Study on compressive performances of carbon nanotube film-protected composite laminates after lightning strike

Compressive performances of composite structures can be significantly decreased due to the lightning strike damage, so the structures with lightning frighten must be considered lightning protection design. In this study, compressive experiments after lightning strikes were conducted on non-protected, 12-layer interlaminar carbon nanotube film (CNF) protected, and traditional surface silver coating (TSSC)-protected composite laminates. A numerical analysis procedure was established, incorporating a lightning strike ablation damage simulation (LSADS) module and compressive residual strength calculation (CRSC) module. The procedure's effectiveness was verified by the experiment results. Based on this procedure, the compressive performances and the possible failure mechanism of laminates after lightning strikes were analyzed. The results show that the laminates with TSSC protection and 12-layer interlaminar CNF protection can increase compressive residual strength compared with non-protected laminates. The predominant compressive damages of the laminates after lightning strikes are fiber-matrix shear damage and fiber fracture damage. Optimized one-layer interlaminar CNF protection with a thickness of 0.36 mm can increase the laminate compressive strength but decrease the structural weight. This study offers a reference and basis for the lightning strike protection design of composite structures. Highlights: CNF in lightning strike protection of composite structures. Compressive failure mechanism of composite laminates after lightning strikes. A numerical procedure to evaluate lightning damage and compressive performances. Design of interlaminar CNF protection.