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The main challenge in preparing body armor is achieving a high protection level by using lightweight materials with minimum cost.

In this study, a three-hybrid multilayered armor system is prepared for protection against a ballistic impact wave. These armor systems consist of glass or ceramic tile as a front layer followed by three intermediate layers made of woven fiber reinforced polymer composites and a back layer made of either aluminum or polypropylene.

All armor systems were successful in impeding the projectile from perforating, that is materials selection played an important role in stopping the ballistic impact wave. Almost an identical ballistic behavior was recorded between the experimental and numerical simulation by using ANSYS AUTODYN which means that the simulation could be used in advance to reduce the time required for practical experiments and the cost of using materials in experimental tests will be lessened. The effect of projectile geometry also had been studied, and it showed a noticeable role in changing ballistic behavior.

The originality of this research is in using carbon and glass fiber which are woven together in addition to adding polypropylene layers in armor preparation.

The ability of light‐weight all fiber‐reinforced polymer‐matrix composite armor and hybrid composite‐based armor hard‐faced with ceramic tiles to withstand the impact of a non‐Armor‐ Piercing (non‐AP) and AP projectiles is investigated using a transient non‐linear dynamics computational analysis. The results obtained confirm experimental findings that the all‐composite armor, while being able to successfully defeat non‐AP threats, provides very little protection against AP projectiles. In the case of the hybrid armor, it is found that, at a fixed overall areal density of the armor, there is an optimal ratio of the ceramic‐to‐composite areal densities which is associated with a maximum ballistic armor performance against AP threats. The results obtained are rationalized using an analysis based on the shock/blast wave reflection and transmission behavior at the hard‐face/air, hard‐face/backing and backing/air interfaces, projectiles’ wear and erosion and the intrinsic properties of the constituent materials of the armor and the projectiles.

This paper aims to investigate the performance of four different textile materials used as an outer shell of the bulletproof vest.

In this paper, four different textile materials were used, polyurethane treatment was applied as a surface coating for the woven samples. Mechanical properties were conducted for all samples; scanning electron microscope and X-ray energy disperse spectroscopy were executed to show the surface morphology of samples and the chemical composition of the coating material.

One-way ANOVA was used to statistically analyse the results, which proved that all variables were highly significantly affected by using different textile materials, despite the stiffness variable being not significantly affected by textile materials. An overall evaluation was done using radar chart, demonstrated that Cordura material accomplished the best functional performance, using two types of calibres 7.62 × 54 mild steel core and 7.62 × 54 armour piercing incendiary; the common mechanism was localized burn because of the incendiary effect of the projectile in addition to tearing mechanism starting from inside because of penetration effect of the steel core.

This work was addressed to analyse the impact of using four different materials on its performance as the outer shell of bulletproof vest to achieve the desired degree of protection.

Clearance rates for nonfatal shootings, especially cases involving gang- and drug-related violence, are disturbingly low in many US cities. Using data from a previously completed project in Boston, we explore the prospects for improving gang/drug nonfatal shooting cases by investing the same investigative effort found in similar gang/drug gun murder cases.

Our analyses primarily focus on a sample of 231 nonfatal shootings that occurred in Boston from 2010 to 2014. Logistic regressions are first used to analyze differences in the likelihood of case clearance for gang/drug nonfatal shooting cases relative to other nonfatal shooting cases. Independent samples t-tests are then used to compare the investigative characteristics of these two different kinds of nonfatal shootings. Next, independent samples t-tests are used to compare the investigation of gang/drug gun assaults relative to the investigation of very similar gang/drug gun homicides.

Results demonstrate that the odds of clearing gang/drug nonfatal shootings are 77.2% less likely relative to the odds of clearing nonfatal shootings resulting from other circumstances. This stark difference in clearance rates is not driven by diminished investigative effort, but investigative effort does matter. Relative to gang/drug gun assaults, gang/drug gun homicides have much higher clearance rates that are the result of greater investigative resources and effort that produces significantly more witnesses and evidence, and generate more forensic tests and follow-up investigative actions.

