SOME FEATURES OF FRAGMENTATION OF AN ALUMINUM PROJECTILE AT VARIOUS VELOCITIES OF PENETRATION INTO A MESH BUMPER

• Published in: Journal of applied mechanics and technical physics 2021-11, Vol.62 (6), p.972-980
• Main Authors: Shumikhin, T. A., Kalmykov, P. N., Lapichev, N. V., Leont’ev, A. I., Martyushov, D. E., Myagkov, N. N., Nomakonova, V. N., Sal’nikov, A. V., Bezrukov, L. N.
• Format: Article
• Language: English
• Subjects: Aluminum base alloys; Applications of Mathematics; Classical and Continuum Physics; Classical Mechanics; Damage patterns; Diameters; Energy; Fluid- and Aerodynamics; Fragmentation; Fragments; Kinetic energy distribution; Mathematical Modeling and Industrial Mathematics; Mechanical Engineering; Physics; Physics and Astronomy; Projectiles; Terminal ballistics; Tungsten; Wire
• ISSN: 0021-8944; 1573-8620
• DOI: 10.1134/S0021894421060122

The fragmentation of projectiles penetrating into thin discrete bumpers is accompanied by material ejections from the front part of the projectile in the direction of its movement. Material ejections from the front part of the projectile and fragments from the rear part of the projectile form two groups of fragments. The distribution of craters formed by these groups of fragments was analyzed; the intensity and nature of the damage they caused and the effect of projectile velocity on the kinetic energy distribution between these groups were determined. Fragments were captured using witness plates of great thicknesses placed at a certain distance behind the steel mesh bumper on the path of movement of fragments. It was found that with an increase in velocity, the fraction of the specific kinetic energy of front ejections increased and the fraction of the kinetic energy of fragments from the rear of the projectile decreased. The kinetic energy distribution was determined in the case of fragmentation of an aluminum alloy projectile of 9 mm diameter on a tungsten mesh (wire diameter 0.5 mm, aperture 3.2 mm). The ration of the diameter of the projectile to the cell size of the tungsten mesh was the same as for the steel mesh. The kinetic energy distributions for tungsten and steel meshes were found to be significantly different, probably due to the strength characteristics of the projectile material and the smaller wire diameter in experiments with tungsten meshes. The damage pattern to the witness plate by a group of small fragments was analyzed.