scholarly journals Constraining a shaped charge jet cavity in a barrier with boundary shields

2016 ◽  
pp. 24-29
Author(s):  
V. D. Golovatenko ◽  
A. V. Golovatenko
Keyword(s):  
Pressure Range ◽  
Wave Length ◽  
Acoustic Method ◽  
The Body ◽  
Shaped Charge ◽  
Linear Charge ◽  
Penetration Process ◽  
Linear Shaped Charge ◽  
Hydrodynamic Wave ◽  
Shaped Charge Jet

We suggest and validate empirically an acoustic method for decelerating and halting the movement of a shaped charge jet in a barrier by means of implementing an acoustic slit in the body of the barrier, the slit being located on the opposite side of the barrier relatively to the mounted linear charge with a profiled liner. We determine the pressure range created by a linear shaped charge with a profiled liner, and provide an estimation of the hydrodynamic wave length for the penetration process.

Towards a Better Understanding of Shaped Charge Jet Formation and Penetration

2019 ◽  
Author(s):  
David W. Price ◽  
Ernest J. Harris ◽  
Frances G. Daykin
Keyword(s):  
Phase 1 ◽  
3D Modelling ◽  
The Body ◽  
Shaped Charge ◽  
Device Design ◽  
Jet Formation ◽  
Shaped Charge Jet ◽  
2D And 3D ◽  
Data Reproducibility ◽  
Technology Demonstrator

Abstract JeMMA, a set of relatively simple shaped-charge devices, has been designed in order to generate suitable data on jet formation, break-up and penetration for code validation purposes. The JeMMA Phase 1 device incorporated a copper liner and six of these shaped charges were manufactured as a technology demonstrator and fired in a special shaped charge facility in December 2016. The radiographic results obtained from the JeMMA Phase 1 and 2 devices, along with data reproducibility between trials, was excellent. This report gives an overview of the Phase 1 and 2 trials, including device design, the results of the firings conducted in Switzerland and details of the subsequent 2D and 3D hydrocode modelling carried out at AWE. The agreement between the data and both 2D and 3D modelling of the experiments is very pleasing, but highlights where further work is required. These JeMMA experiments will enhance the body of relevant data required to provide the validation of the hydrocode materials and modelling methodologies and enable us to better model the jetting threats of our experiments and have higher confidence in the results of the modelling.

About the possibility of using compact projectiles formed by an explosion to break through underwater barriers

2020 ◽  
Author(s):  
V.I. Kolpakov ◽  
S.V. Ladov ◽  
S.V. Fedorov
Keyword(s):  
Finite Thickness ◽  
Water Layer ◽  
The Body ◽  
Shaped Charge ◽  
Design Parameters ◽  
Technical Solution ◽  
Head Part ◽  
Explosive Device ◽  
Shaped Charge Jet ◽  
Through Hole

The paper considers the possibility of using compact projectiles formed by an explosion to break through strong steel barriers of finite thickness protected by a layer of water. There is no problem in penetrating such barriers by high-gradient and high-speed shaped-charge jet of a small diameter formed by shaped charges with ‘high’ conical liners, however, the diameter of the through hole formed in the steel barrier is fairly small and does not meet the defeat criteria for corresponding barriers. To increase the diameter of a through hole in a steel barrier, shaped charges with ‘low’ conical or flat hemispherical liners (in the form of a meniscus) forming compact projectiles can be used, but the movement of such ‘shock cores’ in the water layer is sharply slowed down, up to a complete stop even before interacting with the main steel barrier. The purpose of the paper is to substantiate the possibilities of eliminating this disadvantage when using compact projectiles. Based on theoretical and experimental studies, the paper offers a technical solution related to the known fact of the formation of a cavern (gas cavity) during the movement of a shaped-charge jet in water, expanding as the jet penetrates in the radial direction. In this case, if a known tandem scheme of shaped charges placed one after the other along the axis of the explosive device is used, the first shaped charge, often called pre-charge, will penetrate the body in the head part of the explosive device to the water layer, then form in the latter a cavern up to the main penetrable barrier and the second shaped charge, often referred to as the primary, will form a compact projectile moving to penetrable barrier in the cavity formed by the penetration of shaped-precharge jet in the water. At the same time, due to selecting the necessary delay time between the pre-charge and main charge explosions as well as the design parameters of the pre-charge, the size of the expanding cavity must exceed the size of the compact projectile, excluding its interaction with water up to the approach to the penetrable steel barrier.

