A method for inductive measurement of equivalent electrical conductivity in thin non-consolidated multilayer carbon fibre fabrics

Carbon fibre fabrics are electrically conductive and therefore possess the prerequisites for being inductively heated. In-situ heating by induction could significantly reduce processing time and energy consumption during consolidation of carbon fibre composites, but to control the induction heating process properly the electrical conductivity of the fabric must be known. The work presented in this article puts forward and validates a method for inductively measuring the equivalent electrical conductivity in thin dry multilayer carbon fibre fabrics as a function of the fibre volume fraction by varying the applied pressure on the fabric. The method has been tested on twill weave fabric based on the PAN (polyacrylonitrile) fibre T700S from Toray and the results show good agreement with a simplified model for electrical conductivity in carbon fibre fabrics and existing models for the relation between fibre volume fraction and pressure.