碳纤维复合材料电导率改性与抗雷击性能

传统碳纤维复合材料(CFRP)中的树脂基体电阻率大,在强电流下会产生大量阻性热从而造成损伤,增强其电导率能够有效提高CFRP的雷击防护性能。在树脂基体中添加银粉颗粒进行电导率改性,通过有限元仿真分析银粉含量对雷击防护性能影响,确定CFRP基体中的最佳银粉含量为38%。沿厚度方向电导率的改性效果最佳,提高了217.3倍。使用不同峰值的D波形雷电流对改性CFRP层压板进行模拟雷击实验,并对未改性以及表面铺设铜网的层压板进行相同能级的对照实验,通过目视损伤观察和透视超声扫描比较损伤特征和损伤面积,评估基体改性CFRP的抗雷击性能。结果表明:基体改性可以阻碍表面铺层被击穿,降低纤维断裂翘曲以及分层损伤;峰值电流20 kA、40 kA和60 kA下,铜网防护能使雷击透视损伤面积分别下降100%、86.61%和37.46%,基体改性整体防护能使雷击透视损伤面积分别下降84.02%、81.03%和40.91%。

Electrical conductivity modification and lightning resistance of carbon fiber composites

The resin matrix of traditional carbon fiber composite(CFRP)has a high resistivity,which produces a lot of resistance heat and causes damage under the strong current.Strengthening its conductivity can effectively improve the lightning protection performance of CFRP.The particles of the silver powder were added to the resin matrix for conductivity modification,and the influence of silver powder content on lightning protection performance was analyzed by finite element simulation.The optimum content of silver powder in CFRP matrix was determined to be 38%.The conductivity modification effect along the thickness direction was the best,which was improved by 217.3 times.Simulated lightning strikes test was carried out on the modified CFRP laminates with different peak lightning currents of D waveform,and unmodified laminates and the laminates with copper wire mesh on the surface were compared at the same energy level.The damage characteristics and damage area were compared by visual damage observation and perspective ultrasonic scanning to evaluate the lightning resistance of the matrix modified CFRP.The results show that the matrix modification can prevent the surface layer from breakdown and reduce the fiber fracture warping and lamination damage.Under the peak current of 20 kA,40 kA and 60 kA,the copper wire mesh protection can reduce the lightning damage area by 100%,86.61%and 37.46%,and the matrix modified overall protection can reduce the lightning damage area by 84.02%,81.03%and 40.91%respectively.