For any military equipment There are three main characteristics - mobility, firepower and protection. Today we will talk about defense, about how modern main battle tanks can confidently and successfully counter the threats that they encounter on the battlefield. Let's start with the most important and important - with armor.
When the projectile almost defeated the armor
Until the 60s of the last century, the main material for armor was steel of medium and high hardness. Need to improve tank protection? We increase the thickness of the steel sheets, arrange them at rational angles of inclination, make the upper layers of the armor harder or create such a layout of the tank in order to be able to make the armor as thick as possible in the forehead of the combat vehicle.
However, by the mid-50s of the last century, new types of armor-piercing cumulative projectiles appeared, characterized by extremely high penetration rates. So high that these shells were not held by the armor of either medium or heavy tanks of that time. But on the way there were also anti-tank guided missiles (or, for short, ATGMs), whose penetration reached 300-400 millimeters of steel. And ordinary armor-piercing or sub-caliber shells did not lag behind - their penetration rates increased rapidly.
With all their advantages, the T-54 and T-55 by the end of the 50s and the beginning of the 60s did not have a sufficient level of security.
At first glance, the solution to the problem seemed simple - to increase the thickness of the armor again. But, increasing millimeters of steel, military equipment gets tons excess weight. And this directly affects the mobility of the tank, its reliability, ease of maintenance and manufacturing cost. Therefore, the issue of increasing the protection of the tank had to be approached from the other side.
Projectile sandwich
Arguing in this vein, the designers came to the logical conclusion - you need to find a certain material or combination of materials that would provide reliable protection against a cumulative jet with a relatively small mass.
The furthest developments in this direction have advanced in the Soviet Union, where in the late 50s they began to experiment with fiberglass and light alloys based on titanium or aluminum. The use of these materials in combination with medium hard steel gave a good gain in armor mass. The results of all these studies were embodied in the first main battle tank with combined armor - T-64.
Its upper frontal part was a “sandwich” of an 80 mm steel sheet, two sheets of fiberglass with a total thickness of 105 mm, and another 20 mm steel sheet from the bottom. The frontal armor of the tank was located at an angle of inclination of 68°, which resulted in an even more solid armor thickness. The T-64 tower was also perfectly protected for its time - being cast from steel, it had voids in the forehead to the right and left of the gun, which were filled with aluminum alloy.
Ceramic vs Tungsten
After some time, designers discovered the advantages of ceramics. Possessing 2-3 times less density than steel, ceramics excellently resists the penetration of both a cumulative jet and the core of a feathered sub-caliber projectile.
In the Soviet Union, combined armor using ceramics appeared in the early 70s of the last century on the T-64A main battle tank, where instead of aluminum alloy balls of corundum filled with steel were used as a filler.
T-64A turret armor scheme. Round elements are the same corundum balls that filled the niches in the forehead of the tower to the left and right of the gun.
But not only Soviet Union used ceramics. In the 60s, Chobham combined armor was created in England, which is a package of many layers of steel, ceramics, polymers and binders. At its high cost, Chobham showed excellent resistance against HEAT projectiles and satisfactory resistance against finned tungsten-core sub-caliber projectiles. Subsequently, Chobham armor and its modifications were introduced to the latest Western main battle tanks: the American M1 Abrams, the German Leopard 2 and the British Challenger.
A special mention is the so-called "uranium armor" - a further development of the Chobham armor, which was reinforced with depleted uranium plates. This material is characterized by a very high density and hardness, higher than that of steel. Also, depleted uranium, along with tungsten alloys, is used to make the cores of modern armor-piercing finned sub-caliber projectiles. At the same time, its resistance against cumulative and kinetic armor-piercing projectiles per unit mass is higher than that of rolled homogeneous steel. This is the reason for the use of depleted uranium plates in the frontal armor of the M1 Abrams tank turret in the M1A1HA modification (where HA stands for Heavy Armor).
semi-active armor
Another interesting direction in the development of combined armor is the use of steel plate packs and inert filler. How are they arranged? Imagine a package consisting of a fairly thick steel plate, a layer of inert filler and another steel plate, but thinner. And there are 20 such packages, and they are placed at some distance from each other. This is what the filler for the turret of the T-72B tank looks like, called the "reflective sheet" package.
