Features of Penetration of Cumulative Jet Elements into a Steel Barrier

On the basis of numerical modeling carried out using numerical methods of continuum mechanics, the effect was investigated on the depth of craters formed in steel barriers of various strengths and geometric and kinematic parameters of elongated cylindrical strikers imitating elements of a cumulative jet in the range from 0.3 to 8 km/s. To describe the behavior of the striker and barrier materials, a model of a compressible elastoplastic medium with a variable value of the yield strength is used. It has been established that the classical hydrodynamic theory of the penetration of a cumulative jet into a barrier does not take into account the influence of the inertial movement of the barrier after the actuation of a single element (the effect of the aftereffect period). The existence of three modes of impact interaction is singled out—high-speed, when the elements behave like a liquid body, they work together, but do not slow down; low-speed, when the elements behave like a solid body and are decelerated as a whole; and intermediate, when the elements are decelerated and deformed at the same time. It is shown that the braking mode of copper elements during a high-speed impact on a steel armor barrier is realized at speeds less than 0.8–1 km/s. It is shown that, when a high-speed fragmented cumulative jet interacts with an obstacle, the total depth of armor penetration will be greater than that predicted by the classical hydrodynamic theory of penetration, with a greater speed of the elements and a greater distance between them on one side and a lower strength of the barrier on the other side.