Experimental investigation of lightning protection methods for carbon fiber reinforced polymer

Abstract

Carbon Fiber Reinforced Polymer (CFRP) is a kind of common composite materials which are widely used in aviation and aerospace fields. CFRP materials possess excellent specific strength but worse electric conductivity than traditional metallic materials, which may easily be damaged by lightning strikes. Therefore, to fulfill the safety requirements of aircrafts in lightning environment, experimental investigations of CFRP materials in lightning environment is required. At present, the majority of studies concerning lightning strike damages of CFRP materials are concentrated upon the damage mechanisms of CFRP materials without protection, while the lightning strike damage statuses of protected CFRP materials are seldom be discussed. In the paper, honeycomb sandwich structure CFRP materials which are generally applied on aircrafts were protected by thermal spraying aluminum and weaved copper meshes, respectively. Lightning current waveforms were generated by combined waveform generator which satisfied the requirements of SAE ARP5412A standard. Using those waveforms, lightning current direct effects experiments were conducted to test the specimens. The results demonstrated that thermal spraying aluminum would be better than weaved copper meshes in terms of protecting honeycomb sandwich structure CFRP materials against lightning current strikes.