Damage of Nickel-coated glass/epoxy foam-core composites induced by artificial lightning strikes

In the field of composite materials, many reports have shown that catastrophic structural damage is caused by lightning strikes. In this study, new design concepts were proposed for the lightning-strike protection of nickel-coated glass/epoxy foam-core composites. Instead of using a neat metal mesh, glass fibers were modified with nickel particles via a plating technique to improve their thermal and electrical conductivities. In addition, a thin Invar plate was inserted at the middle of the structure and a foam core was introduced to reduce damage to the structure. Three models with different materials and stacking sequences were used in this study. Severe damage was experimentally observed following artificial lightning at a peak current of approximately 150 kA when considering a waveform A. Furthermore, numerical prediction was performed to identify the damage mechanisms of the structures. Besides the heat flux source, a mechanical source known as the shock wave overpressure was investigated separately as a new factor for dielectric materials. These two sources of lightning were determined as minor reasons for the structural damage. The failure modes were analyzed for further discussion about the failure mechanism in this study.