A study of the perforation of aluminium laminate targets

✍ Scribed by R.L Woodward; S.J Cimpoeru

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 208 KB
• Volume: 21
• Category: Article
• ISSN: 0734-743X
• DOI: 10.1016/s0734-743x(97)00034-1

✦ Synopsis

Experiments are described in which laminated aluminium alloy targets, of a variety of configurations, are perforated by flat-ended and conical penetrators. Target ballistic limit velocities are determined and the results are used to evaluate energy absorption mechanisms and to compare deformation and failure modes. It is demonstrated by modelling that increasing the numbers of layers in multi-layer targets increases the tensile stretching work in perforation. However, since this is accompanied by reductions in other work terms, only small changes are found in total energy absorption, despite large changes in failure geometry. The propensity to stretch and bend or to shear a plug is affected by target exit-side layer thickness relative to projectile diameter, with thick layers tending to favour plugging by a shear mechanism. In targets with thin exit-side layers tensile, rather than shear, mechanisms are apparent in failure and plug separation. A model is developed which treats the perforation of laminates as a two-stage process of indentation on the impact side, and either shear or dishing failure on the exit side, depending on target configuration. For the cases examined the model gives good predictions of the ballistic limit, including distinguishing between differently configured laminates, and correctly accounts for the effect of projectile nose shape. As part of this process, the estimation of dishing energies is improved by accounting for the effect of tangential curvature. In spite of its success in predicting ballistic limits, the model involves some simplifications which do not mirror experimental observations. A notable example is its neglect of the detailed geometric features of deformation. Nevertheless, the model can be used to elucidate design features for laminated targets.