10,277 results on '"BALLISTICS"'
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2. Obtaining the Analytical Solution of the External Ballistics Problem with the Resistance Force Approximations
- Author
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Mishchenko, Andrey V., Orlov, Maxim Yu., editor, and Visakh, P. M., editor
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- 2024
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3. Estimating kinetic energy reduction for terminal ballistics using a hyperparameter-optimized neural network.
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Thompson, Brianna, Sherburn, Jesse, Ross, James, and Zhang, Yi
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ARTIFICIAL neural networks , *KINETIC energy , *BALLISTICS , *MACHINE learning , *RUNNING speed - Abstract
A coupled framework of ballistic simulations and an optimized machine learning (ML) model was developed to accurately predict the kinetic energy reduction of a projectile impacting a target. ML models can require a significant number of data points for proper training, testing, and validation. High-performance computing (HPC) resources can be used to simulate the ballistic impacts of various projectiles against several different target materials using appropriate physics-based hydrocodes. Computational modeling can explore areas where experiments would naturally be cost-prohibitive. These hydrocodes can evaluate large parametric spaces varying the projectile and target variables that are required to train an ML model. In this study a large, generated set of data points was used to develop an optimized artificial neural network (ANN) algorithm to create a fast-running model without prior knowledge of the mathematical relationships between all the input and output variables. The optimized ANN model was developed using Optuna in an HPC environment to tune the hyperparameters needed for the ANN model. This fast-running ML model could then be leveraged to investigate designing optimized targets that could protect against different types of projectiles. The results of this work showed that the optimized ANN model predicted the kinetic energy reduction with a mean absolute percentage error of 2.7% across the validation data. Overall, the optimized ANN model showed excellent agreement across the range of data considered by the computational models. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Investigating the potential of using reed (Phragmites) arrowshafts in prehistoric Europe through mechanical and experimental research.
- Author
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Cetwińska, Aleksandra, Koczan, Grzegorz Marcin, Sadło, Maciej, Cetwiński, Krzysztof, Skrzyński, Grzegorz, and Manasterski, Dariusz
- Abstract
The discovery of a specific form of Late Neolithic object in northeast Poland, commonly interpreted as reed arrowshaft straighteners, prompted investigation into the possible use of reed for archery in the European past. To examine the archery qualities of this raw material, and thus the likely rationale behind the manufacture and use of reed arrowshafts, a number of mechanical and experimental analyses were conducted. The results presented here indicate that reed was well suited for prehistoric archery. This is demonstrated above all by the arrowshaft stiffness required by this discipline, defined as the spine‐force, but also both the technological ease of production of arrows and their ballistic capabilities. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Cutaneous skin defects overlying tangential gunshot wounds: A case series.
- Author
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Nickson, Nikoli M., DeJong, Joyce L., Brooks, Jared K., and Prahlow, Joseph A.
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GUNSHOT wounds , *FORENSIC pathologists , *SKIN injuries , *ENTRANCES & exits , *PROJECTILES , *SKIN - Abstract
In examining deaths resulting from gunshot wounds, it is important to describe the wound pathway created by the projectile. Forensic pathologists must identify all entrance and exit wounds and account for all projectiles. Occasionally, confusion arises as to whether a skin defect represents an entrance wound or not, an exit wound, or some other type of wound. Herein, we propose the descriptor "bullet track skin defect" as a formal description for a superficial skin defect created along the pathway of a projectile within the body. Specifically, we define the "bullet track skin defect" as a partial‐ or full‐thickness skin defect produced by a projectile traveling beneath the skin in a relatively tangential fashion as part of a wound pathway within the body. It is somewhat analogous to a traditional graze or superficial tangential wound, wherein the projectile traveling outside the body strikes the skin tangentially from above, without entering the body. However, the projectile is already traveling within the body with the bullet track skin defect, disrupting the skin tangentially from below rather than from above, without exiting the body. Although these defects are not a common presentation of gunshot wounds, they are certainly not rare. With this case series, we suggest that such defects may be referred to as "bullet track skin defects." Alternative language that can substitute for "bullet track skin defects" includes "bullet track skin wounds" or "bullet track cutaneous defects." [ABSTRACT FROM AUTHOR]
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- 2024
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6. Observing the fragmentation of two expanding bullet types and a full metal-jacketed bullet with computed tomography—a forensic ballistics case study.
- Author
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Oura, Petteri, Niinimäki, Jaakko, Brix, Mikael, Lammentausta, Eveliina, Liimatainen, Timo, Junno, Alina, and Junno, Juho-Antti
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COMPUTED tomography , *BALLISTICS , *BULLETS , *GUNSHOT wounds , *FIRE testing - Abstract
Computed tomography (CT) may have a crucial role in the forensic documentation and analysis of firearm injuries. The aim of this forensic ballistics case study was to explore whether two types of expanding bullets and a full metal-jacketed bullet could be differentiated by inspecting bullet fragments and fragmentation pattern in CT. Three types of.30 caliber bullets (full metal-jacketed Norma Jaktmatch, expanding full-copper Norma Ecostrike, and expanding soft-point Norma Oryx) were test fired from a distance of 5 m to blocks of 10% ballistic gelatine. CT scans of the blocks were obtained with clinical equipment and metal artifact reduction. Radiopaque fragments were identified and fragmentation parameters were obtained from the scans (total number of fragments, maximum diameter of the largest fragment, distance between entrance and the closest fragment, length of the fragment cloud, and maximum diameters of the fragment cloud). The fragmentation patterns were additionally visualized by means of 3D reconstruction. In CT, the bullet types differed in several fragmentation parameters. While the expanding full-copper bullet Ecostrike left behind only a single fragment near the end of the bullet channel, the soft-point Oryx had hundreds of fragments deposited throughout the channel. For both expanding bullets Ecostrike and Oryx, the fragments were clearly smaller than those left behind by the full metal-jacketed Jaktmatch. This was surprising as the full metal-jacketed bullet was expected to remain intact. The fragment cloud of Jaktmatch had similar mediolateral and superoinferior diameters to that of Oryx; however, fragments were deposited in the second half of the gelatine block, and not throughout the block. This case study provides a basis and potential methodology for further experiments. The findings are expected to benefit forensic practitioners with limited background information on gunshot injury cases, for example, those that involve several potential firearms or atypical gunshot wounds. The findings may prove beneficial for both human and wildlife forensics. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Analysis of geometric parameter variation effects on ballistic rocket dynamic performance.
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Putro, Idris Eko, Arifin, Muhammad Subhan, Arira, Muhammad Farras, Sembiring, Javensius, and Wicaksono, Bagus
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GEOMETRIC analysis , *CENTER of mass , *BALLISTICS , *MOMENTS of inertia - Abstract
Analysis of longitudinal and lateral of ballistic rocket dynamics is presented in this paper. The dynamic analysis is carried out by linearizing the equation of motion of the rocket. The effect of an inaccurate geometric parameters of the location of the center of gravity (CG) in the longitudinal direction, location of the center of gravity in the normal direction, moment of inertia Iyy, and nose shape from its on-design parameter on dynamics characteristics, are presented. The effects of variation of these parameters will be analyzed based on its poles location, bode plot, and step response due to input from the control surface. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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8. USE OF SODIUM RHODIZONATE IN FIREARM USE CASES: CAN IT BE USEFUL IN IDENTIFYING THE SHOOTER?