Gang- and drug-related violence generates a bulk of urban nonfatal shootings. Low clearance rates for nonfatal shootings undermine police efforts to hold offenders accountable, disrupt cycles of gun violence, and provide justice to victims. Police should make investments to improve investigative effort such as handling these cases with the same vigor as homicide cases.

The excellent material properties of fibre reinforced composites make them especially attractive for applications in the aerospace and automotive industries. Traditional methods of manufacturing composite structures have proven to be labour intensive and time‐consuming. Robotic fibre placement for fabrication of composite components has been proposed. This approach greatly reduces production cost and time. This paper briefly presents the overall strategy for the establishment of a robotic fibre placement facility. The methodology for development of process planning and programming, simulation, program generator and control is described. In addition, the algorithms for automatic fibre path generation for open and closed surfaces will also be discussed, as well as the control system architecture for the process.

This study presents the design, manufacture and evaluation of a type of 3D hollow woven structure, as a mean for improving ventilation underneath ballistic body armour and thus, thermal comfort.

By means of a computational fluid dynamic package, fluid flows through different cross‐sectional tubular geometries were simulated in order to predict, which structural parameters of the 3D hollow fabrics are optimal to support ventilation.

As the result of the computational analysis four optimised 3D hollow woven structures were selected and generated on a standard weaving loom.

Investigation of thermal comfort of 3D ballistic vests.

The purpose of this paper is to predict the response and perforation of fibre metal laminates (FMLs) subjected to impact by projectiles at different velocities.

A finite element (FE) model is constructed in which recently proposed dynamic constitutive models for fibre reinforced plastic (FRP) laminates and metals are used. Moreover, a recently developed dynamic cohesive element constitutive model is also used to simulate the debonding between FRP laminates and metal sheets. The FE model is first validated against the test data for glass laminate aluminum reinforced epoxy (GLARE) both under dropped object loading and ballistic impact, then used to perform a parametric study on the influence of projectile nose shape on the perforation of FMLs.

It is found that the present model predicts well the response and perforation of GLARE subjected to impact loading in terms of load-time history, load-displacement curve, residual velocity and failure pattern. It is also found that projectile nose shape has a considerable effect on the perforation of GLARE FMLs and that the ballistic limit is the highest for a flat-ended projectile whilst for a conical-nosed missile the resistance to perforation is the least.

Recently developed constitutive models for FRPs and metals, together with cohesive element model which considers strain rate effect, are used in the FE model to predict the behaviour of FMLs struck by projectiles in a wider range of impact velocities; the present model is advantageous over such existing models as Johnson-Cook (JC) + Chang-Chang and JC (+BW) + MAT162 in terms of failure pattern though they produce similar results for residual velocity.

In order to help explain experimental findings related to the stabbing- and ballistic-penetration resistance of flexible body-armor, single-yarn pull-out tests, involving specially prepared fabric-type test coupons, are often carried out. The purpose of this paper is to develop a finite-element-based computational framework for the simulation of the single-yarn pull-out test, and applied to the case of Kevlar® KM2 fabric.

Three conditions of the fabric are considered: neat, i.e, as-woven; polyethylene glycol (PEG)-infiltrated; and shear-thickening fluid (STF)-infiltrated. Due to differences in the three conditions of the fabric, the computational framework had to utilize three different finite-element formulations: standard Lagrangian formulation for the neat fabric; combined Eulerian-Lagrangian formulation for the PEG-infiltrated fabric (an Eulerian subdomain had to be used to treat the PEG solvent/dispersant); and combined continuum Lagrangian/discrete-particle formulation for the STF-infiltrated fabric (to account for the interactions of the particles suspended in PEG, which give rise to the STF character of the suspension, with the yarns, the particles had to be treated explicitly).

The results obtained for the single-yarn pull-out virtual tests are compared with the authors’ experimental counterparts, and a reasonably good agreement is obtained, for all three conditions of the fabric.

To the authors’ knowledge, the present work represents the first attempt to simulate single-yarn pull-out tests of Kevlar® KM2 fabric.