The development of the new API RP2A (22nd edition) parametric static strength prediction equations for planar circular hollow section tubular joints is described. Prediction equations are presented for brace axial, brace in-plane bending, and brace out-of-plane bending loads. The prediction equations are based on screened test databases, augmented, and extended by an extensive new series of validated nonlinear finite element simulations for nonoverlapping K joints, double tee (DT/X) joints, and T joints. The increased reliability (reduced scatter) provided by the new static strength formulation was used to justify a reduction of the load factor of safety to 1.6 from the previous value of 1.7.

1.
Yura
,
J. A.
,
Zettlemoyer
,
N.
, and
Edwards
,
I. F.
, 1981, “
Ultimate Capacity of Circular Tubular Joints
,”
J. Struct. Div.
0044-8001,
107
, pp.
1965
1984
.
2.
van der Valk
,
C. A.
, 1988, “
Factors Controlling the Static Strength of Tubular T Joints
,”
Proceedings BOSS ’88 Conference
, Trondheim, Norway, June.
3.
van der Valk
,
C. A.
, 1991, “
New Aspects Related to the Ultimate Strength of Tubular K and X Joints
,”
Proceedings of the 10th International Conference on Offshore Mechanics and Arctic Engineering
, Stavanger, Norway, June, Vol.
III-B
, pp.
417
422
.
4.
van der Vegte
,
G. J.
,
de Koning
,
C. H. M.
,
Puthli
,
R. S.
, and
Wardenier
,
J.
, 1991, “
The Static Strength and Stiffness of Multiplanar Tubular Steel X-Joints
,”
Int. J. Offshore Polar Eng.
1053-5381,
1
, pp.
42
52
.
5.
Ha
,
C. C.
, and
Pecknold
,
D. A.
, 1998, “
FE Modelling of DT Tubular Joints With Chord Stress
,”
Proceedings of the 17th International Conference on Offshore Mechanics and Artic Engineering
, Lisbon, Portugal, June, Paper No. OMAE 98-560.
6.
Dier
,
A. F.
, and
Turner
,
T. E.
, 1998, “
FE Studies on Joint Classification and K Joints With Unequal Brace Angles
,”
Proceedings of the 17th International Conference on Offshore Mechanics and Arctic Engineering
, Lisbon, Portugal, June, Paper No. OMAE 98-581.
7.
Paul
,
J. C.
,
Makino
,
Y.
, and
Kurobane
,
Y.
, 1993, “
Ultimate Resistance of Tubular Double T-Joints Under Axial Brace Loading
,”
J. Constr. Steel Res.
0143-974X,
24
, pp.
205
228
.
8.
Paul
,
J. C.
,
Ueno
,
T.
,
Makino
,
Y.
, and
Kurobane
,
Y.
, 1993, “
Ultimate Behavior of Multiplanar Double K-Joints of Circular Hollow Section Members
,”
Int. J. Offshore Polar Eng.
1053-5381,
3
, pp.
43
50
.
9.
Lee
,
M. M. K.
, and
Dexter
,
E. M.
, 1999, “
A New Capacity Equation for Axially Loaded Multi-planar Tubular Joints in Offshore Structures
,” OTO Report No. 1999 095, HSE, UK.
10.
Wardenier
,
J.
,
Kurobane
,
Y.
,
Packer
,
J. A.
,
Dutta
,
D.
, and
Yeomans
,
N.
, 1991,
Design Guide for Circular Hollow Section (CHS) Joints Under Predominantly Static Loading
,
CIDECT
,
Verlag TUV, Rheinland, Germany
.
11.
Yura
,
J. A.
, and
Hoadley
,
P. W.
, 1985, “
Ultimate Strength of Tubular Joints Subjected to Combined Loads
,”
Proceedings Offshore Technology Conference
, Houston, TX, May, Paper No. OTC 4854.
12.
Swennson
,
K. D.
, and
Yura
,
J. A.
, 1986, “
Ultimate Strength of Double-Tee Joints: Interaction Effects
,” Phase 3 Final Report,
Ferguson Laboratory, University of Texas at Austin
.
13.
Boone
,
T. J.
,
Yura
,
J. A.
, and
Hoadley
,
P. W.
, 1982, “
Chord Stress Effects on the Ultimate Strength of Tubular Connections
,” Report No. PMFSEL 82-1,
University of Texas at Austin
.
14.
MSL Engineering Limited, 1996, “
Assessment Criteria, Reliability and Reserve Strength of Tubular Joints
,” Doc. Ref. No. C14200R018,
Ascot
, England.
15.
Makino
,
Y.
,
Kurobane
,
Y.
,
Ochi
,
K.
,
van der Vegte
,
G.
, and
Wilmshurst
,
S.
, 1996, “
Database of Test and Numerical Analysis Results for Unstiffened Tubular Joints
,” IIW Doc. No. XV-E-96-220,
Kumamoto University
, Kumamoto, Japan.
16.
Pecknold
,
D. A.
, and
Ha
,
C. C.
, 1998, “
Chord Stress Effects on Ultimate Strength of DT Tubular Joints
,”
Proceedings of the 17th International Conference on Offshore Mechanics and Arctic Engineering
, Lisbon, Portugal, June, Paper No. OMAE 98-565.
17.
Pecknold
,
D. A.
,
Ha
,
C. C.
, and
Mohr
,
W. C.
, 1998, “
Strength of Simple Joints—Effect of Chord Stress and Diameter-to-Thickness Ratio on the Static Strength of DT Tubular Joints Loaded in Brace Compression
,” Report to the American Petroleum Institute, EWI Project No. 42705-CAP,
Edison Welding Institute
, Columbus, OH.
18.