- Author
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Benedetta Pia De Luca
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ballistics ,gunshot residues ,sodium rhodizonate ,case report ,forensic ballistics ,Medicine (General) ,R5-920 - Abstract
The sodium rhodizonate test is a simple colorimetric technique used to identify traces of lead and barium. A positive test provides rapid and photographically documentable results for shots fired at distances not exceeding 50 cm. Usually, this method is not used for identification of the firing hand, which is detected by electron microscopy with energy dispersive analysis (SEM-EDX), requiring the removal of any particles on the surface to be analyzed by STUB. The use of Sodium Rhodizonate, which is undoubtedly less selective, has the disadvantage of target element solubilization (lead and barium) and thus the loss of the preliminary morphological investigation of the particles. The purpose of this paper is to demonstrate that the two indicated methods can be considered complementary in the following order: 1. buffer sampling for electron microscopy investigation (STUB); 2. and subsequent performance of the Sodium Rhodizonate Test. In some special cases, when it is necessary to obtain the result more quickly, with regards to respecting the chronology of the aforementioned tests, it may be useful to carry out the Sodium Rhodizonate Test first, especially when particular and perhaps antiquated weapons were used for suicidal purposes causing considerable gas dispersion and shot residues from the mechanisms. This research illustrates how significant results were obtained substantiating the suicide hypothesis, following the use of an old revolver (year of manufacture around 1915-1920).
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- 2023
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9. Particularities of ballistic spinal injuries and management in an African context (Chad): Study of 27 cases
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Yannick Canton Kessely, Abbia Beidjam Oryon, Ndolembai S. Njesada, Olivier li-Iyané, Félicien G. Toudjingar, Mohameth Faye, Fandebnet Siniki, Ngamai Kotyade, Kader Ndiaye, Aboubacar Aouami, Brahim Soukaya, Traoré Sory, Donald Djasde, Kaimba Bray, Constant Assi, and Momar Codé BA
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Medullary vertebral trauma ,Ballistics ,Arthrodesis ,Surgery ,RD1-811 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
The frequency of ballistic spinal injuries is rising in developing nations around the globe. These injuries lead to a functional prognosis linked to disabling sequelae and vitals in patients, which often results in serious complications and death.This study describes the epidemiological, diagnostic, therapeutic, evolutionary characteristics of Ballistic Medullar-Vertebral trauma (BMVT). It presents the particularities of management in the sub-Saharan African country of Chad.This is a prospective descriptive study of 27 ballistic spinal injury patients conducted over an 18-month period.Ballistic Medullar-Vertebral injuries (BMVI) represented 12.9 % of spinal trauma. The average age of the patients was 31.8, and 40.7 % were between 31 and 40 years of age. Military personnel represented 78 % of the patients. 44.4 % of cases came from the Lake Chad region. 59.3 % of injuries were caused by Kalashnikov’s (AK 47) firearms. 74.1 % of cases were admitted to the emergency department within 12 to 24 h. The diameter of the wounds that corresponded to the entry orifice of the bullet was between 1 and 2 cm in 59.25 % of the cases. A Dural breach was found in 14.8 %. 48.1 % had ASIA C score and none of them met the criteria for spinal cord injury collection and immobilization. The lumbosacral location was reported in 55.6 %, and the type I Roy Camille fracture was found in 70.37 %. Surgical management was performed in 88.9 % cases. Multidisciplinary management of the associated lesions was performed in 25.9 %. 7.4 % of patients with cervical trauma died due to septic shock.Delayed emergency department admissions and limited access to medicalized transportation are main factors to BMVI in Chad. Lesion is predominantly located in the lumbosacral region. Lesions and spinal cord involvement were factors of poor vital and functional prognosis. Surgery plays an important role in management. Socio-professional reintegration remains problematic.
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- 2024
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10. On the relative importance of shocks and self-gravity in modifying tidal disruption event debris streams.
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Fancher, Julia, Coughlin, Eric R, and Nixon, C J
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SUPERMASSIVE black holes , *BALLISTICS , *GRAVITATIONAL fields , *CORONAL mass ejections - Abstract
In a tidal disruption event (TDE), a star is destroyed by the gravitational field of a supermassive black hole (SMBH) to produce a stream of debris, some of which accretes onto the SMBH and creates a luminous flare. The distribution of mass along the stream has a direct impact on the accretion rate, and thus modelling the time-dependent evolution of this distribution provides insight into the relevant physical processes that drive the observable properties of TDEs. Analytic models that only account for the ballistic evolution of the debris do not capture salient and time-dependent features of the mass distribution, suggesting that fluid dynamical effects significantly modify the debris dynamics. Previous investigations have claimed that shocks are primarily responsible for these modifications, but here we show – with high-resolution hydrodynamical simulations – that self-gravity is the dominant physical mechanism responsible for the anomalous (i.e. not predicted by ballistic models) debris stream features and its time dependence. These high-resolution simulations also show that there is a specific length-scale on which self-gravity modifies the debris mass distribution, and as such there is enhanced power in specific Fourier modes. Our results have implications for the stability of the debris stream under the influence of self-gravity, particularly at late times and the corresponding observational signatures of TDEs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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11. High-resolution mapping and dispersion analyses of volcanic ballistics emitted during the 3rd July 2019 paroxysm at Stromboli.
- Author
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Bisson, M., Spinetti, C., Gianardi, R., Strehlow, K., De Beni, E., and Landi, P.
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PARTICLE size determination , *BALLISTICS , *SPATIAL resolution , *VOLCANOES , *POLYGONS , *VOLCANIC eruptions - Abstract
A detailed mapping of volcanic ballistic projectiles emplaced in a defined area, represents the starting point to derive preparatory data in hazard and risk studies of ballistics phenomena. Considering as case study the 3rd July 2019 paroxysmal eruption occurred at Stromboli volcano, we map and analyse at very high spatial resolution (8 cm) the distribution of the ballistic spatter clasts emplaced on the E flank of the volcano. The resulting map identifies and reproduces as geospatial polygon elements 152,228 spatter clasts with areal dimensions from 0.03 to 4.23 m2. Dispersed on 0.407 km2, the spatters cover an area of 29,000 m2 corresponding to an erupted products volume from 2.3 to 7.0 × 103 m3, calculated here for the first time. Spatial analyses indicate that the area mostly affected by the clasts emplacement is between N67.5 and N135 directions, identifying a preferential deposition between N112.50 and N123.75 directions. The clasts size distribution rapidly decreases with the size increase, highlighting a nearly constant ratio small/large clasts regardless the distance from the vent. Finally, additional investigations reveal that clasts dispersion parameters decrease progressively with the distance from the vent only along one direction (N67.5), highlighting how the morphology influences the deposition and remobilisation of mapped ballistics. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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12. Influence of the Gradual Ignition of a Powder in a Gun and of its Nonstationary and Erosion Burning on the Internal Ballistics of a Gunshot.
- Author
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Rusyak, I. G. and Lipanov, A. M.
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BALLISTICS , *POWDERS , *EROSION , *IGNITION temperature , *FIREARMS , *GAS dynamics - Abstract
A mathematical simulation of the internal ballistics of a shot from a gun, depending on the design of the charge of the gun, has been performed. A general system of equations defining the unsteady movement of a two-phase gas–powder mixture in the channel of the barrel of a gun in the one-dimensional approximation is presented. Results of simulation of a shot from a gun charged with tubular powder or chopped powder are presented. The influence of the gradual ignition of a powder in a gun and of its nonstationary and erosion burning in it on the parameters of the ballistic process in the gun and the influence of the mass and disposition of an igniter in the gun on the dynamics of a shot from it were investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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13. Recoil reduction and projectile velocity improvement design of recoilless gun with combustible cartridge.
