A new unified model for dwell and penetration during the impact of long projectiles on thick ceramic targets has been developed using the principles of conservation of mass and momentum. The target response is assumed to occur in a hemispherical region containing nested comminuted, cracked and elastic regions of deformation. A dynamic expanding cavity model is used to capture the stress fields in these regions. The material constitutive behavior is predicted using the extended Mohr-Coulomb (SS-EMC) model, which captures the pressure-dependent shear strength of ceramics with a single set of model constants that are applicable to a wide range of ceramics. Hence, the model can predict important ballistic parameters like the depth of penetration and the penetration resistance of ceramics, and can be used to quantify the benefits of superior mechanical properties. The predictions of the new model are in good agreement with experimental results obtained from long-rod impact tests published in literature. The results of the analysis reveal that the properties of the comminuted material have a greater influence on the ballistic performance of ceramics than those of its intact state. The model is also used to quantify the effect of amorphization on boron carbide.
2021-04-07 08:00:00
