The handout provides an overview of the topics modelling of hub blade connection and determination of stress life curves for spheroidal cast iron.
The question of how to model the bearing in the intersection between the blade and the hub is one topic, which is often discussed. The performed investigation comprises different approaches from direct connection (glued), to compression only support realized with different elements until high end bearing discretization approaches. The way of modelling the bearing can have a significant influence on the results of the calculation. Several investigations have been performed of commonly used modelling techniques and the results are explained.
The synthetic concept is one of the most used concepts in the wind energy industry to determine material design curves for ductile cast iron. Another and more precise approach is the determination of a S/N curve by material test samples, which are extracted from a typical component. Several investigations have been performed for spheroidal cast iron (EN-GJS-400-18U-LT and EN-GJS-700-2 and modifications). The procedure is described and results are explained.