How does this armor work? When the cumulative jet pierces the main steel plate, a high pressure, he swells and pushes the steel plates in front and behind him to the sides. The edges of the holes punched by the cumulative jet in steel plates are bent, deform the jet and prevent its further passage forward.
A niche for the combined armor of the T-72B turret, in which the very packages of "reflective sheets" are located.
Another type of semi-active combined armor is armor with cellular filler. It consists of blocks of cells filled with a liquid or quasi-liquid substance. The cumulative jet, breaking through such a cell, creates a shock wave. The wave, colliding with the walls of the cell, is reflected in the opposite direction, forcing the liquid or quasi-liquid substance to counteract the cumulative jet, causing its deceleration and destruction. A similar type of armor is used on the T-80U main battle tank.
This, perhaps, can complete the consideration of the main types of combined armor of modern armored vehicles. Now it's time to talk about the "second skin" of the main battle tanks - about dynamic protection.
Defend the tank with explosives
The first experiments with dynamic protection began in the middle of the twentieth century, but for many reasons, for the first time this type of protection (abbreviated as DZ) was used in combat much later.
How does dynamic protection work? Imagine a container containing one or more explosive charges and metal throwing plates. Breaking through this container, the cumulative jet causes the explosive to detonate, which causes the throwing plates to move towards the projectile. In this case, the plates cross the trajectory of the cumulative jet, which is forced to break through them over and over again. In addition, because of the throwing plates, the cumulative jet acquires a zigzag shape, deforms and collapses.
According to the principle described above, the first models of dynamic protection worked: the Israeli "Blazer" and the Soviet "Contact-1". However, such a remote sensing was unable to withstand feathered sub-caliber projectiles - these types of projectiles, passing through the explosive, did not cause it to detonate. Therefore, the best minds in the defense design bureaus began work on a new type of universal dynamic protection, which could equally well deal with both cumulative and sub-caliber projectiles.
T-64BV, equipped with dynamic protection "Contact-1".
An example of such protection was the Soviet DZ "Contact-5". Her characteristic feature is that the lid of the dynamic protection container is made of a sufficiently thick steel sheet. Penetrating it, the feathered sub-caliber projectile creates a large number of fragments, which, moving at high speed, cause the detonation of explosives. And then everything happens in the same way as on the first DZ samples - an explosion and a thick throwing plate destroy the sub-caliber projectile and significantly reduce its penetration.
Schematic device of universal dynamic protection.
Another interesting example dynamic protection - DZ "Knife". It is a container containing many small shaped charges. Passing through one of these containers, the cumulative jet or core of a feathered sub-caliber projectile causes the detonation of charges that create many small cumulative jets. These small jets, acting on the attacking cumulative jet or the enemy's feathered sub-caliber projectile, destroy them and break them into separate fragments.
Best defense is attack
“Why don’t we make a system that would shoot shells flying into a tank while still approaching?” This is probably how, about 60 years ago, in the depths of the design bureaus, the idea of \u200b\u200bcreating a KAZ, an active protection complex, was born.
The active protection complex is a set consisting of detection tools, a control system and a destruction system. When a projectile or ATGM flies up to a tank, it is detected by sensors or a radar system and a special ammunition is fired, which, using the force of the explosion, fragments or a cumulative jet, damages or completely destroys the projectile or anti-tank missile.
The principle of operation of the active protection complex.
The most active development of active protection systems was carried out by the Soviet Union. Since 1958, several KAZs of various types have been created. However, one of the active defense systems entered service only in 1983. It was KAZ "Drozd", which was installed on the T-55AD. Subsequently, the Arena active protection complex was created for more modern main battle tanks. And relatively recently, Russian designers have developed the Afganit KAZ, designed for the latest tanks and heavy infantry fighting vehicles on the Armata platform.
