I-V characteristics and temperature response of unidirectional CFRP exposed to simulated lightning current in the fiber direction

This study examined the I-V characteristics and temperature response of unidirectional CFRP exposed to simulated lightning current by performing direct electrical conduction tests that could minimize the effects of thermal flux from the arc root, complex arc behavior, and shock wave. A numerical analysis was carried out to clarify the heating mechanisms. The results show that the electrical conductivity of unidirectional CFRP in the fiber direction under impulse current tests is almost identical to that measured in the steady-state and becomes constant during lightning current increasing. Cross-sectional observation of the specimen revealed that matrix cracks and delamination occurred in the temperature range where the CFRP thermal decomposition occurred. In addition, it was necessary to consider the formation energy of the pyrolysis gas to estimate the temperature response, which was estimated to be approximately 2.163 x 10(7) J/kg for the toughened epoxy CFRP.

Automated summary

This study investigated the electrical and temperature response of unidirectional CFRP under simulated lightning current. The results showed that the electrical conductivity remained constant during lightning current increasing and matrix cracks and delamination occurred in a certain temperature range. It was also necessary to consider the formation energy of pyrolysis gas to estimate the temperature response.