Behaviour of Thin Aluminium Plates Subjected to Impact by Ogive-nosed Projectiles

A pneumatic gas gun has been used to fire ogive-nosed projectiles on aluminium plates (1mm) at varying impact velocities above the ballistic limit. Impact and residual velocities have been measured. Deformation of the target plate was studied. Experimental results formed the basis of a subsequent finite element analysis of the problem using the ABAQUS 6.3 code. The Johnson-Cook plastic flow and fracture model available in the code were utilised. Explicit finite element analysis has been performed to model the perforation phenomenon. Numerical results were significantly improved by reducing the element size up to a certain level beyond which no significant variation in the results was observed. Adaptive meshing has been found to be useful in obtaining the accurate results and avoiding the problem of premature termination of the program due to excessive element distortion. Experimental and numerical results are compared and a good agreement between the two has been found.