Similar complexes were created and are being created abroad. For example, in Israel. Since the issue of protection against ATGMs and RPGs is especially acute for Merkava tanks, it was the Merkavas from Western MBTs that were the first to be massively equipped with Trophy active defense systems. The Israelis also created the KAZ Iron Fist, which is suitable not only for tanks, but also for armored personnel carriers and other light armored vehicles.
Smoke screens and complexes of optoelectronic countermeasures
If the active protection complex simply destroys guided anti-tank missiles flying up to the tank, then the optical-electronic countermeasures complex (or KOEP for short) acts much more subtle. An example of such a COEP is the Shtora, which is installed on the T-90, BMP-3 and the latest modifications of the T-80. How does it work?
A large part of modern anti-tank guided missiles is guided by a laser beam. And when such a missile is aimed at a tank, the KOEP sensors register that the car is irradiated with a laser, and give the appropriate signal to the crew. If necessary, KOEP can also automatically fire a smoke grenade in the right direction, which will hide the tank in the visible and infrared spectrum of electromagnetic waves. Also, having received a signal about laser irradiation, the tank crew can press the desired button - and the KOEP itself will deploy the tank turret in the direction from which a laser-guided missile is aimed at it. All that remains to be done by the gunner and the commander of the combat vehicle is to detect and destroy the threat.
But, in addition to the laser beam, many anti-tank missiles use a tracer for guidance. That is, in the rocket itself in the back there is a source of bright light of a certain frequency. This light is captured by the ATGM guidance system and corrects the flight of the missile so that it goes right on target. And this is where the KOEP floodlights come into play (in the game they can be seen on the T-90). They can emit light of the same frequency as the tracer of an anti-tank missile, thus "deceiving" the guidance system and taking the missile away from the tank.
These "red eyes" of the T-90 are the searchlights of the Shtora KOEP.
Screens and grids
And the last element of protection of modern armored vehicles, which we will talk about today, is all kinds of anti-cumulative screens, grilles and additional armor modules.
The anti-cumulative screen is quite simple - it is a barrier made of steel, rubber or other material, installed at a certain distance from the main armor of the tank or AFV. Such screens can be observed both on tanks of the Second World War and on more modern models of armored vehicles. The principle of their operation is simple: hitting the screen, the cumulative projectile fires prematurely, and the cumulative jet overcomes a certain distance in the air and reaches the main armor of the tank, significantly weakened.
Anti-cumulative gratings act somewhat differently. They are made in the form of plates, deployed with an edge towards the direction from which a threat to the tank may come. When a cumulative projectile collides with the lattice elements, the latter deform the shell of the projectile, the funnel of the cumulative warhead and / or the fuse, thereby preventing the projectile from firing and the cumulative jet from appearing.
Anti-cumulative grilles are especially often installed on light armored vehicles - armored personnel carriers, infantry fighting vehicles or tank destroyers.
And in conclusion - a few words about hinged modular armor. Her very idea is not new - even 70 or more years ago, crews added a little protection where it was lacking. Previously, boards, sandbags, armor sheets from wrecked enemy tanks, or even concrete were used for this. Today, modern polymers, ceramics and other materials are used, showing a high level of protection with low weight. In addition, modern modular armor is designed and manufactured in such a way that its installation and dismantling occurs as quickly as possible. One example of such protection is the MEXAS hinged armor used on the Leopard-1 and Leopard-2 tanks, the M113 and M1126 Stryker armored personnel carriers, and on many other types of military equipment.
That's all.
Use armor properly, don't frame weak spots your tanks under enemy shells and good luck in battles!
Scenarios for future wars, including lessons learned in Afghanistan, will create asymmetrically mixed challenges for soldiers and their ammunition. As a result, the need for stronger yet lighter armor will continue to increase. Modern types of ballistic protection for infantrymen, cars, aircraft and ships are so diverse that it is hardly possible to cover them all within the framework of one small article. Let us dwell on a review of the latest innovations in this area and outline the main directions of their development. Composite fiber is the basis for creating composite materials. The most durable structural materials currently made from fibers, such as carbon fiber or ultra-high molecular weight polyethylene (UHMWPE).