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Liu, Pengzhan, Wang, Guoqiang, Yang, Zhen, and Zhao, Xiongfei
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PROJECTILES , *DRONE aircraft , *BALLISTICS , *FIREARMS , *VELOCITY - Abstract
In the era of unmanned war, with the increasing muzzle velocity requirement, the design of gun is significantly restricted by recoil, especially for guns installed on unmanned aerial vehicles. A recoilless gun with combustible cartridge was designed to eliminate recoil and increase projectile velocity, and the influence of main parameters on recoil was studied. First, a design of a recoilless gun with high projectile velocity is proposed based on combustible cartridge case. Next, a classical interior ballistic model is developed during the recoilless gun firing cycle, and the effect of main parameters of interior ballistics on the performance is investigated. Additionally, simple nonlinear fitting formulae are defined to highlight the variation of recoil momentum with the time of interior ballistic model. Finally, numerical simulation results are compared with the test results to validate the feasibility of the design. The experimental results demonstrate that the classical interior ballistic model can be used to accurately analyze the effect of the parameters on the projectile velocity and the recoil reduction efficiency. The projectile velocity of the recoilless gun could raised to 1200 m/s and the recoil momentum could be eliminated almostly. Therefore, the newly designed recoilless gun effectively eliminates the recoil momentum and significantly improves the projectile velocity. The findings should make an important contribution to the field of engineering applications of recoilless gun. [ABSTRACT FROM AUTHOR]
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- 2023
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14. The effect of ambient temperature on the internal ballistic overload of a large-caliber artillery projectile fuze system.
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Zilong Yang, Deren Kong, and Chunyan Zhang
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TEMPERATURE effect , *PROJECTILES , *ARTILLERY , *SIMULATION software , *BALLISTICS - Abstract
The change of ambient temperature will cause the change of gunpowder burning rate, which will directly affect the ballistic performance of the projectile and cause the change of the overload of the projectile fuze system. In this study, the numerical simulation program of the interior trajectory of a large-caliber gun was established by MATLAB, and the variation rules of the corresponding trajectory parameters at different temperatures were obtained. ANSYS finite element software is used to analyze the force of the projectile fuze system under different ambient temperatures. The results show that under the same loading conditions, with the increase of ambient temperature, the maximum pressure in the gun bore and the muzzle velocity of the projectile increase significantly, and the stress and strain of the projectile fuze system in the bore increase gradually. The numerical simulation results are in good agreement with the theory, which reveals the influence of ambient temperature on the overload in the bore of the projectile fuze system to a certain extent, and provides theoretical support for the study of internal ballistics, charge design and gun use. [ABSTRACT FROM AUTHOR]
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- 2023
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15. Investigation of combustion process in a modular charge system with a primer gap.
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Tianyi Ma, Hao Wang, and Ruyi Tao
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AXIAL flow , *COMBUSTION , *CONSERVATION laws (Physics) , *BALLISTICS - Abstract
To clarify the combustion process of a modular charge system with a primer gap, the rules governing the cartridge movement and pressure change in the chamber are analyzed. Based on the characteristics of the modular charge system, an axisymmetric two-phase flow model of the interior ballistics is established, with the monotonic upward-centered scheme for conservation laws adopted to calculate the combustion process. Compared with the experimental results, the difference in the peak pressure is less than 5%, which indicates that the mathematical model and scheme are reliable and accurate. The results show that, during the initial stage of ignition, the combustible container remains unbroken, and the gas and solid particles are prevented from spreading to the chamber by the end cap of the cartridge. Thus, only the gas inside the igniter tube influences the flow field in the chamber. After the combustible container has broken, the gas and solid particles move rapidly toward the cavity from the combustible container. The axial movement of solid particles is more intense than that of the gas particles, but the radial movement of solid particles is relatively weak. Furthermore, the existence of the primer gap leads to a delay in the ignition time of the solid particles, which delays the rupture time of the igniter tube and the module cartridge. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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16. A review on the effect of ageing on the ballistic properties of solid gun and rocket propellants.
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Pettifer, Ruth and Tod, Dave
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SOLID propellants ,PROPELLANTS - Abstract
This review covers the effect of ageing on solid gun and rocket propellants in terms of their ballistic properties. A brief overview of the types of methods, which can be used to determine such parameters, is provided and the literature is described in terms of broad motivation areas for the research. It has been demonstrated that understanding the effects and outputs of propellants, and how these might be affected by ageing, remains an important area of research in the field of energetic materials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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17. Failure Investigations on Low Velocity Ballistic Impact Deformation of Closed-Cell Aluminum Metal Foam Targets.
- Author
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Suresh Kumar, S., Sabareeswar, R., Siddharth Krishna, S., Suraj, R., and Vishal, B.
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BALLISTICS ,METAL foams ,ALUMINUM foam ,FOAM ,DEFORMATIONS (Mechanics) ,SPECIFIC gravity ,VELOCITY - Abstract
Low velocity ballistic deformation behavior of closed-cell aluminum metal foam targets fabricated by powder metallurgy technique has been investigated. The metal matrix of aluminum (60 micron) was mixed with carbamide (CH
4 N2 O) particles of size one mm. Green samples were obtained by compacting the mixture followed by sintering process using a muffle furnace and the metallic foam thus obtained had an average pore size of 1.5 mm. Compared to metallic material, significant reduction in hardness and density was observed when the porosity was increased from 5 to 30%. Using a gas gun setup, low velocity (100 m/s and conical projectile) ballistic experiments were conducted on metal foam targets to understand the deformation behavior. Not any penetration of the projectile was observed when the percentage of porosity was less than 5%. When the percentage of porosity was increased, the projectile was able to perforate the target as the fracture toughness decreases. The size of fragmented areas of the perforated targets and depth of penetration (DoP) of the projectile were measured. Decrease in DoP (improved ballistic resistance) was observed with the increase in relative density of the closed foam target. Even though the projectile could perforate the foam target, no cracks were observed which enhances the suitability of the metal foams to be used as structural applications of defense vehicles. [ABSTRACT FROM AUTHOR]- Published
- 2024
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18. Protective performance of shear stiffening gel-modified foam against ballistic impact: Experimental and numerical study.
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Huan Tu, Haowei Yang, Pengzhao Xu, Zhe Yang, Fan Tang, Cheng Dong, Yuchao Chen, Lei Ren, Wenjian Cao, Chenguang Huang, Yacong Guo, and Yanpeng Wei
- Subjects
BALLISTICS ,PERSONAL protective equipment ,ETHYLENE-vinyl acetate ,PROJECTILES ,FINITE element method ,ENERGY absorption films - Abstract
As one of the most widely used personal protective equipment (PPE), body armors play an important role in protecting the human body from the high-velocity impact of bullets or projectiles. The body torso and critical organs of the wear may suffer severe behind-armor blunt trauma (BABT) even though the impactor is stopped by the body armor. A type of novel composite material through incorporating shear stiffening gel (STG) into ethylene-vinyl acetate (EVA) foam is developed and used as buffer layers to reduce BABT. In this paper, the protective performance of body armors composed of fabric bulletproof layers and a buffer layer made of foam material is investigated both experimentally and numerically. The effectiveness of STG-modified EVA in damage relief is verified by ballistic tests. In parallel with the experimental study, numerical simulations are conducted by LS-DYNA® to investigate the dynamic response of each component and capture the key mechanical parameters, which are hardly obtained from field tests. To fully describe the material behavior under the transient impact, the selected constitutive models take the failure and strain rate effect into consideration. A good agreement between the experimental observations and numerical results is achieved to prove the validity of the modelling method. The tests and simulations show that the impact-induced deformation on the human body is significantly reduced by using STG-modified EVA as the buffering material. The improvement of protective performance is attributed to better dynamic properties and more outstanding energy absorption capability of the composite foam. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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19. Ballistic design and testing of a composite armour reinforced by CNTs suitable for armoured vehicles.
