  Penetration models and calculating algorithms are presented, describing the
dynamics and fracture of composite armor shields penetrated by high-speed small
arms. A shield considered consists of hard (metal or ceramic) facing and
multilayered fabric backing. A simple formula is proved for the projectile
residual velocity after perforation of a thin facing. A new plastic-flow jet
model is proposed for calculating penetration dynamics in the case of a thick
facing of ceramic or metal-ceramic FGM materials. By bringing together the
developed models into a calculating algorithm, a computer tool is designed
enabling simulations of penetration processes in the above-mentioned shields
and analysis of optimization problems. Some results of computer simulation are
presented. It is revealed in particular that strength proof of pliable backing
can be better as compared with more rigid backing. Comparison of calculations
and test data shows sufficient applicability of the models and the tool.
