Showing papers on "Ballistic impact published in 2019"
TL;DR: In this article, a review of ballistic textiles and composites involved in the ballistic application including body armour is presented, and various technical approaches used for better understanding of the very complex process of the ballistic impact mechanisms and their responses to the materials are discussed.
180 citations
TL;DR: In this paper, a comparison of behavior and energy absorption of neat Kevlar fabric and polymer matrix composites under high velocity impact loading was performed by firing a 10-mm hemispherical projectile onto neat fabric and composites in a velocity range of 30-150m/s for two and four-layer samples.
69 citations
TL;DR: In this paper, the energy dissipation mechanisms related to the contribution of fique fabric and fibers composites were analyzed in terms of distinct failure modes, visually supported by scanning electron microscopy.
Abstract: Multilayered Armor Systems (MASs) with a front ceramic followed by synthetic fabric are currently used against high velocity ammunition. In these armors, the front layer, which shatters the ceramic and spalls the bullet, is followed by an intermediate layer, usually plies of synthetic aramid fabric (Kevlar®). In the present work, the intermediate Kevlar® layer was replaced by an equal thickness layer of two configuration of fique fibers, as fabric or aligned fibers. Both fique fabric and aligned fibers in amounts of 10, 20 and 30 vol% were used to reinforced polyester matrix composite. Ballistic impact tests against high velocity 7.62 caliber ammunition revealed that the plain polyester as well as the fique fabric and aligned fiber composites have a relatively similar shock impedance performance as that of the Kevlar®. Indentation around 16–20 mm in witness clay for MASs with fique fabric and aligned fique fiber polyester composites as second layer, were better than that of 23 mm for Kevlar®. These values attended the US National Institute Justice standard, which requires a maximum of 44 mm for body protection. The energy dissipation mechanisms related to the contribution of fique fabric and fibers composites were analyzed in terms of distinct failure modes, visually supported by scanning electron microscopy. These were found to be the same mechanisms recently disclosed for aramid fabric and other natural fibers composites.
50 citations
TL;DR: In this paper, the effects of interply stacking sequences on the ballistic and structural performance of UHMwPE composite hard ballistic panels have been studied and the most dramatic positive hybrid effect was observed for a front-facing hybrid configuration resulting in a significant 30% reduction in back-face signature (BFS) with a more than two times improvement in flexural yield strength.
47 citations
TL;DR: In this article, the impact behavior of glass fiber-reinforced polymer (GFRP) laminates was investigated using digital image correlation (DIC) in order to monitor strain and out-of-plane deformation in panels with nanoreinforced matrices, and the results of full-field deformation, exit velocity and energy absorption measurements from the ballistic tests showed significant improvements in impact resistance for the panels made from nanomodified epoxies relative to the unmodified epoxy matrix.
Abstract: In this paper, experimental studies on the ballistic impact behaviour of nanomodified glass fibre-reinforced polymer (GFRP) are reported. The epoxy matrix of the GFRP was modified by the addition of graphene platelets (GNPs), carbon nanotubes (CNTs), combined hybrid hexagonal boron nitride nanosheets (BNNS)/CNT, and combined boron nitride nanotubes (BNNTs)/GNPs nanoparticles. Ballistic impact tests were carried out on GFRP laminates at two projectile velocities of 76+-1 m s−1 for full-field deformation measurements and 134.3+-1.7 m s−1 for perforation tests.
The behaviour of the plates during impact was recorded using digital image correlation (DIC), in order to monitor strain and out-of-plane deformation in panels with nanoreinforced matrices. Following penetrative impact tests, pulse thermography was used to characterise the delamination of impacted plates. The results of full-field deformation, exit velocity and energy absorption measurements from the ballistic tests show significant improvements in impact resistance for the panels made from nanomodified epoxies relative to laminates with the unmodified epoxy matrix. The highest absolute absorbed energy was observed for the GFRP panels fabricated using the epoxy matrix loaded with BNNT/GNP at 255.7 J, 16.8% higher than the unmodified epoxy matrix.
46 citations
TL;DR: In this paper, the ballistic behavior of aramid/epoxy composites plates of various thicknesses produced by vacuum infusion and impacted by actual projectiles of different geometries were studied through experimental and numerical approach.
43 citations
TL;DR: In this paper, a nonlinear finite element model based on continuum damage mechanics is established to investigate the damage modes and failure mechanisms of carbon fiber reinforced aluminum laminates (CRALLs) under high velocity impact.
