scholarly journals EXPERIMENTAL STUDY ON PERFORATION OF BRITTLE LAYERED OBSTACLES

2021 ◽  
Vol 83 (2) ◽  
pp. 137-150
Author(s):  
N.V. Baniсhuk ◽  
S.Yu. Ivanоva ◽  
K.Yu. Osipenko
Keyword(s):  
Experimental Study ◽  
Brittle Materials ◽  
Reverse Order ◽  
Ballistic Limit ◽  
Velocity Range ◽  
Protective Properties ◽  
Limit Velocity ◽  
Exit Speed ◽  
Ballistic Limit Velocity ◽  
Artificial Stone

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.

scholarly journals Ballistic Limit Estimation Approaches for Ballistic Resistance Assessment

2020 ◽  
Vol 70 (1) ◽  
pp. 82-89
Author(s):  
Beya Tahenti ◽  
Frederik Coghe ◽  
Rachid Nasri
Keyword(s):  
Extreme Values ◽  
Impact Testing ◽  
Estimation Methods ◽  
Experimental Sample ◽  
Ballistic Limit ◽  
Ballistic Resistance ◽  
Limit Velocity ◽  
Resistance Assessment ◽  
Ballistic Limit Velocity ◽  
Set Up

The armour technologist conducts ballistic impact testing either for evaluating armour materials and systems or for studying material’s defeating mechanism. Most standards make use of the ballistic limit velocity for ballistic assessment. This is the bullet impact velocity that leads to the protection perforation in 50 per cent of the cases. Various models have been emerged to estimate this key metric. The present article summarises the popular models developed for ballistic limit estimation. An attempt is made to point out models’ strength and weakness. First, the experimental set-up used for that goal is displayed. Next, a concise overview of ballistic limit estimation methods is presented. Lastly, a discussion is dedicated to model’s comparison and analysis. This literature survey reveals that the main drawback of already existing methods is that they are purely statistical. Moreover, existing methods are based on the normality assumption of perforation velocities which tends from -infinity to infinity. The main conclusion of this survey is that the presented methods offer a comparable accuracy in estimating the ballistic limit velocity. However, a given variability is remarked when extreme values estimation is of interest, impact velocities leading to low and high perforation probability. Finally, existing models’ performances decay with the reduction of the experimental sample size which represent a constraining requirement in ballistic resistance assessment.

A Predictive Non-Dimensional Scaling Law for the Plate Perforation of Several Aluminum Alloys by Fragment-Simulating Projectiles

2019 ◽  
Author(s):  
Weinong Chen ◽  
Zherui Guo
Keyword(s):  
Aluminum Alloys ◽  
Scaling Law ◽  
Limit Equation ◽  
Ballistic Limit ◽  
Limit Velocity ◽  
Dimensional Scaling ◽  
Material Problem ◽  
Plate Perforation ◽  
Ballistic Limit Velocity ◽  
Aluminum Armor Plates

Abstract An equation was previously-presented to predict the ballistic-limit velocity for the perforation of aluminum armor plates by fragment-simulating projectiles (FSP). The ballistic-limit equation was presented in terms of dimensionless parameters so that the geometric and material problem scales are identified. Previously published predictions and data for two different FSP projectile calibers (12.7 mm and 20 mm) and two different strength aluminum alloys show the scaling law to be accurate. In this paper we extend the same concept to several other alloys and show that this scaling law is predictive.

scholarly journals Ballistic limit velocity of tungsten alloy spherical fragment penetrating Ti/Al3Ti-laminated composite target plates

2020 ◽  
Vol 29 ◽  
pp. 2633366X2092224 ◽  
Author(s):  
Yingbin Liu ◽  
Chufan Yin ◽  
Xiaoyan Hu ◽  
Meini Yuan
Keyword(s):  
Similarity Theory ◽  
Laminated Composite ◽  
Tungsten Alloy ◽  
Target Area ◽  
Ballistic Limit ◽  
Composite Target ◽  
Area Density ◽  
Limit Velocity ◽  
Ballistic Limit Velocity ◽  
Different Thickness

To determine the ballistic limit velocity of titanium–titanium tri-aluminide (Ti/Al3Ti)-laminated composites under the action of tungsten alloy spherical fragments, a type of 12.7 mm ballistic gun loading system was used to test the tungsten alloy spherical fragments vertically impacting the Ti/Al3Ti-laminated composite targets with different thickness. The relationship between the ballistic limit velocity and the target area density of the Ti/Al3Ti-laminated composite was obtained. As the area density increased, the ballistic limit velocity and the ballistic energy absorbed by the target plate also enhanced. Based on the dimensional analysis and similarity theory, a simulation law of tungsten alloy spherical fragments penetrating Ti/Al3Ti-laminated composite targets with different thickness was studied and an empirical formula for the ballistic limit velocity was obtained. The research results had an important application value for the optimal design of the light armor protection structure.

