EXPERIMENTAL STUDY ON PERFORATION OF BRITTLE LAYERED OBSTACLES

Abstract

An experimental study of the process of perforation of plates made of brittle materials by rigid strikers has been carried out. The strikers were accelerated to the required speed with a pneumatic gun. Both homogeneous plates and obstacles from several plates glued together, put together without gluing, or spaced relative to each other were considered as targets. The results of experiments on the perforation of plexiglass plates by rigid spherical bodies at impact velocities of 100–200 m/s are presented. Qualitative features of the fracture at different velocities of impact are revealed. For the samples considered, it was found that spaced plates reduce the velocity of the striker during penetration more effectively than the same plates putted together. A set of experiments were also carried out on perforation of two combined plates made of various brittle materials: plexiglass, ceramics, artificial stone (polyacryl, quartz) by a rigid spherical striker for a velocity range of 200–350 m/s. For each considered combination of plates, a ballistic limit (ballistic limit velocity, BLV, at which the striker penetrates the obstacle with zero exit speed) was experimentally established, which characterizes the protective properties of the barrier. The effect on the ballistic limit of the order of the layers was studied. As a result, it was found that for all selected pairs of materials, a larger ballistic limit was achieved when a less dense and less brittle plexiglass layer was located behind a denser plate (made of ceramic or artificial polyacrylic or quartz stone). The reverse order of the layers led to a decrease in the ballistic limit in all cases. Photographs illustrating the nature of the destruction of the plates are presented.