Study of action integral affecting the direct effects of lightning strike on CFRP

Numerical simulation method is a simple but effective method in the study of the damage behavior of carbon fiber reinforced polymer (CFRP) caused by lightning strike. A method to evaluate the internal damage area of CFRP is developed in this paper by superposing the temperature field of each layer, and damage effects of two kinds of CFRPs caused by different types of lightning currents are investigated based on finite element method. The results show that action integral has a great affection on damage results, and the types of the lightning currents may slightly influence the propagation of the temperature along the thickness direction. Internal damage area will keep equal when the action integral of the lightning currents is the same.