Non-destructive characterisation of carbon-fibre-reinforced plastics by means of eddy-currents

The paper presents eddy-current methods for non-destructive testing and characterisation of CFRP. In order to understand eddy-current propagation in CFRP, a method has been developed to reconstruct current distribution in CFRP from the magnetic field. On the basis of these investigations, high-frequency eddy-current sensors have been developed to characterise CFRP non-destructively. Together with a mechanical scanner, the sensors can be used to evaluate both the structure and the flaws. The paper describes fibre orientation measurements with high angular resolution, tests on the homogeneity of the fibre distribution, steps in estimation of ageing, some fundamentals of testing for delamination, cracks and fibre fracture and the inspection of smart materials.