Transparent protection: the search for new solutions
Perlucor ceramic semi-crystalline material is available in different forms and for different uses, many manufacturers of transparent protection use it for their combined solutions.
Increasing the situational awareness of drivers and crews has become a key problem, since asymmetric warfare requires a better assessment of the situation around the vehicle, both in terms of operation and in terms of safety.
The latter is largely related to the environment, when often the combat vehicle moves on urban roads, clogged with civilian traffic from cars, motorcycles, bicycles and pedestrians; any incident can have serious consequences on the relationship with the local population, adversely affect the operation “to conquer hearts and minds”. Strictly speaking, from the point of view of the military, the ability to see what should be seen in the immediate vicinity allows the driver to fully use the capabilities of the machine, and the paratroopers to fully appreciate the situation and increase the effectiveness of their actions when landing from the car.
In an increasingly virtual world, numerous companies are engaged in digital solutions, often referred to as “transparent protection”, using sensors to provide the driver and crew with images with which they can “play”, and ultimately adding elements of virtual reality to them to enhance level of driving or combat effectiveness. While wide screens in the troop compartment of armored personnel carriers or infantry fighting vehicles are becoming quite commonplace, while driver’s fully virtual jobs are being tested, ergonomic considerations remain at the forefront. Moreover, larger transparent surfaces are increasingly used. Recently, light armored vehicles, mainly used for reconnaissance missions, are equipped with wide frontal and side windows. The same applies to the military transport category of the MRAP, which appeared during the conduct of hostilities in Iraq and Afghanistan at the start of the 2000. As for combat vehicles, some companies practice the use of wide windshields in order to improve the visibility of the outside world for the driver and commander.
As a rule, the average mass ratio between traditional transparent protection and opaque armor is approximately 4: 1. Since armored glass is always located in the upper part of the car, the problem is not only in the mass itself, which reduces the effective payload, but also in the center of gravity, which inevitably rises, reducing stability. In addition, the usual transparent protection does not fit into the rule of increasing the level of protection, because problems with light transmission and distortion of the picture grow with the thickness of the glass. Another key element in the transparent armor equation is cost: the exotic solutions already offered by many manufacturers are mainly based on transparent ceramics, but they remain much more expensive than traditional glasses.
However, in order to realistically assess the additional costs, we must balance between “for” and “against”: lighter glass means either an increase in the payload capacity, or reduced wear of mechanical components. Since the thickness is also reduced, this saves a lot of glass frames. Many currently manufactured machines with a basic level of protection can accept interchangeable kits to increase this level, and this is fully true for transparent armor. A lighter solution that provides a full level of protection avoids adding a set of transparent protection that creates significantly more problems than adding a set of opaque armor regarding: first, characteristics, since optical properties become critical, and second, logistics, since with a set of transparent armor handle with greater caution than opaque protection kits. Manufacturers of transparent armor solve other issues, including: service life - the strength of bulletproof glass decreases with time; cost - the longer the service life, the less impact on the costs of the life cycle of the machine; resistance to external factors, such as sandstorms; the ability to withstand large temperature differences, such as using the air conditioning system in very hot areas.
As mentioned, the advantage of all digital systems is the simplified implementation of virtual technologies, when elements of virtual reality can be easily added. However, this is partially feasible for armored glass, for example, projection of driving-related data on the windshield is currently implemented in commercial vehicles (this is a further development of the instrument panel projection technology on the cockpit windshield).
The German company GuS is one of the main European manufacturers of armored glass for military purposes. Recently, it has managed to reduce its specific density by more than 10%, respectively, to reduce the thickness and increase the light transmittance. Its newest products include glass with 4 Protection Level, the density of which is now 294 kg / m2, thickness 124 mm and light transmission 73%, its glass with Protection Level 3 almost 20% lighter than the previous version, its characteristics are correspondingly 177 kg / m2, 86 mm and 85%. GuS, whose bulletproof glass was installed on many vehicles operated by the Bundeswehr in Afghanistan, also developed a cost-effective solution called “quick repair”, which allows you to quickly return those machines whose transparent surfaces were damaged by scratches, without replacing the whole windshield. In 2017, the German company from Lubbecke should show a new material based on transparent ceramics, developed in collaboration with CeramTec (see below), able to withstand threats ranging from Level 2 to Level 4. GuS is also one of the main suppliers of periscopes, most European tracked and wheeled armored vehicles are equipped with these systems. She developed wide periscopes with an enlarged vertical field of view, which provides optimal visibility for the driver and commander and replaces the windshield, while guaranteeing high levels of protection, up to 4 or 5. This can significantly reduce the cost and weight of a typical 4 Level windshield weighing more than 300 kg, while the GuS solution adds just 50 kg to the mass of the car.
