Numerical Simulation of Perforation of Aluminum Plates by Tumbling Projectiles
Numerical simulations of the perforation of 4.8 mm thick 6061-T6 aluminum target plates by tumbling cylindrical projectiles with a 12.7 mm diameter, 38.1 mm long, were performed using DYNA3D, a non-linear, three-dimensional finite element code. Impact angle (or yaw angle with a zero oblique angle) of the projectile ranged from 0° to 50°. Initial velocity and oblique angle were 450 m/s and 5°. An elasto-plastic material model was considered for the targets with the failure criterion based on the ultimate tensile strain, while the projectile was treated undeformable. The slide surface “SAND” was employed to simulate the perforation process involving failures such as plugging and petaling. The numerical results were in good accord with corresponding experimental data in terms of final velocity and final oblique angle of the projectile as well as crater length of the target. A detailed description of motion history of the projectile during the perforation was in excellent agreement with that obtained from the analytical model. It was found that the impact angle can increase the velocity drop and change the trajectory of the projectile noticeably. The crater length of the target subjected to tumbling impact was apparently larger than those in normal impact (zero impact angle). Impact at an angle above 50° has almost the same effect as side-on impact at an impact angle of 90° for the given velocity and target thickness presently investigated.