Influence of target span and boundary conditions on ballistic limit of thin aluminum plate

摘要

A collective study was performed to probe the influence of projectile nose shape, target span and target boundary condition on ballistic limit of thin aluminium plates. 1mm thick 1100-H12 aluminium target plates were normally impacted by ogive and blunt nosed projectiles of 19 mm diameter and 50.8 mm length. The target span was varied as 95, 190, 285, 380, 475, 570, 665 and 760 mm whereas the target boundary condition was studied by varying the fixity at the target circumference region as 100%, 75%, 50% and 25%. ABAQUS/Explicit finite element code using Johnson-Cook elasto-viscoplastic material model were employed to carry out the numerical simulation. To validity of numerical results are revealed by experiments performed on pressure gun in the sub-ordnance velocity regime. The numerical as well as experimental study revealed that the ballistic limit of thin target plate was significantly affected by target span as well as target circumference fixity. The ballistic limit increases with increase in target span diameter while opposite trend was observed with increase in the region of fixity.