Comparison of wind turbine blade structural models of different levels of complexity against experimental data

As the design process of a wind turbine blade is highly iterative, one needs to perform the same calculations several times. During that process, the kind of structural model that should be used must be chosen carefully, trying to obtain a good compromise between precision and model setup and computational time. This paper compares four different blade structural models having different levels of complexity. These models are compared to each other and also with experimental results with respect to their abilities to analyze blade cross-sectional properties, natural frequencies, deflection, strains, buckling strength, and composite strength. This comparison shows that even if the 3D shell finite element model is the more precise and is the only one that can manage the regions of the blade where the cross-sectional shape changes quickly, the strength of material based models gives accurate results. Even the simpler model, based on blade shape simplification, gives conservative and accurate results at a very low computational cost.