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Penetration and perforation performance of the rock targets by hard projectiles is suitable for understanding the ballistic behavior of the strategic and important structures such as protective structures, bunkers, ammunition stores, and nuclear power plants that are sensitive to missile impacts. In this study, ballistic penetration tests and numerical simulations were performed to examine the behavior of geo-material targets against hard projectile impacts. The granitic rock plates were used as target materials, and the projectiles were made of hardened 4340 steel. A loading-rate dependent shear failure model was suggested based on experimental data andimplemented into LS-DYNA using a usermaterial subroutine. The ballistic test results were used to validate the suggested model. The numerical ballistic data simulated experimental behaviors relatively well. [ABSTRACT FROM AUTHOR]

This research deals with the experimental and numerical investigation of ballistic protection provided by a combination of perforated and base armour plates. A 7.62 mm armour piercing projectile was used during the experimentation to determine the ballistic response of an aluminum base armour plate and a combination of steel perforated and aluminum base armour plate. The armour piercing projectiles were able to penetrate the base armour plate while the combination of perforated and base armour plates was able to stop the penetration of the armour piercing projectile. A finite element method based numerical model was developed to investigate the defeating phenomenon of perforated and base armour plate combination. The brittle fracture caused by the bending of the projectile core due to the asymmetric impact was predicted and the resulting fragments of the projectile were unable to penetrate the base armour plate. Craters were formed on the surface of the base armour plate from the impact of the projectile fragments. The numerical model was able to predict the hole growth and penetration of projectile when only the base armour plate was impacted by the projectile. [ABSTRACT FROM AUTHOR]

The subject of the paper is a description of a simple test from the field of terminal ballistics and the handling of issues arising during its simulation using the numerical techniques of the finite element method. With regard to the possible excessive reshaping of the finite element mesh there is a danger that problems will arise such as the locking of elements or the appearance of negative volumes. It is often necessary to introduce numerical extensions so that the simulations can be carried out at all. When examining local damage to structures, such as the penetration of the outer shell or its perforation, it is almost essential to introduce the numerical erosion of elements into the simulations. However, when using numerical erosion, the dissipation of matter and energy from the computational model occurs in the mathematical background to the calculation. It is a phenomenon which can reveal itself in the final result when a discrepancy appears between the simulations and the experiments. This issue can be solved by transforming the eroded elements into smoothed particle hydrodynamics particles. These newly created particles can then assume the characteristics of the original elements and preserve the matter and energy of the numerical model. [ABSTRACT FROM AUTHOR]

Studies of ballistic penetration into metal plates and their numerical simulation currently play a vital role in the defence sector. However, no congruent results have been presented so far, especially when it comes to impact on welded plates. Furthermore, these issues are investigated for normal impacts and very few have made an attempt for oblique impacts. Thus the aim of the present work is to conduct numerical simulation using Abaqus/Explicit in order to evaluate the ballistic performance of similar and dissimilar welded plates subjected to various bullet velocities and impact angles. The effect of post weld residual stresses and associated plastic damage on the ballistic performance of similar (Al6061) and dissimilar (Al 6061- SS 304) welded plates is also determined. The energy absorbed by the welded plates for various configurations was determined and the results are critically evaluated. [ABSTRACT FROM AUTHOR]