Over the past decades, many composite materials have been created or improved, known under the trademarks KEVLAR, TWARON, DYNEEMA, SPECTRA. They are made by chemical bonding either para-aramid fibers or high-strength polyethylene.
Aramids (Aramid) - a class of heat-resistant and durable synthetic fibers. The name comes from the phrase "aromatic polyamide" (aromatic polyamide). In such fibers, the chains of molecules are strictly oriented in a certain direction, which makes it possible to control their mechanical characteristics.
They also include meta-aramids (for example, NOMEX). Most of them are copolyamides, known under the brand name Technora produced by the Japanese chemical concern Teijin. Aramids allow for a greater variety of fiber directions than UHMWPE. Para-aramid fibers such as KEVLAR, TWARON and Heracron have excellent strength with minimal weight.
High tenacity polyethylene fiber Dyneema, produced by DSM Dyneema, is considered the most durable in the world. It is 15 times stronger than steel and 40% stronger than aramid for the same weight. This is the only composite that can protect against 7.62mm AK-47 bullets.
Kevlar- well-known registered trademark of para-aramid fiber. Developed by DuPont in 1965, the fiber is available in the form of filaments or fabric, which are used as a basis in the creation of composite plastics. For the same weight, KEVLAR is five times stronger than steel, yet more flexible. For the manufacture of the so-called "soft bulletproof vests" KEVLAR XP is used, such "armor" consists of a dozen layers of soft fabric that can slow down piercing and cutting objects and even bullets with low energy.
NOMEX- another DuPont development. Refractory fiber from meta-aramid was developed back in the 60s. last century and first introduced in 1967.
Polybenzoimidazole (PBI) - a synthetic fiber with an extremely high melting point that is nearly impossible to ignite. Used for protective materials.
branded material Rayon is recycled cellulose fibers. Since Rayon is based on natural fibers, it is neither synthetic nor natural.
SPECTRA- composite fiber manufactured by Honeywell. It is one of the strongest and lightest fibers in the world. Using proprietary SHIELD technology, the company has been producing ballistic protection for the military and police units based on SPECTRA SHIELD, GOLD SHIELD and GOLD FLEX materials for more than two decades. SPECTRA is a bright white polyethylene fiber that is resistant to chemical damage, light and water. According to the manufacturer, this material is stronger than steel and 40% stronger than aramid fiber.
TWARON- tradename durable heat-resistant para-aramid fiber manufactured by Teijin. The manufacturer estimates that using the material to protect armored vehicles can reduce armor weight by 30–60% compared to armor steel. The Twaron LFT SB1 fabric, produced using proprietary lamination technology, consists of several layers of fibers located at different angles to each other and interconnected by a filler. It is used for the production of lightweight flexible body armor.
Ultra high molecular weight polyethylene (UHMWPE), also called high molecular weight polyethylene - class of thermoplastic polyethylenes. Synthetic fiber materials under the brands DYNEEMA and SPECTRA are extruded from the gel through special dies that give the fibers the desired direction. The fibers consist of extra-long chains with a molecular weight of up to 6 million. UHMWPE is highly resistant to aggressive media. In addition, the material is self-lubricating and extremely resistant to abrasion - up to 15 times more than carbon steel. In terms of friction coefficient, ultra-high molecular weight polyethylene is comparable to polytetrafluoroethylene (Teflon), but is more wear-resistant. The material is odorless, tasteless, non-toxic.
Combined armor
Modern combined armor can be used for personal protection, armor Vehicle, naval vessels, aircraft and helicopters. Advanced technology and low weight allow you to create armor with unique characteristics. For example, Ceradyne, which recently became part of the 3M concern, entered into an $80 million contract with the US Marine Corps to supply 77,000 high-protection helmets (Enhanced Combat Helmets, ECH) as part of a unified program to replace protective equipment in the US Army, Navy and KMP. The helmet makes extensive use of ultra-high molecular weight polyethylene instead of the aramid fibers used in the manufacture of helmets. previous generation. Enhanced Combat Helmets are similar to the Advanced Combat Helmet currently in service, but thinner. The helmet provides the same protection against bullets. small arms and fragments, as the previous samples.
