Subcomponent testing: Trailing edge

Sub-component testing of a trailing edge segments which were cutout from a rotor blade of a wind turbine has been demonstrated to successfully work under static compression, e.g., buckling. However, the actual and representative loading a blade is subjected to in field is a cyclic tension-compression or tension-tension load depending on the position along the blade span. This loading can provoke the initiation of tunneling cracks in the adhesive layer. To this end, this work presents a new load frame design for a sub component test capable to withstand these loads. The frame successfully resisted  load spectra of about 2.9 Mio. cycles while step-wise increasing the maximum strain up to 3,000 μm/m at a test frequency of 3 Hz. No significant damage was observed.