Bulletproof Vests Research Articles

Medical Provider Ballistic Protection at Active Shooter Events.

There is some controversy about whether ballistic protective equipment (body armor) is required for medical responders who may be called to respond to active shooter mass casualty incidents. In this article, we describe the ongoing evolution of recommendations to optimize medical care to injured victims at such an incident. We propose that body armor is not mandatory for medical responders participating in a rapid-response capacity, in keeping with the Hartford Consensus and Arlington Rescue Task Force models. However, we acknowledge that the development and implementation of these programs may benefit from the availability of such equipment as one component of risk mitigation. Many police agencies regularly retire body armor on a defined time schedule before the end of its effective service life. Coordination with law enforcement may allow such retired body armor to be available to other public safety agencies, such as fire and emergency medical services, providing some degree of ballistic protection to medical responders at little or no cost during the rare mass casualty incident. To provide visual demonstration of this concept, we tested three "retired" ballistic vests with ages ranging from 6 to 27 years. The vests were shot at close range using police-issue 9mm, .40 caliber, .45 caliber, and 12-gauge shotgun rounds. Photographs demonstrate that the vests maintained their ballistic protection and defeated all of these rounds.

Numerical and Experimental Research on the Impact of the Twaron T750 Fabric Layer Number on the Stab Resistance of a Body Armour Package

Faculty of Mechanical Engineering, Department of Mechanics and Applied Computer Science, Military University of Technology, Kaliskiego 2, 00-908 Warsaw, Poland E-mail: dsokolowski@wat.edu.pl, wbarnat@wat.edu.pl Abstract The aim of the paper was to research how the depth of penetration in dependence on the fabric layer number used in the ballistic package is changed. During the research, the following methodology was adopted: the object of study was Twaron T750 fabric, specially dedicated for use in bulletproof vests. Then a numerical model consisting of 35 layers of fabric was established, from which the following parameters were selected for registration: depth of the knife’s penetration, displacement, velocity and acceleration. Then experimental studies were carried out which reflected the numerical model. In the next step a numerical model was validated and variants for the number of layers included in the package were created. The computing environment was commercial software LS-Dyna. Experimental studies were recorded using a super-high-speed camera PhantomV12. The studies were conducted on the basis of the NIJ Standard -0115.00 norm.

The tearing properties of textiles with steiner tree structure

Tearing properties of textiles has drawn much attention due to recent applications to bullet-proof or explosion-proof vests. However, the tearing process is very complex, which is influenced by bulk material and geometrical factors as well, and there is no a matured theory for the tearing process, which limits optimal design of the textiles. Despite many experimental studies, we still lack fully understanding of the tearing process. In this paper, tearing properties of textiles with Steiner tree structure are studied experimentally and theoretically in order to develop a reliable mathematical model. The theoretical analysis elucidates that cell size and the cell's material in a structure cell of Steiner tree are the two main factors affecting the tearing properties, which are verified experimentally. The theoretical prediction of tearing strength will be greatly benefit for geometrical structure design for textile materials in the future.

Application of Synthetic Mineral Alloys as Materials for Bulletproof Vests and Products for Different Objects Protection

Authors study ballistic properties of the material which has never been used for impact protection and the presented results prove that synthetic mineral alloys belong to the field of bulletproof ballistic protection and particularly to the means of objects’ protection from kinetic threats. Although the material has been described in connection with such specific embodiments as SVD and a cumulative jet, it is evident that many alternatives and modifications of their application for various protective articles are possible.

Bullet Proof Vest using Non-Newtonian Fluid

Bullet proof vests, made of Kevlar are used for preventing projectiles from injuring humans. Soft armours are capable of protecting humans from low energy projectiles while hard-plate reinforced armours use metal plates, which weigh over 14+ kg for protection against high energy projectiles. NonNewtonian fluids which have time dependent properties (particularly viscosity) are prepared and tested for energy absorbing properties.It was proved that when Kevlar was used with Oobleck sample, the deformation produced in test plate was reduced considerably as compared to that of only Kevlar sample.