- Author
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Tsirogiannis, Evangelos Ch., Daskalakis, Evangelos, Hassan, Mohamed H., Omar, Abdalla M., and Bartolo, Paulo
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ARMORED military vehicles ,BALLISTICS ,METALLIC composites ,CARBON nanotubes ,POWDER metallurgy - Abstract
This paper is investigating the use of composite armour reinforced by nanomaterials, for the protection of light armoured (LAV) and medium armoured military vehicles (MAV), and the interaction between the composite materials and high-performance ballistic projectiles. Four armour materials, consisted of front hybrid fibre reinforced polymer cover layer, ceramic strike-face, fibre reinforced polymer intermediate layer and the metal matrix composite reinforced backplate, were manufactured and assembled by adhesive technology. The proposed laminated protection system is suitable for armoured ground vehicles; however, it could be used as armour on ground, air and naval platforms. The design of the protection system, including material selection and thickness, was elaborated depending on the performance requirements of Level 4 + STANAG 4569 military standard (projectile 14.5 mm ( 114 mm API B32) and especially on a design philosophy which is analysed with the specifications. The backplate of this new composite is a hybrid material of Metal Matrix Composite (MMC) reinforced with carbon nanotubes (CNTs), manufactured with the use of powder metallurgy technique. The composite backplate material was morphologically, mechanically and chemically analysed. Results show that all plates are presenting high mechanical properties and ballistic characteristics, compared to commonly used armour plates. Real military ballistic tests according to AEP - STANAG 4569 were carried out for the total composite armour systems. After the ballistic tests, AA2024-CNT3 showed the best protection results, compared with the other plates (AA2024-CNT1 and AA2024-CNT2), with the projectile being unable to fully penetrate the composite plate. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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20. An internal ballistic model of electromagnetic railgun based on PFN coupled with multi-physical field and experimental validation.
- Author
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Benfeng Gu, Haiyuan Li, and Baoming Li
- Subjects
ELECTROMAGNETIC rail guns ,BALLISTICS ,SPECTROMETERS ,MAGNETIC flux density ,STRESS-strain curves - Abstract
To accelerate the practicality of electromagnetic railguns, it is necessary to use a combination of threedimensional numerical simulation and experiments to study the mechanism of bore damage. In this paper, a three-dimensional numerical model of the augmented railgun with four parallel unconventional rails is introduced to simulate the internal ballistic process and realize the multi-physics field coupling calculation of the rail gun, and a test experiment of a medium-caliber electromagnetic launcher powered by pulse formation network (PFN) is carried out. Various test methods such as spectrometer, fiber grating and high-speed camera are used to test several parameters such as muzzle initial velocity, transient magnetic field strength and stress-strain of rail. Combining the simulation results and experimental data, the damage condition of the contact surface is analyzed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. Ballistic armor—a study on the impact of air gun pellets on jean cloth
- Author
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B. G. Chinmayi, Ashwini Kumar, and M. S. Arjun
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Ballistics ,Entry hole ,Pellets ,Jeans ,Track length ,Law in general. Comparative and uniform law. Jurisprudence ,K1-7720 ,Medicine (General) ,R5-920 - Abstract
Abstract Background Ballistics deals with the study of projectile propulsion, flight, and impact in any medium. Different garment materials can have varying effects when it comes to the penetration of pellets into the body. Body armor has been around for a long time. Dhal, a curving strip of rhino hide, was possibly the first armor in India, used for sword fighting or defense against arrows and spears. It gave way to steel armor, which protected the body’s essential organs from spear and arrow strikes. The current study is primarily concerned with how jeans material, when employed as body armor, contributes to the inquiry. The present study also examines how airgun pellets fired at various ranges affect jeans clothing wrapped around gel blocks. Results The study concluded that when fired at varied ranges, there was no significant variation in the diameters of the entry holes on clothing material. The gel block covered with jeans clothing was not found to be more damaged. Conclusions The findings also indicate that pellets had larger track lengths regardless of the range from which they were fired.
- Published
- 2023
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22. New alginate-gelatine method for casting of staining inside firearm barrels
- Author
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Schyma, Christian and Berthold, Matthias
- Published
- 2024
- Full Text
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23. A Comprehensive Review of Wound Ballistics: Mechanisms, Effects, and Advancements
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Kaur, Gurleen, Mukherjee, Debhjit, and Moza, Bhavika
- Published
- 2023
- Full Text
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24. Dynamic response of thin targets under ballistic impact
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Stergiou, Theodosios
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Ballistics ,Impact ,Polyurea ,Thin Target ,Non-axisymmetric projectiles ,FEA ,Simulations ,Finite element method ,Numerical experiments ,Numerical Analysis ,ballistics experiments ,Impact analysis ,Polyurea Coating - Published
- 2022
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25. Analysis of the Possibility of Elimination of Threats Resulting from the Modification of Bullet Trajectory after Hitting the Target in Garrison Shooting Ranges
- Author
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Józef GACEK, Wojciech KOPERSKI, Bronisław MARCINIAK, Ryszard WOŹNIAK, Dariusz TYMIŃSKI, Ewa MORZYK, Konrad SUSKA, Przemysław SIDELNIK, and Przemysław LEWANDOWSKI
- Subjects
ballistics ,shooting range ,ricochet ,Electronics ,TK7800-8360 ,Chemical engineering ,TP155-156 - Abstract
. During shooting operations in garrison shooting ranges, a phenomenon of random deflection of the bullet flight path was noticed which may cause secondary reflections from accidentally hit technical and ballistic shooting range elements and the ground of the actual plane of the shooting range (ricochets posing a threat to people and property within the shooting range and safety zones). Minimisation of this phenomenon must be considered during the design and operation of the shooting ranges. In 20202022 the Military Institute of Armament Technology (Zielonka, Poland) carried out tests with the aim of determining the impact of the shooting target or military target material or design (hereinafter referred to as the targets) on the risk of occurrence of modifications of bullet trajectory that cause the bullets to leave the shooting zone. The paper presents example results of these tests that show, but are not limited to, that the reasons to modify the direction of the bullet path after target penetration and any ricochets include: target material (flat or corrugated sheet metal, cardboard, plywood, etc.), target wooden legs, and even metal elements fixing the legs to the target. On the basis of the test it was shown that the metal targets prohibited on intermediate lines may cause significant deflections of the bullet flight path after penetration and dangerous ricochets. Due to the reason presented above, the metal targets are placed on the last line of targets before the main bullet trap only where the technical and ballistic parameters of the bullet trap ensure that any ricochets are captured. It was stated that the contact targets used on intermediate target lines and provided with wooden legs may cause bullet trajectory changes comparable to or even greater than in the case of the prohibited metal targets. To this end it is advisable to establish legal framework covering the ballistic inspection of the target materials to be used in garrison shooting ranges.
- Published
- 2023
- Full Text
- View/download PDF
26. Comparison of four ballistic and thrusting target materials: An experimental and Bayesian approach using static testing of stone and steel arrow tips.
