Calculation of the Cross Sectional Properties of Large Wind Turbine Blades

Abstract

This paper presents a computational approach for the calculation of the mechanical properties of large wind turbine blades. The relation between the geometric discretization of anisotropic cross sections via line elements and the calculation of its mechanical properties is analyzed. The composite material theoretical background is based on a vector variant of the classical lamination theory embedded into a geometrically exact large deformation-small strain thin-walled beam formulation; transverse shear and out of plane warping are considered. The impact of the geometric reconstruction on the accuracy of the mechanical properties is studied using both rectangular and trapezoidal elements. It is shown that line based algorithms can give very accurate results provided the cross section geometry is well represented.