An asymmetric hybridization strategy for enhancing bird-strike resistance of composite laminates

Improving the delamination resistance of composite laminates under bird-strike loading is critical for resin-matrix composite fan blades. This study aims to improve the bird-strike resistance of composite laminates, thereby providing guidance for hybrid layup design. The impact response of carbon/glass hybrid laminates is systematically investigated through sub-element level experiments and numerical simulations. The experimental and numerical results show that hybridization increased the critical delamination velocity and effectively suppressed the growth of delamination damage with increasing impact velocity. The enhanced delamination resistance is primarily attributed to the compliant glass-fiber plies, which improve strain compatibility and reduce stiffness mismatch, thereby alleviating the high interlaminar stress concentration that drives delamination in the CFRP laminate. A novel asymmetric hybrid layup strategy is further proposed based on the through-thickness shift of the peak interlaminar stress envelope. With a properly designed asymmetric layup, the composite laminate can achieve better delamination resistance than its symmetric counterpart while reducing the risk of wrinkle deformation at high hybrid ratios. These findings provide a mechanistic basis and layup-design guidance for hybrid laminates, with potential application in the bird-strike resistance design of composite fan blade structures.