- Author
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Mullen, Damon, Sitton, Jase, Story, Brett, Buchanan, Briggs, Walker, Robert S., Eren, Metin I., and Bebber, Michelle R.
- Subjects
- *
PENETRATION mechanics , *PEAK load , *THRUST , *STEEL , *PROJECTILES , *WEAPONS - Abstract
Researchers use a variety of target materials, and sometimes combinations of materials, in their archaeological experiments to examine thrust‐spear or projectile penetration, impact angle, durability, and other issues involving prehistoric hunting weaponry. This variety of target materials is beneficial to archaeological science in several ways, but it may also hinder the comparison of results because many of these target materials do not necessarily share similar physical properties. Here, we assess the penetration properties of four different target materials—store‐bought meat, clay, and two types of gelatin—via static penetration tests of a modern broadhead‐tipped arrow and a stone‐tipped projectile attached to an Instron Universal Materials Tester. Our analyses of load‐deflection curves, peak load, and work energy demonstrate how the four target materials are similar in some ways but different in others, which suggests that researchers may strategically employ one or several depending on the question asked or hypothesis tested. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
27. Transit time thermalization and the stochastic wave energization of ions in quasi-perpendicular shocks.
- Author
-
Stasiewicz, Krzysztof
- Subjects
- *
ION acoustic waves , *MAGNETIC ions , *SHOCK waves , *WIND power , *BALLISTICS , *SOLAR wind , *MAGNETIC fields , *THERMAL instability , *MECHANICAL shock - Abstract
It is shown that the ratio of the proton convective gyroradius r Ep, to the width of the shock ramp D , controls the thermalization process of ions in quasi-perpendicular shocks. When r Ep/ D > 1, the solar wind beam energy is rapidly converted to gyration (thermal) energy by a universal, transit time thermalization (TTT) mechanism that does not require any collisions, waves, or instabilities. The TTT of ions on magnetic field gradients is followed by stochastic wave energization (SWE) on electric field gradients. Ions heated by TTT and SWE processes are subject to additional ballistic surfing acceleration caused by the convection field in the shock front. These three fundamental ion energization mechanisms are studied with test-particle simulations in a realistic shock model, and are shown to be consistent with magnetospheric multiscale measurements in the Earth's bow shock. It is also shown that shock reflected ions are produced by the SWE process and not by the cross-shock potential. An explanation for downstream oscillations in quasi-perpendicular shocks is also provided. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
28. An efficient two-phase flow calculation method based on grid mergence and dimension transformation.
- Author
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Zhang, Bozi, Cheng, Shenshen, Tao, Ruyi, and Jiang, Kun
- Subjects
- *
FLOW simulations , *BALLISTICS , *TRUST , *DATA transmission systems , *TWO-phase flow - Abstract
Two-phase flow numerical methods are applied in internal ballistics widely, which has made higher fidelity analysis with minimal cost become an urgent demand. Current methods are based on independent dimension, and there is no definite conversion criterion and data transmission method, which have limited the application of efficient hybrid models applied to calculation. In this paper, we propose a hybrid method by linking a two dimensional (2D) model to a one dimensional (1D) model for two-phase flow. First, 1D and 2D two-phase flow models are established according to the flow field states in different phases. Next, the criterion of conversion between the two models is established, which is a quantitative index to judge the degree of radial effect and axial effect. Finally, dimension transformation in the radial direction and grid mergence in the axial direction are conducted to complete the whole computing model. The simulation results show that the hybrid method is more efficient in the interior ballistic process and maintains the level of trust in classical codes. Compared with the 2D method, the hybrid method significantly improves the computational efficiency by 86.5%. By analyzing the state in the chamber, the accuracy of the conversion criterion is confirmed. This criterion can be used as the transformation criterion of the hybrid model to form the standard multi-dimensional calculation transformation criterion of interior ballistics and may be promising for the rapid simulation of two-phase flow in interior ballistics. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
29. Surface modification of kevlar fabric with a novel sulfonyl aryl containing monomer and its influence on inter yarn friction.
- Author
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Agarwal, Gaurav, Sharma, Indu, Prakash, Jyoti, Kumar, Pal Dinesh, and Verma, Sanjeev K
- Subjects
- *
POLYPHENYLENETEREPHTHALAMIDE , *YARN , *IMPACT response , *MONOMERS , *ARYL group , *ETHYL esters , *SULFONYL compounds - Abstract
The ballistic impact response of Kevlar textiles is significantly influenced by the friction between the yarns. It increases the dissipation of energy when yarns begin to displace relative to one another and it also results in to transfer of load to a larger area during ballistic impacts. In the present work, a novel sulfonyl aryl group containing monomer acrylic acid-2-(toluene sulphonyl amine)-ethyl ester (AATSAEE) was synthesized by a three-step process with ethanol amine and p-toluene sulfonic acid as starting material. The monomer was homopolymerized and grafted on Kevlar fabric by UV-induced free radical polymerization technique. Benzoyl peroxide (BPO) was used as initiator. Utilizing spectroscopic and thermal gravimetric methods, the monomer, precursor, and the homopolymer were characterized. The yarn pull-out tests on unmodified and AATSAEE grafted Kevlar fabrics were performed on Universal Tensile Tester at a steady speed of the upper jaw of 50 cm min−1. Increases in yarn pull out force have been noted with grafting of AATSAEE on Kevlar fabric. The peak force increases around 284% with grafting which indicates an increase in friction forces. When these yarns start to move apart from one another due to friction factors, the fabric's energy dissipation increases and it may results in to increase in energy absorption at the time of ballistic impacts. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
30. Multi-Layer Fabric Composites Combined with Non-Newtonian Shear Thickening in Ballistic Protection—Hybrid Numerical Methods and Ballistic Tests.
- Author
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Roszak, Maciej, Pyka, Dariusz, Bocian, Mirosław, Barsan, Narcis, Dragašius, Egidijus, and Jamroziak, Krzysztof
- Subjects
- *
NON-Newtonian fluids , *FRACTURE mechanics , *SILICA gel , *LAMINATED textiles , *BALLISTICS , *IMPACT loads , *PSEUDOPLASTIC fluids - Abstract
Multi-layer fabrics are commonly used in ballistics shields with a lower bulletproof class to protect against pistol and revolver bullets. In order to additionally limit the dynamic deflection of the samples, layers reinforced with additional materials, including non-Newtonian fluids compacted by shear, are additionally used. Performing a wide range of tests in each case can be very problematic; therefore, there are many calculation methods that allow, with better or worse results, mapping of the behavior of the material in the case of impact loads. The search for simplified methods is very important in order to simplify the complexity of numerical fabric models while maintaining the accuracy of the results obtained. In this article, multi-layer composites were tested. Two samples were included in the elements subjected to shelling. In the first sample, the outer layers consisted of aramid fabrics in a laminate with a thermoplastic polymer matrix. The middle layer contained a non-Newtonian shear-thickening fluid enclosed in hexagonal (honeycomb) cells. The fluid was produced using polypropylene glycol and colloidal silica powder with a diameter of 14 µm in the proportions of 60/40. The backing plate was made using a 12-layer composite made of Twaron® para-aramid fabrics with a DCPD matrix—not yet used in a wide range of ballistics. Then, numerical simulations were carried out in the Abaqus/Explicit dynamic analysis. The Johnson–Cook constitutive strength model was used to describe the behavior of elastic–plastic materials constituting the elements of the projectiles. For the non-Newtonian fluid, a Up-Us EOS was used. The inner layers of the fabric were treated as an orthotropic material. Complete homogenization of the sample layers was carried out, thanks to which each layer was treated as a homogeneous continuum. As a parameter of fracture mechanics for shield components, the strain criterion was used with the smooth particles hydrodynamics method (SPH). Then, the results of simulations were compared with the results of the ballistic test for both samples placed next to each other, which resulted in the formation of a multi-layer composite in one ballistic test subjected to impact loads during firing with a 9 × 19 mm Parabellum FMJ projectile with an initial velocity of 370 ± 10 m/s. The results of numerical tests are very similar to the ballistic tests, which indicates the correct mapping of the process and the correct conduct of layer homogenization. The applied proportions of the components in the non-Newtonian fluid allowed a reduction in the deflection compared to previous studies. Additionally, the proposal to use a DCPD matrix allowed to obtain a much lower deflection value compared to other materials, which is a novelty in the field of production of ballistic shields. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
31. Enhancement of passive daytime radiative cooling performance with a novel hybrid strategy of integrating double-layer nanoparticle-based coating and ballistic thermal rectifier.