scholarly journals Experimental and Numerical Study on the PG-7VM Warhead Performance against High-Hardness Armor Steel

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3020
Author(s):  
Paweł Żochowski ◽  
Radosław Warchoł ◽  
Maciej Miszczak ◽  
Marcin Nita ◽  
Zygmunt Pankowski ◽  
...  
Keyword(s):  
Numerical Model ◽  
Numerical Study ◽  
High Hardness ◽  
The Body ◽  
Shaped Charge ◽  
Steel Plates ◽  
Technical Documentation ◽  
Jet Formation ◽  
Depth Of Penetration ◽  
Shaped Charge Jet

Analyses presented in the article were carried out in order to characterize the main parameters of the shaped charge jet formed due to detonation of the PG-7VM warhead. As opposed to the previously published studies in which rolled homogeneous armored steel was mainly used as a target, in the current work the warhead penetration capability was determined against more contemporary high-hardness (500 HB) ARMSTAL 30PM steel armor with precisely determined mechanical properties. The research included experimental depth of penetration tests and their numerical reproduction in the LS-Dyna software. Special attention was paid to factors that could perturbate the shaped charge jet formation process and under- or overestimate its penetration capability. For this reason, warheads were X-ray inspected for structural discrepancies (voids or air inclusions in explosive, misalignment between the body, explosive, and liner, or lack of contact between the explosive and the liner) and properties of materials (explosive, targets, and most important warhead components) were analyzed before the experiments. The numerical model of the warhead was defined more accurately than in previously published studies, since it was based on the real grenade dimensions and its technical documentation. Thanks to this, the depth of penetration of the target made of ARMSTAL 30PM armored steel plates by the shaped charge jet formed from the PG-7VM warhead obtained by numerical simulation was consistent with the experimental results and equaled 278 mm and 280 mm, respectively. The difference between the experimental and numerical value was smaller than 1%, which confirms that the developed methodology of modeling allows users to properly reproduce the PG-7VM shaped charge jet formation and target penetration processes. A verified numerical model of the shaped charge jet penetration into a steel target was used to determine depth of penetration in function of stand-off distance for the PG-7VM warhead. A maximum depth of penetration of about 317 mm was obtained for the stand-off distance of 360 mm, which may indicate the potential direction of modernization of warheads.

Influence of Rock Types on the Penetration by Linear Shaped Charge Jet with Uneven Thickness Clad in Cutting Excavation

2011 ◽  
Vol 261-263 ◽  
pp. 1665-1668
Author(s):  
Lian Jun Guo ◽  
Ai Ping Fei
Keyword(s):  
Crack Length ◽  
Iron Ore ◽  
Shaped Charge ◽  
Rock Material ◽  
Good Effect ◽  
Rock Types ◽  
Linear Shaped Charge ◽  
Shaped Charge Jet

In order to analysis the crack lengths of the different rocks which penetrated by the linear shaped charge jet with uneven thickness clad for cutting excavation, the ANSYS/LS-DYNA code was used to simulate the penetrating process which three kinds of rocks had been penetrated. The results show that: through simulating the penetrate process by eight kinds of linear shaped charge jet with uneven thickness clad, the longest crack was found in Gneiss, the shortest crack was found in Iron ore and the crack length of Granite in between. For the linear shaped charge in this record, the good effect was obtained through taking the uneven thickness clad which vary rate was 2%.The linear shaped charge jet with vary rate of less than 2% slightly was suitable for Gneiss, the linear shaped charge jet with vary rate of more than 2% slightly was suitable for Iron ore, and if Granite was penetrated by linear shaped charge jet with uneven thickness clad, the shaped charge which has 2% vary rate would be more appropriate. It is believe that through the features of penetrated rocks mentioned in the paper, new rock material can be applied easily for pre-splitting blasting engineering in cutting excavation.

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