42 citations
TL;DR: In this paper, the authors presented a thorough experimental campaign of both the material constituents and the composite, including loads in the different directions (longitudinal and transverse tension, shear, delamination, etc.) at low and high strain-rates, and ballistic tests.
41 citations
TL;DR: In this article, a new type of sandwich composite panels using 3D-mats with interconnected channels sandwiched between Kevlar® layers have been manufactured in this research work, and the core of the panels have been filled with high-performance 600'nm silica based Shear Thickening Fluids (STF) dispersed in polyethylene glycol of molecular weight 200'g/mol (PEG-200) to study its effect in improving the energy dissipation of the material.
37 citations
TL;DR: In this article, the performance of 3D warp interlock fabric panels against NIJ (National Institute of Justice) standard-0101.06 Level-IIIA was investigated with a semi-automatic loom in GEMTEX Laboratory.
36 citations
TL;DR: An effective and efficient methodology based on a strain-rate-dependent material model that can be applied to the simulations of ballistic impact on woven composites is presented in this article, where a meso-heterogeneous model of R-glass-fibre woven composite was built and validated by tensile tests.
TL;DR: The results show that macroscopic tubulanes are remarkable high load-bearing, hypervelocity impact-resistant lightweight structures that are the architectural analogues of cross-linked carbon nanotubes.
Abstract: Lightweight materials with high ballistic impact resistance and load-bearing capabilities are regarded as a holy grail in materials design. Nature builds these complementary properties into materials using soft organic materials with optimized, complex geometries. Here, the compressive deformation and ballistic impact properties of three different 3D printed polymer structures, named tubulanes, are reported, which are the architectural analogues of cross-linked carbon nanotubes. The results show that macroscopic tubulanes are remarkable high load-bearing, hypervelocity impact-resistant lightweight structures. They exhibit a lamellar deformation mechanism, arising from the tubulane ordered pore structure, manifested across multiple length scales from nano to macro dimensions. This approach of using complex geometries inspired by atomic and nanoscale models to generate macroscale printed structures allows innovative morphological engineering of materials with tunable mechanical responses.
TL;DR: In this paper, the yarn crimp effect on energy absorption exhibits significant in the consideration of yarn count, weave density and areal density of fabric, and the authors aim to optimize fabric architecture of soft armour panel in order to improve ballistic performance without increasing weight.
TL;DR: In this paper, the ballistic behavior of multilayer graphene polymer composite (MGPC) was investigated, where the graphene membranes were embedded in polyethylene at varied depth and subjected to impingement by spherical projectiles traveling at varied translational velocities and impact angles.
TL;DR: In this article, an investigation of STF-impregnated fabric panels against ballistic impact, and attempts to identify the failure mechanisms of such panels under high velocity impact, were presented.
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TL;DR: A detailed and timely progress of soft body armour against stab and ballistic impact is presented in this paper, where classification and the evolution of body armour is briefly presented, demons are briefly described, and a detailed discussion of body-armour design is discussed.
Abstract: A detailed and timely progress of soft body armour against stab and ballistic impact is presented in this monograph. The classification and the evolution of body armour is briefly presented, demons...
TL;DR: In this article, the authors compared the ballistic impact damage behaviors between the three-dimensional angle-interlock woven fabric and its reinforced composite (3D angle interlock woven composite).
Abstract: This paper compares the ballistic impact damage behaviors between the three-dimensional angle-interlock woven fabric and its reinforced composite (three-dimensional angle interlock woven composite)...
TL;DR: In this paper, a single layered spray formed 7055 aluminum alloy was investigated under two different heat treatment (T6 and T74) against deformable 6 mm tungsten alloy (W-Ni-Fe) core projectile impact (1250m/s).
TL;DR: In this article, a laminated woven bamboo/woven E glass/unsaturated polyester composite is developed to combat a ballistic impact from bullet under shooting test, and the results show that the composites withstood 4825m/s ± 5 limit of bullet velocity, satisfying the NIJ test at level II.
TL;DR: In this paper, the preparation and rheological properties of a shear thickening fluid (STF) were discussed. And the physical properties of the composites were determined by ballistic penetration, drop-tower, and yarn pull-out tests.
