Определение динамического предела текучести гетерогенных преград с заданной пористостью

The effectiveness of modern protective structures that are based on high-hardness materials and lightweight alloys is governed by the dynamic response of a system under high-velocity loading. Gaining deeper insight into the energy-dissipation mechanisms in such targets requires the development of accurate methods for the real-time experimental measurement and validation of the material penetration and failure models. This work investigates the dynamic interaction of a spherical steel body with monolithic and composite targets. The values of dynamic yield strength of the materials constituting the ceramic and cermet layered systems were determined, and the failure mechanisms of the latter were characterized. The results of numerical simulation, which were obtained using the Russian software package "Reactor3D", were compared against the crater depth profiles measured in high-velocity field experiments. Analysis of the penetration velocity revealed a stepwise deceleration of the spherical striker, which is consistent with the wave nature of dynamic resistance of the material. The dynamic yield strength of the aluminum substrate was found to increase substantially during the phase of intense deformation. In the composite targets, a two-stage crater formation mechanism was identified: the high-hardness front layer (ceramic or cermet) absorbs the main impulse and breaks into fragments, after which the flow of high-velocity debris of the failed layer excavates a cavity in the substrate. It is shown that the proposed approach can be used to estimate the dynamic yield strength of the D16T aluminum alloy to within 10% of the experimental value, and to compute the effective dynamic yield strength of the composite layered target.