Impact penetration response of fiber metal laminates padded with 3D continuous fiber-reinforced polyurethane foam

Novel composite combinations are needed to meet the broad mechanical requirements for lightweight structures by integrating various properties within a single structure. This includes high structural rigidity and impact resistance with low overall density. Fiber metal laminates (FMLs) are advanced composite materials composed of an alternating stacking sequence of metal alloys layers and fiber-reinforced polymers. However, FMLs exhibit lower puncture deformation potential compared to fiber-reinforced thermoplastics (FRTPs). To address this limitation, polyurethane (PUR) foam with 3D continuous fiber-reinforcement, is investigated as padding. The FML, manufactured via thermoforming, is based on basalt fiber-reinforced polyamide 6 and two layers of aluminum alloy. The PUR foam is fabricated through structural reaction injection molding and reinforced with a spacer fabric. Subsequently, low velocity impact tests are conducted for this novel composite and its single components. The results unveil significant insights into the impact behavior of the materials. The highest perforation resistance of 81 J is achieved by the FML padded with 3D continues fiber-reinforced polyurethane foam while offering equal deformation capability as without reinforced PUR foam. These findings underscore the superior impact performance of the fiber metal laminate padded with 3D continues fiber-reinforced polyurethane foam, offering valuable insights for the advancement of impact-resistant materials in various engineering applications.