Modelling of lightning-induced dynamic response and mechanical damage in CFRP composite laminates with protection

The inclusion of CFRP composites in the mainframe of a modern aeroplane presents a special problem regarding lightning strike threat. During a lightning strike, a large amount of electrical energy is delivered onto the surface of CFRP composites in a short time, inducing the ionised plasma to expand at supersonic speed. The sudden plasma expansion may create a shock wave propagating in the CFRP composite, which can cause severe deformation and even damage to the composite. In this study, a mechanistic finite element (FE) model with a plasma expansion-induced pressure model was developed to predict the dynamic response and mechanical damage in CFRP composites with full electrical-thermal lightning protection. The failure behaviours of intralaminar damage and interlaminar delamination of the CFRP composites were considered in the FE model. The FE model was validated using data from an artificial lightning experiment available in the literature. Further, the FE model was used to investigate the effects of the lightning current waveform, the energy conversion rate, and the size of the composite panel on the dynamic response, intralaminar damage and interlaminar delamination of CFRP composites under a strike of a high lightning current.