scholarly journals Simulating Lateral Drift of a Shaped Charge Jet in ALEGRA

2019 ◽  
Author(s):  
Matthew J. Coppinger ◽  
W. Casey Uhlig ◽  
John H. J. Niederhaus
Keyword(s):  
Velocity Gradient ◽  
Explosive Charge ◽  
Shaped Charge ◽  
Analytical Models ◽  
Depth Of Penetration ◽  
Lateral Drift ◽  
The Difference ◽  
Shaped Charge Jet ◽  
Jet Axis ◽  
Penetration Velocity

Abstract Shaped charge jet (SCJ) research has long been an active area for industrial, academic, and defense organizations. Traditionally, the depth of penetration (DOP) has been one of the most important metrics for the evaluation of shaped charge jet performance, and early 1D analytical penetration models based on hydrodynamic penetration were created with this metric in mind [1]. As the standoff of a shaped charge jet increases, the DOP reaches a maximum and then begins to decrease. A simple 1D hydrodynamic penetration model must account for the totality of the jet material on axis penetrating, and as a result experimental DOP at longer standoffs is lower than the analytical models predicted. Some analytical models reasoned that since a velocity gradient evolves as a SCJ forms, contributions to penetration from jet material below a minimum jet or penetration velocity should be eliminated. These were better able to account for the difference between analytical hydrodynamic and experimental DOPs [2]. The actual difference between analytical hydrodynamic penetration theory and experimentally recorded values is now regarded to be a result of 3D phenomena including particle tumbling and motion transverse to the jet axis known as lateral drift [2]. The origins of these 3D phenomena have been attributed to sources including variability in the uniformity of the explosive charge or the microstructure of the liner [2,3].

scholarly journals Study on Penetration Performance of Rear Shaped Charge Warhead

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6526
Author(s):  
Yanan Du ◽  
Guanglin He ◽  
Yukuan Liu ◽  
Zhaoxuan Guo ◽  
Zenghui Qiao
Keyword(s):  
Numerical Simulation ◽  
Experimental Verification ◽  
Simulation Method ◽  
Shaped Charge ◽  
Experimental Results ◽  
Target Plate ◽  
Depth Of Penetration ◽  
Steel Target ◽  
Shaped Charge Jet ◽  
Control Cabin

In guided munitions, the shaped charge jet (SCJ) warhead is located behind the simulation compartment (including the control cabin, the steering gear cabin, and the guidance cabin). Therefore, the order of penetration of the SCJ is the simulation cabin and the target. To study the penetration performance of the SCJ to the target plate, the numerical simulation method is used to study the penetration performance of the designed warhead for the steel target at different standoffs, and the depth of penetration (DOP) at the best standoff is obtained, that is, the DOP of the steel target is about 128 mm. Additionally, the penetration performance of the SCJ warhead to target is studied by numerical simulation and experimental verification. Numerical simulation and experimental results show that the DOP of the SCJ warhead to the steel target is 50 mm without the simulation cabin, and about 30 mm with the simulation cabin. The results show that the penetration performance of SCJ is greatly weakened under the condition of non-optimal standoff, but the rear shaped charge warhead still has a strong penetration performance after completing the penetration of the simulated cabin.

scholarly journals Elastic–plastic modelling of shaped charge jet penetration

2006 ◽  
Vol 462 (2076) ◽  
pp. 3663-3681 ◽  
Author(s):  
Roman Novokshanov ◽  
John Ockendon
Keyword(s):  
Free Boundary ◽  
Local Scale ◽  
Shaped Charge ◽  
The Self ◽  
High Rate ◽  
Metal Target ◽  
Elastic Plastic ◽  
Shaped Charge Jet ◽  
Self Consistency ◽  
Penetration Velocity

This paper concerns the mathematical modelling of high-rate penetration of a metal target by a shaped charge device that produces a high-velocity jet. A key objective is to predict the penetration velocity, be it subsonic, transonic or supersonic. We do this by considering, on the local scale near the tip of the penetrated cavity, an elastic–plastic free boundary problem that takes into account the residual stresses produced by the moving plasticized region of the target. It is the self-consistency of this elastic–plastic model that dictates predictions for the penetration velocity.