Sgt. Kyle Keenan shows close-range 9mm pistol bullet dents on his Advanced Combat Helmet, sustained in July 2007 during an operation in Iraq. Composite fiber helmet is able to effectively protect against small arms bullets and shell fragments.
A person is not the only thing that requires the protection of individual vital organs on the battlefield. For example, aircraft need partial armor to protect the crew, passengers and on-board electronics from fire from the ground and striking elements of the warheads of air defense missiles. In recent years, many important steps have been taken in this area: innovative aviation and ship armor has been developed. In the latter case, the use of powerful armor is not widely used, but it is of decisive importance when equipping ships conducting operations against pirates, drug dealers and human traffickers: such ships are now being attacked not only by small arms of various calibers, but also by shelling from hand-held anti-tank grenade launchers.
Protection for large vehicles is manufactured by TenCate's Advanced Armor division. Her series of aviation armor is designed to provide maximum protection at the minimum weight to allow it to be mounted on aircraft. This is achieved by using the TenCate Liba CX and TenCate Ceratego CX armor lines, the lightest materials available. At the same time, the ballistic protection of the armor is quite high: for example, for TenCate Ceratego it reaches level 4 according to the STANAG 4569 standard and withstands multiple hits. In the design of armor plates, various combinations of metals and ceramics are used, reinforcement with fibers of aramids, high molecular weight polyethylene, as well as carbon and fiberglass. The range of aircraft using TenCate armor is very wide: from the Embraer A-29 Super Tucano light multifunctional turboprop to the Embraer KC-390 transporter.
TenCate Advanced Armor also manufactures armor for small and large warships and civilian vessels. Booking is subject to critical parts of the sides, as well as ship premises: weapons magazines, the captain's bridge, information and communication centers, weapons systems. The company recently introduced the so-called. tactical naval shield (Tactical Naval Shield) to protect the shooter on board the ship. It can be deployed to create an impromptu gun emplacement or removed within 3 minutes.
QinetiQ North America's LAST Aircraft Armor Kits take the same approach as mounted armor for ground vehicles. Parts of the aircraft that require protection can be strengthened within one hour by the crew, while the necessary fasteners are already included in the supplied kits. Thus, they can be quickly upgraded transport aircraft Lockheed C-130 Hercules, Lockheed C-141, McDonnell Douglas C-17, as well as Sikorsky H-60 and Bell 212 helicopters, if the conditions of the mission require the possibility of fire from small arms. The armor withstands hit by an armor-piercing bullet of 7.62 mm caliber. Protection of one square meter weighs only 37 kg.
transparent armor
The traditional and most common vehicle window armor material is tempered glass. The design of transparent "armor plates" is simple: a layer of transparent polycarbonate laminate is pressed between two thick glass blocks. When a bullet hits the outer glass, the main impact is taken by the outer part of the glass "sandwich" and the laminate, while the glass cracks with a characteristic "web", well illustrating the direction of dissipation of kinetic energy. The polycarbonate layer prevents the bullet from penetrating the inner glass layer.
Bulletproof glass is often referred to as "bulletproof". This is an erroneous definition, since there is no glass of reasonable thickness that can withstand an armor-piercing bullet of 12.7 mm caliber. A modern bullet of this type has a copper jacket and a core made of a hard dense material - for example, depleted uranium or tungsten carbide (the latter is comparable in hardness to diamond). In general, the bullet resistance of tempered glass depends on many factors: caliber, type, bullet speed, angle of impact with the surface, etc., so the thickness of bullet-resistant glass is often chosen with a double margin. At the same time, its mass also doubles.
PERLUCOR is a material with high chemical purity and outstanding mechanical, chemical, physical and optical properties.
Bulletproof glass has its well-known disadvantages: it does not protect against multiple hits and is too heavy. Researchers believe that the future in this direction belongs to the so-called "transparent aluminum". This material is a special mirror-polished alloy that is half the weight and four times stronger than tempered glass. It is based on aluminum oxynitride - a compound of aluminum, oxygen and nitrogen, which is a transparent ceramic solid mass. In the market, it is known under the brand name ALON. It is produced by sintering an initially completely opaque powder mixture. After the mixture melts (melting point of aluminum oxynitride - 2140°C), it is rapidly cooled. The resulting hard crystalline structure has the same scratch resistance as sapphire, i.e. it is virtually scratch-resistant. Additional polishing not only makes it more transparent, but also strengthens the surface layer.
