Effect of liner material and explosive type on penetration effectiveness of shaped charge

Author(s):  
S Zaki ◽  
Emad Uddin ◽  
B Rashid ◽  
A Mubashar ◽  
Samiur R Shah

Shaped charges are used in many civilian and military applications. This study focuses on the effects of liner material and the type of explosive on the development of shaped charge jet. This was carried out by experimentation and numerical finite element-based modelling. Shaped charges were tested on a steel plate during the experimentation and the experimental data were used to validate the developed numerical model of the shaped charge. A hydrocode-based finite element model was able to predict the perforation and jet formation for the shaped charge, as well as the characteristics of the holes formed in the target plate. Several variations of the numerical model with the change of liner material and the filled explosive showed that the higher explosive resulted in higher velocity jet. The jet formation and velocity of jet were compared to determine the better performing combination of the material and explosive for the given shaped charge geometry. The underlying mechanisms were discussed in detail and compared with the previous studies.

2014 ◽  
Vol 664 ◽  
pp. 128-137
Author(s):  
Kamal Guendouz ◽  
Ayoub Sayhi ◽  
Wang Cheng

In this work, the shaped charge jet formation depends on different parameters which can has effect on jet behavior such as jet velocity, breakup and penetration. Jet radius or liner thickness, shell thickness, liner material density, α angle and stand-off distance are evaluated in purpose to investigate their effect on performance of shaped charge jet velocity and jet breakup phenomena, also we investigate the effect of stand-off distance on shaped charge jet penetration into steel target. We also studied the performance of some protective shields materials in order to assure more protection for vehicle structure against shaped charge jet penetration. For that, different materials were used as armors such as: kevlar epoxy, polyethylene, glass epoxy, steel-1006 and Al2O3 ceramic. These protective shields were evaluated in order to show their performance against shaped charge penetration into target. To do so, adopted explicit dynamic analyzing program Autodyn basing on finite element were used to simulate shaped charge jet formation and penetration. Autodyn-2D simulationshighlight the efficiency of our work comparing with the experiments done in literature and Birkhoff’s theory. In other terms, increasing in shell thickness, alpha angle and liner densityenhance jet breakup time, protective shields layered armor of steel-1006, steel 1006 with polyethylene and steel-1006 with Al2O3ceramic give more protection for structure against shaped charge jet penetration comparing with others armors.


2020 ◽  
Vol 11 (1) ◽  
pp. 20190123 ◽  
Author(s):  
Giulia Luraghi ◽  
Jose Felix Rodriguez Matas ◽  
Gabriele Dubini ◽  
Francesca Berti ◽  
Sara Bridio ◽  
...  

An acute ischaemic stroke appears when a blood clot blocks the blood flow in a cerebral artery. Intra-arterial thrombectomy, a mini-invasive procedure based on stent technology, is a mechanical available treatment to extract the clot and restore the blood circulation. After stent deployment, the clot, trapped in the stent struts, is pulled along with the stent towards a receiving catheter. Recent clinical trials have confirmed the effectiveness and safety of mechanical thrombectomy. However, the procedure requires further investigation. The aim of this study is the development of a numerical finite-element-based model of the thrombectomy procedure. In vitro thrombectomy tests are performed in different vessel geometries and one simulation for each test is carried out to verify the accuracy and reliability of the proposed numerical model. The results of the simulations confirm the efficacy of the model to replicate all the experimental setups. Clot stress and strain fields from the numerical analysis, which vary depending on the geometric features of the vessel, could be used to evaluate the possible fragmentation of the clot during the procedure. The proposed in vitro / in silico comparison aims at assessing the applicability of the numerical model and at providing validation evidence for the specific in vivo thrombectomy outcomes prediction.


