Dynamic behavior of carbon fiber honeycomb sandwich structures subjected to high-velocity soft-body impact

The all-carbon fiber honeycomb sandwich structure was fabricated, and the deformation and failure of the structure under soft-body impact were investigated by means of experiments and numerical simulations. Impact tests were carried out using gelatin projectiles and the structural responses were captured using digital image correlation (DIC). The results show that the maximum out-of-plane deformation of the structure exhibits an approximately linear relationship with the impact velocity. Within the impact velocity range of 78–162 m/s, the maximum structural deformation increases from 2.5 mm to over 15 mm until structural failure occurs, and the structure presents four distinct failure modes as the impact velocity rises. A corresponding simulation model was constructed in Abaqus and validated against experimental observations in terms of deformation histories and failure modes. Based on the validated model, the deformation behavior and energy dissipation mechanisms of individual structural components during impact were analyzed in detail. The honeycomb core absorbs the majority of the impact energy throughout the process. Furthermore, parametric studies were performed to examine the effects of honeycomb core density, out-of-plane height, face sheet thickness, and impact angle on impact resistance. Specifically, increasing core density can direct the projectile to dissipate the impact kinetic energy through lateral flow, thereby effectively reducing the overall structural deformation. These findings provide valuable guidance for the optimized design of lightweight sandwich structures subjected to high-velocity soft-body impact.