EYE ON CHINA

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Savunma Sanayinde Kullanılan İleri Kompozit Malzemeler ve Uygulama Alanları

Normal 0 21 false false false TR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Normal Tablo"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0cm; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;} Composites are materials that obtained by bringing together two or more different materials in a certain ratio and appropriate circumstances to gain the desired purpose. Due to the high strength/density ratio, composites are widely used. Their low density contributes fuel economy savings in vehicles and advantageously to increase speed. Also because of their low density, military equipments such as armours, weapons can be carried with less effort. The applications of composites in defence industry are increasing. The composite materials which are used in military aircrafts such as planes, helicopters; armoured vehicles such as tanks and panzers; heavy trucks for using military transportation, bullet proof vest, weapon bodies are used more and more in different applications. In recent years, with developing technology, the role and application areas of composite materials in defence industry are increasing rapidly. The use of composite materials in liquid armour, unmanned aerial vehicle, tank and aircraft armour, aircraft tail and wing components and landing field makes significant contributions to the development of the defence industry. In this study, the benefits of composite materials in the defence industry and its applications are discussed in detail.

Thermal Manikin Evaluation of Gender Sweat Differences While Wearing a Ballistic Vest

The purpose of this research was to determine if gender-related thermoregulatory differences impacted relative humidity levels in the microclimate while wearing a unisex ballistic vest. Data was collected using a sweating thermal manikin customized to simulate high-intensity sweat rates. Sensors were used to collect microclimate data between the uniform layers. The male and female thermal manikin exhibited no significant differences in microclimate data in the layers of the back of the uniform while wearing the ballistic vest. There was a significant statistical difference between the male and female manikin for the frontal region with women exhibiting lower RH values. Without the ballistic vest, the female manikin exhibited significantly lower RH values in the microclimate region, both front and back. There were no significant differences in RH values for the male thermal manikin with versus without the ballistic vest.

Experimental determinations of the eigenmodes for composite bars made with carbon and Kevlar-carbon fibers

For modal identification, the single-point excitation method has been widely used in modal tests and it consists in applying a force in a given point and recording the vibratory structure response in all interest points, including the excitation point. There will be presented the experimental recordings for the studied bars (with Kevlar-carbon or carbon fibers), the frequency response function in Cartesian and polar coordinates. By using the frequency response functions we determine the eigenparameters for each bar. We present the final panel of the eigenmodes (with the damping factors, eigenfrequencies and critical damping) for each considered bar. Using the eigenfrequency of the first determined eigenmode, the bars stiffness has been determined. The presented bars can be used in practical engineering for: car or bus body parts, planes body parts, bullet-proof vests, reinforcements for sandwich beams, and so on.

Evaluation of load carriage systems used by active duty police officers: Relative effects on walking patterns and perceived comfort

ObjectivesThis study aimed to examine the effects of two different load carriage systems on gait kinematics, temporospatial gait parameters and self-reported comfort in Swedish police. Methods21 active duty police officers were recruited for this crossover study design. Biomechanical and self-report data was collected on two testing occasions. On occasion 1, three dimensional kinematic data was collected while police wore a/no equipment (control), b/their standard issues belt and ballistic protection vest and c/a load bearing vest with ballistic protection vest. Police then wore the load bearing vest for a minimum of 3 months before the second testing occasion. ResultsThe load bearing vest was associated with a significant reduction in range of motion of the trunk, pelvis and hip joints. Biomechanical changes associated with the load bearing vest appeared to reduce with increased wear time. In both the standard issue belt condition and the load bearing vest condition, police walked with the arms held in a significantly greater degree of abduction. Self-report data indicated a preference for the load bearing vest. ConclusionThe two load carriage designs tested in this study were found to significantly alter gait kinematics. The load bearing vest design was associated with the greatest number of kinematic compensations however these reduced over time as police became more accustomed to the design. Results from this study do not support selection of one load carriage design over the other and providing individuals with the option to choose a load carriage design is considered appropriate.

