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Mechanisms of projectile defeat and ballistic resistance of thin targets impacted by tip-deformable conical projectiles have been discussed in the context of the influence of apex angle of the projectile. Transition in target local failure modes occurred as the projectile apex angle was altered. The effect on projectile deformation and ballistic properties has also been discussed. A brief discussion on projectile deformation mechanism and projectile defeat near ballistic limit velocities with supporting experimental evidence is included. Numerical simulation using ABAQUS/Explicit has been able to effectively predict the projectile deformation and associated target behavior. [ABSTRACT FROM AUTHOR]

The paper deals with a possibility of the local repairing of damaged composite armours. The proposed repairs can be performed directly in the field, allowing thus to recover the full ballistic protection in a short time. Several solutions (temporary or permanent) were designed and tested both experimentally and using numerical simulations. Overlapping of the damaged area with patch from armour steel after filling the hole with ceramic balls showed to be optimal as a temporary repair. The calculation clearly showed that the depth of penetration of the projectile is reduced in all cases of designed permanent repairs in comparison to original armour configuration. The experiments confirmed supposed enhancing of ballistic resistance, but only some repair techniques met the requirements of multi-hit testing. However, the reason of failure after multi-hit could be clearly explained with the help of used numerical simulations. [ABSTRACT FROM AUTHOR]

In this study, the penetration behaviour of a Mild Steel Cored (MSC) round, 7.62 mm in diameter and 39 mm in length, commonly known as the AK47 round, was studied since it still forms an important part of the threat spectrum for personnel body armour systems. Likewise, boron carbide strike face materials were selected since this armour material is often the material of choice for ultralightweight body armour systems for protection against this particular threat. The presence of two, relatively soft, intermediate materials (the copper jacket and filler material of the bullet, and a fibre-reinforced polymer cladding layer on the ceramic) between the mild steel core and the boron carbide target was examined using reverse ballistics techniques, flash x-radiography and round recovery measurements. This was supported by selective numerical simulations using the computer code ANSYS-AUTODYN. It was found that stripping of the jacket, from the AK47 MSC rounds, makes a difference to its penetrating ability: the mild steel core is significantly reduced in length, and mass, when the jacket is not present. The magnitude of this effect is much greater than previously reported for high-strength steel-cored rounds and for tungsten carbide-cored rounds. The penetration event appears to be a twostage process: mushrooming of the mild steel core on, or near, the surface of the ceramic, followed by a linear erosion process as the core penetrates the ceramic itself. The second step has not been reported previously for MSC rounds. [ABSTRACT FROM AUTHOR]

The ballistic performance of thin aluminium targets and influence thereon of different circumferential fixity conditions were studied both experimentally and by finite element simulations. A pressure gun was employed to carry out the experiments while the numerical simulations were performed on ABAQUS/Explicit finite element code using Johnson–Cook elasto-viscoplastic material model. 1 mm thick 1100-H12 aluminium plates of free span diameter 255 mm were normally impacted by 19 mm diameter ogive and blunt nosed projectiles. The boundary conditions of the plate were varied by varying the region of fixity along its circumference as 100%, 75%, 50% and 25% in experiments and the numerical simulations. Further, simulations were carried out to compare the response of the plates with 50% and 75% continuous fixity with those with two and three symmetrical intermittent regions of 25% fixity respectively. The variation in the boundary condition has been found to have insignificant influence on the failure mode of the target however; it significantly affected the mechanics of target deformation and its energy absorption capacity. The ballistic limit increased with decrease in the region of fixity. It decreased for intermittent fixity in comparison with equivalent continuous fixity. And, it has been found to be higher for the impact with projectile having blunt nose in comparison with the one having ogive nose. [ABSTRACT FROM AUTHOR]

This study aims to investigate the penetration of a projectile into a surrogate human tissue numerically, using Finite Element (FE) simulation. 20% Balistic Gelatin material (BG) is simulated with an elasto-plastic hydrodynamic constitutive law, and then impacted by steel spheres at different velocities. The results from the FE simulations are compared with existing experimental data and other analytical equations from the literature. To our knowledge, this is the first study to investigate a projectile penetration by numerical simulation, and then compare the results with analytical and experimental data from previous studies. This developed model gives encouraging results for further investigations of penetrating impact of projectile in the human body. [ABSTRACT FROM AUTHOR]