2015 ◽  
Vol 65 (4) ◽  
pp. 279 ◽  
Author(s):  
Cheng Wang ◽  
Jianxu Ding ◽  
Haitao Zhao

<p>In this paper, the effect of liner material of the shaped charge on jet formation and its penetration capability is investigated by experimental and numerical methods. Liner materials investigated in this paper are copper, steel, and aluminium, respectively. Pulse X-ray photographic technology to shoot the formation of jet is employed to obtain the tip velocity and the diameter of jet. A two-dimensional multi-material code is designed to simulate the entire process from jet formation to penetrating a target. A markers on cell lines method is utilised to treat the multi-material interface. The results show that aluminium jet has the highest velocity with the poorest penetration capability. Copper jet has the strongest penetration capability with a velocity higher than that of steel jet, but lower than that of aluminium jet. The simulated results agree with the experimental results very well. It also indicates that the code developed can not only address large distortion problems but also track the variation of multi-material interfaces. It is favourable to simulate the explosive loading on thin-wall structure such as shaped charge. It is proved that authors’ method is feasible and reliable for optimising the structure of shaped charge jet to dramatically improve its tip velocity and penetration capability, and provides an important theoretic basis for designing high explosive anti-tank warhead.</p><p><strong>Defence Science Journal, Vol. 65, No. 4, July 2015, pp. 279-286, DOI: http://dx.doi.org/10.14429/dsj.65.8648</strong></p>


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3020
Author(s):  
Paweł Żochowski ◽  
Radosław Warchoł ◽  
Maciej Miszczak ◽  
Marcin Nita ◽  
Zygmunt Pankowski ◽  
...  

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.


2010 ◽  
Vol 148-149 ◽  
pp. 744-748 ◽  
Author(s):  
Yan Long Kang ◽  
Jian Wei Jiang ◽  
Shu You Wang ◽  
Jian Bing Men

This paper investigates the penetration performance of shaped charge against multi-layer target. A titanium alloy liner of shaped charge is proposed in order to obtain large perforated hole. Jet formation and penetrating into multi-layer target was calculated by hydro code AUTODYN. For different liner material include titanium alloy, mild steel and Cu, the explosion energy conversion, jet tip velocity and jet length, also the penetration performance are studied. It is found that the kinetic energy of jet is larger and the shape of jet is podgier when the liner material is titanium alloy, the perforated hole diameter on multi-layer improved 20% compare with the mild steel and Cu liner, the numerical simulation is good agreement to experimental results.


Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 875
Author(s):  
Jie Wu ◽  
Yuri Hovanski ◽  
Michael Miles

A finite element model is proposed to investigate the effect of thickness differential on Limiting Dome Height (LDH) testing of aluminum tailor-welded blanks. The numerical model is validated via comparison of the equivalent plastic strain and displacement distribution between the simulation results and the experimental data. The normalized equivalent plastic strain and normalized LDH values are proposed as a means of quantifying the influence of thickness differential for a variety of different ratios. Increasing thickness differential was found to decrease the normalized equivalent plastic strain and normalized LDH values, this providing an evaluation of blank formability.


2021 ◽  
Vol 309 ◽  
pp. 01214
Author(s):  
M.V.N Mohan ◽  
Ramesh Bhagat Atul ◽  
Vijay Kumar Dwivedi

Carbon/Carbon composites finds its applications in several high temperature applications in the field of Space, Aviation etc. Designing of components or sub systems with carbon/carbon composites is a challenging task. It requires prediction of elastic properties with a very high accuracy. The prediction can be normally done by analytical, numerical or experimental methods. At the design stage the designers resort to numerical predictions as the experimental methods are not feasible during design stage. Analytical methods are complex and difficult to implement. The designers use numerical methods for prediction of elastic properties using Finite Element Modeling (FEM). The spatial distribution of fibers in matrix has an effect on results of prediction of elastic constants. The generation of random spatial distribution of fibers in representative volume element (RVE) challenging. The present work is aimed at study of effect of spatial distribution of fiber in numerical prediction of elastic properties of unidirectional carbon/carbon composites. MATLAB algorithm is used to generate the spatial distribution of fibers in unidirectional carbon/carbon composites. The RVE elements with various random fiber distributions are modeled using numerical Finite element Model using ABAQUS with EasyPBC plugin. The predicted elastic properties have shown significant variation to uniformly distributed fibers.


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