Modelling and inversion of carbon fibre composite structures using high-frequency eddy current imaging

The fibre tow structure of each unidirectional ply is modelled using orientation dependant 2D conductivity tensor waveforms, and virtual 2D ECT scans are simulated by shifting the waveforms within the model mesh. The results demonstrate that idealised electromagnetic characteristics of the CFRP structure can be successfully modelled compared with experimental data and that 2D ECT data of complex CFRP layers structures can be simulated with improved computational speeds, up to 5x faster compared to standard approaches. Automated data-analysis tools, including Radon transform (RT) and 2D FFT, are employed to validate the simulated 2D scan data through the characterisation of fibre orientations and simulated 2D scans used to evaluate the orientation inversion techniques. The results demonstrate that RT analysis detects fibre orientations with better accuracy, precision and consistency than equivalent 2D FFT analysis techniques.