Damage analysis of panel sandwich reinforced with different fiber type under high-velocity projectile impact

This study presents an experimental–numerical investigation of the ballistic response of asymmetric sandwich structures with aluminum–ceramic composite foam cores, aluminum face sheets, and intermediate fiber-reinforced composite laminates with various stacking sequences. Particular emphasis is placed on the measurement methodology and quantitative evaluation of impact parameters. Ballistic tests were performed using 5.56 × 45 mm NATO M193 and SS109 projectiles and 7.62 × 51 mm NATO M80 bullets. Projectile velocities were determined using synchronized optical gates and high-speed camera imaging, enabling accurate pre- and post-impact velocity measurements and energy calculations. The recorded signals were processed to determine projectile velocity reduction, absorbed kinetic energy, and specific energy absorption, with repeatability verified through multiple trials. The results indicate that the laminate architecture significantly affects projectile destabilization and energy dissipation. Hybrid carbon–glass configurations provided the highest ballistic efficiency, reaching velocity reductions of up to 100 m/s for the M193 projectile. Finite element simulations conducted in Abaqus/Explicit with Johnson–Cook and Hashin damage models were validated against experimental data, showing residual velocity discrepancies below 3%. The proposed measurement framework enables reliable quantification of ballistic performance and provides a validated basis for the design and optimization of lightweight protective sandwich structures.