Comparative analysis of nonlinear dynamic response for offshore wind turbine structures under incoming wind speed.

Taking NREL 5 MW large offshore wind turbine as a research object, a theoretical model considering geometrical nonlinearity is established, and the dynamic response analysis is carried out. Besides, the blade scaled model is processed and used in the wind tunnel test. The numerical results show that the response values of displacement and Mises stress for the blade, as well as the increment of displacement and stress for each blade section, rise nonlinearly with the equal amplitude of incoming wind speed, regardless of the single-blade model or the whole machine model. The inter-structure coupling effect is more obvious with the increase in income wind speed. The difference of maximum blade displacement between two models first decreases and then increases along the wing span direction. Furthermore, the difference of Mises stress increases gradually with the same increment in incoming wind speed and decreases nonlinearly from the middle to both sides. [ABSTRACT FROM AUTHOR]