3D monitoring of delamination growth in a wind turbine blade composite using optical coherence tomography

• An OCT system was designed for the characterization of glass fiber composite.
• The microstructure and the delamination within the composite were revealed.
• 3D crack surfaces during delamination growth were displayed.
• Crack jump was observed during delamination growth in the composite specimen.

In this paper, delamination and delamination growth in a glass fiber composite used for the spar webs in wind turbine blades is investigated by optical coherence tomography (OCT). The cross-sectional and volumetric images clearly showed the microstructure and the crack within the specimen. After applying an optimized signal processing algorithm, 3D crack growth measured using OCT were demonstrated for the first time to the best of our knowledge. The crack structures inside the composite material at different stages during the delamination growth were revealed.