Numerical Study of Shape and Density Effect on Semi-Infinite Metallic Target Under Hypervelocity Impact

Abstract

Numerical investigations are conducted to examine the penetration depth of ellipsoid-shaped projectiles into semi-infinite aluminum targets under conditions of hypervelocity impact. These results are then compared against empirical equations developed by various researchers for spherical projectiles. The semi-infinite aluminum target, sized at [Formula: see text][Formula: see text]mm, is composed of Al7075-T651. The projectiles are fashioned from Al-7075-T651, steel, and boron carbide. The projectile’s shape factor was determined using the L/d ratio, specifically for the symmetrical ellipsoidal shape. Employing Ansys Autodyn, a 3-dimensional finite element model (FEM) is created and calibrated using existing experimental findings from the literature. The validation utilized the Johnson–Cook (JC) and Johnson–Holmquist (JH-2) material models for both the targets and projectiles. These validated models are subsequently employed to analyze how the ellipsoid projectile’s shape and density influenced their interaction with the semi-infinite targets. Furthermore, the investigation also encompassed an analysis of the resulting crater shapes generated by the hypervelocity impact of both metallic and nonmetallic projectiles. It is observed that for a definite SF, max[Formula: see text] depth of penetration is observed due to steel project as compared to boron carbide and aluminum projectile. Both the diameter of the crater and the height of the bulge ([Formula: see text] are directly proportional to the impact velocity and density of projectiles, and inversely proportional to SF. However, for a particular material and impact velocity of the projectile, in the case of [Formula: see text], there are no clear-cut observations displayed it seems like a mixed variation.