High-velocity impact simulation of bilayer alumina/steel armor

A methodology is developed to simulate bilayer alumina/steel armor under high-velocity normal impact at STANAG 4569 level II and investigate the resultant material performance, failure mechanisms, and stress wave management. Impact from a 7.62×39 mm armor-piercing incendiary (API) BZ projectile incident at 700 m s−1 is modeled. The finite-element method (FEM) is used, incorporating decomposition to smoothed-particle hydrodynamics (SPH) particles in LS-DYNA R13.1. Verification is against experimental results in [1].

The simulations results agree well with the experimental results in [1], displaying: the characteristic Hertzian cone cracking, radial cracking in the ceramic layer, the removal of the soft brass jacket of the projectile during impact, and the projectile core blunting and erosion. The deflection of the backplate is sensitive to simulation parameters such as hourglass control and contact algorithm controls. These parameters have been tuned in this study to achieve agreement to the experimental measurements to within 21%.

[1] P. Zochowski et al., “Comparison of Numerical Simulation Techniques of Ballistic Ceramics under Projectile Impact Conditions,” Materials (Basel)., vol. 15, no. 1, 2022, doi: 10.3390/ma15010018.