Customised Design of Multifunctional Ballistic Vests of Secret Wearing

Customised Design of Multifunctional Ballistic Vests of Secret Wearing

Experimental investigation of the influence of wool structures on the stab resistance of woven body armor panels

In the production of body armor panels, multilayer aramid fabrics are normally used. A main problem of these panels is the high weight and consequential lower comfort for the wearer. In a recent survey it was shown that most officers in the United States would prefer an improved comfort and also reduced weight in their ballistic vests. To reduce layers with a concomitance of the same safety standards, the panel has to be improved. One solution is to reduce the slippage of the yarns during the penetration of the knife and with this to increase the absorbed impact energy. The tests showed that the placement of a layer of wool fabric on the top of the aramid panel changes the penetration behavior. The main goal of this work is the investigation of the influence of the woven wool structure over the penetration of aramid panels. For this investigation, the stab resistance of five aramid fabrics with different properties and patterns combined with one layer of wool on the top and bottom of the panel has been tested and compared against pure aramid panels, according to the VPAM test instruction “Stab- and Impact Protection”. In addition, an optical evaluation of the stab tests has been done using a high-speed camera. Also, the stab recess in the aramid layers was evaluated optically, using a digital microscope. The experimental results confirm that wool can increase the stab resistance of body armor panels, but results are dependent on the properties and pattern of the aramid fabrics, too.

Experimental and Numerical Analysis of Bulletproof Armor Made from Polymer Composite Materials

This work focuses on the preparation of polymer matrix composite specimens by (Hand Lay-Up) method to make bulletproof armor from the unsaturated polyester resin (UP) as a matrix reinforced by Kevlar fibers at different volume fractions with and without (3%) of Al2O3 powder. The tensile test was performed for these composite specimens which include: (modulus of elasticity, tensile strength and elongation percentage), in addition of ballistic test were studied. The results of this work show that the values of tensile test increase with increasing the volume fraction of fibers. And the values of tensile test of a composite reinforced by kevlar fibers and addition (3%) of Al2O3 powder was less than those composite without addition of Al2O3 powder. The numerical method based on FEM was used to analysis of the bullet proof armor ballistic test of the composite specimens by finding the values of stresses, strains and deformations. The numerical results that obtained from the program (ANSYS 14.5) represent the maximum value of stress happened to the composite specimens when reinforced by eight layers of the kevlar, and vice versa to the deformations and strain also the numerical results shown a good agreement with results that were obtained experimentally. Results of ballistic test of composite specimens show the volume fraction of fibers has an effect on the deformations of the front face and back face of these composite specimens. And the values of the ballistic test for the composite reinforced by kevlar at eight layers give the best values from other each of composite specimens.

Methods And Criteria For Selecting The Suitable Materials To Achieve The New Ballistic Protection Vest Designed To Womens

Abstract Women’s participation in the activities, which were limited only for men in the past, has increased over the years. Since women are not in the majority, the protective equipment they wear has not been developed for their use. In our project, we are intending to identify the available materials and technologies to produce new composite materials for ergonomic ballistic protection equipment for women from national defense system, in the respect of providing better fit and mobility to the wearer. The main goal of the project is to apply a design and materials that offers more comfort to the wearers (female soldiers) using the best available technologies and materials. This paper presents the methods and the criteria to select the best materials suitable for achieving a new ballistic protection vest designed especially for women from national defense system, in order to meet the requirements regarding the protection against ballistic threats and the comfort demands too.

High and Low Speed Impact Characteristics of Nanocomposites

Nanocomposites attracted the attention of scientists due to their superior mechanical, thermal, chemical and electrical properties. This research studied the impact of adding carbon nanotubes (CNTs) to the woven Kevlar laminated composites on the high and low speed impact characteristics. Different percentages of CNTs were added to the woven Kevlar-Vinylester composite materials. An in-house developed drop weight testing apparatus was utilized for the low speed impact testing. Two different concentrations of the CNTs were added to a 15-layer woven Kevlar laminates, 0.32 wt% and 0.8 wt%. The results showed that: The 0.32 wt % CNT sample enhanced the interlaminar strength of the composite without enhancing the energy absorption capacity whereas, the 0.8 wt % CNT sample did not improve the impact resistance of the Kevlar composite.For the high speed impact tests, a bulletproof vest was prepared using woven Kevlar, resin, and CNTs at 1.5 w% percentage. The ballistic shooting was carried out by a professional shooter using a 30 caliber and 9 mm bullets for the tests. The CNT bulletproof sample bounced back the 30 caliber copper alloy bullet with no penetration.