Modern bulletproof glasses are made in three layers: an aluminum oxynitride panel is located on the outside, then tempered glass, and everything is completed with a layer of transparent plastic. Such a “sandwich” not only perfectly withstands armor-piercing bullets from small arms, but is also able to withstand more serious tests, such as fire from a 12.7 mm machine gun.
Bullet-resistant glass, traditionally used in armored vehicles, even scratches sand during sandstorms, not to mention the impact on it of fragments of improvised explosive devices and bullets fired from AK-47s. Transparent "aluminum armor" is much more resistant to such "weathering". A factor holding back the use of such a remarkable material is its high cost: about six times higher than that of tempered glass. The "clear aluminium" technology was developed by Raytheon and is now offered under the name Surmet. At a high cost, this material is still cheaper than sapphire, which is used where particularly high strength (semiconductors) or scratch resistance (glasses) is needed. wrist watch). Since more and more big companies are being attracted to produce transparent armor. production capacity, and the equipment allows you to produce sheets of ever larger area, its price as a result can be significantly reduced. In addition, production technologies are constantly improving. After all, the properties of such a “glass”, which does not succumb to shelling from an armored personnel carrier, are too attractive. And if you remember how much "aluminum armor" reduces the weight of armored vehicles, there is no doubt: this technology is the future. For example: at the third level of protection according to the STANAG 4569 standard, a typical glazing area of 3 square meters. m will weigh about 600 kg. Such a surplus greatly affects the driving performance of an armored vehicle and, as a result, its survivability on the battlefield.
There are other companies involved in the development of transparent armor. CeramTec-ETEC offers PERLUCOR, a glass ceramic with high chemical purity and outstanding mechanical, chemical, physical and optical properties. The transparency of PERLUCOR material (over 92%) allows it to be used wherever tempered glass is used, while it is three to four times harder than glass, and also withstands extremely high temperatures (up to 1600 ° C), exposure to concentrated acids and alkalis.
IBD NANOTech transparent ceramic armor is lighter than tempered glass of the same strength - 56 kg/sq. m against 200
IBD Deisenroth Engineering has developed transparent ceramic armor comparable in properties to opaque samples. new material lighter than armored glass by about 70% and can, according to IBD, withstand multiple bullet hits in the same areas. The development is a by-product of the process of creating a line of armored ceramics IBD NANOTech. During the development process, the company created technologies that allow gluing a large-area “mosaic” of small armored elements (Mosaic Transparent Armor technology), as well as laminating gluing with reinforcing substrates made of Natural NANO-Fibre proprietary nanofibers. This approach makes it possible to produce durable transparent armor panels, which are much lighter than traditional ones made of tempered glass.
The Israeli company Oran Safety Glass has found its way into transparent armor plate technology. Traditionally, on the inner, “safe” side of the glass armored panel, there is a reinforcing layer of plastic that protects against flying glass fragments inside the armored vehicle when bullets and shells hit the glass. Such a layer can gradually become scratched during inaccurate rubbing, losing transparency, and also tends to peel off. ADI's patented technology for strengthening armor layers does not require such reinforcement while observing all safety standards. Other innovative technology from OSG - ROCKSTRIKE. Although modern multi-layered transparent armor is protected from the impact of armor-piercing bullets and shells, it is subject to cracking and scratching from fragments and stones, as well as gradual delamination of the armor plate - as a result, the expensive armor panel will have to be replaced. ROCKSTRIKE technology is an alternative to metal mesh reinforcement and protects glass from damage by solid objects flying at speeds up to 150 m/s.
