Experimental and numerical study on the damage mechanism of CFRP/Al composite plates under hypervelocity impact

Carbon-fiber-reinforced polymer (CFRP)/aluminum (Al) hybrid configurations have been widely utilized in aerospace and defense applications; however, their behavior and damage mechanisms under hypervelocity impact are not yet fully elucidated. In this study, the hypervelocity impact response of composite plates comprising a CFRP layer and an Al backing plate was investigated both experimentally and numerically. Six impact tests were conducted at velocities ranging from 2000 to 4000 m/s, encompassing both normal and oblique impact scenarios. High-speed photography was employed to capture the dynamic impact events, whereas post-impact computed tomography (CT) scanning enabled quantitative assessment of damage morphology. Numerical simulations were performed using the finite element model-smoothed particle hydrodynamics adaptive coupling method to model the impact response. The damage mechanism of the composite plate was found to involve three stages: CFRP perforation, Al penetration, and debris expansion. CT scan analyses facilitated quantitative characterization of petaling damage in the Al backing plate, and the underlying formation mechanisms were elucidated by studying the sequential process of perforation, crack initiation, and crack propagation. In conclusion, this study provides a comprehensive understanding of the hypervelocity impact damage mechanisms in CFRP/Al composite plates.