Application of Cavity Expansion Analysis to Penetration Problems

摘要

Cavity Expansion Analysis (CEA) is extended in three different areas: (a)analysis of ductile targets accounting for finite boundaries and finite ductility; (b) analysis of brittle ceramics considering the cracking and comminution behavior; and (c) development of a new penetration model for metals to overcome limitations of the existing models. CEA is modified to account for a finite boundary and to incorporate the effects of finite ductility of metallic targets, which develop tensile cracks. The results of the analyses are shown to be in good agreement with test data. A constitutive behavior based on the current understanding of the brittle behavior is used to derive quasi-static and dynamic cavity expansion pressures. Important material parameters that affect the penetration resistance are identified. The cavity expansion pressure derived in this analysis is in excellent agreement with experimental penetration resistance values. A new approach is hypothesized to model the penetration in ductile targets. In addition to the elastic and plastic zones, a 'damaged zone' zone is recognized in the target. In comparison to the existing models, the new approach shows superior agreement with experimental data, both for low and high velocities.