Determination of Ballistic Limits of GLARE 5 Fiber-Metal Laminates: The Influences of Geometry, Thickness and Stacking Sequence

2011 ◽  
Author(s):  
A. Seyed Yaghoubi ◽  
B. Liaw
Keyword(s):  
Volume Fraction ◽  
Velocity Versus ◽  
Specimen Thickness ◽  
Stacking Sequence ◽  
Ballistic Limit ◽  
Fiber Metal Laminates ◽  
Limit Velocity ◽  
Fiber Metal ◽  
Ballistic Limit Velocity

In this paper, GLARE 5 fiber-metal laminates (FMLs) of two different geometries: 152.4mm×101.6mm (6″×4″) plate and 254mm×25.4mm (10″×1″) beam and with various thicknesses and stacking sequences were impacted by a 0.22 caliber bullet-shaped projectile using a high-speed gas gun. Velocities of the projectile along the ballistic trajectory were measured at different locations. For both geometries, the incident projectile impact velocity versus the residual velocity was plotted and numerically fitted according to the classical Lambert–Jonas equation for the determination of ballistic limit velocity, V50. The results showed that V50 varied in a parabolic trend with respect to the metal volume fraction (MVF) and the specimen thickness for both geometries. It was found that by changing the geometry from a plate to a beam, the ballistic limit velocity increased. On the other hand, changing the stacking sequence had a less pronounced effect on V50 for both geometries. The quasi-isotropic beam and plate specimens offered relatively higher ballistic limit velocities compared to other types of stacking sequences in their own geometrical groups. Furthermore, the cross-ply and unidirectional beam specimens showed relatively higher V50 compared to their plate counterparts. Experimental results showed that the ballistic limit was almost the same for the quasi-isotropic layup FMLs of both plate and beam geometries.

The Numerical Method as Applied to Impact Resistance Analysis of Ogival Nose Projectiles on 6061-T651 Aluminum Plates

2012 ◽  
Vol 28 (4) ◽  
pp. 715-726 ◽  
Author(s):  
Y.-L. Chen ◽  
H.-C. Chen
Keyword(s):  
Numerical Method ◽  
Predictive Model ◽  
Penetration Depth ◽  
High Speed ◽  
Ballistic Limit ◽  
Residual Velocity ◽  
Finite Element Software ◽  
Limit Velocity ◽  
Aluminum Plates ◽  
Ballistic Limit Velocity

ABSTRACTThis research takes the resistance formula of spherical cavity expansion theory as its foundation. It establishes a predictive model of the residual velocity, ballistic limit velocity, and penetration depth of ogival nose projectiles striking metal target plates at high speed. They are aimed at 6061-T651 aluminum plates of different thicknesses using the iterative algorithm of the numerical method, thereby investigating the theoretical calculation of the residual velocity, penetration depth, ballistic limit velocity, and changes in resistance of ogival nose projectiles when making a normal impact target. In addition to analyzing the resistance undergone by the projectile nose section, this predictive model also considers the effects of friction resistance of the projectile shank section. In this research, we also used the finite element software LS-DYNA to perform a simulated analysis on the penetration depth of the aluminum plate after normal perforation by ogival nose projectiles. Ballistic test experiments were then performed using 0.30” AP (armor piercing) bullets. Finally, a comparative analysis was performed based on the theoretical model, experiments, and numerical simulation results.

Numerical Investigation on Ballistic Limit Velocity of Armour Materials

2018 ◽  
Vol 8 (3) ◽  
Author(s):  
Suresh Periyasamy ◽  
Ramabalan Sundaresan ◽  
Natarajan Uthirapathy
Keyword(s):  
Single Layer ◽  
Honeycomb Structure ◽  
Ballistic Limit ◽  
Numerical Work ◽  
Limit Velocity ◽  
Military Vehicles ◽  
Al 7075 ◽  
Ballistic Limit Velocity ◽  
Ansys Workbench

The Threats to public security and premises security are on the rise because of increasing terrorism and violence. Safety of individual is a matter of concern, hence there is need to develop bullet resistant solutions for soldiers, tanks, and other military vehicles. This case study is concerned with designing the plates which are made up of different materials and structures and finding the ballistic limit velocity (BLV) by analyzing and comparing them. In this work, the ballistic limit velocity of Al 7075-T6, Al 5083H116, Titanium, Kevlar 149 materials were investigated numerically. Initially single layer plates made of Al 5083H116, Al 7075-T6 and Titanium were analyzed individually and it was found that Titanium plate yielded better ballistic limit velocity value than the other two materials. The numerical work was further extended with sandwich structures with / without honeycomb core. Al 7075-T6 material was considered for the front and rear face of the sandwich armour. And for the core portion Kevlar 149 (without honeycomb) and Al 7075-T6 (with honeycomb) were considered. Commercial software Ansys-workbench was used through the analysis. The result of the case study indicated that Al 7075-T6 with honeycomb structure yields greater ballistic limit velocity and it has 22.58% more BLV value than the solid single layer Al 7075-T6.

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