scholarly journals Effect of Cover Plate on the Ballistic Performance of Ceramic Armor

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Miao Sun ◽  
Wuxiong Cao ◽  
Diqi Hu ◽  
Nana Zhang ◽  
Runqiang Chi
Keyword(s):  
Plate Thickness ◽  
Cover Plate ◽  
Ballistic Performance ◽  
Transition Velocity ◽  
Free Mode ◽  
Long Rod ◽  
Lower Limits ◽  
Insight Into ◽  
Velocity Region ◽  
Cover Plates

The interface defeat and dwell can effectively improve the ballistic performance of ceramic armors under high velocity impact of long rod projectiles. Confinement conditions along both axial and radial directions of ceramic armors can affect these behaviors. With the aim of giving an insight into the effect of cover plate thickness and connection mode of cover plates with confining tubes on these behaviors, numerical simulations were performed in which the confined silicon carbide (SiC) targets with cover plates were impacted by tungsten rods. The pressure on the surfaces of SiC targets with fixed cover plates are compared to that with free cover plates, showing that the plates fixed with the confining tubes can produce higher pressure by way of wedging. With the increase in cover plate thickness, the dwell duration of the tungsten rods on the ceramic interface gradually grows. In addition, the upper and lower limits of transition impact velocities for the SiC targets with cover plates in different connection modes (i.e., free or fixed) were obtained and analyzed. The results show that the increase rate of the transition velocity region for the cover plate with the fixed-mode is relatively stable and lower than with the free-mode. On this basis, the fixed cover plate contributes higher ballistic performances to the SiC target than the free cover plate. It is also noteworthy that the size of transition velocity region does not enlarge linearly with the increase in cover plate thickness due to the slow growth of the upper limit. Accordingly, thickness thresholds exist, which are 5 mm and 6 mm for the fixed and free cover plates, respectively. Considering the ballistic performance and economy, the cover plate with the thickness ranging from 3 mm to 5 mm, i.e., 1.5~2.5 times of the tungsten rod diameter, is ideal for the structural dimensions in this paper.

Investigation on the ballistic performance of rubber-aluminum (AA7075-T651) laminated plates reinforced with borosilicate glass balls

2021 ◽  
pp. 146442072110444
Author(s):  
Hasan Kasım
Keyword(s):  
Penetration Depth ◽  
Borosilicate Glass ◽  
Plate Thickness ◽  
High Strength ◽  
Laminated Plates ◽  
Front Face ◽  
Ballistic Performance ◽  
Multiwalled Carbon ◽  
The Matrix ◽  
Aluminum Plates

In this study, the ballistic behavior of protective armor plates (PaP) obtained by curing between high structural strength AA7075-T651 aluminum plates by reinforcing with glass balls of two different rubber mixtures whose damping properties were developed with carbon nanotube and glass bubbles fillers were investigated. A total of six PaPs at 27, 30, and 35 mm heights were prepared using two different matrix damping rubbers. High-strength liner rubber used in air bellows is vulcanized on the front and back surfaces of PaPs. Between the PaPs, Ø15.875 and Ø6.747 mm, borosilicate glass balls were placed in a particular arrangement that coincides with the middle of the matrix rubber and does not have any gaps. Liner rubber cured on the front face has managed to hold the energy by forming a layer like clothing around the bullet cores. Glass balls between PAPs play an essential role in the energy absorption of GB-filled mixtures. In contrast, in MWCNT-filled mixtures, they act as a second damping element. The ballistic performance of PAPs prepared with multiwalled carbon nanotubes was determined to be better than those prepared with Glass Bubbles. Thanks to the superior mechanical properties and high aspect ratio of MWCNTs, the penetration and swelling heights of the matrix damping rubbers prepared to have excellent results compared to glass bubbles. With the increase in the thickness of the PaPs prepared with MWCNTs, the deformation effect of the penetration depth and bulging height created by the bullet on the anterior and posterior surfaces decreased. As the thickness of PaP increased from 27 mm to 35 mm, penetration depth decreased by 38%, and bulging height reduced by 35%. The amount of penetration and swelling increased in PaPs using rubber filled with glass bubbles. As the plate thickness increased, the damping feature decreased and the glass balls were activated, and the bullet was stopped.

