Multiplanar tubular KK-joints are one of the most popular joint types in offshore structures, which are exposed to cyclic loads and fatigue damages. In this paper, a fatigue prediction method based on scaled model test is proposed. First, a scaled KK-joint, including deviations for model simplification, was designed based on sensitive analysis and similarity analysis. Then, static and fatigue tests on the scaled model under axial loading were performed, by which hot spot stress (HSS) distributions and the maximum HSS were recorded. From the test, the fatigue crack initiates from the location of the maximum HSS and propagates along the weld toe. Finally, the maximum HSS of original KK-joint was deduced by finite element analysis (FEA), and then, the fatigue life was predicted accordingly and compared with the rule-based result.

References

1.
Lee
,
M. M. K.
,
1999
, “
Strength, Stress and Fracture Analyses of Offshore Tubular Joints Using Finite Elements
,”
J. Constr. Steel Res.
,
51
(
3
), pp.
265
286
.
2.
ABS
,
2003
,
Fatigue Assessment of Offshore Structure
,
American Bureau of Shipping
,
Washington, DC
.
3.
DNV
,
2010
,
Fatigue Design of Offshore Steel Structures
,
Det Norske Veritas
,
Oslo, Norway
.
4.
Karamanos
,
S. A.
,
Romeijn
,
A.
, and
Wardenier
,
J.
,
2002
, “
SCF Equations in Multi-Planar Welded Tubular DT-Joints Including Bending Effects
,”
Mar. Struct.
,
15
(
2
), pp.
157
173
.
5.
N'diaye
,
A.
,
Hariri
,
S.
,
Pluvinage
,
G.
, and
Azari
,
Z.
,
2009
, “
Stress Concentration Factor Analysis for Welded, Notched Tubular T-Joints Under Combined Axial, Bending and Dynamic Loading
,”
Int. J. Fatigue
,
31
(
2
), pp.
367
374
.
6.
Shao
,
Y.
,
Zhi
,
F.
, and
Seng
,
T.
,
2009
, “
Prediction of Hot Spot Stress Distribution for Tubular K-Joints Under Basic Loadings
,”
J. Constr. Steel Res.
,
65
(
10–11
), pp.
2011
2026
.
7.
Woghiren
,
C. O.
, and
Brennan
,
F. P.
,
2009
, “
Weld Toe Stress Concentrations in Multi-Planar Stiffened Tubular KK Joints
,”
Int. J. Fatigue
,
31
(
1
), pp.
164
172
.
8.
Hoon
,
K.
,
Wong
,
L.
, and
Soh
,
A.
,
2001
, “
Experimental Investigation of a Double-Plate Reinforced Tubular T-Joint Subjected to Combined Loadings
,”
J. Constr. Steel Res.
,”
57
(
9
), pp.
1015
1039
.
9.
Chen
,
J.
,
Chen
,
J.
, and
Jin
,
W.
,
2010
, “
Experiment Investigation of Stress Concentration Factor of Concrete-Filled Tubular T Joints
,”
J. Constr. Steel Res.
,
66
(
12
), pp.
1510
1515
.
10.
Qian
,
X.
,
Jitpairod
,
K.
,
Marshall
,
P.
,
Swaddiwudhipong
,
S.
,
Ou
,
Z.
,
Zhang
,
Y.
, and
Pradana
,
M. R.
,
2014
, “
Fatigue and Residual Strength of Concrete-Filled Tubular x-Joints With Full Capacity Welds
,”
J. Constr. Steel Res.
,
100
(
13
), pp.
21
35
.
11.
Qian
,
X.
,
Petchdemaneengam
,
Y.
,
Swaddiwudhipong
,
S.
,
Marshall
,
P.
,
Ou
,
Z.
, and
Nguyen
,
C. T.
,
2013
, “
Fatigue Performance of Tubular x-Joints With PJP Welds: I—Experimental Study
,”
J. Constr. Steel Res.
,
2013
(
90
), pp.
49
59
.
12.
Chen
,
Y.
,
Tong
,
Z.
,
Hua
,
H.
,
Wang
,
Y.
, and
Gou
,
H.
,
2009
, “
Experimental Investigation on the Dynamic Response of Scaled Ship Model With Rubber Sandwich Coatings Subjected to Underwater Explosion
,”
Int. J. Impact Eng.
,
36
(
2
), pp.
318
328
.
13.
Gordo
,
J. M.
, and
Soares
,
C. G.
,
2015
, “
Experimental Evaluation of the Ultimate Bending Moment of a Slender Thin-Walled Box Girder
,”
ASME J. Offshore Mech. Arct. Eng.
,
137
(
2
), p.
021604
.
14.
Elshafey
,
A. A.
,
Haddara
,
M. R.
, and
Marzouk
,
H.
,
2009
, “
Dynamic Response of Offshore Jacket Structures Under Random Loads
,”
Mar. Struct.
,
22
(
3
), pp.
504
521
.
15.
Sakai
,
Y.
,
Hosaka
,
T.
,
Isoe
,
A.
,
Ichikawa
,
A.
, and
Mitsuki
,
K.
,
2004
, “
Experiments on Concrete Filled and Reinforced Tubular k-Joints of Truss Girder
,”
J. Constr. Steel Res.
,
60
(
3
), pp.
683
699
.
16.
Schumacher
,
A.
,
Borges
,
L. C.
, and
Nussbaumer
,
A.
,
2009
, “
A Critical Examination of the Size Effect Correction for Welded Steel Tubular Joints
,”
Int. J. Fatigue
,
31
(
8
), pp.
1422
1433
.
17.
Schuring
,
D. J.
,
1977
, “
Scale Models in Engineering
,”
J. INCE/Jpn.
,
3
, pp.
21
26
.
18.
Madenci
,
E.
, and
Guven
,
I.
,
2007
,
The Finite Element Method and Applications in Engineering Using ansys®
,
Springer
,
Berlin
.
19.
API
,
1993
,
Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms Load and Resistance Factor Design
,
American Petroleum Institute
,
Washington, DC
.
20.
AWS
,
1996
,
Structural Welding Code-Steel
,
American Welding Society
,
Miami, FL
.
21.
Wylde
,
J. G.
, and
Nald
,
A.
,
1980
, “
The Influence of Joint Dimensions on the Fatigue Strength of Welded Tubular Joints
,”
Int. J. Fatigue
,
2
(
1
), pp.
31
36
.
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