冲击电流作用下碳纤维复合材料的导电特性

摘要

针对碳纤维复合材料(CFRP)在航空航天领域应用时的雷电损伤机理以及无损检测的问题,建立了CFRP非破坏性冲击动态伏安特性测试平台,对碳纤维复合材料的动态伏安特性的测量方法进行了研究.通过对流经CFRP上动态电流以及两端动态电压的测试,研究CFRP在非破坏脉冲电流作用下的动态伏安特性.研究发现:冲击电流的幅值、波形以及测量电极均会对CFRP的动态伏安特性产生比较明显的影响.随着冲击电流幅值的增加,CFRP的动态伏安特性曲线在电流上升阶段出现明显的向上偏移;在电流下降阶段,其所对应的动态伏安特性曲线会向下偏移直至趋于重合.当施加在CFRP上的冲击电流的持续时间变长时,明显看出CFRP的动态伏安特性上升阶段和下降阶段所包围的区域逐渐减小.当测量电极尺寸增加时,流过CFRP上的动态电流幅值增大了15％,其动态伏安特性曲线会逐渐向下移动,且随着冲击电流幅值增加,不同测量电极所时应的伏安特性曲线逐渐接近.研究结果为碳纤维复合材料在雷电直接作用时其导电行为以及损坏机理的研究提供了一定的实验基础与理论依据,为碳纤维复合材料的无损检测提供了新的实验思路.%A dynamic volt-ampere characteristic test platform of CFRP is established and the dynamic volt-ampere characteristic measurement method of carbon fiber composite is studied to solve the problem of lightning damage mechanism and non-destructive testing of carbon fiber reinforced polymer (CFRP) in aerospace applications.The dynamic voltammetry behavior of CFRP under non-destructive pulsed current is studied by testing the dynamic current flowing through CFRP and the dynamic voltage at both ends.It is found that the amplitude,waveform of impact current and measurement electrode have significant effects on the dynamic voltammetry behavior of CFRP.With the amplitude of impact current increasing,the dynamic voltammetry characteristic curve of CFRP shows a significant upward shift in the current rise phase;the dynamic amplitude of the dynamic voltammetry curve will shift downward until it tends to overlap in the current failing stage.When the wavelength of the impulse current applied to the CFRP becomes longer,it is clearly observed that the surrounded zones by ascent stage and descent stage of the dynamic volt-ampere characteristic of the CFRP becomes smaller.When the measured electrode size increases,the dynamic current amplitude flowed through the CFRP increases by 15 ％,and the dynamic voltammetry characteristic curve gradually moves down.When the impact current amplitude increases,the dynamic voltammetry characteristic curves with different measured electrodes are getting closer.These results provide a certain experimental basis and theoretical basis for the study of the conductive behavior and the damage mechanism of the carbon fiber composite material in the direct action of the lightning.It also provides a new experimental idea for the non-destructive testing of the carbon fiber composite.