- Author
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Alimohammadian, Mehdi and Dinarvand, Saeed
- Subjects
- *
THERMAL shock , *ELECTRIC current rectifiers , *THERMAL resistance , *LIGHT transmission , *SURFACE coatings , *THERMAL stability , *BALLISTICS - Abstract
To date, various designs have been proposed to increase the efficiency of radiative coolers with approaches such as changes in materials and their properties, size and shape of the elements, and structures geometry. In the present work, an attempt has been made to obtain this important issue by presenting an innovative strategy from a new perspective. In this strategy, by keeping the face exposed to solar energy away from the body, heat distribution can be inhibited, which leads to a decrease in body temperature. This act simultaneously provides a higher operating temperature for the emitter section, thereby enhancing the exergy of the system. On the other hand, the presence of the thermal diode allows the surface of the object to continue to radiate its heat. Hence, several experiments were designed and performed to evaluate the performance of the strategy by an experimental apparatus built for this purpose. Initially, the rectification ratio results of constructed rectifier mirrors showed that the light transmission amount in the forward path is nearly 44% higher than in the reverse direction. In the next step, the temperature measurement of the samples showed the sub-ambient temperature for the present work with a difference of 9 and 2 °C, against direct sunlight and the night sky, respectively. This model also has a high-temperature difference of about 13, 11, and 6.5 °C during the day and 1.6, 0.5, and 0.5 °C at night below the other three samples. This superiority was maintained in cloudy weather conditions as well as thermal shock stability. One of the most important applications of radiation coolers is in the aerospace industry. In this particular application, in addition to cooling, it is vital to protect the equipment against thermal shock caused by sudden and extreme temperature differences in space. Due to obtaining results such as efficient cooling rate, and high resistance to thermal shock, this concept provides a practical vision for improving the spacecraft's cooling systems. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. Experimental and Theoretical Method for Determining the Law of Constant-Volume Combustion of a High-Density Propellant.
- Author
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Rogaev, K. S., Ishchenko, A. N., Samorokova, N. M., D'yachkovskii, A. S., and Sidorov, A. D.
- Subjects
- *
PROPELLANTS , *COMBUSTION , *BALLISTICS , *NOZZLES , *PSYCHOLOGICAL burnout , *PROJECTILES - Abstract
A promising direction in barrel ballistics aimed at increasing the muzzle velocity of a projectile is the use of new propellants as an attached charge. This paper presents an experimental and theoretical method for determining the law of propellant combustion in a manometric experiment (in a closed volume). Within the framework of this method, a small number of experiments could be sufficient to determine a change in the law of combustion during the propellant burnout and depending on pressure. This method is demonstrated on the example of processing three experiments with model high-density propellant. The laws of combustion of high-density propellants, obtained in this study, can later be used to calculate the gas-dynamic parameters of a shot from a barrel system or a nozzle bomb (in a semi-closed volume) using these propellants. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. Essentials of Forensic Ballistics
- Author
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Pandey, Pankaj Kumar, Harshey, Abhimanyu, Yadav, Murali Manohar, Srivastava, Ankit, Shrivastava, Pankaj, editor, Lorente, Jose Antonio, editor, Srivastava, Ankit, editor, Badiye, Ashish, editor, and Kapoor, Neeti, editor
- Published
- 2023
- Full Text
- View/download PDF
34. Implementation of Trajectory Propagator for Artillery Projectiles Based on Artificial Neural Networks
- Author
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Bragado, Alejandro Céniz, Solera-Rico, Alberto, Gómez, M. A., Karakoc, T. Hikmet, Series Editor, Colpan, C Ozgur, Series Editor, Dalkiran, Alper, Series Editor, Le Clainche, Soledad, editor, Chen, Xin, editor, and Ercan, Ali Haydar, editor
- Published
- 2023
- Full Text
- View/download PDF
35. Mechanism of Improving Ballistic Performance of Kevlar through Impregnation of Nanoparticles
- Author
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Bablu, Muhammad Ali, Manimala, James M., Mates, Steven, editor, Eliasson, Veronica, editor, and Allison, Paul, editor
- Published
- 2023
- Full Text
- View/download PDF
36. Analysis of Impact Strength on Polymer Matrix Composites Using Projectile Parameters for Combat Vehicle Application
- Author
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Palani, S., Karthik, S., Rajaravi, C., Ganapathy Srinivasan, R., Cavas-Martínez, Francisco, Editorial Board Member, Chaari, Fakher, Series Editor, di Mare, Francesca, Editorial Board Member, Gherardini, Francesco, Series Editor, Haddar, Mohamed, Editorial Board Member, Ivanov, Vitalii, Series Editor, Kwon, Young W., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, Natarajan, Elango, editor, Vinodh, S., editor, and Rajkumar, V., editor
- Published
- 2023
- Full Text
- View/download PDF
37. Using an Interpolation Model of the Gravitational Potential for High-Precision Ballistic Calculations
- Author
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Kuznetsov, A. A., Fukin, I. I., Bazov, S. M., Zavialova, N. A., Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Jing, Zhongliang, editor, and Strelets, Dmitry, editor
- Published
- 2023
- Full Text
- View/download PDF
38. Ballistic performances of the hourglass lattice sandwich structures under high-velocity fragments.
- Author
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He-xiang Wu, Jia Qu, and Lin-zhi Wu
- Subjects
BALLISTICS ,SANDWICH construction (Materials) ,PERFORMANCE evaluation ,COMPUTER simulation ,STRUCTURAL dynamics - Abstract
In this paper, the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of fragments. Attention is paid to elucidating the influences of rod cross-section dimensions, structure height, structure layer, and rod inclination angle on the deformation mode, ballistic performances, and ability to change the ballistic direction of fragments. The results show that the ballistic performances of hourglass lattice sandwich structures are mainly affected by their structural parameters. In this respect, structural parameters optimization of the hourglass lattice sandwich structures enable one to effectively improve their ballistic limit velocity and, consequently, ballistic performances. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Enhanced structural damage behavior of liquid-filled tank by reactive material projectile impact.
