FINITE ELEMENT INVESTIGATION OF BEHAVIOUR OF SPACED PLATES SUBJECTED TO PROJECTILE IMPACT

Abstract

The present study is based on the influence of projectile nose shape on the ballistic resistance of single, layered and spaced 1100-H12 aluminum targets. Three-dimensional numerical simulations were carried out with the help of ABAQUS/Explicit finite element code. Single plate of 1 mm thick 1100-H12 aluminum target was impacted normally by blunt, ogive and hemispherical nosed projectiles of 19 mm diameter. The impact velocity of projectiles was varied and the ballistic limit of the target was obtained. To study the effect of layered target on the ballistic limit, the single plate was replaced by double layered plate of 0.5 mm thickness. Similarly, to investigate the effect of spacing on the ballistic limit, the double layered plate of 0.5 mm thickness was separated by a predefined spacing of 10 mm, 20 mm and 30 mm. At each configuration the target was impacted by blunt ogive and hemispherical nosed projectiles to obtain the ballistic limit. It was found that the monolithic plate offered highest resistance against each of the three projectiles as compared to layered in-contact as well as spaced plates of equivalent thickness. The layered in-contact plate on the other hand, was found to be superior to stop the projectiles than that of the spaced plate. The variation of spacing between the plates however, did not influence the ballistic limit significantly. The results of the present study were compared with the experimental and axi-symmetric numerical results available in literature on double layered plate of 0.5 mm thickness. A close correlation between the present three-dimensional numerical simulations and previous experimental results was found for blunt and ogive nosed projectiles. For hemispherical nosed projectiles however, the results of numerical simulations were found to be slightly over predicted.