Infantry protection
Modern body armor combines special protective fabrics and hard armor inserts for additional protection. This combination can even protect against 7.62mm rifle bullets, but modern fabrics are already capable of stopping a 9mm pistol bullet on their own. The main task of ballistic protection is to absorb and dissipate the kinetic energy of a bullet impact. Therefore, the protection is made multi-layered: when a bullet hits, its energy is spent on stretching long, strong composite fibers over the entire area of the body armor in several layers, bending the composite plates, and as a result, the bullet speed drops from hundreds of meters per second to zero. To slow down a heavier and sharper rifle bullet traveling at a speed of about 1000 m / s, inserts of hard metal or ceramic plates are required along with fibers. The protective plates not only dissipate and absorb the energy of the bullet, but also blunt its tip.
A problem for the use of composite materials as protection can be sensitivity to temperature, high humidity and salty sweat (some of them). According to experts, this can cause aging and destruction of the fibers. Therefore, in the design of such bulletproof vests, it is necessary to provide protection from moisture and good ventilation.
Important work is also being done in the field of body armor ergonomics. Yes, body armor protects against bullets and shrapnel, but it can be heavy, cumbersome, restrict movement and slow down the movement of an infantryman so much that his helplessness on the battlefield can become almost a greater danger. But in 2012, the US military, where, according to statistics, one in seven servicemen is female, began testing body armor designed specifically for women. Prior to this, female military personnel wore male "armor". The novelty is characterized by a reduced length, which prevents chafing of the hips when running, and is also adjustable in the chest area.
Body armor using Ceradyne ceramic composite armor inserts on display at Special Operations Forces Industry Conference 2012
The solution to another drawback - the significant weight of body armor - can occur with the start of the use of the so-called. non-Newtonian fluids as "liquid armor". A non-Newtonian fluid is one whose viscosity depends on the velocity gradient of its flow. At the moment, most body armor, as described above, uses a combination of soft protective materials and hard armor inserts. The latter create the main weight. Replacing them with non-Newtonian fluid containers would both lighten the design and make it more flexible. AT different time The development of protection based on such a liquid was carried out by different companies. The British branch of BAE Systems even presented a working sample: packages with a special Shear Thickening Liquid gel, or bulletproof cream, had about the same protection indicators as a 30-layer Kevlar body armor. The disadvantages are also obvious: such a gel, after being hit by a bullet, will simply flow out through the bullet hole. However, developments in this area continue. It is possible to use the technology where impact protection is required, not bullets: for example, the Singapore company Softshell offers sports equipment ID Flex, which saves from injuries and is based on a non-Newtonian fluid. It is quite possible to apply such technologies to the internal shock absorbers of helmets or infantry armor elements - this can reduce the weight of protective equipment.
To create lightweight body armor, Ceradyne offers armor inserts made of hot-pressed boron and silicon carbides into which fibers of a composite material are pressed in a special way. Such a material withstands multiple hits, while hard ceramic compounds destroy the bullet, and composites dissipate and dampen its kinetic energy, ensuring the structural integrity of the armor element.
There is a natural analogue of fiber materials that can be used to create extremely light, elastic and durable armor - the web. For example, the cobweb fibers of the large Madagascar Darwin spider (Caerostris darwini) have an impact strength up to 10 times higher than that of Kevlar threads. To create an artificial fiber similar in properties to such a web, the decoding of the spider silk genome and the creation of a special organic compound for the manufacture of heavy-duty threads would allow. It remains to be hoped that biotechnologies, which have been actively developing in recent years, will someday provide such an opportunity.
Armor for ground vehicles
The protection of armored vehicles continues to increase. One of the most common and proven methods of protection against anti-tank grenade launchers is the use of an anti-cumulative screen. The American company AmSafe Bridport offers its own version - flexible and lightweight Tarian nets that perform the same functions. In addition to low weight and ease of installation, this solution has another advantage: in case of damage, the mesh can be easily replaced by the crew, without the need for welding and locksmithing in case of failure of traditional metal gratings. The company has signed a contract to supply the United Kingdom Department of Defense with several hundred of these systems in parts now in Afghanistan. The Tarian QuickShield kit works in a similar way, designed to quickly repair and fill gaps in traditional steel lattice screens of tanks and armored personnel carriers. QuickShield is delivered in a vacuum package, occupying a minimum habitable volume of armored vehicles, and is also now being tested in "hot spots".