Abstract: Shear thickening fluids (STFs) have been developed for various applications such as body armor, viscoelastic dampers, and sports equipment. In this paper, the preparation and rheological properties of an STF are discussed. STF/Kevlar composites were made using ethanol as the cosolvent. The physical properties of the composites were determined by ballistic penetration, drop-tower, and yarn pull-out tests. The ballistic penetration was tested at a projectile velocity of 180 m/s. The ballistic penetration tests showed that adding the STF could obviously increase the energy dissipation. In addition, the weight of the composites may be reduced by 37% while their ballistic resistance is maintained. The knife drop-tower tests showed that adding the STF may improve the energy absorption by 20%. The yarn pull-out test demonstrated that the maximum pull-out force of the STF/Kevlar composites is 3.17 times that of neat Kevlar. The enhancements in the physical properties were apparently associated with the addition of the STF.
TL;DR: In this paper, an improved multi-scale finite element model of woven fabrics was developed for evaluating ballistic responses of multi-ply woven fabrics, which was composed of a meso-and a macro-scale model that were coupled through node-sharing at the interface to improve wave propagation responses.
TL;DR: In this article, the effect of scale geometry and other impact parameters on the ballistic protection provided by a bio-inspired segmented ceramic armour was analyzed using finite element modeling (FEM).
Abstract: Nature has evolved ingenious armour designs, like the flexible carapaces of armadillo and boxfish consisting of hexagonal segments connected by collagen fibres, that serve as bioinspiration for modern ballistic armours. Here, Finite element modelling (FEM) used to analyze the effect of scale geometry and other impact parameters on the ballistic protection provided by a bioinspired segmented ceramic armour. For this purpose, the impact of cylindrical fragment simulating projectiles (FSPs) onto alumina-epoxy non-overlapping scaled plates was simulated. Scale geometrical parameters (size, thickness and shape) and impact conditions (FSP diameter, speed, location) are varied and the amount of damage produced in the ceramic tiles and the final residual velocity of the FSP after the impact are evaluated. It is found that segmentation drastically reduces the size of the damaged area without significantly reducing the ballistic protection in centred impact, provided the tile size is kept over a critical value. Such critical tile size (∼20 mm, inscribed diameter, for impacts at 650 m/s) is independent of the scale thickness, but decreases with projectile speed, although never below the diameter of the projectile. Off-centred impacts reduce the ballistic protection and increase the damaged area, but this can be minimized with an appropriate tile shape. In this sense and in agreement with the natural hexagonal tiles of the boxfish and armadillo, hexagonal scales are found to be optimal, exhibiting a variation of ballistic protection—measured as reduction of projectile speed—with impact location under 12%. Design guidelines for the fabrication of segmented protection systems are proposed in the light of these numerical results.
TL;DR: In this paper, the role of glass-ceramics in multi-layer ballistic systems is discussed, and a brief description of ballistic impact and the properties related to it is given.
Abstract: The military ballistic protection market has reached approximately US$ 10 billion/year, and the civil market is also very significant and is steadily increasing, which drives research for new ballistic protection alternatives. Materials currently used and under development as transparent ballistic protection devices include glasses, glass–ceramics, single and polycrystalline ceramics, and polymer-composites. Glass–ceramics are a less expensive, versatile alternative to currently used transparent ceramics. Glass–ceramics are generally harder, stiffer, tougher, and stronger than glasses, and can be made transparent or opaque, according to the needs of the protective system. They can be easily shaped in simple or complex forms, are much less expensive than carbides and nitrades, and are less dense than transparent alumina or spinel. This positive combination of properties makes glass–ceramics suitable for a wide range of applications. However, for an effective development of new transparent glass–ceramics (TGC), it is vital to understand which key properties must be optimized. In this review, we compile information on the role of each material in multi-layer ballistic systems, give a brief description of ballistic impact, and the properties related to it, and discuss the development of TGC to be used as ballistic protection. Our aim is to describe the most important ballistic protection materials and to indicate the pathways that research on TGC for ballistic protection have taken. We finish by concluding that there are still several opportunities that warrant further research on this particular application of glass–ceramics.
TL;DR: In this paper, the authors investigated damage mechanisms and deformation of honeycomb sandwich structures reinforced by functionally graded face plates under ballistic impact and found that the structure conformed to ballistic impact.
Abstract: This study investigates damage mechanisms and deformation of honeycomb sandwich structures reinforced by functionally graded face plates under ballistic impact. The honeycomb sandwich structure con...
TL;DR: In this paper, a spray-formed Al alloy was synthesized by spray forming followed by hot extrusion, later subjected to (T6 and T74) aging treatments and its mechanical properties were examined.
