Fatigue life distribution and size effect in ductile cast iron for wind turbine components

The present paper deals with the experimental determination and statistical analysis of high cycle fatigue properties of EN-GJS-400-18-LT ductile cast iron. Constant amplitude axial fatigue tests were performed at room temperature at R = 0 and R = −1. In order to evaluate the size effect, fatigue tests were carried out on two sets of specimens with different dimensions. The specimen diameters were 21 mm and 50 mm. Statistical analysis of fatigue data was done by means of the Weibull distribution, and P– S– N diagrams were established. The established P– S– N diagrams showed that the Weibull distribution is well fit to the scatter of the experimentally obtained fatigue life data. Weibull’s weakest-link method was used to evaluate the size effect. It made a satisfactory prediction of the fatigue strength for specimens with different dimensions.