Wind turbine blades are susceptible to damage due to fatigue as well as impact by flying objects and parts broken off failed blades of nearby wind towers. Localized, permanent compression of the foam core and delamination of the fibrous composite face sheets are typical damage modes and can lead to progressive structural failure. Sandwich structures modified by inclusion of flexible polyurethane (PU) layers within the cross section are examined under both impact and dynamic loads. Finite element models of sandwich structures with conventional and modified designs show that sandwich designs modified with PU interlayes exhibit reduced foam core crushing and the associated overall energy dissipation.
Bahei-El-Din, Yehia; Shazly, Mostafa; El-Habbal, I.; and Elbahy, Y., "Modified sandwich structures for improved impact resistance of wind turbine blades" (2010). Centre for Advanced Materials. 10.