Dynamic Cylindrical Cavity Expansion of Compressible Strain-Hardening Materials

We developed models for the dynamic expansion of cylindrical cavities from zero initial radii for compressible, elastic-plastic, rate-independent materials with powerlaw strain-hardening. Results from cavity-expansion models were used to derive perforation models to predict residual velocities and ballistic limits for rigid, conicalnose projectiles perforating strain-hardening target plates. We compared the numerical results from models for incompressible and compressible materials to show the effect of compressibility. To verify the models, we also compared the model predictions of residual velocities and ballistic limits with the data from terminal-ballistic experiments with tungsten projectiles impacting 5083-H131 aluminum armor plates at normal incidence. Very good agreement was obtained for impact velocities between 200 and 1,200 m/s and 12.7, 50.8, and 76.2-mm thick targets.