Assembly strategies of wind turbine towers for minimum fatigue damage

The aim of this paper is to present a method to obtain the dynamic response of a wind turbine tower in time domain by means of the generation of time series and to estimate the associated fatigue damage by means of a Rainflow counting algorithm. The proposed method is based on assuming the vortex shedding is a bidimensional phenomena and on following a classical modal superposition method to obtain the structure dynamic response. Four dierent wind turbine tower geometric congurations have been analyzed in a range of usual wind velocities and covering extreme wind velocities. The obtained results have shown that, depending on the turbulence intensity and the mean wind velocity, there are tower geometric congurations more advantageous from the fatigue load standpoint. Consequently, the presented model can be utilized to dene assembly strategies oriented to fatigue damage minimization.