Parametric study of the effect of wrinkle features on the strength of a tapered wind turbine blade sub-structure

Out of plane wrinkle defects are a major cause of strength reduction in structural composites. Therefore, this paper presents the numerical modelling of a wind turbine blade sub-structure with a tapered beam and a wrinkle. The model is validated against preliminary static tensile tests of a sub-structure without a wrinkle. There is a very good correlation between the predicted and experimentally obtained load at final delamination. A parametric study is then performed using the validated model to determine which wrinkle features are the most important to measure and include when determining the strength of a wrinkled wind turbine blade sub-structure. From the study, it is concluded that the maximum wrinkle angle is the most important feature, but the depth and wash out degree are also important under the right conditions.