Calculation of effective section stiffness properties for wind turbine blades using homogenization



The structural behavior of wind turbine blades can be accurately modeled using beam models. The accuracy in the predictions using beam models depends on the degree of accuracy in the prediction of the effective section properties. A simple and efficient method compared with full 3D analysis is developed for the prediction of effective section properties for prismatic slender members of any arbitrary cross-section shape. The technique, which is based on the superposition principle, is developed to include the shear deformation modes in predicting the effective stiffness properties. A homogenization scheme based on strain energy equivalence is employed for calculating the effective properties. The method can accurately predict the full stiffness matrix including the off-diagonal terms. Also a procedure for finding the locations of the weighted centroid and the shear center is presented. The results for four different cross-section shapes including a wind turbine blade section are validated using an existing analysis technique, Variational Asymptotic Beam Sectional Analysis. Copyright © 2012 John Wiley & Sons, Ltd.