Efficient Beam-Type Structural Modeling of Rotor Blades

The present paper presents two recently developed numerical formulations which enable accurate representation of the static and dynamic behaviour of wind turbine rotor blades using little modeling and computational effort. The first development consists of an intuitive method to extract fully coupled six by six cross-section stiffness matrices with limited meshing effort. Secondly, an equilibrium based beam element accepting directly the stiffness matrices and accounting for large variations in geometry and material along the blade is presented. The novel design tools are illustrated by application to a composite section with bend-twist coupling and a real wind turbine blade.