Abstract: The experiments of impacting the aluminum foam sandwich panels by spherical, pointed and flat nose projectiles launched from gas gun were carried to study the dynamic properties of aluminum foam sandwich structure. Based on LS-DYNA software, the impacts of different projectiles on aluminum foam sandwich panels are simulated, and the influences of different projectile shapes and speed on the energy absorption characteristics of sandwich panels are analyzed. The experimental results are well in agreement withe the simulated results. The results show that the deformation mode of pointed projectile is basically the same as that of spherical projectile, the flat nose projectile damages the sandwich panels more seriously during penetrating, the front and rear panels exhibit a tear failure mode, and the compacted aluminum foam is bonded to the rear panel after penetration. The head of pointed projectile is sharp, the contact area between the warhead and the target is small, and the penetration force is large. The contact area between the warhead of flat noise projectile and the target is large, and the penetration force is small, but the target damage area is large and the impact is more effective. The impact effect of spherical projectile is between those of pointed and flat nose projectiles: the improvement in the thicknesses and material properties of front and sandwich panels can better improve the penetration resistance of aluminum foam sandwich panel at low impact speed; the proportion of energy absorption of rear panel increases gradually, the improvement in the thickness and material properties of rear panel can improve the penetration resistance of sandwich panel at high impact speed. Key

Key words: aluminumfoamsandwichpanel, shapeofprojectile, impact, deformationmode, anti-penetrationtest