- Author
-
Jianwen Xie, Yuanfeng Zheng, Zhenyang Liu, Chengzhe Liu, Aoxin Liu, Pengwan Chen, and Haifu Wang
- Subjects
PROJECTILES ,BALLISTICS ,HYDRODYNAMICS ,CHEMICAL energy ,STRUCTURAL dynamics - Abstract
A series of ballistic experiments were performed to investigate the damage behavior of high velocity reactive material projectiles (RMPs) impacting liquid-filled tanks, and the corresponding hydrodynamic ram (HRAM) was studied in detail. PTFE/Al/W RMPs with steel-like and aluminum-like densities were prepared by a pressing/sintering process. The projectiles impacted a liquid-filled steel tank with front aluminum panel at approximately 1250 m/s. The corresponding cavity evolution characteristics and HRAM pressure were recorded by high-speed camera and pressure acquisition system, and further compared to those of steel and aluminum projectiles. Significantly different from the conical cavity formed by the inert metal projectile, the cavity formed by the RMP appeared as an ellipsoid with a conical front. The RMPs were demonstrated to enhance the radial growth velocity of cavity, the global HRAM pressure amplitude and the front panel damage, indicating the enhanced HRAM and structural damage behavior. Furthermore, combining the impact-induced fragmentation and deflagration characteristics, the cavity evolution of RMPs under the combined effect of kinetic energy impact and chemical energy release was analyzed. The mechanism of enhanced HRAM pressure induced by the RMPs was further revealed based on the theoretical model of the initial impact wave and the impulse analysis. Finally, the linear correlation between the deformation-thickness ratio and the non-dimensional impulse for the front panel was obtained and analyzed. It was determined that the enhanced near-field impulse induced by the RMPs was the dominant reason for the enhanced structural damage behavior. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. On the effect of pitch and yaw angles in oblique impacts of smallcaliber projectiles.
- Author
-
Fras, Teresa
- Subjects
PROJECTILES ,IMPACT (Mechanics) ,ANGLES ,BALLISTICS ,COMPUTER simulation - Abstract
A terminal ballistic analysis of the effects of 7.62 mm X 51 AP P80 rounds on inclined high-strength armor steel plates is the focus of the presented study. The findings of an instrumented ballistic testing combined with 3D advanced numerical simulations performed using the IMPETUS Afea® software yielded the conclusions. The experimental verification proved that slight differences in the pitch-andyaw angles of a projectile upon an impact caused different damage types to the projectile's core. The residual velocities predicted numerically were close to the experimental values and the calculated core deviations were in satisfactory agreement with the experimental results. An extended matrix of the core deviation angles with combinations of pitch-and-yaw upon impact angles was subsequently built on the basis of the numerical study. The presented experimental and numerical investigation examined thoroughly the influence of the initial pitch and yaw angles on the after-perforation projectile's performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Machine learning for predicting the outcome of terminal ballistics events.
- Author
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Ryan, Shannon, Sushma, Neeraj Mohan, A. V., Arun Kumar, Berk, Julian, Hashem, Tahrima, Rana, Santu, and Venkatesh, Svetha
- Subjects
BALLISTICS ,MACHINE learning ,PREDICTION models ,ARTIFICIAL neural networks ,PERFORMANCE evaluation - Abstract
Machine learning (ML) is well suited for the prediction of high-complexity, high-dimensional problems such as those encountered in terminal ballistics. We evaluate the performance of four popular ML-based regression models, extreme gradient boosting (XGBoost), artificial neural network (ANN), support vector regression (SVR), and Gaussian process regression (GP), on two common terminal ballistics' problems: (a) predicting the V
50 ballistic limit of monolithic metallic armour impacted by small and medium calibre projectiles and fragments, and (b) predicting the depth to which a projectile will penetrate a target of semi-infinite thickness. To achieve this we utilise two datasets, each consisting of approximately 1000 samples, collated from public release sources. We demonstrate that all four model types provide similarly excellent agreement when interpolating within the training data and diverge when extrapolating outside this range. Although extrapolation is not advisable for ML-based regression models, for applications such as lethality/survivability analysis, such capability is required. To circumvent this, we implement expert knowledge and physics-based models via enforced monotonicity, as a Gaussian prior mean, and through a modified loss function. The physics-informed models demonstrate improved performance over both classical physics-based models and the basic ML regression models, providing an ability to accurately fit experimental data when it is available and then revert to the physics-based model when not. The resulting models demonstrate high levels of predictive accuracy over a very wide range of projectile types, target materials and thicknesses, and impact conditions significantly more diverse than that achievable from any existing analytical approach. Compared with numerical analysis tools such as finite element solvers the ML models run orders of magnitude faster. We provide some general guidelines throughout for the development, application, and reporting of ML models in terminal ballistics problems. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
42. Ballistic Impact Response of Skin-Gelatin Composite Target Behind the UHMWPE Soft Armor.
- Author
-
Cao, Yanfeng, Wen, Cun, and Wang, Yongjuan
- Abstract
At present, compound targets are usually used to evaluate the mechanism of weapon injury and killing efficiency as well as the protective performance of soft armor. In order to study the ballistic impact response of the skin-gelatin composite target under the protection of UHMWPE panel, the structural design scheme of UHMWPE panel with different specifications was drawn up and prepared. Ballistic impact experiments were carried out on the UHMWPE panel with 7.62 mm pistol projectile, and the damage morphology, residual velocity and energy absorption mechanism of the target plate were analyzed. The finite element models of 7.62 mm pistol bullet penetrating UHMWPE panel and UHMWPE panel-skin-gelatin were constructed, and the impact response characteristics and damage morphology of the composite target were analyzed under different area densities, incident velocities and angles of attack. The results showed that different specifications and processes will affect the protective performance of UHMWPE panel. With the increase of incident velocity and angle of attack, the concave depth of the panel becomes larger and the damage becomes more serious. Furthermore, in the process of penetration, the constraint definition of the model will affect the stress propagation of the composite target. This study provides a new idea for the evaluation of weapon injury mechanism and killing efficiency and the evaluation of protective performance of body armor. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
43. The Effect of Ballistic Parameters of Meteoroids on Their Destruction in the Earth's Atmosphere.
- Author
-
Andrushchenko, V. A. and Syzranova, N. G.
- Abstract
The problems of the motion and destruction of large cosmic bodies under the influence of thermal and force loads in the Earth's atmosphere are considered. Based on the modified physical theory of meteors, a mathematical model of the trajectories of the motion of such bodies during the penetration of the planet's atmosphere is constructed. A computational experiment is carried out for known meteoroids selected as the reference ones in order to determine the effect of the ballistic parameters of the entry of these meteoroids (the angle of inclination of the trajectory to the Earth's surface and velocity) on the process of their destruction in the Earth's atmosphere. It is shown that these characteristics have a significant influence on the motion and destruction of cosmic bodies. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
44. Temperature influences of the recoil characteristics for aluminum honeycomb buffer in the tether-net launcher.
- Author
-
Wen-hui Shi, Shuai Yue, Chun-bo Wu, Zhou Liu, Zhi Liu, Bei-bei Zhao, Zhong-hua Du, and Guang-fa Gao
- Subjects
HONEYCOMB structures ,SPACE vehicles ,FIREWORKS ,TEMPERATURE effect ,BALLISTICS - Abstract
Fluctuations in outer space's temperature would affect the spacecraft's regular operation. This paper aims to study the temperature influences of the aluminum honeycomb buffer in the tether-net launcher. Firstly, a buffer structure was designed to attenuate the pyroshock generated by the pyrotechnic device. Secondly, the mechanical properties of aluminum honeycomb at different temperatures were obtained through quasi-static compression experiments. Then, the internal ballistic responses of the launcher were gained by the closed bomb tests and the equivalent classical interior ballistic model. Finally, the recoil performance of the launcher with aluminum honeycomb buffer at different temperatures was studied. It is revealed that the aluminum honeycomb crushing force gradually decreases with the temperature increases. The peak pressure, burning rate coefficient and velocity increase while the peak time decreases with the temperature increase for the interior ballistics. For the launcher recoil responses, the average launch recoil decreases if the aluminum honeycomb doesn't enter the dense stage. The impact acceleration, projectile velocity and displacement increase as the temperature increase. The paper spotlights the temperature's influence on the recoil characteristics of the aluminum honeycomb buffer, which provides a new idea for buffering technology of pyrotechnic devices in a complex space environment. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
45. Investigation on the ballistic performance of the aluminum matrix composite armor with ceramic balls reinforcement under high velocity impact.
