scholarly journals Fragmentation of Millimeter-Size Hypervelocity Projectiles on Combined Mesh-Plate Bumpers

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Aleksandr Cherniaev ◽  
Igor Telichev
Keyword(s):  
Numerical Study ◽  
Orbital Debris ◽  
Aluminum Plate ◽  
Projectile Velocity ◽  
Two Component ◽  
Ballistic Properties ◽  
Unmanned Spacecraft ◽  
Metallic Meshes ◽  
Aluminum Mesh ◽  
Positive Results

This numerical study evaluates the concept of a combined mesh-plate bumper as a shielding system protecting unmanned spacecraft from small (1 mm) orbital debris impacts. Two-component bumpers consisting of an external layer of woven mesh (aluminum or steel) directly applied to a surface of the aluminum plate are considered. Results of numerical modeling with a projectile velocity of 7 km/s indicate that, in comparison to the steel mesh-combined bumper, the combination of aluminum mesh and aluminum plate provides better fragmentation of small hypervelocity projectiles. At the same time, none of the combined mesh/plate bumpers provide a significant increase of ballistic properties as compared to an aluminum plate bumper. This indicates that the positive results reported in the literature for bumpers with metallic meshes and large projectiles are not scalable down to millimeter-sized particles. Based on this investigation’s results, a possible modification of the combined mesh/plate bumper is proposed for the future study.

Numerical Study on the Anti-Ballistic Properties of Metal Encapsulating Ceramic Composite Armors

2015 ◽  
Vol 723 ◽  
pp. 26-30 ◽  
Author(s):  
Jiang Ren Lu ◽  
Xin Li Sun ◽  
Xing Hui Cai ◽  
San Qiang Dong ◽  
Guo Liang Wang
Keyword(s):  
Ceramic Composite ◽  
Numerical Study ◽  
Three Dimensional ◽  
Ceramic Block ◽  
Ballistic Resistance ◽  
Limit Velocity ◽  
Ballistic Properties ◽  
Ballistic Limit Velocity ◽  
The Impact ◽  
Two Hybrid

The impact responses and ballistic resistance of the metal encapsulating ceramic composite armors with same area density and two hybrid cores are investigated. The hybrid cores include square metallic lattice with ceramic block insertions, and square metallic lattice with ceramic ball insertions and void-filling epoxy resin. Three-dimensional (3D) finite element (FE) simulations are carried out for each composite armors impacted by bullet with 12.7mm diameter. The focus is placed on the energy absorption capabilities and ballistic limit velocity of different composite armors. Results indicate that two kind of armors can improve the ballistic resistance properties and save mass of 22% and 25% compared to the homogeneous 4340 steel, respectively.

scholarly journals Current Status of Unmanned Spacecraft Design to Limit Orbital Debris

2012 ◽  
Vol 10 (ists28) ◽  
pp. Tr_33-Tr_36
Author(s):  
Noriko Kanai EMURA ◽  
Haruhisa MATSUMOTO ◽  
Kumi NITTA ◽  
Satomi KAWAMOTO ◽  
Masumi HIGASHIDE
Keyword(s):  
Orbital Debris ◽  
Current Status ◽  
Spacecraft Design ◽  
Unmanned Spacecraft

A Numerical Investigation on the Effect of Hydrogen and Syngas Addition on the Ignition of JP-8 Surrogates

2012 ◽  
Author(s):  
Thomas Helma ◽  
S. K. Aggarwal
Keyword(s):  
Numerical Investigation ◽  
Ignition Delay ◽  
Equivalence Ratio ◽  
Numerical Study ◽  
Flame Structure ◽  
Flame Temperature ◽  
Kinetic Mechanism ◽  
Smoke Point ◽  
Temperature Profiles ◽  
Two Component

A numerical study is carried out investigating the effect of hydrogen and syngas addition on the ignition of two JP-8 surrogates, a two-component surrogate and a six-component surrogate. This six-component surrogate has previously been found to accurately simulate the smoke point, volatility, flame temperature profiles, and extinction limits of JP-8, while the two component surrogates has been shown to reproduce the flame structure predicted with the six-component surrogate. CHEMKIN 10101 is used to simulate ignition in a closed homogenous reactor under adiabatic and isobaric conditions. The parameters include temperature ranging from 850–1250 K, pressure of 20 atm, and equivalence ratio ϕ = 1.0. The CRECK-0810 kinetic mechanism, involving 341 species and 9173 reactions, is used to model the ignition chemistry. For the conditions studied, the addition of H2 or syngas in small quantities has no effect on the ignition behavior of either the surrogates or their individual components. Addition of H2 or syngas in larger quantities increases and decreases the ignition delay at low and high temperatures, respectively. For the conditions investigated, the ignition behavior of both the surrogates is predominantly determined by the ignition chemistry of n-dodecane.

