Impact of resin-rich layer on the through-thickness resistivity of carbon fiber reinforced polymers

Increasing applications of carbon fiber reinforced polymers exploiting its electrical properties demand a good understanding of the electrical conduction mechanisms of carbon fiber reinforced polymer. Resin-rich interface, which is not uncommon to exist between composite laminae, not only affect the mechanical properties, but also the electrical conduction behavior. This study focuses on the impact of resin-rich layer on the through-thickness resistivity of carbon fiber reinforced polymer. Electrical characterizations are carried out on dry fiber tow systems as well as cured composites. Through-thickness resistivity changes of dry fibers with the sizing are compared against fibers without the sizing layer, and cured composites with added resin-rich layer against the composite laminates without the resin-rich layer. A localized Joule heating theory is proposed to explain the difference in the electrical responses. The theoretical and experimental investigations should prove useful for the development of quantitative models with Joule heating to describe electrical resistivity behavior of carbon fiber reinforced polymer.