Penetration Mechanisms and Ballistic Performance of TiC-TiB2 Composite Armour under the Impact of Long-Rod Kinetic-Energy Projectiles

2011 ◽  
Vol 391-392 ◽  
pp. 236-241
Author(s):  
Yu Zhong Yang ◽  
Jian Bin Xin
Keyword(s):  
Steady State ◽  
Ceramic Tile ◽  
Ceramic Tiles ◽  
Ballistic Performance ◽  
Third Stage ◽  
Long Rod ◽  
Initial Shock ◽  
Shrink Fit ◽  
The Impact ◽  
Different Thickness

Based on preparing TiC-40mol%TiB2 composite by combustion synthesis under high gravity, the ballistic targets with different-thickness ceramic tiles were achieved by lateral, cover and back confinements of shrink-fit steel. Ballistic testing showed that as the thickness of ceramic tile was smaller than 12 mm, the penetration of the ceramic tile was mainly controlled by the combination of the initial-shock and steady-state penetration, resulting in poor ballistic performance of the ceramic. As the thickness of ceramic tile was larger than 12 mm, the penetration of the ceramic tile was controlled by the combination of steady-state and third-stage (projectile deceleration and erosion acceleration) penetration, resulting in improved ballistic performance of the ceramic.

Solar activity influences on planetary atmosphere evolution: Lessons from observations at Venus, Earth, and Mars

2019 ◽  
Vol 15 (S354) ◽  
pp. 241-258
Author(s):  
J. G. Luhmann
Keyword(s):  
Solar Activity ◽  
Space Physics ◽  
Planetary Atmosphere ◽  
Energy Inputs ◽  
Weather Observations ◽  
Ion Production ◽  
History Of ◽  
Planetary Magnetic Field ◽  
Lower Limits ◽  
Insight Into

AbstractThe Pioneer Venus and Venus Express missions, and the Mars Express and MAVEN missions, along with numerous Earth orbiters carrying space physics and aeronomy instruments, have utilized the increasing availability of space weather observations to provide better insight into the impacts of present-day solar activity on the atmospheres of terrestrial planets. Of most interest among these are the responses leading to escape of either ion or neutral constituents, potentially altering both the total atmospheric reservoirs and their composition. While debates continue regarding the role(s) of a planetary magnetic field in either decreasing or increasing these escape rates, observations have shown that enhancements can occur in both situations in response to solar activity-related changes. These generally involve increased energy inputs to the upper atmospheres, increases in ion production, and/or increases in escape channels, e.g. via interplanetary field penetration or planetary field ‘opening’. Problems arise when extrapolations of former loss rates are needed. While it is probably safe to suggest lower limits based simply on planet age multiplied by currently measured ion and neutral escape rates, the evolution of the Sun, including its activity, must be folded into these estimations. Poor knowledge of the history of solar activity, especially in terms of coronal mass ejections and solar wind properties, greatly compounds the uncertainties in related planetary atmosphere evolution calculations. Prospects for constraining their influences will depend on our ability to do a better job of solar activity history reconstruction.

Numerical Study of High Velocity Impact onto MMC/Ceramic Layered Systems

2016 ◽  
Vol 715 ◽  
pp. 210-215
Author(s):  
Seung Hwan Lee ◽  
Minh Lee
Keyword(s):  
Mild Steel ◽  
Ceramic Tile ◽  
Volume Fraction ◽  
Numerical Study ◽  
Tungsten Alloy ◽  
Layered Systems ◽  
Depth Of Penetration ◽  
Ballistic Performance ◽  
Long Rod ◽  
The Impact

Metal Matrix Composites (MMCs) can be applied to military applications due to the light weight and the ballistic performance. In this study, a numerical simulation has been performed for the penetration of a long-rod penetrator into MMC/Ceramic layered systems. The impact velocity is 1.5km/s and the length to diameter (L/D) ratio is 10.6. First, the ballistic performances of each candidate materials are examined by doing the semi-infinite target simulation to estimate the depth of penetration (DOP) data. The materials included in this study are four (tungsten alloy, mild steel, SiC, MMC. The MMC materials are SiC/Al7075 (volume fraction around 45%). For a reference data, the impact simulation into mild-steel target only was also carried out. Finally, the main simulation is performed by varying the position of ceramic tile at three types of the thickness of ceramic tile. The residual velocity, residual mass and residual kinetic energy of the long-rod are obtained from the simulation. Based on these predicted values, the optimum system of the layered plate has been estimated.

