Statistical analysis of manufacturing defects on fatigue life of wind turbine casted Component

Hesam Mirzaei Rafsanjani, John Dalsgaard Sørensen, Krishnendu Mukherjee, Søren Fæster, Asger Sturlason

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Wind turbine components experience heavily variable loads during its lifetime and fatigue failure is a main failure mode of casted components during their design working life. The fatigue life is highly dependent on the microstructure (grain size and graphite form and size), number, type, location and size of defects in the casted components and is therefore rather uncertain and needs to be described by stochastic models. Uncertainties related to such defects influence prediction of the fatigue strengths and are therefore important in modelling and assessment of the reliability of wind turbine components. The defect distribution is usually affected by the manufacturing process. In this paper, two methods of casting, sand casting and chill casting are considered. These are compared in statistical analyses of a large number of representative test samples using two basic stochastic models for the fatigue life, namely LogNormal and Weibull distributions. The statistical analyses are performed using the Maximum Likelihood Method and the statistical uncertainty is estimated. Further, stochastic models for the fatigue life obtained from the statistical analyses are used for illustration to assess the reliability of a representative component in an offshore wind turbine.
Original languageEnglish
Title of host publicationProceedings of International Conference on Safety & Reliability of Ships, Offshore & Subsea Structures 2014
Number of pages6
PublisherASRANet Ltd.
Publication date2014
ISBN (Electronic)978-0-9553550-9-7
Publication statusPublished - 2014
EventInternational Conference on Safety & Reliability of Ships, Offshore & Subsea Structures - Glasgow, United Kingdom
Duration: 18 Aug 201420 Aug 2014


ConferenceInternational Conference on Safety & Reliability of Ships, Offshore & Subsea Structures
CountryUnited Kingdom

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