Wind turbine rotor blade full-scale tests typically utilize plywood load frames to introduce forces normal to the length of the blade. Plywood frames are low cost and easily milled to the unique profile of a rotor blade. A sub-component test supplements full-scale tests by focusing on a region exposed to specific loading scenarios. However, these tests require an alternative load introduction frame, capable of introducing both axial forces and bending moments. There- fore, novel plywood/steel load frames were designed and glued to the fiber reinforced polymer structure of the blade. The axial loads are thus transferred via a shear-loaded adhesive layer. The paper describes the integrity analysis using the design resistance from a representative experiment and taking into account thermal residual stress. The design model was finally validated in a non-destructive blade sub-component experiment using an acoustic emission system.

We acknowledge the support provided by the European Commission's Seventh Framework Programme within the IRPWind project (609795), the Future Concept Fatigue Strength of Rotor Blades project granted by the German Federal Ministry for Economic Affairs and Energy (BMWi) (0325939) and the Senator for Health, Environment and Consumer Protection of the Free Hanseatic City of Bremen within the ERDF programme Bremen 2014-2020 (201/PF IWES Zukunftskonzept Betriebsfestigkeit Rotorblätter Phase I), and the SmartBlades2 project granted by the BMWi (0324032B). Moreover, we would like to thank SSP Technology A/S for providing the wind turbine blade model and the blade specimen for this research.