Ballistic Performance of TiC-TiB2 Composite Armour under the Impact of Long-Rod Tungsten Alloy Projectiles of 1.4 km · s-1

2013 ◽  
Vol 544 ◽  
pp. 310-315
Author(s):  
Xue Gang Huang ◽  
Zhong Min Zhao ◽  
Long Zhang
Keyword(s):  
Layered Composite ◽  
Tungsten Alloy ◽  
Ti Alloy ◽  
Impact Point ◽  
Layered Composites ◽  
Micro Hardness ◽  
Ballistic Performance ◽  
Long Rod ◽  
High Gravity Field ◽  
The Impact

Based on using combustion synthesis in high-gravity field to prepare the solidified TiC-TiB2 composites, the layered composites of the ceramic to Ti-6Al-4V at graded composition were achieved by fusion joint and atomic inter-diffusion between liquid TiC-TiB2 and Ti-6Al-4V substrate. The mechanical properties showed that the relative density, micro-hardness and fracture toughness of TiC-TiB2 ceramic layer measured 98.5%, 21.5 GPa and 13.5 ± 2.5 MPa • m0.5, respectively, and the shear strength at joint of TiC-TiB2 to Ti-6Al-4V measured 450 ± 25 MPa. By conducting DOP test to evaluate ballistic performance of the ceramic and layered-composite targets against long-rod KE projectiles at impact velocity of 1.4 km • s-1, it was obtained the mass efficiency 3.28 of the solidified TiC-TiB2 was achieved as the impact point of the projectile was nearby the centre of the target, whereas the mass efficiency 3.18 of the layered composite with the solidified ceramic to Ti-6Al-4V was also achieved even if the impact point of the projectile was at the edge of the target. By combining penetration damage of the targets with the dynamic behavior of the ceramic, it was obtained that the layered composite achieved by the joint of the solidified ceramic to Ti-6Al-4V not only improve ballistic performance of the ceramic, but also weaken the sensitivity of the ceramic target against the impact point of KE projectile by tearing the joint of the ceramic with Ti alloy to restrain formation and propagation of conical crack and fracture cone in the ceramic.

Cover Confinement and Ballistic Performance of TiC-TiB2 Ceramic Armor under the Impact of Long-Rod KE Penetrator of 1400 m·s-1

2013 ◽  
Vol 833 ◽  
pp. 130-135
Author(s):  
Xiao Bo Lu ◽  
Hong Bo Liu ◽  
Hai Xing Lu
Keyword(s):  
Ceramic Tile ◽  
Front Surface ◽  
Tungsten Alloy ◽  
Ballistic Performance ◽  
Ceramic Target ◽  
Long Rod ◽  
Surface Confinement ◽  
The Impact ◽  
Ceramic Targets ◽  
Ballistic Testing

By conducting DOP test to evaluate the ballistic performance of confined TiC-TiB2 ceramic targets against long-rod tungsten alloy penetrators under the impact of 1400 m · s-1, the coorelations of the steel cover confining the ceramic tile and ballistic performance of TiC-TiB2 ceramic targets were discussed. The results of ballistic testing showed that the steel covers in thickness of 1.5 mm and 3.5 mm failed to support laterally-confined ceramics due to their insufficient stiffness, resulting in poor ballistic performance of the ceramic targets with the mass efficiency smaller than 2.0. The cover in thickness larger than 10 mm had enough stiffness to ensure the mass efficiency of the ceramic target higher than 2.5. It is considered that with minimal front-surface confinement, the ejecta plume of the pulverized ceramic becomes less divergent, and this focusing of the ejected materials has the effect of further eroding the penetrator, thereby increasing the ballistic performance of the ceramic.

