Flexible risers are used in the oil industry to transport liquids and gas from the seafloor to extraction and production equipment at the sea surface. Ongoing research aims at using composite materials instead of steel, in order to reduce weight and increase stiffness. Ensuring an optimal load transfer between the composite and metal components is very important. This paper presents an improved method for anchoring a flat fiber-reinforced tendon using a double grip system with self-locking grips. The novelty is the combination of new experimental results and finite element (FE) analysis to develop a superior dry friction grip. Experimental results are carried using a dedicated test setup, through which the test parameters can be accurately controlled. The efficiency of the grip system during pullout is superior to results obtained with flat grips. Numerical results offer an in-depth understanding of the influence between friction, geometrical parameters, and performance, making it possible to optimize the design. Results show that this grip system offers immediate technical applications, in a variety of conditions.

References

References
1.
Rytter
,
J.
,
2002
, “
A Novel Compression Armour Concept for Unbonded Flexible Pipes
,”
Annual Offshore Technology Conference
, Houston, TX, May 6–9, pp.
573
577
.
2.
Bryant
,
M.
,
2007
, “
Nonmetallic Unbonded Flexible Pipes for Deep Water
,”
2nd International Oil Conference and Exhibition
, Society of Petroleum Engineers, Veracruz, Mexico, June 27–30, pp.
104
108
.
3.
Nielsen
,
N. J. R.
,
Glejbøl
,
K.
, and
Kulakov
,
V.
,
2001
, “
Innovative Un-Bonded Flexible Pipe Design With Hybrid CFRP/Metal Armour
,” Deep Offshore Technology, pp.
1
10
.
4.
Al-Mayah
,
A.
,
Soudki
,
K. A.
, and
Plumtree
,
A.
,
2001
, “
Experimental and Analytical Investigation of a Stainless Steel Anchorage for CFRP Prestressing Tendons
,”
PCI J.
,
46
(
2
), pp.
88
100
.
5.
Al-Mayah
,
A.
,
Soudki
,
K.
, and
Plumtree
,
A.
,
2007
, “
Novel Anchor System for CFRP Rod: Finite-Element and Mathematical Models
,”
J. Compos. Constr.
,
11
(
5
), pp.
469
476
.
6.
Schmidt
,
J. W.
,
Bennitz
,
A.
,
Täljsten
,
B.
,
Goltermann
,
P.
, and
Pedersen
,
H.
,
2012
, “
Mechanical Anchorage of FRP Tendons—A Literature Review
,”
Constr. Build. Mater.
,
32
, pp.
110
121
.
7.
Rytter
,
J.
,
Portnov
,
G.
, and
Kulakov
,
V.
,
2005
, “
Anchoring and a Load Transfer Technique in Uniaxial Tension of Unidirectional High-Strength Composites
,”
Mech. Compos. Mater.
,
41
(
3
), pp.
217
228
.
8.
Burtscher
,
S. L.
,
2008
, “
Wedge Anchorage for CFRP Strips
,”
J. Compos. Constr.
,
12
(
4
), pp.
446
453
.
9.
Portnov
,
G. G.
,
Kulakov
,
V. L.
, and
Arnautov
,
A. K.
,
2013
, “
Grips for the Transmission of Tensile Loads to a FRP Strip
,”
Mech. Compos. Mater.
,
49
(
5
), pp.
457
474
.
10.
Costache
,
A.
,
Glejbøl
,
K.
,
Sivebæk
,
I. M.
, and
Berggreen
,
C.
,
2015
, “
Friction Joint Between Basalt-Reinforced Composite and Aluminum
,”
Tribol. Lett.
,
59
(
2
), p.
30
.
11.
ISO
,
1998
, “
Geometriske produktspecifikationer (GPS). Overfladebeskaffenhed. Profilmetode. Termer, definitioner og overfladebeskaffenhedsparametre
,” Dansk Standard, Denmark, Standard No. ISO 4287.
12.
Zenkert
,
D.
,
2006
,
Foundations of Fibre Composites: Notes for the Course: Composite Lightweight Structures
,
DTU
, Lyngby, Denmark.
13.
Foye
,
R.
,
1972
, “
The Transverse Poisson’s Ratio of Composites
,”
J. Compos. Mater.
,
6
(
2
), pp.
293
295
.
14.
Costache
,
A.
,
Glejbøl
,
K.
,
Sivebæk
,
I. M.
, and
Berggreen
,
C.
, “
Numerical Investigation of Friction Joint Between Basalt Reinforced Composite and Aluminum
,”
Proc. Inst. Mech. Eng., Part J
(submitted).
You do not currently have access to this content.