A coupled aeroelastic damage progression model for wind turbine blades

The prediction of damage progression in composite wind turbine blades, especially under dynamic aeroelastic conditions, is usually a cumbersome multi-step process with significant manual user intervention. In this paper a novel approach is presented where the different components of this process – dynamical structural analysis under varying aerodynamic and deterministic loads, and damage progression – are integrated into one reduced-order model capable of predicting the occurrence and progression of damage in real time. Key to this integration is the use of an effective one-dimensional model of the turbine blade known as thin-wall beam model, which allows for the reconstruction of a three-dimensional stress field of a volume given by the blade. This stress field can then be used to assess damage and locally modify the structural properties to account for the presence of damage, leading to a reduced load carrying capacity. The model was previously tested in its components, demonstrating a good agreement of the predicted structural and static damage progression behaviour compared to detailed high-order finite-element models of the same blade. Once validated, the model was applied to severe load cases and the potential for real-time predictions of damage progression was demonstrated.