Effect of Spherical and Conical Fragment Shape on Damage of Steel Target Plate in Ballistic Applications

Recent numerical and experimental studies revealed that projectile shapes such as blunt, hemispherical and conical shapes significantly affect residual velocity of projectile as well as the failure mode and the energy absorption of target plate during the penetration in low velocity impact regime. However, in literature few studies have been undertaken on influence of fragment shapes on target plate failure mode in ordinance to hypervelocity impact regime. Therefore, in this study, finite element investigation of penetration characteristic and failure mode of steel target plate impacted by stainless steel spherical and conical fragments in velocity range of 400–2000 m/s, has been performed using the nonlinear finite element code LS-DYNA which is extensively used for impact analysis. The simulation model employs Johnson–Cook constitutive model coupled with Gruneisen equation of state (EOS) and erosion contact algorithm, to accurately predict the large strain developed in target plate due to impact of different fragment shapes (spherical and conical). The simulation results of spherical fragment shape are corroborated with literature experimental observations. The lower fragment perforation time and lower energy absorption of target plate suggested conical fragment would produce better lethality characteristics than spherical fragment of same and material used in fragment generated warheads.