Experimental and numerical study of the behavior of a Glass Fiber Reinforced Plastic plate under oblique impact

2020 ◽  
pp. 002199832096566
Author(s):  
MV Zhikharev ◽  
OA Kudryavtsev ◽  
MS Pavlovskaya
Keyword(s):  
Numerical Study ◽  
Oblique Impact ◽  
Steel Sphere ◽  
Glass Fiber Reinforced Plastic ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic ◽  
Ballistic Properties ◽  
Inclination Angles ◽  
Oblique Impacts ◽  
Level Model

Experimental and numerical studies on the effect of oblique impacts on the ballistic properties of GFRP were carried out. Ballistic tests of specimens using a steel sphere with a diameter of 6.35 mm were performed for inclination angles from the normal of 0, 15, 30, 45, and 60 degrees. Ballistic curves and ballistic limits for each case were obtained, and a function approximating these results was proposed. The size of the delamination area at different angles was also analyzed. The results showed that the most catastrophic failures cases of impact were impacts with angles of 0°–30°. Computational studies of impact loading during oblique impacts were carried out in LS-DYNA using the mesoscale yarn-level model (MSM). Finally, numerically obtained ballistic limits and damaged areas were compared with experimental ones.

scholarly journals Preliminary Comparative Investigations on Ballistic Properties of Intermediate Cartridges

2020 ◽  
Vol 11 (4) ◽  
pp. 27-44
Author(s):  
Dawid Goździk ◽  
Bartosz FIKUS ◽  
Jacek KIJEWSKI
Keyword(s):  
Drag Coefficient ◽  
Research Methods ◽  
Projectile Velocity ◽  
Preliminary Results ◽  
Ballistic Properties ◽  
Ballistic Test

The preliminary results of comparative investigations on intermediate cartridges were presented in this paper. The research focused mainly on the adopted assumptions and verification of research methods. Pressure ballistic test barrels, manufactured according to NATO EPVAT standards, were used for tests. The pressure courses of propellant gases in the barrel and the projectile velocity at four points of the bullet trajectory were measured. The pressure impulses, R100 parameter at 50 m and average bullet drag coefficient were calculated for each type of cartridge. The results allowed for a preliminary ballistic comparison of the most popular types of intermediate cartridges.

A Composite Consisting of a Set of Hexagonal Ceramic Bars - The Numerical Study of the Ballistic Resistance

2011 ◽  
Vol 471-472 ◽  
pp. 1142-1146 ◽  
Author(s):  
Sebastian Stanislawek ◽  
Andrzej Morka ◽  
Tadeusz Niezgoda
Keyword(s):  
Reference Model ◽  
Numerical Study ◽  
Rigid Wall ◽  
Material Behavior ◽  
Aluminum Plate ◽  
Three Dimension ◽  
Projectile Impact ◽  
Ballistic Resistance ◽  
Behavior Simulation ◽  
The Impact

The paper presents a numerical study of a double layer composite panels impacted by a AP (Armor Piercing) 51WC projectile. The standard panel is built with aluminum and Al2O3 ceramic continuum layers while the studied model consists of the same aluminum plate but the front one is built with a set of hexagonal ceramic bars. The bar width and the impact position influence on the ballistic resistance are analyzed and compared with the reference solution. The problem has been solved with the usage of the modeling and simulation methods as well as finite elements method implemented in LS-DYNA software. Space discretization for each option was built by three dimension elements guarantying satisfying accuracy of the calculations. For material behavior simulation specific models including the influence of the strain rate and temperature changes were considered. Projectile Tungsten Curbide and aluminum plate material were described by Johnson-Cook model and ceramic target by Johnson-Holmquist model. In the studied panels the area surrounding back edges was supported by a rigid wall. The obtained results show interesting properties of the examined structures considering their ballistic resistance. All tests has given clear results about ballistic protection panel response under WC projectile impact. Panels consisting of sets of hexagonal ceramic bars are slightly easier to penetrate, reference model is stronger by 19% for smaller bars and by only 7% for bigger rods. Despite this fact, the ceramic layer is much less susceptible to overall destruction what makes it more applicable for the armor usage. Furthermore, little influence of the projectile impact point and consequently a part of the bar which is first destroyed is proved.

NUMERICAL STUDY OF TRANSIENT EVAPORATION OF MOVING TWO-COMPONENT FUEL DROPLETS

2012 ◽  
Vol 22 (6) ◽  
pp. 493-513 ◽  
Author(s):  
S. Raghuram ◽  
Vasudevan Raghavan
Keyword(s):  
Numerical Study ◽  
Fuel Droplets ◽  
Two Component
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