Intrinsically conductive resin as a functional repair for ECF/CFRP against simulated lighting strike: An experimental study

Non-metallic coatings offer promising applications for protecting carbon fiber-reinforced plastics (CFRP) from lightning, preserving the strengths of epoxy-based composites without galvanic corrosion concerns. This study explores the electrically conductive polyaniline-based resin's dual role: as protective coating and repair solution for traditional ECF/CFRP lightning protection. We evaluated the impact of coating thickness and surface roughness on lightning resistance. A 0.4 mm thick coating with a 400-grit pretreatment demonstrated minimal damage after a -40 kA simulated lightning strike, maintaining 96 % residual strength. Central to this study was the resin's capability as a functional repair for the conventional ECF LSP system. When employed to repair the damaged ECF/CFRP panel, the resin showcased its efficacy by preserving more than 95 % of the system's residual strength even after a subsequent -20 kA lightning strike. These results indicate the proposed conductive resin could be a new practical repair approach for lightning strike damage to the conventional ECF layer.