Toft, Henrik Stensgaard1; Sørensen, John Dalsgaard1
Michael H. Faber, Koehler Jochen, Kazuyoshi Nishijima
1 Department of Civil Engineering, The Faculty of Engineering and Science, Aalborg University, VBN2 Division of Structural Mechanics, The Faculty of Engineering and Science, Aalborg University, VBN3 Research Group of Wind Turbines, The Faculty of Engineering and Science, Aalborg University, VBN4 The Faculty of Engineering and Science (ENG), Aalborg University, VBN
In the present paper a probabilistic design approach to fatigue design of wind turbine blades is presented. The physical uncertainty on the fatigue strength for composite material is estimated using public available fatigue tests. Further, the model uncertainty on Miner rule for damage accumulation is also estimated based on test results. The results show that Miners rule gives a non-conservative estimate on the accumulated damage at failure. The reliability of a wind turbine blade is estimated for both out-of-plane and in-plane loading using three different design standards. The estimated annual reliability index is in general slightly higher than the target reliability implicitly used in IEC 61400–1. However, the reliability varies significantly between different load cases if a simple constant life diagram is used for representing the fatigue strength.
Icasp11 : Proceedings of the 11th International Conference on Applications of Statistics and Probability in Civil Engineering: Zurich, Switzerland, 1 - 4 August 2011, 2011, p. 1185-1192