This paper develops a full structural model of a horizontal axis wind turbine, including three blades, a rigid hub, a tubular tower and a rigid nacelle using beam finite element approach. The beam element model is linear with 14 DOF and arbitrary cross section that considers the rotational velocity, shear center, warping and gyroscopic effects, stiffening due to the rotation and all the structural couplings which has been already developed by the same authors and here is modified to include the transverse shear and concentrated mass effects. The blade and the tower properties are considered to be variable along each element to reduce the model size and hence the running time. Another model of the same turbine by shell elements is created in ABAQUS. To validate the accuracy of the proposed model the natural frequencies, mode shapes and the frequency and dynamic responses of the model are extracted and compared with ABAQUS results. In addition, the effects of the rotor speed and the blade pitch angle on the modal properties of the turbine are studied.

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