NUMERICAL SIMULATIONS OF THE INFLUENCE OF TARGET SPAN AND BOUNDARY CONDITION ON THE BALLISTIC LIMIT

Abstract

The present study is based on the three-dimensional numerical simulations wherein aluminum target plates of varying span diameter were impacted normally by hardened steel projectiles. 1 mm thick 1100-H12 aluminum targets of three different span diameters i.e. 204 min, 255 mm and 500 mm were impacted by blunt, ogive and hemispherical nosed projectiles of 19 mm diameter and 52.5 grams mass. A variation in the target span can have considerable influence on the resistance of target if all the other parameters such as target thickness, projectile nose shape, impact velocity and angle of incidence are kept constant. hi each case the impact velocity of the projectile was varied to obtain the ballistic limit. Both the target span as well as the projectile nose shape were found to have significant influence on the ballistic limit. For a given projectile the ballistic limit was found to increase with an increase in the target span. For each span diameter, the target offered highest ballistic limit against hemispherical nosed projectile followed by blunt and ogive nosed projectiles respectively. The results of the numerical simulations were compared with those of the experiments available in literature. Failure mode of the target was also found to be affected by the projectile nose shape as well as the target span diameter. The effect of target boundary condition on the ballistic resistance was also studied. ABAQUS/explicit finite element code was used to carry out the numerical simulations.