Theoretical model for dynamic response of aluminum foam sandwich targets by truncated cone-nosed projectiles

Based on classical dynamic cylindrical cavity expansion theory, a nine-step penetration and perforation process of aluminum foam sandwich targets by truncated cone-nosed projectiles are developed theoretically. In the theoretical model, the friction, shear strength, and the force for tearing the cells in the core at the periphery of the projectile are considered, and the resistance force and instantaneous velocity are achieved from this process. On this basis, the effects of the geometry of projectiles, core thickness, and impact velocities of projectiles on absorbed energy are also analyzed. Simple composite failure criteria will be applied in the fracture and perforation of the face sheet, core, and back sheet. It is shown that the diameter of projectile and core thickness have significant influence on the ballistic velocity of the projectile, which is important for the impact response and absorbed energy of the sandwich. Numerical simulation at various impact velocities is also performed, and there is a good agreement between the numerical predictions and the analytical measurements.