scholarly journals Simulating lateral drift of a shaped charge jet in ALEGRA

2020 ◽  
Vol 136 ◽  
pp. 103415
Author(s):  
Matthew J. Coppinger ◽  
W. Casey Uhlig ◽  
John H.J. Niederhaus
Keyword(s):  
Shaped Charge ◽  
Lateral Drift ◽  
Shaped Charge Jet

The Role of Kelvin–Helmholtz Instabilities on Shaped Charge Jet Interaction With Reactive Armor Plates

2010 ◽  
Vol 77 (5) ◽  
Author(s):  
Andreas Helte ◽  
Ewa Lidén
Keyword(s):  
Parametric Study ◽  
Impact Angle ◽  
Shaped Charge ◽  
Contact Forces ◽  
Moving Plate ◽  
Protection Mechanism ◽  
Frictional Forces ◽  
The Difference ◽  
Shaped Charge Jet ◽  
The Impact

Reactive armor panels have been used for many years as very efficient add-on armor against shaped charge warheads. The main features of the defeat mechanisms of the armor are therefore well known. The origin of the irregular disturbances on the shaped charge jet, which leads to the severe fragmentation and scattering of the jet, is however not described in literature. As this scattering of the jet provides the main protection mechanism of the armor, it is of interest to understand the details of the interaction and the origin of the disturbances. Some experimental observations have been made showing that the backward moving plate often displaces the jet relatively smoothly while it is the interaction with the forward moving plate that causes the disturbances that leads to fragmentation and scattering of the jet. In this work, a mechanism for the interaction is proposed based on the theory of Kelvin–Helmholtz instabilities, which explains the origin of the disturbances on the jet due to the interaction with the forward moving plate. Numerical simulations have been performed to show the difference in the mechanisms of backward and forward moving plates when interacting with the jet. The impact angle of the plate seems to be the dominant parameter for the onset of instabilities. A parametric study has also been performed on how different interaction and material parameters influence the development of instabilities of the interface between the jet and the armor plate. The parametric study shows that low-strength jets promote development of instabilities, a tendency that is amplified by frictional forces between the materials. The influence of the plate strength is more complex due to the influence of the structural stability on the contact forces. The effect of friction and melting of the metals in the boundary layer to the development of the instabilities is discussed. A microscopic study of the edge of the penetration channel has been made, which shows that the materials have been melted during the interaction between the plate and the jet.

scholarly journals Study on the Interference Process of Liquid Radial Reflux on the Stability of a Shaped Charge Jet

2021 ◽  
Vol 11 (17) ◽  
pp. 8044
Author(s):  
Youer Cai ◽  
Xudong Zu ◽  
Yaping Tan ◽  
Zhengxiang Huang
Keyword(s):  
Theoretical Analysis ◽  
Composite Structure ◽  
High Speed ◽  
Side Wall ◽  
Shaped Charge ◽  
Bottom Plate ◽  
Depth Of Penetration ◽  
X Ray ◽  
Shaped Charge Jet ◽  
Filled Composite

The process of liquid radial reflux interference during jet penetration in a liquid-filled composite structure is divided in this study into three stages: bottom plate reflection interference, side-wall reflection interference, and side-wall secondary reflection interference. The calculation model of the velocity interval of the disturbed jet and the residual penetration depth of the jet has been established through theoretical analysis. Results show that the liquid-filled composite structure can interfere with the high-speed section of the shaped charge jet. The accuracy of the theoretical analysis in this paper has been verified through numerical simulation, X-ray, and depth-of-penetration experiments. Among the results, those of the X-ray experiment show that the liquid-filled composite structure has interference on the tip of the shaped charge jet, which provides a possibility for the application of the liquid-filled composite structure to ammunition safety and other extreme cases.

scholarly journals Explosive Device for Current Switching

2014 ◽  
Vol 59 (3) ◽  
pp. 1115-1118
Author(s):  
P. T. Bogdanovich ◽  
A.A. Komorny ◽  
B.A. Tarnopolsky
Keyword(s):  
Explosive Charge ◽  
Shaped Charge ◽  
Inert Material ◽  
Current Switching ◽  
Grooved Surface ◽  
Explosive Device ◽  
Jet Penetration ◽  
Explosive Devices ◽  
Shaped Charge Jet

Abstract The present paper deals with explosive devices for switching of kiloampere and megaampere current. The parameters of cumulation from a grooved surface and the parameters of shaped charge jet penetration into a barrier were analyzed depending on the initial properties of the explosive charge, the inert material and the barrier.

