The design of welded structures for the fatigue limit state is normally carried out by means of either linear or bilinear S-N curves, which have been found adequate to predict crack initiation only. To properly assess the effects of the design, fabrication, inspection, and repair strategy for structure degradation due to crack growth, fracture mechanics (FM) models need to be applied. In this paper, alternative S-N and FM formulations of fatigue are investigated. The probabilistic fracture mechanics approach predicts the fatigue life of welded steel structures in the presence of cracks under random spectrum loading. It is based on a recently proposed bi-linear relationship to model fatigue crack growth. Uncertainty modeling, especially on fatigue crack growth parameters, is undertaken with the aid of recently published data in support of the bilinear crack growth relationship. Results pertaining to the fatigue reliability and fatigue crack size evolution are presented using the Monte Carlo simulation technique and the emphasis is placed on a comparison between the linear and bilinear crack growth models. Variations in the system configuration, service life, and coefficients of crack growth laws have been studied on the parametric basis

References

References
1.
NTS, 1998, Design of Steel Structures, NORSOK Standard N-004, Norwegian Technology Standards Institution, Oslo, Norway.
2.
Timothy
,
D. R.
and
Marios
,
K. C.
,
2004
, “
Fatigue and Fracture Simulation of Welded Bridge Details Through a Bi-Linear Crack Growth Law
,”
Struct. Safety
,
26
(2), pp.
141
158
.10.1016/S0167-4730(03)00038-9
3.
De Souza
,
G. F. M.
and
Gonclaves
,
E.
,
1997
, “
Fatigue Performance of Deep Water Suspended Piping Systems
,”
Int. J. Pressure Vessels Piping
,
72
(1), pp.
27
36
.10.1016/S0308-0161(97)00006-9
4.
DET NORSKE VERITAS, 2004, “
Fatigue Strength Analysis of Offshore Steel Structures
,” Recommended Practice-203.
5.
Wirsching
,
P. H.
,
1984
, “
Fatigue Reliability for Offshore Structures
,”
J. Struct.Eng.
,
110
(10), pp.
2340
2356
.10.1061/(ASCE)0733-9445(1984)110:10(2340)
6.
Zheng
,
R.
and
Ellingwood
,
B. R.
,
1998
, “
Stochastic Fatigue Crack Growth in Steel Structures Subject to Random Loading
,”
Struct. Safety
,
20
(4), pp.
303
323
.10.1016/S0167-4730(98)00020-4
7.
Soares
,
C. G.
and
Garbatov
,
Y.
,
1996
, “
Fatigue Reliability of the Ship Hull Girder
,”
Mari. Struct.
,
9
(
3–4
), pp.
495
516
.10.1016/0951-8339(95)00032-1
8.
Teixeira
,
A. P.
and
Guedes Soares
,
C.
,
2009
, “
Reliability Analysis of a Tanker Subjected to Combined Sea States
,”
Probabilist. Eng. Mech.
,
24
(
4
), pp.
493
503
.10.1016/j.probengmech.2009.03.001
9.
Ayala-Uragra
,
E.
and
Moan
,
T.
,
2007
, “
Fatigue Reliability-Based Assessment of Welded Joints Applying Consistent Fracture Mechanics Formulations
,”
Int. J. Fatigue
,
29
(3), pp.
444
456
.10.1016/j.ijfatigue.2006.05.010
10.
King
,
R. N.
,
Stacey
,
A.
, and
Sharp
,
J. V.
,
1996
, “
A Review of Fatigue Crack Growth Rates for Offshore Steels in Air and Seawater Environments
,”
Proceedings of the 15th International Conference on Offshore Mechanics and Arctic Engineering
, pp.
341
348
.
11.
Leira
,
B. J.
,
Karunakaran
,
D.
, and
Bjorset
,
A.
,
1998
, “
Fracture and Fatigue Reliability Assessment of Deepwater Risers
,”
Proceedings of the 17th International Conference on Offshore Mechanics and Arctic Engineering
, Lisbon, Portugal, pp.
1
8
.
12.
Zhao
,
W.
,
Stacey
,
A.
, and
Prakash
,
P.
,
2002
, “
Probabilistic Models of Uncertainties in Fatigue and Fracture Reliability Analysis
,”
Proceedings of the 21st International Conference on Offshore Mechanics and Arctic Engineering
, Oslo, Norway, pp.
557
578
.
13.
BS7608,
1993
, “
Code Practice for Fatigue Design and Assessment of Steel Structures
,” British Standards Institution, London.
14.
Haibach
,
E.
,
1970
, “
Contribution to Discussion. The Welding Institute Conference on Fatigue of Welded Structures
,” Brighton, UK.
15.
IIW,
2002
, “
Recommendation for Fatigue Design of Welded Joints and Components
,” International Institute of Welding I, Paris, Document No. XIII-1539-96/XV-845-96.
16.
Madsen
,
H. O.
,
Krenk
,
S.
, and
Lind
,
N. C.
,
1986
,
Methods of Structural Safety
,
Prentice-Hall
,
Englewood Cliffs, NJ
.
17.
Lotsberg
,
I.
and
Sigurdsson
,
G.
,
2005
, “
Assessment of Input Parameters in Probabilistic Inspection Planning for Fatigue Cracks in Offshore Structures
,”
Proceedings of the 9th International Conference on Structural Safety and Reliability
, ICOSSAR’05, Rome, Italy.
18.
Moan
,
T.
,
Hovde
,
G. O.
, and
Blanker
,
A. M.
,
1993
, “
Reliability Based Fatigue Design Criteria for Offshore Structures Considering the Effect of Inspection and Repair
,”
Proceedings of the 25th Offshore Technology Conference
, Houston, Vol.
2
, pp.
591
600
.
19.
Paris
,
P. C.
and
Erdogan
,
F.
,
1963
, “
Critical Analysis of Crack Propagation Laws
,”
ASME J. Basic Eng.
,
85
(4), pp.
528
34
.10.1115/1.3656900
20.
BS7910,
2005
, “
Guide on Methods for Assessing the Acceptability of Flaws in Metallic Structures
,” British Standards Institution, London, UK.
21.
Khan
,
R. A.
and
Ahmad
,
S.
,
2007
, “
Dynamic Response and Fatigue Reliability of Marine Risers Under Random Loads
,”
Proceedings of the ASME 26th International Conference on Offshore Mechanics and Arctic Engineering
(
OMAE 2007
), San Diego, CA, June 10–15, ASME Paper No. OMAE2007-29235, pp. 183–191.10.1115/OMAE2007-29235
You do not currently have access to this content.