Modelling the electrical behaviour of carbon/epoxy composites and monitoring changes in their microstructure during oven and autoclave curing using electrical impedancemetry
Résumé
Developing technical means in the aim to monitoring the state and the microstructural changes in high performances composite parts during their manufacturing has aroused the interest of several researchers and companies. Here it is proposed to use the composite laminated part itself as a sensor of the changes occurring in its own microstructure during curing owing to electrical impedancemetry. A new and detailed modelling of 3D electrical behaviour of unidirectional (U.D.) carbon/epoxy composite is settled considering inter-plies and intra-plies conduction. Electrical impedance (Z) measurement performed on composites laminates during their curing enabled a full characterisation of a U.D. single ply as well as an 8 plies laminate. Changes recorded in Z are next successfully correlated to composite thermoset matrix viscosity, gelation and vitrification showing thus the power of impedancemetry.