Özet:

The aerodynamic loads of a wind turbine blade under complicated offshore wind conditions were analyzed using Davenport wind spectrum model, which represents the real working conditions closely. Finite element model of the blade was generated by using UG and ANSYS, and qualitative analysis and quantitative simulation were carried out to investigate the dynamic stability of the wind turbine blade. The numerical results indicate that the blade vibration diverges when the frequency of wind speed is close to the first-order natural frequency of the blade, which eventually leads to the occurrence of instability phenomena. It was also found that both waving amplitude and the maximum Mises stress of the blade increase nonlinearly with the average wind speed. However, the maximum Mises stress increases almost linearly with elastic modulus under vibration divergence. Finally, some characteristics for the critical values of the maximum Mises stress and the stable or/and unstable regions, due to variation of the elastic modulus and the horizontal distance between the blade and the tower frame, were further discussed.

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