A Comparative Analysis of Carbon Fiber–Reinforced Polymers Subjected to Lightning Damage Tests with Conical Electrodes and Jet Diverting Electrodes

The results in the damage testing of carbon fiber–reinforced polymers (CFRPs) subjected to simulated lightning strikes are affected by the type of discharge electrodes employed in the laboratory. In this work, two kinds of discharge electrodes, a conical electrode and a jet diverting electrode, were discussed for use in the CFRP-lightning strike testing. The CFRP damage responses to different electrodes were characterized and compared in terms of surface damage area, internal delamination, temperature distribution, pressure distribution, high-temperature gas expansion, and residual flexural strength. The electric arc formed by the conical electrode was more concentrated than that under the jet diverting electrode configuration, thereby producing a smaller surface and internal damage area but a deeper damage depth. The residual mechanical properties of CFRPs tested with the conical electrode decreased significantly under lightning strikes. The discharge channel was uncontrollable by utilizing the jet diverting electrode, and the test results were more dispersed than the results under the conical electrode, which was not conducive to the damage analysis or the repetition of testing. Therefore, the conical electrode is recommended in CFRP-lightning damage testing.