Numerical simulations of shaped charge jet penetration into concrete-like targets

2017 ◽  
Vol 8 (2) ◽  
pp. 237-259 ◽  
Author(s):  
Feng Hu ◽  
Hao Wu ◽  
Qin Fang ◽  
Jinchun Liu
Keyword(s):  
Penetration Depth ◽  
Constitutive Models ◽  
Shaped Charge ◽  
Standoff Distance ◽  
Depth Of Penetration ◽  
Whole Process ◽  
Jet Penetration ◽  
Metal Liner ◽  
Shaped Charge Jet ◽  
The Military

Shaped charge jet has been widely applied in the military and energy sources’ extraction fields; while the related investigations on the shaped charge jet penetration into concrete-like target are still limited, a series of numerical simulation works are conducted in this article. Holmquist–Johnson–Cook and Johnson–Cook models are used to describe the concrete-like targets and metal liner/casing of the shaped charge, respectively. The whole process including the formation, elongation in the air, and penetration into concrete-like target of shaped charge jet is reproduced using the multi-material arbitrary Lagrange–Euler algorithm and fluid–structure interaction method implemented in LS-DYNA. Simultaneously, the striking velocities of the jet (both tip and tail) and the damage of target (diameter and depth of penetration borehole) are derived. The above constitutive models, the corresponding material parameters, and the finite element algorithms are validated by comparing with the available tests’ data. The analyses of parametric influences are further performed. It indicates that for the unfragmented shaped charge jet, the penetration depth increases and the average penetration borehole diameter decreases with the standoff distance increasing, respectively; the compressive strength of concrete target has slight influence on the penetration depth of shaped charge jet; the diameter of shaped charge jet penetration borehole with aluminum liner is larger, while that with copper liner has a deeper penetration depth. It can also be found that the influence of explosive type on the penetration performance of shaped charge jet is negligible at small standoff distance, while the explosive LX-14 performs better than explosives Octol, B, and 8701 at larger standoff distance.

Investigation on the Impact and Penetration Performance of the Particulated Jet into Concrete Targets

2019 ◽  
Author(s):  
Qi-feng Zhu ◽  
Qiang-qiang Xiao ◽  
Zheng-xiang Huang ◽  
Xu-dong Zu ◽  
Xin Jia
Keyword(s):  
Titanium Alloys ◽  
Nickel Titanium ◽  
Shaped Charge ◽  
Ti Alloy ◽  
Depth Of Penetration ◽  
Experiment Method ◽  
Coherent Jet ◽  
Shaped Charge Jet ◽  
The Impact ◽  
Penetration Depths

Abstract In this study, the performance of titanium alloys (TC21, TC1), nickel-titanium (Ni-Ti) alloy, and zirconium-niobium (Zr-Nb) alloy lined shaped charge impact and penetration into concrete targets are investigated experimentally. Shaped charge jet radiographs reveal that the resulting jets of titanium alloys and Ni-Ti alloy exhibit particulate, radially dispersed behaviors, whereas that of the Zr-Nb alloy is coherent. Cavity diameters, penetration depths and parameters of the impact craters generated by the jets were analyzed using the depth of penetration (DOP) experiment method. Data indicate that the particulated jet causes more extensive damage to the surface of the concrete targets compared to the coherent jet. The penetration depth decreases to some degree, but the cavity diameter increases significantly. Penetration efficiency varies with degree of dispersion of the particulated jet and, as such, is also sensitive to stand-off distance.

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.

Sign in / Sign up

Export Citation Format

Share Document