Abstract: 7055 aluminium (Al) alloy was synthesized by spray forming followed by hot extrusion, later subjected to (T6 & T74) aging treatments and its mechanical properties were examined. To investigate the ballistic behavior of the semi-infinite aluminum alloy target material, ballistic test with two different types of projectiles 7.62 mm soft steel core and 7.62 mm armor-piercing hard steel core projectiles were carried out. Excellent mechanical properties such as; higher strength UTS 708 MPa, fracture to elongation 12.8% and hardness 240 HV were achieved in the T6 condition owing to the MgZn2 phase and Al3Zr strengthening particles. Ballistic performance of the 7055-T6 target was superior to the T74 heat treated condition in terms of depth of penetration, crater diameter, strength, ductility and hardness. The target materials were deformed seriously against armor-piercing hard steel projectile impact as compared to soft steel core projectile. The microstructure was modified within the 1–1.5 mm area from the crater wall. The spray formed Al alloy have a good combination of strength and ballistic performance under the T6 heat treatment condition in comparison of T74 and other alloys produced by conventional forming methods.
TL;DR: In this article, the microstructure evolution of single layered aluminum alloys was investigated by optical microscopy, scanning electron microscopy (SEM), electron back scattering diffraction (EBSD), and X-rays diffraction pattern (XRD) analysis.
TL;DR: In this paper, the microstructural evolution and mechanical responses of carbon nanotube films upon ballistic impact were explored by molecular dynamics simulations, which are validated by penetration experiments, and the results indicated that high stiffness and strength of carbon Nanotubes offer excellent mechanical resistance, while the reversible nature of intertube interaction endows the film self-healable capabilities.
TL;DR: In this paper, the authors investigate the role of the mechanical properties and geometry in determining the overall damage on a glass plate subjected to a ballistic impact and observe a power-law dependence between the total damage and the fracture energy of the glass plate.
Abstract: Most glasses are often exposed to impact loading during their service life, which may lead to the failure of the structure. While in situ experimental studies on impact-induced damage are challenging due to the short timescales involved, continuum-based computational studies are complicated by the discontinuity in the displacement field arising from the propagation of cracks. Here, using peridynamics simulations, we investigate the role of the mechanical properties and geometry in determining the overall damage on a glass plate subjected to ballistic impact. In particular, we analyze the role of bullet velocity, bullet material, and elastic modulus, fracture energy, and radius of the plate. Interestingly, we observe a power-law dependence between the total damage and the fracture energy of the glass plate. Through an auto-regressive analysis of the evolution of cracks, we demonstrate that the self-affine growth of cracks leads to this power-law dependence. Overall, the present study illustrates how peridynamics simulations can offer new insights into the fracture mechanics of glasses subjected to ballistic impacts. This improved understanding can pave way to the design and development of glasses with improved impact-resistance for applications ranging from wind-shields and smart-phone screens to ballistics.
TL;DR: In this paper, a hybrid fiber composites combining stiff composites with soft composites are developed to improve the ballistic impact resistance of composite beams while maintaining good quasi-static loading bearing capacity.
28 Mar 2019-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the authors compared the performance of high-nitrogen steel (HNS) and RHA steel plates against 14.5-mm AP and AK-47 mild steel core (7.62mm × 39mm, deformable) at velocities of 740´±´10´m/s and 1000´±'' 10´m´s respectively.
Abstract: Hot-rolled high-nitrogen steel (HNS) plates were evaluated against AK-47 mild steel core (7.62 mm × 39 mm, deformable) and 14.5 mm armour piercing (AP) (14.5 mm × 114 mm, hard steel core) projectiles. The ballistic results of HNS plates were compared with conventionally used Rolled Homogeneous Armour (RHA) steel plates. The ballistic tests on HNS and RHA steel plates with different thicknesses were conducted against AK-47 mild steel core and 14.5 mm AP projectiles at velocities of 740 ± 10 m/s and 1000 ± 10 m/s respectively, in order to find out the minimum thickness required to stop the projectile without perforation. In comparison to RHA steel, HNS exhibited higher ballistic performance (in terms of minimum areal density required) against both AK-47 mild steel core and 14.5 mm armour piercing projectiles. The ballistic results against 14.5 mm AP was studied using an analytical model reported in literature. Detailed post ballistic (microstructural and hardness measurements) investigations were carried out to understand the ballistic performance of the two steels. Further, an attempt has been made to correlate the initial microstructure and mechanical properties with the failure mechanisms activated during ballistic impact and the resulting ballistic performance.