Fatigue Damage Analysis of Offshore Structures using Hot-Spot Stress and Notch Strain Approaches
António Mourão, José A.F.O. Correia, José M. Castro, Miguel Correia, Grzegorz Lesiuk, Nicholas Fantuzzi, Abílio M.P. De Jesus, Rui A.B. Calcadadownload PDF
Abstract. In offshore structures, the consecutive environmental and operational loading lead to an ever-changing stress state in the topside structure as well as in the substructure, which for offshore jacket-type platforms (called of fixed offshore structures) commonly used, result in fatigue damage accumulation. A wide variety of codes and recommended practices provide approaches in order to estimate the fatigue damage in design phase and remaining life in existing structures. In this research work, fatigue damage accumulation analyses applied to an offshore jacket-type platform using hot-spot stress and notch strain approaches are presented. These analyses are performed using wave information from the scatter diagram collected in North Sea. The wave loads used in this analysis were obtained using the Stokes 5th order wave theory and Morrison formula. The jacket-type offshore structure under consideration has a total height of 140.3 meters, a geometry at mud line of 60×80 meters and composed by tubular elements.
Fatigue Damage, Hot-Spot Stresses, Notch Strain, Offshore Structures
Published online 5/25/2019, 9 pages
Copyright © 2019 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA
Citation: António Mourão, José A.F.O. Correia, José M. Castro, Miguel Correia, Grzegorz Lesiuk, Nicholas Fantuzzi, Abílio M.P. De Jesus, Rui A.B. Calcada, Fatigue Damage Analysis of Offshore Structures using Hot-Spot Stress and Notch Strain Approaches, Materials Research Proceedings, Vol. 12, pp 146-154, 2019
The article was published as article 21 of the book Experimental Mechanics of Solids
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 V. Michalopoulos and M. Zaaijer, “Simplified fatigue assessment of offshore wind support structures accounting for variations in a farm”, European Wind Energy Association Annual Conference and Exhibition 2015, EWEA 2015 – Scientific Proceedings 2015.
 A. Aeran, S. Siriwardane, O. Mikkelsen, and I. Langen, “An accurate fatigue damage model for welded joints subjected to variable amplitude loading”, in IOP Conference Series: Materials Science and Engineering, 2017, vol. 276, no. 1, p. 012038: IOP Publishing. https://doi.org/10.1088/1757-899x/276/1/012038
 R. Kajolli, “A new approach for estimating fatigue life in offshore steel structures”, MSc. Thesis, 130 pages, University of Stavanger, Norway, 2013.
 DNV GL Group. DNVGL-RP-C203: Fatigue design of offshore steel structures, 2016.
 F. Conti, L. Verney, and A. Bignonnet, “Fatigue assessment of tubular welded connections with the structural stress approach”, Fatigue Design 2009, 25-26 November 2009, Senlis, France, 8 pages.
 CEN-TC 250. EN 1993-1-9: Eurocode 3, Design of steel structures – Part 1-9: Fatigue. European Committee for Standardization, Brussels; 2003.
 DNV GL Group. DNVGL-OS-C201: Structural design of offshore units – WSD method, 2015.
 DNV GL Group. DNV-RP-C205: Environmental Conditions and Environmental Loads, 2014.
 A. Mourão. “Fatigue analysis of a jacket-type offshore platform based on local approaches”, MSc Thesis, 193 pages, Civil Engineering, Faculty of Engineering, University of Porto, Porto, Portugal, 2018.
 António Mourão, J.A.F.O. Correia, J.C. Rebelo, M.Correia, N. Fantuzzi and R. Calçada, “Fatigue wave loads estimation using Morison formula for an offshore jacket-type platform”, 19th International Colloquium on Mechanical Fatigue of Metals, Porto, Portugal, 2018.
 Recommendations for Fatigue Design of Welded Joints and Components. International Institute of Welding, doc. XIII-2151r4-07/XV-1254r4-07; Paris, France, October 2008.
 A. Fernández‐Canteli, E. Castillo, H. Pinto, and M. López‐Aenlle, “Estimating the S–N field from strain–lifetime curves,” Strain, vol. 47, pp. e93-e97, 2011. https://doi.org/10.1111/j.1475-1305.2008.00548.x
 A. M. De Jesus, H. Pinto, A. Fernández-Canteli, E. Castillo, and J. A. Correia, “Fatigue assessment of a riveted shear splice based on a probabilistic model,” International Journal of Fatigue, vol. 32, no. 2, pp. 453-462, 2010. https://doi.org/10.1016/j.ijfatigue.2009.09.004
 DNV GL Group. DNVGL-RP-C208: Determination of Structural Capacity by Non-linear finite element analysis Methods, 2016.
 F. Öztürk, J. Correia, C. Rebelo, A. De Jesus, and L. S. da Silva, “Fatigue assessment of steel half-pipes bolted connections using local approaches,” Procedia Structural Integrity, vol. 1, pp. 118-125, 2016. https://doi.org/10.1016/j.prostr.2016.02.017