Pecknold
,
D. A.
,
Ha
,
C. C.
, and
Mohr
,
W. C.
, 1999, “
Strength of Simple Joints—Static Strength of DT Tubular Joints Loaded in Brace Compression or In-Plane Bending
,” Report to the American Petroleum Institute, EWI Project No. 42705-CAP,
Edison Welding Institute
, Columbus, OH.
19.
Pecknold
,
D. A.
,
Ha
,
C. C.
, and
Mohr
,
W. C.
, 2000, “
Ultimate Strength of DT Tubular Joints With Chord Preloads
,”
Proceedings of the 19th International Conference on Offshore Mechanics and Arctic Engineering
, New Orleans, LA, February, Paper No. OMAE2000/OSU OFT-4203.
20.
Pecknold
,
D. A.
,
Park
,
J. B.
, and
Koppenhoefer
,
K. C.
, 2001, “
Ultimate Strength of Gap K Tubular Joints With Chord Preloads
,”
Proceedings of the 20th International Conference on Offshore Mechanics and Arctic Engineering
, Rio de Janeiro, Brazil, June, Paper No. OMAE01/OFT-1214.
21.
Pecknold
,
D. A.
,
Park
,
J. B.
, and
Koppenhoefer
,
K. C.
, 2003, “
Static Strength of Gap K Tubular Joints With Chord Preloads Under Brace Axial and Moment Loads
,” Report to the American Petroleum Institute, EWI Project No. 42705-CAP,
Edison Welding Institute
, Columbus, OH.
22.
Dier
,
A. F.
, and
Lalani
,
M.
, 1995, “
Strength and Stiffness of Tubular Joints for Assessment/Design Purposes
,”
Proceedings Offshore Technology Conference
, Houston, TX, May, Paper No. OTC 7799.
23.
Togo
,
T.
, 1967, “
Experimental Study on Mechanical Behavior of Tubular Joints
,” Doctoral dissertation, Osaka University, Osaka, Japan (in Japanese).
24.
Weinstein
,
R.
, and
Yura
,
J. A.
, 1985, “
The Effect of Chord Stresses on the Static Strength of DT Tubular Connections
,” Report No. PMFSEL 85-1,
University of Texas at Austin
.
25.
Bjornoy
,
O. B.
, and
Collberg
,
L.
, 1991, “
Static Strength of Tubular Joints-PhaseII. Analyses and Tests of Gap and Overlap K-Joints
,” Veritec Report No. 91-3393, A.S. Veritec, Oslo, Norway.
26.
Bolt
,
H. M.
,
Seyed-Kebari
,
H.
, and
Ward
,
J. K.
, 1992, “
The Influence of Chord Length and Boundary Conditions on K Joint Capacity
,”
Proceedings 2nd International Conference on Offshore and Polar Engineering
, San Francisco, CA, June.
27.
Karsan
,
D. I.
,
Marshall
,
P. W.
,
Pecknold
,
D. A.
,
Bucknell
,
J.
, and
Zettlemoyer
,
N.
, 2005, “
The New API RP2A, 22nd Edition Tubular Joint Design Practice
,”
Proceedings Offshore Technology Conference
, Houston, TX, May, Paper No. OTC 17236.
28.
Dier
,
A. F.
, and
Lalani
,
M.
, 1998, “
New Code Formulations for Tubular Joint Static Strength
,”
Proceedings 8th International Symposium on Tubular Structures
, Singapore, August, pp.
107
116
.
29.
Dexter
,
E. M.
, and
Lee
,
M. M. K.
, 1994, “
Effect of Overlap on Strength of K Joints in CHS Tubular Members
,”
Proceedings 6th International Symposium on Tubular Structures
, Melbourne, Australia, December, pp.
581
588
.
30.
Healy
,
B. E.
, 1994, “
A Numerical Investigation into the Capacity of Overlapped Circular K-Joints
,”
Proceedings 6th International Symposium on Tubular Structures
, Melbourne, Australia, December, pp.
563
571
.
31.
Gazzola
,
F.
,
Lee
,
M. M. K.
, and
Dexter
,
E. M.
, 1999, “
Strength Prediction of Axially Loaded Overlap Tubular K Joints
,”
Proceedings of the 9th International Offshore and Polar Engineering Conference
, Brest, France, June.
32.
Gazzola
,
F.
,
Lee
,
M. M. K.
, and
Dexter
,
E. M.
, 1999, “
Strength Sensitivities of Overlap Tubular K-Joints Under Axial Loading
,”
Proceedings of the 9th International Offshore and Polar Conference
, Brest, France, June.
33.
Kurobane
,
Y.
,
Makino
,
Y.
, and
Ochi
,
K.
, 1984, “
Ultimate Resistance of Unstiffened Tubular Joints
,”
J. Struct. Eng.
0733-9445,
110
(
2
), pp.
385
400
.
34.
Marshall
,
P. W.
, 2004, “
Review of Tubular Joint Criteria
,”
Proceedings, ECCS-AISC Conference on Design of Connections
, Amsterdam, The Netherlands, June, pp.
457
467
.
35.
Dier
,
A. F.
, and
Lalani
,
M.
, 1997, “
Guidelines on Strengthening and Repair of Offshore Structures
,”
Proceedings BOSS ’97, Structures
, Vol.
3
,
Delft University
,
The Netherlands
, July.
36.
Tebbett
,
I. E.
,
Beckett
,
C. D.
, and
Billington
,
C. J.
, 1979, “
The Punching Shear Strength of Tubular Joints Reinforced With a Grouted Pile
,”
Proceedings Offshore Technology Conference
, Houston, TX, May, Paper No. OTC 3463.
37.
UEG
, 1985, “
Design of Tubular Joints for Offshore Structures
,”
UEG Publication UR33
,
Underwater Engineering Group
,
UK
,
3
vols.
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