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

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.

2017 ◽  
Vol 27 (9) ◽  
pp. 1352-1379 ◽  
Author(s):  
PS Patil ◽  
NK Naik

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.


2018 ◽  
Vol 10 (02) ◽  
pp. 1850020 ◽  
Author(s):  
Reza Mohamadipoor ◽  
Ehsan Zamani ◽  
Mohammad Hossein Pol

Penetration of flat-ended cylindrical projectiles into thin laminated composite plates was investigated analytically and experimentally. An analytical modeling was carried out for thin laminated composite plates by developing a new function for deflection by computing Von Karman nonlinear strains and by using the principle of energy balance. During the perforation process, different regions were considered for the plate, such as fracture region, elastic deformation region, delamination region, and undeformed region. The energy absorbed by each region was measured in small time intervals. To validate this model, the ballistic experiment is performed on the thin laminated composite plate near and beyond ballistic limit velocity. The samples were made from plain woven glass/epoxy using a hand lay-up method. In addition to the initial velocity, the residual velocity of the projectile was also measured using two parallel laser curtains. A comparison drawn between analytical and experimental results demonstrated a good consistency in the residual velocity of the projectile. Finally, the distribution of strains along the plate thickness direction over time, the different amounts of absorbed energy of the failure modes, delamination radius, and energy are assessed at near and beyond ballistic limit velocity.


2020 ◽  
Vol 70 (1) ◽  
pp. 82-89
Author(s):  
Beya Tahenti ◽  
Frederik Coghe ◽  
Rachid Nasri

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.


Author(s):  
Weinong Chen ◽  
Zherui Guo

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.


Author(s):  
A. Seyed Yaghoubi ◽  
B. Liaw

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.


2012 ◽  
Vol 28 (4) ◽  
pp. 715-726 ◽  
Author(s):  
Y.-L. Chen ◽  
H.-C. Chen

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.


Author(s):  
Suresh Periyasamy ◽  
Ramabalan Sundaresan ◽  
Natarajan Uthirapathy

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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