Abstract: Aramid fiber has good electrothermal insulation and flame retardant properties. In this paper, aramid fiber fabric was used as the isolation layer between metal copper mesh and carbon fiber composite laminates and three kinds of composite laminates with structure of non-aramid fiber, a layer of aramid fiber and two layers of aramid fiber were prepared. The lightning protection efficiency of composite laminates containing aramid fiber under the action of lightning current C and D waves and the influence of aramid fiber thickness on the lightning protection efficiency of composite laminates were analyzed. At the meantime, the lightning protection mechanism of aramid fiber fabric as isolation layer was discussed. The results show that under the action of lightning current C-wave and D-wave, the area damage of the first layer of carbon fiber with a layer of aramid fiber is reduced by 69.1% and 78.9% respectively and the depth damage is reduced by 72.2% and 68.8% respectively. The carbon fiber laminates containing two layers of aramid fiber have no lightning damage. It is proved that the aramid fiber can effectively resist the current flowing in the direction of thickness, reducing the current density and the lightning ablation damage of the CFRP laminates greatly. This study provides a strong support for the later design of aircraft lightning protection structure.

Key words: aramid fiber, CFRP laminates, lightning damage, lightning protection