PSI - Issue 38

Hendrik Bissing et al. / Procedia Structural Integrity 38 (2022) 372–381 Hendrik Bissing, Markus Knobloch, Marion Rauch / Structural Integrity Procedia 00 (2021) 000 – 000

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3. Conclusion This paper has presented the application of the TSM with the purpose of providing a more reliable fatigue life assessment method for wind turbine supporting structures. The TSM has been proven valid for fatigue assessment by a Monte-Carlo simulation that provides a random superposition of crack initiation and crack propagation life. Probabilistic distributions for material and geometry inputs that either originate from experimental tests or literature have been compiled and the influence of these parameters is analysed for each submodel. From the results illustrated in this paper, the following general conclusions and recommendations for future research in this field can be derived: • The impact of single parameters for the submodels can be assessed in a quality manner and also quantified depending on their probabilistic distribution. • The scatter of some input parameters, e.g. the stress concentration factor K t , is of major importance within the TSM, whereas other input parameters, e.g. hardening coefficient K’, do not influence the fatigue service life significantly. • The TSM is a multi-parameter concept that provides realistic results for the notch case ‘ butt weld ’ . • The TSM presents a concept that facilitates an efficient use of the material enabling cost efficient energy production by onshore wind turbines. 4. Acknowledgements The research is supported and funded by the German Federation of Industrial Research Associations “Otto von Guericke” e.V. (AiF) and the Research Association for Steel Application FOSTA (IGF -No. 20987 N), which is gratefully acknowledged. The authors also thank SEH Engineering for providing the test specimens, and Siemens Gamesa Renewable Energy for providing FE calculations of the stress concentration factor K t . References Bissing, H.; Knobloch, M.; Rauch, M. (2021). Improving economic efficiency of wind energy using data-based fatigue assessment methods. In: IABSE Congress Ghent 2021 - Structural Engineering for Future Societal Needs. Coffin, L. F.; Tavernelli, J. F. (1959). The cyclic straining and fatigue of metals. In: Trans. Metall. Soc. (215), pp. 794 – 807. Deutscher Stahlbau-Verband (1996): Stahlbau-Handbuch. Für Studium und Praxis; in zwei Bänden. 3., neu bearb. Aufl. Köln: Stahlbau-Verl.-Ges. Deutsches Institut für Bautechnik (2012): Richtlinie für Windenergieanlagen – Einwirkungen und Standsicherheitsnachweise für Turm und Gründung. Schriften des Deutschen Instituts für Bautechnik, Reihe B, Heft 8, Fassung Oktober 2012. EN 1993-1-9:2012. DIN EN 1993-1-9/NA: 12/2010: Eurocode 3: Bemessung und Konstruktion von Stahlbauten – Teil 1-9: Ermüdung". Forman, R. G.; Kearney, V. E.; Engle, R. M. (1967). Numerical Analysis of Crack Propagation in Cyclic-Loaded Structures. In: J. Basic Engineering 89 (3), pp. 459 – 463. DOI: 10.1115/1.3609637. Joint Committee on Structural Safety JCSS, (2002). PROBABILISTIC MODEL CODE. Available online at https://www.jcss - lc.org/publications/jcsspmc/part_iii.pdf, checked on 09.06.2021. Manson, S. S. (1960). Cyclic life of ductile materials. In: Thermal Stresses in Design, pp. 139 – 144. Mettu, S.; Shivakumar, V.; Beek, J.; Yeh, F.; Williams, L.; Forman, R. et al. (1999). NASGRO 3.0: A software for analyzing ag ing aircraft. Morrow, J. D. (1965). Cyclic plastic strain energy and fatigue of metals. In: ASTM STP 378, pp. 45 – 87. Newman, J.C., Jr.; Raju, S. (1981). AN EMPIRICAL STRESS-INTENSITY FACTOR EQUATION FOR THE SURFACE CRACK. In: Engineering Fracture Mechanics 15 (No. 1-2), pp. 185 – 192. Olivier, R.; Ritter, W. (1979). Wöhlerlinienkatalog für Schweißverbindungen aus Baustählen. Teil 1: Stumpfstoß. Deutscher Verlag für Schweißtechnik. Düsseldorf (DVS Berichte, Band 56/I) (Ed.). Pachoud, A. J.; Manso, P. A.; Schleiss, A. J. (2017): New parametric equations to estimate notch stress concentration factors at butt welded joints modeling the weld profile with splines. In: Engineering Failure Analysis 72, pp. 11 – 24. DOI: 10.1016/j.engfailanal.2016.11.006. Paris, P.; Erdogan, F. (1963). A Critical Analysis of Crack Propagation Laws. In: J. Basic Engineering 85 (4), pp. 528. DOI: 10.1115/1.3656900. prEN 1993-1-1:2019. CEN/TC 250: Eurocode 3 - Design of steel structures - Part 1-1: General rules and rules for buildings. Ramberg, W.; Osgood, W. R. (1943). Description of stress – strain curves by three parameters. In: NACA Techn. Rep. 902. Röscher, S.; Knobloch, M. (2019). TWO‐STAGE‐MODEL FOR THE PROGNOSIS OF FATIGUE LIFE: APPLICATION TO BUTT WELDS. In: ce/papers 3 (3-4), pp. 597 – 602. DOI: 10.1002/cepa.1106.