EXPERIMENTAL AND NUMERICAL STUDY OF PECULIARITIES OF HIGH-VELOCITY INTERACTION BETWEEN A PROJECTILE AND DISCRETE BUMPERS
A high-velocity impact interaction of a polyethylene projectile and aluminium projectile with string and mesh bumpers was investigated experimentally and numerically with the projectile velocity varying in the range of ~1.7-3.8 km/s. Experiments were carried out using the two-stage light-gas gun. The numerical modelling was carried out by SPH method with the aid of the Ls-Dyna code of version 971. The study was aimed at detecting the peculiarities of projectile fragmentation during its interaction with discrete bumpers. It was shown that the projectile fragmentation on the string and mesh bumper is characterized by forming jets of fragments ejected from the front part of the projectile along and across its movement direction. The jets intensity depends on the geometrical parameters of the cell of the discrete bumper; velocities of the jets can exceed the initial projectile velocity. The numerical modelling evaluates the revealed cumulative effect as follows: the velocity of the fragments in the jets exceeds the original projectile velocity up to the factor of ~1.5 in case when the projectile is aimed towards the cell centre.