Wind turbine rotor blade full-scale tests 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 upgraded load introduction frame capable of introducing axial forces and bending moments. To develop such a frame structure, a generic small-scale load introduction frame was designed and proved as a concept in this work. The specimen was a double-lap shear adhesive joint bonding a glass fiber reinforced polymer composite, representing the blade, to plywood, representing the frame, tested under uni-axial tension. The bond line of the specimen was modeled analytically and numerically. A digital image correlation system recorded the experimental full-field strain. Furthermore, a validation of the models was performed.

The authors acknowledge the support provided by the German Federal Ministry for Economic Affairs and Energy (BMWi) (0325939) as a part of the Future Concept Fatigue Strength of Rotor Blades project and by the Senator for Health, Environment and Consumer Protection of the Free Hanseatic City of Bremen within the ERDF program Bremen 2014-2020 (201/PF_IWES_Zukunftskonzept_Betriebsfestigkeit_Rotorblätter_Phase_I).