Effectively Reduced Damages with Increased Through-thickness Electrical Conductivity of CFRPs Against Artificial Lighting Strike

Abstract

Most common method to make Carbon Fabric Reinforced Plastics (CFRPs) electrical conductive is to add conductive fillers, but how much through planeelectrical conductivity is needed to be safe against lightning strikes has not been investigated yet. In this work, three Carbon Fabric Reinforced Plastics (CFRPs) panels with 0.8, 0.56 and 0.17 S/cm Through-thickness electrical conductivity respectively are prepared using a conductive polymer-based conductive resin. Thermal degradation and de-doping of the conductive polymer were capitalized to design the composite panels with various electrical conductivities. Prepared CFRP panels were tested against simulated lightning current of 40 kA. The effect of the Through-thickness electrical properties on the effectiveness against lightning strike is characterized using various techniques. The most severe damage after lightning strike usually occur due to the rapid increase in the temperature due to Joule’s effect. This suggest that the damage behavior of the CFRP panels are highly dependent on the orthotropic electrical conductive nature of the specimen. By increasing the through-thickness electrical conductivity, orthotropic behavior of CFRPs are tried to mitigate. A thermography camera was used to observe the temperature profile on the surface of the samples at the time of impulse current arc attachment to the samples. Least rise in temperature was observed with high through-thickness electrical conductivity samples. Ultrasonic non-destructive testing images confirmed the least damage to sample with electrical conductivity of 0.8 S/cm.