Manufacturing and performance evaluation of NiTi-based fiber metal laminates for adaptive aerospace structures

In this study, Nickel-Titanium (NiTi) based fiber metal laminates (FMLs) were manufactured using a combination of resin infusion and compression molding manufacturing process. To improve interfacial adhesion and wettability, NiTi sheets were anodized in a sulfuric acid solution. Additionally, an array of 1 mm holes was drilled in the NiTi sheet to facilitate through-thickness resin flow. The interfacial strength was assessed using single cantilever beam (SCB) tests, while flexural behavior and shape recovery performance were examined under cyclic bending up to 80 % of the failure strain. Low-velocity impact tests were also conducted at various energy levels. The FMLs exhibited strong interfacial bonding, with an interfacial fracture energy of 0.84 N/mm, corroborated by microscopic analysis. Under cyclic flexural loading, the laminates demonstrated full shape recovery within three thermal cycles, with minimal degradation in mechanical properties over the rest of the cycles. Impact testing revealed effective impact resistance and structural integrity at all tested energy levels. These results highlight the potential of NiTi-based smart FMLs for use in adaptive aerospace structures requiring recoverable deformation, high bonding performance, and reliable impact resistance.