Experimental and Modelling of Lightning Damage to Carbon Fibre-Reinforced Composites under Swept Stroke

Lightning swept stroke creates multiple lightning attachments along an aircraft in flight. This introduces distinct structural damage compared to that from a single-point lightning current injection test in laboratory. This study presents both experimental and numerical studies on lightning damage in carbon fibre-reinforced polymer (CFRP) composites under swept stroke. Coupled electrical-thermal finite element (FE) models were proposed to predict lightning damage to CFRP composites under single-point current injection and swept stroke, respectively. A lightning swept stroke testing method was proposed by embedding a copper wire inside the composites to simulate multiple lightning attachments on the composites. The FE-predicted damage from single-point current injection and swept stroke were comparable to those obtained from the experiments with a deviation less than 23%, demonstrating the effectiveness of the proposed FE model. Finally, the FE model was further utilised to gain insights into the failure mechanism of CFRP composites under swept stroke associated with different skip distances and peak currents. This paper provides an experimental method and a FE model for obtaining the LS damage of CFRP composite by swept stroke.