Traditional glass panel from the company GuS after hitting three bullets. In 2017, the company must announce new solutions based on ceramics
The German company IBD, a leading manufacturer of armored protection, has developed lightweight solutions based on nanoceramics.
The German company IBD, being one of the suppliers of booking solutions, is actively using ceramics technology, especially nano-ceramics. Thus, it is not a surprise that a company specializing in opaque armor has developed transparent armor based on ceramics, which has already been used in practice for some time, but is now at the last qualification stage in two countries. The 3 Level Solution has a density of 56 kg / m2, which is less than a third compared to conventional armored glass. The technology is based on a special bonding process, which allows IBD to form small tiles into a large transparent panel, which will then be covered with supporting layers of tempered glass. According to IBD, the diffraction is less than that of conventional bulletproof glass, and the rest of the optical properties are at least as good. The company is constantly working to reduce the cost, its goal is to produce products no more than 50% more expensive than standard solutions.
The French company Saint-Gobain is also active in the field of transparent protection, offering both traditional and ceramic solutions. The latter are known under the brand SAFirE, they provide a decrease in surface density by 65% compared to standard glass with a decrease in thickness of more than 30%.
Isoclima supplies Iveco with most of the armored glass for the LMV Lince armored car; in the picture is the glass after the shooting at the shooting range Nettuno
The Italian company Isoclima is currently making armored glass panels for windshields that allow dry installation; sealing them prevents the ingress of solvents and moisture and allows you to replace the glass using the same frame. Regarding the characteristics, judging by the latest available data, the 3 level is provided at 157-162 density kg / m2 and mm thickness 9, and the 2 level at 125-130 kg / m2 mm and 59 mm, however, the Isoclima research unit quite possibly improved the ratio “ protection / mass. Iveco DV is currently installing Isoclima glass on its LMV, MMV and Astra trucks equipped with armored cabs. According to the company, customers are also beginning to request armored glass for protection against 12,7-mm bullets, and it can provide a similar level of protection at 235 kg / m2 glass density and 108 mm thickness. Isoclima is also working on ceramic solutions, mostly in collaboration with CeramTec. The company develops glue with the same reflectance as transparent ceramics so that the glue line between the tiles is almost invisible. To provide multi-hit capabilities, 90 x 90 mm tiles are used, the entire panel with an area of 500 x 500 mm, glued together with such tiles, can withstand a hit of up to 12 bullets. Isoclima aims to reduce weight by 35% and thickness by 40%. However, if you do not need resistance to hit 20-mm FSP (Fragment Simulating Projectile - standard [in NATO] fragmentation simulator. A cylindrical striker with a blunt platform and a height approximately equal to the diameter. In the caliber 20 mm imitates a typical fragment 155 mm fragmentation bomb ), then Isoclima believes that a weight reduction of 50% is achievable.
Glass Isoclima Level 3 after hitting seven 7.62x54R B32 armor-piercing bullets shot out of a Dragunov sniper rifle
The Israeli company Oran Safety Glass (OSG) is one of the world leaders in the field of transparent protection. The top product under the CeraLite brand was developed in collaboration with the German company CeramTec. Like the entire transparent protection based on ceramics, CeraLite is made of several tiles glued together in panels of the required size. According to an Israeli company, Crystallized Materials (CM) technology allows weight reduction by 50-60%. If standard glass STANAG 4 level, made according to traditional technology (glass plus polycarbonate), has a density of 284 kg / m2, then at CeraLite it decreases by almost 50% to 146 kg / m2, to which you can add a reduction of 40% of the frame mass for glass. It also has better light transmission due to its reduced thickness, and also improves the performance of night vision goggles compared to regular glasses. When struck, CeraLite behaves better than classic glass, the “web” of cracks around the impact point decreases, and the multi-impact characteristics increase. CeraLite has been tested in German and American laboratories and is currently being offered in parallel with European and American customers. The cost remains an order of magnitude higher than the cost of conventional solutions, although in the past two years it has been reduced by 30%. That is, this type of transparent armor is used only when the mass problem is very critical.
The German company Kasiglas offers plastic solutions down to the 4 Level, which guarantee good visibility even after several hits.
