Identification of Inflow Fluid Dynamics Parameters That Can Be Used To Scale Fatigue Loading Spectra of Wind Turbine Structural Components

We have recently shown that the alternating load fatigue distributions measured at several locations on a wind turbine operating in a turbulent flow can be described by a mixture of at least three parametric statistical models. The rainflow cycle counting of the horizontal and vertical inflow components results in a similar mixture describing the cyclic content of the wind. We believe such adescription highlights the degree of nonGaussian characteristics of the flow. We present evidence that the severity of the low-cycle, high-amplitude alternating stress loads seen by wind turbine components are a direct consequence of the degree of departure from normality in the inflow.