[3A2] Eddy current directional probe optimisation for in-line monitoring of automated fibre production
M Mussatayev, Q Yi, M Fitzgerald, P Wilcox and R Hughes
University of Bristol, UK
Automated fibre production (AFP) helps to increase the production rates of carbon fibre-reinforced plastics (CFRPs). However, the in-line inspection of the AFP remains a challenge in the non-destructive evaluation (NDE) field. This research investigates a directional eddy current probe developed and tested for in-line detection of common AFP composite prepreg defects such as in-plane (waviness) and out-of-plane (wrinkles). The initial studies were conducted to identify the ideal directional transmit and differential receiver eddy current testing (ECT) sensor configurations for the detection of out-of-plane wrinkling in cured carbon fibre composites. The response of the developed ECT sensor was different to cured and uncured carbon fibre composite materials. Thus, the main part of the research comprises information from several studies by changing the main design parameters of the proposed EC system, namely pickup coil dimensions (aspect ratio), the relative angle between two pickup coils and the excitation frequency, to redesign the probe to be sensitive to fibre orientation. The obtained results demonstrated a novel method for designing in-line ECT monitoring sensors for wrinkle detection in CFRP manufacturing.
