Oblique impact on single, layered and spaced mild steel targets by 7.62 AP projectiles

Abstract

The ballistic performance of monolithic and multi-layered in contact and spaced mild steel target plates has been studied at normal and oblique impact against 7.62 AP projectiles with an objective to ascertain the effect of angle of obliquity. Numerical simulations have been performed on ABAQUS/Explicit finite element code and typical results obtained have been validated by earlier experimental results, Gupta and Madhu [1,2]. The Johnson–Cook elasto-viscoplastic material model calibrated by the authors for mild steel was employed in the numerical simulations. Close correlation of typical experimental and numerical results validated the numerical procedure and the calibrated model.Ballistic limits of monolithic mild steel targets of thicknesses 4.7, 6, 10, 12 and 16mm each impacted at 0, 30 and 45ᵒ obliquity were numerically computed. The ballistic limits of in contact layered and spaced targets of equivalent thickness 10mm (3.33 + 3.33 + 3.33mm) were also computed at 0, 30 and 45° obliquity. For 60° angle of obliquity, the monolithic target experienced project ricochet, in contact layered target, projectile embedment, and the spaced target, projectile perforation. At low angles of obliquity, the difference between the ballistic performance of monolithic, layered in contact and spaced targets was not significant. As the angle of obliquity increased, each studied configuration was found to have distinct ballistic performance.Simulations were also done for three layered target of 4.7 and 6mm thick plate and spacing was varied to study its effect on their ballistic resistance. The variation of spacing at normal impact was found to have influence as long as the spacing was smaller than the projectile length.