- Author
-
Ansari, Ali, Akbari, Tayebeh, and Pishbijari, Masoomeh Rahimi
- Subjects
BALLISTICS ,ALUMINUM ,COMPOSITE materials ,NUMERICAL analysis ,KINETIC energy - Abstract
In this research, the ballistic behavior of the ceramic-reinforced aluminum matrix composite plates is investigated to provide an optimal design for protecting against 7.62 mm bullet at the speed of 800 m/s experimentally and numerically. The target materials are Al5083 alloy as the metal matrix and alumina ceramic balls as the reinforcement. To simulate a 3D numerical model, ABAQUS FE code has been utilized. After validation the numerical model by experiments, the effect of ceramic ball weight percentage include 15%, 30% and 45% and the target thickness 20, 25 and 30 mm is considered on the ballistic results like the kinetic energy, residual velocity and depth of penetration. Finally, it was found that the specimen with 25 mm thickness and 30% alumina is optimum based on existing ballistic protection criteria. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
46. Experiment/simulation correlation-based methodology for metallic ballistic protection solutions.
- Author
-
Cosquer, Yohan, Longère, Patrice, Pantalé, Olivier, and Gailhac, Claude
- Subjects
COMPUTER simulation ,BALLISTICS ,FINITE element method ,ALUMINUM alloys ,PROJECTILES - Abstract
A methodology is developed based on the coupling of a finite element code with an optimisation module for the design of land vehicle armouring composed of lightweight aluminium alloy and high strength steel plate. Following an experiment/simulation correlation, a numerical model has been built and calibrated considering monolithic plates and then verified considering a bi-metal protection against tungsten carbide projectile mimicking the core of a 7.62x51 AP8 ammunition. In addition, a method is proposed to obtain the v
res - vi curve for the full 7.62x51 AP8 bullet from the vres - vi curve obtained from the core only. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
47. Design of Multi-layered Protection Against Guided Mortar Threats Yhrough Numerical Modeling.
- Author
-
Thawani, Bonny, Kiat Lim, Seng, Brown, Laura, Critchley, Richard, and Hazael, Rachael
- Subjects
MORTARS (Ordnance) ,NUMERICAL analysis ,LIGHTWEIGHT materials ,PENETRATION mechanics ,BALLISTICS - Abstract
The trade e off between protection and weight is a constant consideration when designing a portable protective solution. Greater mobility is a desirable attribute and protection must therefore adapt, prompting a demand for lightweight, simple to construct, low-cost and effective ballistic protection systems. High strength and ductility, wave spreading capability and good energy absorption are key properties for ballistic protection. Four materials, polycarbonate, Kevlar®-epoxy, polyurethane foam, and aluminium alloy, possess these properties and were selected for analysis by numerical simulation. Multilayered configurations were proven to be an optimal solution, by exploiting the advantages of each material without having large penalties of mass and cost. Numerical modelling using ANSYS AUTODYN® is used to simulate monolithic and multi-layered target configurations, to obtain the penetration mitigation performance. The results are analysed to select configurations based on different requirements, such as lowest cost, lowest mass, best performance, and optimal configuration which balanced the three key parameters mentioned. The optimal configuration of Aluminium, Kevlar-Epoxy, Polyurethane, and Polycarbonate has layers with thickness of 7, 3, 38, 2 mm respectively with a total mass of 7.97 kg, total cost of $39.86 and penetration of 29.34% (14.67 mm). Polynomial relationships between performance and mass/cost are also determined. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
48. The radio-induced immune response: ballistics is key.
- Author
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Mirjolet, Céline and Baude, Jérémy
- Subjects
- *
IMMUNE response , *BALLISTICS , *TRANSLATIONAL research , *CD8 antigen , *TUMOR growth - Abstract
A letter published in the Journal of Translational Medicine discusses the immune response triggered by radiation therapy (RT). The letter explains that RT can have both immunomodulatory and immunosuppressive effects on the immune system. The authors conducted a study comparing two types of RT, shield RT (SRT) and conformal RT (CRT), and found that CRT was more effective at delaying tumor growth and improving survival due to a stronger CD8+ TIL-mediated immune response. The study also revealed that monocytes played a critical role in activating CD8+ TILs after CRT. The authors emphasize the importance of accurately describing the irradiation technique used in preclinical studies and highlight the need for further research on the immune mechanisms underlying RT efficacy. [Extracted from the article]
- Published
- 2023
- Full Text
- View/download PDF
49. Pronking and bounding allow a fast escape across a grassland populated by scattered obstacles
- Author
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Francesco Righini, Marina Carpineti, Fabio Giavazzi, and Alberto Vailati
- Subjects
animal movement ,stotting ,pronking ,bounding ,predation and escape ,ballistics ,Science - Abstract
Some quadrupeds have evolved the ability of pronking, which consists in leaping by extending the four limbs simultaneously. Pronking is typically observed in some ungulate species inhabiting grassland populated by obstacles such as shrubs, rocks and fallen branches scattered across the environment. Several possible explanations have been proposed for this peculiar behaviour, including the honest signalling of the fitness of the individual to predators or the transmission of a warning alert to conspecifics, but so far none of them has been advocated as conclusive. In this work, we investigate the kinematics of pronking on a two-dimensional landscape populated by randomly scattered obstacles. We show that when the density of obstacles is larger than a critical threshold, pronking becomes the gait that maximizes the probability of trespassing in the shortest possible time all the obstacles distributed across the distance fled, and thus represents an effective escape strategy based on a simple open-loop control. The transition between pronking and more conventional gaits such as trotting and galloping occurs at a threshold obstacle density and is continuous for a non-increasing monotone distribution of the height of obstacles, and discrete when the distribution is peaked at a non-zero height. We discuss the implications of our results for the autonomous robotic exploration on unstructured terrain.
- Published
- 2023
- Full Text
- View/download PDF
50. Perspective Armour-Piercing Intermediate Cartridge Projectile
- Author
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Krzysztof PIASTA and Przemysław KUPIDURA
- Subjects
mechanical engineering ,armour-piercing rounds ,small arms ,ballistics ,projectile ,Electronics ,TK7800-8360 ,Chemical engineering ,TP155-156 - Abstract
Ongoing military conflicts, along with a constant evolution of individual protection devices, have shown an urgent need of development in terms of the armour piercing capability of standard infantry small arms ammunition. The following paper includes a brief overview of the existing armour-piercing intermediate rounds, in an effort to define the most reasonable design of a perspective armour-piercing projectile. Therefore, various projectiles were designed and evaluated in terms of their external ballistic performance for chosen initial conditions, followed by preliminary internal and terminal ballistic calculations that were performed in order to assess the most reasonable outcome.
- Published
- 2023
- Full Text
- View/download PDF
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