Low-velocity impact resistance of bio-inspired interlayer hybrid composite laminates with a gradient waviness structure

This study explores a bio-inspired design methodology for interlayer layups in hybrid carbon fiber reinforced polymer composites to enhance impact resistance. An impact-resistant and damage tolerance gradient waviness structure is discovered in the rapid mandible strike of trap-jaw ants. Inspired by this natural design, a gradient waviness structure was incorporated into fiber interlayer formation to improve impact resistance. Bio-inspired interlayer hybrid laminates, combining unidirectional fibers with multiple woven fabric arrangements, were fabricated using a mold press forming technique. The results demonstrate that the bio-inspired gradient waviness structure plays a crucial role in limiting crack propagation and generating large in elastic deformation. The 3K-PUP laminate exhibited a 10.2 % increase in peak contact force, an impressive 80.7 % reduction in damage area upon impact, and a 46.2 % increase in energy dissipation compared to traditional laminates. Additionally, the hybrid laminates displayed superior load-bearing capacity, with the 3K-PUP laminate achieving a 6.6 % increase in residual compressive strength. The bio-inspired laminates effectively provided crack tip shielding and enhanced fracture resistance mechanisms, significantly improving damage tolerance against through-the-thickness diffusion of impact damage. Statement of Significance: An impact-resistant and damage tolerance gradient waviness structure is discovered in the rapid mandible strike of trap-jaw ants. Inspired by this natural design, a gradient waviness structure was incorporated into fiber interlayer formation to improve impact resistance. Bio-inspired interlayer hybrid laminates, combining unidirectional fibers with multiple woven fabric arrangements, were fabricated using a mold press forming technique. The results demonstrate that the bio-inspired gradient waviness structure plays a crucial role in limiting crack propagation and generating large in elastic deformation. The bio-inspired laminates effectively provided crack tip shielding and enhanced fracture resistance mechanisms, significantly improving damage tolerance against through-the-thickness diffusion of impact damage.