Ship structures will always be subjected to and suffer from fatigue damage and fracture. However, we can become better at utilizing the materials and the structures and operating them more wisely, leading to less maintenance, extended service life and enhanced safety if we can improve the fatigue damage prediction. In this study, a fatigue model useful for ship routing is presented. Similar to the ship-routing design for the expected time of arrival and fuel reduction, the objective here is to demonstrate the possibility and benefits of ship route planning which lead to a reduction in fatigue damage accumulation. In the context of ship fatigue route planning, uncertainty analysis of the fatigue assessments of container ships is discussed. The proposed ship-routing fatigue model is employed in case studies on two container vessels to illustrate the possible benefits to the fatigue safety of ship structures. Sea environments in the application are obtained from hindcast wave data and a spatiotemporal wave model. The results show that the fatigue damage of the studied container ship structures could be decreased by more than 50% if awareness and knowledge of fatigue in ship route planning are employed.
Det Norske Veritas. Fatigue assessment of ship structures. Classification Note 30.7, Det Norske Veritas, Hövik, Norway, June2010.
2.
StorhaugG. Experimental investigation of wave induced vibrations and their effect on the fatigue loading of ships. PhD Thesis, Department of Marine Technology, Norwegian University of Science and Technology, Trondheim, Norway, 2007.
3.
Marine Accident Investigation Branch. Report on the investigation of the structural failure of MSC Napoli English Channel on 18 January 2007. Report 9/2008, Marine Accident Investigation Branch, Southampton, Hampshire, UK, 2008.
4.
Weather Routing Inc. Fleet routing, http://www.wriwx.com/ (2011, accessed 1 September 2011).
MaoWRingsbergJWRychlikIStorhaugG. Development of a fatigue model useful in ship routing design. J Ship Res2010; 54(4): 281–293.
8.
MaoWRingsbergJWRychlikILiZ. Theoretical development and validation of a fatigue model for ship routing. J Ships Ocean Structs2011. Epub ahead of print. DOI: 10.1080/17445302.2011.62037110.1080/17445302.2011.620371.
9.
MaoWRingsbergJWRychlikIStorhaugG. Comparison between a fatigue model for voyage planning and measurements of a container vessel. In ASME 28th international conference on ocean, offshore and Arctic engineering, Honolulu, HI, USA, 31 May–5 June 2009, paper OMAE2009-79235. New York: ASME.
10.
Det Norske Veritas. Environmental conditions and environmental loads. Recommended Practice, Det Norske Veritas, Hövik, Norway, April2010.
11.
MaoWRychlikIStorhaugG. Safety index of fatigue failure for ship structure details. J Ship Res2010; 54(3): 197–208.
12.
ChenH. A dynamic program for minimum cost ship routing under uncertainties. PhD Thesis, Department of Ocean Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA, 1978.
13.
FagerholtK. Optimal fleet design in a ship routing problem. Int Trans Opl Res1999; 6(5): 453–464.
14.
Det Norske Veritas. SESAM user’s manual Waveship. DNV Sesam Report 93-7080/Rev.1, Det Norske Veritas, Hövik, Norway, October1993.
15.
StorhaugGHeggelundSE. Measurements of wave induced vibrations and fatigue loadings onboard two container vessels operating in harsh wave environment. In: Design and operation of container vessels, London, UK, 3–4July2008, pp. 81–100. London: Royal Institution of Naval Architects.
16.
LiZRingsbergJW. Fatigue routing of container ships – assessment of contributions to fatigue damage from wave induced torsion and horizontal and vertical bending. Ships Ocean Structs2011. Epub ahead of print. DOI: 10.1080/17445302.2011.55936810.1080/17445302.2011.559368
17.
FrickeW. Fatigue analysis of welded joints: state of development. Mar Structs2003; 16(3): 185–200.
18.
DowlingNECalhounCAArcariA. Mean stress effects in stress-life fatigue and the Walker equation. Fatigue Fracture Engng Mater Structs2009; 32(3): 163–179.
SureshS. Fatigue of materials. 2nd edition.Cambridge: Cambridge University Press, 1998.
21.
JohannessonPSvenssonTde MaréJ. Fatigue life prediction based on variable amplitude tests – methodology. Int J Fatigue2005; 27(8): 954–965.
22.
AgerskovH. Fatigue in steel structures under random loading. J Constr Steel Res2000; 53(3): 283–305.
23.
BengtssonARychlikI. Uncertainty in fatigue life prediction of structures subject to Gaussian loads. Probabilistic Engng Mech2009; 24(2): 224–235.
24.
American Bureau of Shipping. Guidance notes on spectral-based fatigue analysis for vessels, American Bureau of Shipping, Houston, TX, USA, 2010.
25.
MaddoxS. Recommended hot spot stress design S–N curves for fatigue assessment of FPSOs. In: 11th international offshore and polar engineering conference & exhibition, Stavanger, Norway, 17–22 June 2001, vol IV, pp. 97–104. Cupertino, California: International Society of Offshore and Polar Engineers.
26.
BerganPGLotsbergIFrickeW. An overview of the FPSO: fatigue capacity JIP. In: ASME 21st international conference on ocean, offshore and Arctic Engineering, Oslo, Norway, 23–28 July 2002, paper OMAE2002-28538. New York: ASME.
FrickeW. Recommended hot spot analysis procedure for structural details of FPSOs and ships based on round-robin FE analyses. In: 11th international offshore and polar engineering conference & exhibition, Stavanger, Norway, 17–22 June, 2001, vol IV, pp. 89–96. Cupertino, CA: International Society of Offshore and Polar Engineers.
29.
LiZRingsbergJW. Direct calculations of fatigue damage of ship structure details. In: ASME 30th international conference on ocean, offshore and Arctic engineering, Rotterdam, The Netherlands, 19–24 June 2011, paper OMAE2011-49758. New York: ASME.
30.
LiZRingsbergJWMaoW. Fatigue damage assessment of container ships concerning wave-induced torsion. In: ASME 29th international conference on ocean, offshore and Arctic engineering, Shanghai, People’s Republic of China, 6–11 June 2010, paper OMAE2010-20140. New York: ASME.
31.
OlsenASSchrøterCJensenJJ. Wave height distribution observed by ships in the North Atlantic. J Ships Offshore Structes2005; 1(1): 1–12.
32.
MaoW. Fatigue assessment and extreme prediction of ship structures. PhD Thesis, Department of Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden, 2010.
