An Investigation of AL7075-T651 Plate Perforation Using Different Projectile Nose Shapes

In this study, the ballistic resistance of monolithic and double-layered plates made of AL7075-T651 are evaluated using the non-linear finite element code LS-DYNA®. Plate simulations are carried out using 20 mm diameter, 197g mass hardened steel projectiles with blunt and ogival nose shapes. Penetration simulations of 20 mm monolithic plates made of AL7075-T651 are performed with both Lagrange and ALE methods and the results are compared with literature experimental studies. Simulations are performed with both 2D axisymmetric and 3D solid elements and Modified Johnson Cook constitutive equation is utilized. Moreover, Cockcroft-Latham fracture criterion is used for material behavior of metallic plates. In addition to the material model validation studies, different options for contact, hourglass and timestep definitions, several types of 2D and 3D elements are evaluated and the results are compared under the effects of blunt and ogival projectile nose shapes and various impact velocities.