Influence of Grounding Modes on the Damage of Carbon Fiber Reinforced Plastics subjected to Lightning Strikes

Simulated lightning first return stroke currents (A component) were used to conduct lightning strike tests on CFRP samples with six different grounding modes. Visual inspection, optical microscope and scanning acoustic microscope were used to observe the top surface damage, internal damage and delamination of the tested samples. The analysis shows that the top surface damaged morphologies of the composites are similar under different grounding modes, but the damaged lengths have an obvious difference in different directions. Under the same grounding modes, whether the bottom surface of the samples is grounded or not, the internal damages are close to each other. The internal damages under the left-right-side-grounding, four-side-grounding and upper-down-side-grounding modes are different.