Evaluating the Effectiveness of Aluminum Coatings on Patch-Repaired Composites Using Electro-Thermal Analysis

Lightning-induced ablation can severely compromise the structural integrity of composite materials. While metallic coatings have been widely studied for lightning protection, this study focuses on a different application—applying aluminum coatings to repaired composite materials. The goal is to address the challenge of ensuring that composite structures can withstand subsequent lightning strikes after repair. This study utilized an electro-thermal coupling finite element analysis model to assess the damage to laminates and the effectiveness of identical material patches for repairs. It is found that although patched laminates may experience more severe ablation damage when subjected to the same lightning strike, the application of an aluminum coating can significantly mitigate damage. Furthermore, this study improved the aluminum coating scheme, investigating the impact of coating width and shape on its lightning protection efficacy. The results indicate that a cross-shaped aluminum coating provides significant advantages in protecting repaired laminates against lightning strike, with a significant reduction compared to the uncoated controls. However, it was noted that narrowing the coating width could limit the coating’s ability to handle high current densities, potentially affecting its protective capabilities. These insights may contribute to the advancement of composite material repair strategies and the development of innovative protective structures against lightning damage.