[2A4] Factors affecting in-line eddy current testing of automated carbon fibre placement
Robert R. Hughes
CAME School of Engineering, University of Bristol, UK
Production rate is the most significant cost driver in composite manufacturing processes today, with inspection & rework comprising a large proportion of the manufacturing time. This is, in part, due to rudimentary and time-consuming inspection methods being used. While automated fibre placement (AFP) systems have advanced the reliability of layup processes, reducing inspection requirements, machine-laid components are still often inspected 100% manually. Monitoring component quality non-destructively during layup would significantly reduce the time spent inspecting parts and thereby greatly increase the production rate of composite components. Non-contact eddy-current testing (ECT) is one potential technique capable of achieving this aim without interfering with or contaminating the lay-up process. In this study, ECT methods and data-analysis techniques are evaluated in experimentally simulated AFP environments to explore the AFP manufacturing conditions may affect in-line monitoring of carbon-fibre layup quality. The study experimentally explores how sensitive ECT methods are to manufacturing errors and structural concerns, including; fibre volume fraction (FVF) and ply orientation, as well as how they respond to variations in AFP application conditions, such as applied pressure and temperature. The experimental results are examined, and recommendations made for the application and analysis of ECT methods for in-line monitoring of AFP composites.
