Delamination Detection in Composite T-Joints of Wind Turbine Blades using Microwaves

The wind turbine is playing an increasingly important role in the generation of green electricity. The structural integrity and maintenance of the wind turbine blade is a critical issue in service due to the harsh operating environments. In this paper, the delamination in glass fibre composite joints of a wind turbine blade is detected using the non-contact microwave imaging with an open-ended waveguide. The existence and extent of the delaminated region could be found from the generated images. Thickness variation and the presence of the web can be identified as well. The optimum inspection frequency range is investigated, which offers a reference for future applications. By comparison, the phase profiling provided by the scanning shows better performance for the delamination detection rather than the magnitude profiling.