New transparent armor is installed on special vehicles of the special operations forces of the Israeli armed forces. Moving toward exotic solutions does not stop research and development in more traditional areas. OSG's latest 4 level transparent protection solution has an 269 density kg / m2 and a thickness 122 mm, i.e. the mass is reduced by 5% compared to previous glasses. The company participates in two large American programs JLTV and M-ATV. It is clear that in both cases OSG offers its own ADI solution, which is distinguished by the fact that, instead of polycarbonate, another patented material is used on the internal surfaces. The shatter-proof material was developed by OSG to have thermal characteristics close to those of glass, since this significantly reduces delamination, which is one of the main problems that reduce the lifetime of transparent protection. The tests were carried out at very low and at very high temperatures from -40 ° C to + 70 ° C and at humidity above 90%; after nearly two years of continuous testing, the sample was still in good condition. According to the company, the ADI system can serve twice as long as traditional armored glass, which significantly reduces the life cycle costs of a vehicle, although the purchase price may be slightly higher. As for situational awareness, OSG is developing a touch version of the ScreeneX, which features a digital screen built into the windshield, allowing you to maximize the size of the driver’s workplace.
The German company KRD Group has developed technologies that made it possible to obtain a completely plastic transparent protection. Initially, its products were promoted through another company; KRD appeared only a couple of years ago and its products are now known under the brand name Kasiglas. The company has developed a multi-layer material made from pure high-transparent plastic that guarantees light transmission over 90%. This makes it possible to obtain flat as well as curved shapes with unprecedented molding angles. Products with Protection Levels 2, 3 and 4 are available, respectively, with density 144, 238 and 396 kg / m2 and thickness 121, 201 and 330 mm. Although the Kasiglas material is thicker than standard bulletproof glass, it provides higher transparency and retains better visibility even with a few bullets when standard glass cannot provide any visibility at all. Comparative tests conducted in Italy showed that a prototype with a third level of protection withstood six 7.62 x 51 mm armor-piercing bullets and six 7.62 x 54 mm armor-piercing missiles from close range, while maintaining good visibility. Other tests conducted in Germany have shown that the frame and glass remain intact after a mine explode or IED. Kasiglas panels with 3 Level protection also ensure that consecutive and simultaneous fragments of a missile charge in the sector from 0 ° to 45 ° and ingress of RPG-7 grenades at an angle of 45 °.
Resistance to multiple hits and high resistance to an explosive wave, strong impact, projectile type shells, fragmentation charges is one of the main advantages of plastic solutions, but the disadvantages are weight and thickness. In cooperation with the German Bundeswehr, KRD is implementing a program to develop a hybrid ceramic-plastic solution aimed at using the strengths of the two materials. This study has three objectives: to confirm the technical feasibility of such a solution, to develop a solution with a fourth level of protection with an acceptable mass and thickness, and to develop a lightweight solution with a third level of protection. The first characteristic has been verified; also tested the 4 Level Solution with a density of 270 kg / m2, which has the properties of plastic, withstanding the explosion of mines and IEDs, but leaves ceramics with the ability to resist armor-piercing bullets. As for visibility after multiple hits, it depends on the energy of bullets and shells. The solution with the 4 Protection Level maintains good visibility after hitting 7,62-mm bullets, but the visibility after hitting 14,5-mm bullets is only partially retained; that is, the characteristics are worse than those of completely plastic solutions, but higher than those of glass.
The company is currently working on integrating its hybrid solution into a vehicle for testing and preparing for qualification. The product is at the level of technological readiness TRL 6-7 (final revision and preparation for the series), while on the market this solution will be available at the end of 2017-mid 2018 of the year. As for the cost, it should be about 200% higher than the cost of all-glass solutions.
CERAMTEC-ETEC: Transparent ceramics from Europe
French company Saint-Gobain supplies a complete line of traditional transparent solutions for the military market.
The solution based on ceramics offered by the Israeli company OSG; transparent ceramics supplied by Ceramtec-ETEC
The German company from the city of Lohmar is the main supplier for most German and European manufacturers who develop transparent ceramics based protection. CeramTec-ETEC has developed the Perlucor polycrystalline ceramic material, which combines the excellent qualities of sapphire - a solid crystal that has a strictly oriented multilayer structure with strong atomic and ionic bonds - with glass qualities that are characterized by a disordered structure and weaker energy bonds between the elements. Perlucor retains the chemical bonds of sapphire, but is optically and mechanically isotropic, like glass. The latter characteristic simplifies the production process and reduces the cost compared to sapphire; according to CeramTec-ETEC, cost reduction is in excess of 60%. As for weight and thickness, the use of Perlucor in transparent protection systems can save from 40 to 60%. In addition, high scratch resistance increases the service life by 2-5 times. Thus, Perlucor material is used not only in sets of transparent protection: the company has developed a technology for gluing a layer with a thickness of less than one millimeter to the front side of the glass, which allows it to increase its service life by 3-10 times.
Materials used:
www.shephardmedia.com
www.gus-germany.com
www.ibd-deisenroth-engineering.de
www.saint-gobain.com
www.isoclima.net
www.osg.co.il
www.kasiglas.de
www.etec-ceramics.com
www.wikipedia.org
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