Thermal Comfort Difference on Gender under Military Garment System Using Thermal Manikin

To protect military personnel's lives, the military provides, and requires personnel to wear, a military garment system, which includes a ballistic vest. In this study, three levels of a military garment system were tested to measure the thermal and evaporative resistances under the garment system. In addition, for female military personnel who wear ballistic vests designed for men, this study compared the thermal comfort values by gender through thermal manikin tests. The results concluded the need for better designed ballistic vests for improving the ventilation system.

“It’s All About the Body”: The Bodily Capital of Armed Response Officers in South Africa

In this article, I analyze the role of bodily capital in the daily policing practices of armed response officers, a specific type of private security officers, in Durban, South Africa. Based on 20 months of ethnographic fieldwork, I argue that the masculinized bodily capital of armed response officers is a key source of their sovereign power; it plays a central role in how they acquire and exert authority. Furthermore, I argue that an analysis of bodily capital should not solely analyze the actual flesh of the body, but must include particular equipment (such as bulletproof vests and firearms) that is experienced as a part of the body.

Improving UV Resistance of Fibers: Idealized Computational Model Predicting the Distribution of UV Blocking Cylindrical Nanoparticles in Protective Polymeric Layer

High strength fibers such as PBO and Kevlar are used to produce composites, bulletproof vests, tendons of giant scientific balloons, and other high performance products. These fibers, however, are known to degrade upon exposure to Ultraviolet (UV) radiation which causes premature failure of the end-products. Improving UV resistance of high strength fibers like PBO through methods such as adding UV inhibiting particles during filament spinning or dyeing/coating process is not only extremely difficult, but often fails to provide the adequate UV protection. As an alternative to conventional approaches, UV protection of high performance yarns/braids can be effectively achieved by covering them with a polymeric sheath containing dispersed UV inhibiting nanoparticles. In this work, a computational model was developed to optimize critical factors such as thickness (weight) of the protective sheath and the amount of UV blockers for a given particle size, which influence the UV protective efficiency of the sheath. In order to simulate three-dimensional dispersion of nanoparticles in a polymer matrix, the model considers a random distribution of cylindrical nanoparticles of different size, aspect ratio, and volume fraction in a three-dimensional volume of protective sheath of a given length, width, and thickness. 2D visualization and image analysis techniques were utilized to determine the area projected by the particles on the x-y plane (areal coverage provided by nanoparticles). The areal coverage values obtained from the model were found to be higher than the experimental results due to the agglomeration of nanoparticles in the sheath caused during the polymer compounding process. However, the purpose of the model is to serve as a benchmarking tool to aid in the design and development of UV protective sheaths and films, and not to estimate absolute UV protection values. Analysis of the relationship between areal coverage and various input parameters in the model show that areal coverage increases with an increase in particle volume fraction and film thickness, and a decrease in particle diameter and length. It was also found that areal coverage was more significantly influenced by particle aspect ratio than by particle length.

Study on the Arrangement of Fabric Materials for Multi-Layer Soft Body Armor Based on their Mechanical Properties

Abstract The arrangement of protective material of bullet proof vest is important for face and back strike when all backing materials are hybrid. In this paper, three hybrid protective materials, as UD aramid fabric, Polyethylene (PE) and laminated woven aramid fabric (Argus) were used in this work. The bullet proof vest made of these combinations of materials to wear flexible and comfortable. It was found that the mechanical properties, as work of rupture of material, Young's modulus, bursting strength and penetration stroke at bursting, give trend to arrange the face and back strike for bullet proof vest, the increasing of work of rupture enables energyabsorbing mechanisms and the materials with high work of rupture enable to absorb energy to predict the arrangement of the layers before shooting.

“Biosteel”: an exciting product from nature that is superior to many manmade alternatives

AbstractBiotechnology continues to offer routes for many exciting and unique products. Researchers genetically altered goats with a spider gene. These goats produce milk that contains a protein that can be extracted to produce biosteel fibers for use in bulletproof vests. It is referred to as “biosteel” to highlight its strength comparable to steel. This review paper describes the important aspects of produced dragline spider silk proteins via cell culture techniques using silk genes derived from two species of weaving spiders. These fibers were tested for a number of mechanical properties and compared to natural spider silk. In effect, fibers of biosteel were able to absorb similar amounts of energy as natural spider silk by stretching further. As opposed to most other synthetic fibers, biosteel is ecofriendly both in terms of its composition and production process.