Ballistic impact performance of spaced multilayered and monolithic composite targets: Analytical and experimental studies

2017 ◽  
Vol 27 (9) ◽  
pp. 1352-1379 ◽  
Author(s):  
PS Patil ◽  
NK Naik
Keyword(s):  
Energy Absorption ◽  
Experimental Studies ◽  
Target Thickness ◽  
Ballistic Impact ◽  
Ballistic Limit ◽  
Composite Target ◽  
Impact Performance ◽  
Limit Velocity ◽  
Ballistic Limit Velocity ◽  
Energy Dissipated

Ballistic impact performance of spaced multilayered and monolithic composite targets is presented based on propagation of stress wave and energy balance within the target and the impacting projectile. The energy dissipated by the impacting projectile gets absorbed by the composite target through several energy absorbing mechanisms. Specifically, studies are performed on spaced bilayered target separated by air gap and monolithic target having the same total thickness. Energy absorption due to several mechanisms, contact force, projectile velocity, projectile tip displacement, and kinetic energy of the projectile with respect to time are presented. Also, ballistic limit velocity (VBL) and total energy absorption of the target with respect to target thickness have been evaluated. Spaced bilayered composite targets have higher ballistic limit velocity compared to monolithic composite targets from total target thickness of 16–28 mm. Monolithic composite targets have higher ballistic limit velocity compared to spaced bilayered composite targets up to total target thickness of 16 mm and beyond target thickness of 28 mm. Experimental studies were performed for the validation of analytical results. The analytically predicted value of ballistic limit velocity matches well with the experimental value.

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.

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.

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.

scholarly journals EFFECTS OF VOLUME OF CARBON NANOTUBES ON THE ANGLED BALLISTIC IMPACT FOR CARBON KEVLAR HYBRID FABRICS

2020 ◽  
Vol 18 (2) ◽  
pp. 229
Author(s):  
Elias Randjbaran ◽  
Dayang L. Majid ◽  
Rizal Zahari ◽  
Mohamed T. H. Sultan ◽  
Norkhairunnisa Mazlan
Keyword(s):  
Carbon Nanotubes ◽  
Impact Resistance ◽  
Target Material ◽  
Ballistic Impact ◽  
Impact Behavior ◽  
Ballistic Limit ◽  
Damaged Zone ◽  
Fabric Composites ◽  
Ballistic Limit Velocity ◽  
Equal Thickness

Investigations of the angled ballistic impact behavior on Carbon Kevlar® Hybrid fabrics with assorted volumes of carbon nanotubes (CNTs) into epoxy are presented. The ballistic impact behavior of the epoxy composites with/without CNTs is compared. Individual impact studies are conducted on the composite plate made-up of Carbon Kevlar Hybrid fabrics with diverse volumes of CNTs. The plate was fabricated with eight layers of equal thickness arranged in different percentages of CNTs. A conical steel projectile is considered for a high velocity impact. The projectile is placed very close to the plate, at the centre and impacted with sundry speeds. The variation of the kinetic energy, the increase in the internal energy of the laminate and the decrease in the velocity of the projectile with disparate angles are also studied. Based on the results, the percentage of CNTs for the ballistic impact of each angle is suggested.  The solution is based on the target material properties at high ballistic impact resistance, the inclined impact and the CNT volumes. Using the ballistic limit velocity, contact duration at ballistic limit, surface thickness of target and the size of the damaged zone are predicted for fabric composites.

scholarly journals EXPLICIT FORMULA FOR DEPTH OF PENETRATION OF CONE-NOSED IMPACTOR INTO ANISOTROPIC SHIELDS

2020 ◽  
Vol 82 (1) ◽  
pp. 100-106
Author(s):  
A.V. Dubinsky
Keyword(s):  
Finite Thickness ◽  
Normal Component ◽  
Experimental Studies ◽  
Quadratic Function ◽  
Functionally Graded ◽  
Ballistic Limit ◽  
Depth Of Penetration ◽  
Explicit Formulas ◽  
Penetration Mechanics ◽  
Ballistic Limit Velocity

The field of application of Functionally Graded Materialsis steadily expanding, which stimulates research in the relevant areas. In relation to penetration mechanics, these are primarily experimental studies of multilayer barriers consisting of plates “in contact” with various mechanical properties. Despite intensive research, explicit formulas for integral penetration characteristics (penetration depth and ballistic limit) cannot be obtained, except for the case when sequential penetration of layers (barriers with large gaps between layers). In this article, explicit formulas for the depth of penetration into an semi-infinite shield and for the ballistic limit velocity applying penetration into a shield of a finite thickness are derived assuming that the hardness of the barrier material varies continuously depending on barrier depth. The theoretical analysis is based on a model that represents the normal stress at points on the surface of the penetrating body that are in contact with the barrier as a quadratic function of the normal component of local impactor velocity with a zero linear term (the Vitman - Stepanov model). Difference of the dynamic hardness in different points of impactor-barrier contact is taken into account. It is also assumed that the nose of the striker has the form of a straight circular cone and the initial stage of penetration when the striker is not completely immersed in the barrier is ignored.

Study on Ballistic Characteristics of Glass-Epoxy-Rubber Sandwiches

2020 ◽  
Vol 978 ◽  
pp. 245-249
Author(s):  
Rajole Sangamesh ◽  
Hiremath Shivashankar ◽  
K.S. Ravishankar ◽  
S.M. Kulkarni
Keyword(s):  
Natural Rubber ◽  
Energy Absorption ◽  
Experimental Validation ◽  
Absorption Capacity ◽  
Velocity Variation ◽  
Ballistic Limit ◽  
Ballistic Performance ◽  
Energy Absorption Capacity ◽  
Ballistic Limit Velocity ◽  
The Impact

This article focuses on the Finite Element (FE) analysis of the ballistic performance of the polymer composites consisting of natural rubber (NR), glass-epoxy (GE) and glass-rubber-epoxy (GRE) sandwich of different thicknesses (3, 6 and 9 mm) under the impact of the conical nose projectile for a velocity variation of (180, 220 and 260 m / s). FE modeling was carried out in direction to forecast the energy absorption, ballistic limit velocity and failure damage mode of the target materail. The significant influence of thickness, interlayer and sandwiching effect was studied: the lowest ballistic limit was obtained for 3 mm thick GE. Energy absorption capacity of GRE sandwich was highest among the natural rubber and GE. In future, the work can be extended for the experimental validation purpose, so that these polymer composite materials could be utilized to defence sector for bullet-proofing.

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