Damage behavior of CFRP subjected to simulated lightning current under air, reduced-pressure air, and N2 environments

This study examined lightning strike damage behaviors of carbon fiber reinforced plastic (CFRP) laminates under air (0.1 MPa), reduced-pressure air (0.02 MPa), and N-2 (0.1 MPa) environments to elucidate the effects of atmospheric environments on lightning damage. Simulated lightning current in accordance with SAE-ARP 5412B was applied to each specimen. The maximum current peak value was defined as 40 kA. CFRP laminates under reduced-pressure air (0.02 MPa) exhibited slight damage compared with that under atmospheric-pressure air. By contrast, CFRP laminates under N-2 sustained considerably more damage than under air (0.1 MPa). High-speed observations revealed that the atmospheric gas and pressure affect the arc root behavior. Finite element analysis was conducted based on experimentally obtained results to model lightning strike damage. The arc root length captured using a high-speed camera was incorporated into the analytical model. Numerical analysis results showed good correspondence with experimentally obtained results. These experimental and analytical results indicate that arc root behavior strongly affects lightning strike damage.