Finite element simulation of the behaviours of laminated armour systems against blast wave and projectile dynamic impacts

For investigating the blast wave and fragment/projectile protective performance of laminated armour systems, backed with, or without, air spacers, two-dimensional finite element models were developed using the commercial finite element software Autodyn. In this investigation, four differently shaped projectiles, including flat-faced cylindrical projectile, blunt cylindrical projectile, ogive-nose projectile and spherical projectile, were considered. The blast load was simplified as a triangular pulse. For validating the present models, a comparison of the present numerical results with the analytical and expermental results available in literature was conducted. A good agreement between them was noted. Subsequently, a parametric study was conducted to examine the effects of the key parameters on the dynamic responses of an armour systems against blast wave or projectile impact. The results indicated that the residual (or exit) velocity of projectile, the rear surface deflection of the armour system against a projectile impact and the peak value of the pressure measured in a water body simultant are dependent on the armour component property and configuration. Under the assumption that the components of laminated armour systems are perfectly bonded together and remain so on impact, the results showed that the inclusion of an air spacer onto the rear surface of the armour system may play an important role in reducing the peak pressure, residual (or exit) velocity of the projectile and the rear surface deflection of the armour system.