Modeling the structural dynamics of horizontal axis wind turbine

As the horizontal axis wind turbines are getting larger, their dynamic behavior is becoming more important. Dynamic analysis gives a knowledge how to improve efficiency and safety also in small wind turbines. This article describes FEM model of upwind, three-bladed wind turbine. Geometry of each component Is generated separately and then assembled together by transformation matrices. Material of the blades is composite, the tower is assumed to be made of steel. The blades are modeled by shell elements. The model takes into account aerodynamic load of blades and tower, inertia forces due to rotation of the rotor. The aerodynamic loads, calculated according to the modified Blade Element Momentum theory are attached to aerodynamic centers. The model is ready to be used in transient analysis and also for investigation of material and geometric modification. The transient analysis contains calculation of deflection and stress distribution in the wind turbine.