NUMERICAL SIMULATION OF DUCTILE TARGET SUBJECTED TO NORMAL AND OBLIQUE IMPACT BY VARYING NOSE SHAPED PROJECTILES

Abstract

The present study is based on the influence of projectile nose shapes and angle of obliquity on the ballistic resistance of ductile targets, critical angle of ricochet for different shapes of projectile was also determined. Three-dimensional numerical simulations were carried out to study the ballistic resistance of ductile targets subjected to normal impact. 12 mm thick Weldox 460 E steel targets were impacted by 20 mm diameter conical nosed projectiles and 1 mm thick 1100-H12 aluminum targets were impacted by 19 mm diameter ogive nosed projectiles. The internal nose angle of conical projectile was varied (33.4°, 60°, 90, 1200, 1500 and 180°)and found to have significant effect on the ballistic limit of 12 mm thick Weldox 460; E steel target. Similarly, the caliber radius head (CRH) of ogive nosed projectile was varied (0,'!1, i 1.5 8, 2, 2.5) and found to have significant effect on the ballistic limit of 1 mm thick 1100-1112 aluminum target. The ballistic limit of 12 mm thick Weldox 460 E steel target increased almost . linearly with the decrease in the projectile nose angle. While the ballistic limit of 1 mm thick 1100-H12 aluminum target increased as the CRH increased from 0 to 0.5 and with further increase in CRH to 1.0, 1.5, 2.0 and 2.5 its values were found to drop quite significantly in case of normal impact. To study the effect of target obliquity 12 mm thick Weldox 460 E steel target was impacted by 20 mm diameter projectiles with six different nose angles at 0° (normally), 150 , 30°, 45° and 60° obliquity or until the occurrence of projectile ricochet. The ballistic limit of the target was obtained corresponding to each angle of obliquity and projectile nose shape. The ballistic limit was found to increase with an increase in the angle of target obliquity and decrease in projectile nose angle. The variation of critical angle of ricochet with projectile nose angle and impact velocity was also studied. It was found that the critical angle of ricochet increased with an increase in projectile nose angle as well as impact velocity. ABAQUS/Explicit finite element code was used to carry out the numerical analysis.