discussed. Test results obtained from a four-point bending fatigue experiment are in good agreement with the results of the numerical simulations. A series of modifications of the standard connection are simulated to gain a better understanding in the influence of geometrical and material parameters on the connection’s performance. It was found that not all existing coupling modifications are improving the connection’s performance. It can be concluded that critical evaluation of the performance of existing coupling modifications is necessary and finite element analyses are proven to be a useful tool for this.

1.
Griffin
,
R. C.
,
Kamruzzaman
,
S.
, and
Strickler
,
R. D.
, May 2004, “
Casing Drilling Drill Collars Eliminate Downhole Failures
,”
Offshore Technology Conference
, Houston, TX.
2.
Ellington
,
P.
, and
Pendleton
,
G.
, 2006, “
Thread Integrity Feature for Expandable Connections
,” U.S. Patent No. US7,025,135B2.
3.
DeLange
,
R. W.
, and
Evans
,
M. E.
, 2003, “
Threaded and Coupled Connection for Improved Fatigue Resistance
,” U.S. Patent No. US6,609,735B1.
4.
Verdillon
,
L.
, 2004, “
Fatigue-Resistant Threaded Bevelled Tubular Element
,” U.S. Patent No. US6,752,436B1.
5.
Galle
,
E. M.
, Sr.
, and
Galle
,
E. M.
, Jr.
, 2002, “
Threaded Connector for Pipe
,” U.S. Patent No. US6,494,499B1.
6.
Assanelli
,
A. P.
,
Xu
,
Q.
,
Benedetto
,
F.
,
Johnson
,
D. H.
, and
Dvorkin
,
E. N.
, 1997, “
Numerical/Experimental Analysis of an API 8-Round Connection
,”
ASME J. Energy Resour. Technol.
0195-0738,
119
(
2
), pp.
81
88
.
7.
Dvorkin
,
E. N.
, and
Toscano
,
R. G.
, 2003, “
Finite Element Models in the Steel Industry, Part II: Analyses of Tubular Products Performance
,”
Comput. Struct.
0045-7949,
81
(
8–11
), pp.
575
594
.
8.
Guangjie
,
Y.
,
Zhenqiang
,
Y.
,
Qinghua
,
W.
, and
Zhentong
,
T.
, 2006, “
Numerical and Experimental Distribution of Temperature and Stress Fields in API Round Threaded Connection
,”
Eng. Failure Anal.
1350-6307,
13
(
8
), pp.
1275
1284
.
9.
2008, ABAQUS Version 6.8 Example Problems Manual, Axisymmetric Analysis of a Threaded Connection, Dassault Systèmes.
10.
Chen
,
J. J.
, and
Shih
,
Y. S.
, 1999, “
A Study of the Helical Effect on the Thread Connection by Three Dimensional Finite Element Analysis
,”
Nucl. Eng. Des.
0029-5493,
191
(
2
), pp.
109
116
.
11.
Zhong
,
A.
, May 2007, “
Thread Connection Response to Critical Pressures
,”
Abaqus Users’ Conference
, Paris, France, pp.
690
706
.
12.
Van Wittenberghe
,
J.
,
De Baets
,
P.
,
De Waele
,
W.
, and
Van Autrève
,
S.
, June 2009, “
Numerical and Experimental Study of the Fatigue of Threaded Pipe Couplings
,”
Contact and Surface Conference
, Algarve, Portugal.
13.
1996, “
Specification for Threading, Gauging and Thread Inspection of Casing, Tubing and Line Pipe Threads (U.S. Customary Units)
,” API Specification 5B American Petroleum Institute, 14th ed.
14.
2000, “
Specification for Line Pipe
,” API Specification 5L American Petroleum Institute, 42nd ed.
15.
Clinedinst
,
W. O.
, 1976, “
Joint Strength Formulas for API Threaded Line Pipe
,” API Circular PS-1533.
16.
MacDonald
,
K. A.
, and
Deans
,
W. F.
, 1995, “
Stress Analysis of Drillstring Threaded Connections Using the Finite Element Method
,”
Eng. Failure Anal.
1350-6307,
2
(
1
), pp.
1
30
.
You do not currently have access to this content.