Static Response of Beam-Like Structures for the Analysis of Wind Turbine Blades With Different Levels of Fidelity

Beam models are often used to represent wind turbine blades in aeroelastic simulation tools. With the development of longer and more flexible blades, larger deflections are experienced, making it essential to re-assess the accuracy of such models on a regular basis. In this study, the static response of beam-like structures containing key geometric characteristics of wind turbine blades (taper, twist and initial curvature) is computed by different numerical models, to compare the accuracy of the beam model in the aeroelastic tool HAWC2 against high-fidelity three-dimensional finite element models. It is concluded that the beam model can calculate accurate results for anisotropic structures of linearly varying properties undergoing large deflections. Relative differences up to 10% in maximum tip displacement and twist angle are observed and can be explained by inaccuracies in the calculation of cross-sectional properties and cross-sectional deformation (e.g., the Brazier effect).