Fatigue reliability of deck structures subjected to correlated crack growth

Abstract

The objective of this work is to analyse fatigue reliability of deck structures subjected to correlated crack growth. The stress intensity factors of the correlated cracks are obtained by finite element analysis and based on which the geometry correction functions are derived. The Monte Carlo simulations are applied to predict the statistical descriptors of correlated cracks based on the Paris-Erdogan equation. A probabilistic model of crack growth as a function of time is used to analyse the fatigue reliability of deck structures accounting for the crack propagation correlation. A deck structure is modelled as a series system of stiffened panels, where a stiffened panel is regarded as a parallel system composed of plates and are longitudinal. It has been proven that the method developed here can be conveniently applied to perform the fatigue reliability assessment of structures subjected to correlated crack growth.

Keywords

crack growth / fatigue reliability / deck structures / correlation / stiffened panel

References

[1] ANSYS Online Manuals, Release 11, 2009

[2] BS7608 British Standard BS7608, Code of practice for fatigue design and assessment of steel structures. London, BSI, 1993

[3] BS7910 British Standard BS7910, Guide to methods for assessing the acceptability of flaws in metallic structures. London, BSI, 2005

[4] Chakarov K, Garbatov Y, Guedes Soares C. Fatigue analysis of ship deck structure accounting for imperfections. International Journal of Fatigue, 2008, 30(10–11): 1881-1897

[5] DNV Rules for classification of ship, hull structural design, ship with length 100 meters and above. Det Norske Veritas, 2003

[6] Feng GQ, Garbatov Y, Guedes Soares C. Fatigue reliability of a stiffened panel subjected to correlated crack growth. Structural Safety, 2012, 36–37: 39-46

[7] Feng GQ, Garbatov Y, Guedes Soares C. Probabilistic model of the growth of correlated cracks in a stiffened panel. Engineering Fracture Mechanics, 2012, 84: 83-95

[8] Ferro G, Cervetto D. Hull girder reliability. Proceedings of the Ship Structural Symposium, 1984, 89-110

[9] Garbatov Y, Guedes Soares C. Fatigue reliability of maintained welded joints in the side shell of tankers. Journal of Offshore Mechanics and Arctic Engineering, 1998, 120: 2-9

[10] Garbatov Y, Guedes Soares C. Bayesian updating in the reliability assessment of maintained floating structures. Journal of Offshore Mechanics and Arctic Engineering, 2002, 124(3): 139

[11] Garbatov Y, Guedes Soares C. Assessment of the uncertainties introduced by different fatigue damage models for ship structural details. Proceedings of the 29th International Conference on Offshore Mechanics and Arctic Engineering (OMAE2010), 2010, New York: ASME

[12] Garbatov Y, Guedes Soares C. Fatigue reliability assessment of welded joints of very fast ferry subjected to combined load. International Journal of Maritime Engineering (RINA Transactions Part A), 2011, 153(A4): 231-241

[13] Garbatov Y, Rudan S, Guedes Soares C. Assessment of geometry correction functions of tanker knuckle details based on fatigue tests and finite element snalysis. Journal of Offshore Mechanics and Arctic Engineering, 2004, 126(3): 220-226

[14] Gaspar B, Garbatov Y, Guedes Soares C. Effect of uncertain weld shape on the structural hot-spot stress distribution. Analysis and Design of Marine Structures, 2009, 267-278

[15] Gaspar B, Garbatov Y, Guedes Soares C. Effect of weld shape imperfections on the structural hot-spot stress distribution. Ships and Offshore Structures, 2011, 6(1–2): 145-159

[16] Guedes Soares C, Garbatov Y. Fatigue reliability of the ship hull girder accounting for inspection and repair. Reliability Engineering & System Safety, 1996, 51(3): 341-351

[17] Guedes Soares C, Garbatov Y. Reliability of maintained ship hull subjected to corrosion and fatigue. Structural Safety, 1998, 20: 201-219

[18] Hart D, Rutherford S, Wichham A. Structural reliability analysis of stiffened panels. Transactions Royal Institution of Naval Architects (RINA), 1986, 128: 293-310

[19] Hasofer AM, Lind NC. An exact and invariant first-order reliability format. Journal of Engineering Mechanics Division, 1974, 100: 111-121

[20] Miner MA. Cumulative Damage in Fatigue. Journal of Applied Mechanics -Transactions of the ASME, 1945, 12(3): A159-A164

[21] Palmgren A. Die Lebensdauer von Kugellagern. VDI-Zeitschrift 68, 1924

[22] Paris P, Erdogan F. A critical analysis of crack propagation laws. Journal of Basic Engineering, 1963, 85: 528-534

[23] Petershagen H, Friecke W. Fatigue crack propagation in plate panels with welded stiffeners. IIWDoc XIII-1272-88. Cambridge, IIW, 1988

[24] Rubinstein R, Kroese D. Simulation and the Monte Carlo method, 2008, Hoboken, New Jersey: John Wiley & Sons, Inc.

[25] Wirsching PH. Probabilistic fatigue analysis. Probabilistic structural mechanics handbook, 1995, New York: Chapman and Hall

[26] Yuen BKC, Taheri F, Gharghouri M. Fatigue life prediction of welded stiffened 350WT steel plates. Marine Structures, 2006, 19(4): 241-270