Ballistic Performance of TiC-TiB2 Composite Armour under the Impact of Long-Rod Tungsten Alloy Projectiles of 1.4 Km·s-1

2011 ◽  
Vol 492 ◽  
pp. 132-137
Author(s):  
Xue Gang Huang ◽  
Zhong Min Zhao ◽  
Long Zhang ◽  
Chun Yin
Keyword(s):  
Steady State ◽  
Ceramic Tile ◽  
Tungsten Alloy ◽  
Ceramic Tiles ◽  
Ballistic Performance ◽  
Third Stage ◽  
Long Rod ◽  
Initial Shock ◽  
Shrink Fit ◽  
The Impact

Based on preparing TiC-40mol%TiB2 composite by combustion synthesis under high gravity, the ballistic targets with different-thickness ceramic tiles were achieved by lateral, cover and back confinements of shrink-fit steel. Ballistic testing showed that as the thickness of ceramic tile was smaller than 12 mm, the penetration of the ceramic tile was mainly controlled by the combination of the initial-shock and steady-state penetration, resulting in poor ballistic performance of the ceramic. As the thickness of ceramic tile was larger than 12 mm, the penetration of the ceramic tile was controlled by the combination of steady-state and third-stage (projectile deceleration and erosion acceleration) penetration, resulting in improved ballistic performance of the ceramic.

Coating Life Prediction for Water Ballast Tank

2005 ◽  
Author(s):  
R. E. Melchers ◽  
X. L. Jiang ◽  
K. J. Lu
Keyword(s):  
Life Prediction ◽  
Practical Implication ◽  
Plate Thickness ◽  
Surface Preparation ◽  
Ballast Tank ◽  
Independent Expert ◽  
Key Factor ◽  
Ballast Tanks ◽  
Dry Film Thickness ◽  
Insight Into

Corrosion is the key factor responsible for the degradation of ship structures and in no place is this truer than water ballast tanks. Coating protection system is a continual research interest for classification societies and coating industries. Up to now, most coating performance analyses are qualitative not quantitative. Coating life prediction is almost always based on experience and various assumptions, due to unavailability of practical data support systems. This paper describes a preliminary impartial investigation of coating life carried out with interviewees from the Australian Defence Science and Technology Organization (DSTO), shipyards, coating supplier and an independent expert. Plate surface, edges and welds in ballast tank were considered and the influences of dry film thickness (DFT) and surface preparation (SP) are addressed. The investigation gives some insight into the life of practical coating systems for water ballast tanks. Coating life is proposed to be representable by a normal distribution when corrosion breakdown is below 10% of plate thickness, which is of practical implication.

IV.—Studies in Edrioasteroidea. IV. The Edrioasters of the Trenton Limestone

1914 ◽  
Vol 1 (4) ◽  
pp. 162-171
Author(s):  
F. A. Bather
Keyword(s):  
Double Series ◽  
British Museum ◽  
Floor Plate ◽  
Outer Margin ◽  
Cover Plate ◽  
Museum Specimens ◽  
Downward Slope ◽  
Slight Depression ◽  
Cover Plates

The Cover-plates of the radial grooves are preserved here and there in specimen, notably over the oral centre (Pl. X, Figs. 1, 2, 5, 7, 8), but in B they are preserved over the whole of the grooves and the mouth, though pressed down on to the floor of the grooves and into the peristome (Pl. XI, Fig. 1). Cover-plates are also present in the British Museum specimens, and are almost complete in E 16054.Each cover-plate corresponds in position with a floor-plate; so that, like the floor-plates, the cover-plates form a double series of alternating plates meeting in a zigzag median suture. The almost straight or slightly rounded outer margin of each cover-plate fits into a bevelled facet just within the rounded edge of the radial groove where the floor-plate begins its downward slope (Pl. X, Figs. 5, 7). This feature is well shown in specimen B, and there the floor-plate also shows, on each, side of the facet, and distinct from the peripodium, a slight depression, possibly for the insertion of a muscle or ligament, or possibly for the reception of the accessory cover-plate shortly to be described.

Sign in / Sign up

Export Citation Format

Share Document