Fatigue Assessment of Eccentrically Loaded Flange Connections in Wind Energy Turbines

Tubular steel towers of wind turbines are fatigue loaded structures that are exposed to time-variant stresses because of turbine operation. A critical point within the tower structure are the ring flange connections, which connect the individual tower sections with preloaded bolts. This article publishes two procedures for verifying the fatigue safety of bolts in ring flange connections with the help of experimental und numerical investigations under consideration of bending effects. The authors point out the problem on the basis of experimental and numerical investigations and give recommendations for future flange design.