Improving the Fatigue Strength of Butt Welds in the As-Welded and Grit-Blasted Condition for Steel Towers of Wind Turbines

Butt welds are one of the most common structural details in wind turbine steel towers. In this paper, results from fatigue tests on butt welds in the as-welded and grit-blasted conditions are presented. In addition, finite element analyses were performed using the effective notch stress and the crack propagation approaches. By using macroscopic measurements and three-dimensional scan, the notch effect of the weld seam was considered. These results were compared with results from fatigue tests. On the basis of a successful alignment between simulation and experiment, the possibility to discuss the fatigue resistance influencing variables from the seam geometry is presented.