Effect of through-thickness electrical conductivity of CFRPs on lightning strike damages

Making carbon fiber reinforced plastics electrically conductive is an amended solution to the current lightning strike protection technology. However, optimization of the through-thickness electrical conductivity to meet a safety requirement of aircraft against lightning strikes remains unexplored. In this work, four carbon fiber reinforced plastics panels with different through-thickness electrical conductivity were fabricated using a polyaniline-based conductive resin. Their through-thickness electrical conductivity was tailored to achieve specific values using a controlled thermal treatment. The fabricated carbon fiber reinforced plastics panels were tested against a simulated lightning current of 40 kA, and the influence of through-thickness electrical properties on the performance of lightning strike protection was studied. Thermography data and ultrasonic non-destructive testing images confirmed least damage on the sample with higher electrical conductivity. Specimen with through-thickness electrical conductivity of around 110 S/m was able to retain about 92% of the residual flexural strength after the lightning test.