AmSafe Bridport TARIAN anti-cumulative screens can be easily installed and repaired
Ceradyne, already mentioned above, offers DEFENDER and RAMTECH2 modular armor kits for tactical wheeled vehicles, as well as trucks. For light armored vehicles, composite armor is used, protecting the crew as much as possible under severe restrictions on the size and weight of the armor plates. Ceradyne works closely with armor manufacturers to give armor designers the opportunity to take full advantage of their designs. An example of such deep integration is the BULL armored personnel carrier, jointly developed by Ceradyne, Ideal Innovations and Oshkosh as part of the MRAP II tender announced by the US Marine Corps in 2007. One of its conditions was to protect the crew of the armored vehicle from directed explosions, the use of which has become more frequent while in Iraq.
The German company IBD Deisenroth Engineering, which specializes in the development and manufacture of defense equipment for military equipment, has developed the Evolution Survivability concept for medium armored vehicles and main battle tanks. The integrated concept uses the latest developments in nanomaterials used in the IBD PROTech line of protection upgrades and is already being tested. On the example of the modernization of the protection systems of the MBT Leopard 2, this is an anti-mine reinforcement of the bottom of the tank, side protective panels to counter improvised explosive devices and roadside mines, protection of the roof of the tower from air blast ammunition, active protection systems that hit guided anti-tank missiles on approach, etc.
BULL armored personnel carrier - an example of deep integration of Ceradyne protective technologies
The Rheinmetall concern, one of the largest manufacturers of weapons and armored vehicles, offers its own ballistic protection upgrade kits for various vehicles of the VERHA series - Versatile Rheinmetall Armor, "Rheinmetall Universal Armor". The range of its application is extremely wide: from armor inserts in clothing to the protection of warships. Both the latest ceramic alloys and aramid fibers, high molecular weight polyethylene, etc. are used.
The invention relates to the field of development of means of protecting equipment from armor-piercing bullets.
Progress in the creation of highly effective destructive weapons and the increase in the requirements for armor protection determined by it led to the creation of multilayer combined armor. The ideology of combined protection consists in a combination of several layers of dissimilar materials with priority properties, including a front layer of extra hard materials and a high-strength energy-intensive rear layer. Ceramics of the highest category of hardness are used as materials for the frontal layer, while its task is reduced to the destruction of the hardened core due to the stresses that arise during their high-speed interaction. The rear retaining layer is designed to absorb kinetic energy and block fragments resulting from the impact interaction of a bullet with ceramics.
Known technical solutions designed to protect surfaces with complex geometric relief - US patents No. 5972819 A, 26.10.1999; No. 6112635 A, 09/05/2000, No. 6203908 B1, 03/20/2001; patent of the Russian Federation No. 2329455, 20.07.2008. Common in these solutions is the use of small-sized ceramic elements in the frontal high-hard layer, as a rule, in the form of bodies of revolution, among which elements in the form of cylinders are most widely used. At the same time, the efficiency of the ceramics is increased by using convex sloping ends on one or both sides of the cylinders. In this case, when the projectile hits the oval surfaces of the ceramics, the mechanism of withdrawing or knocking the bullet off the flight path operates, which significantly complicates the work of overcoming the ceramic barrier. In addition, the use of small-sized ceramics in this case provides a higher level of survivability compared to the tiled version due to a significant reduction in the affected area and partial local maintainability of structures, which is very important for practice.
At the same time, the high efficiency of multilayer armor is determined not only by the properties of the materials of the main layers, but also by the conditions of their interaction during a high-speed impact, in particular, by acoustic contact between the ceramic and back layers, which makes it possible to partially transfer elastic energy to the back substrate.
Modern ideas about the mechanism of impact interaction of an armor-piercing core and combined protection are as follows. At the initial stage, when the core meets the armor, its penetration into the ceramic does not occur due to the fact that the latter has a significantly higher hardness compared to that of the core, then the core is destroyed due to the generation of high stresses in it that occur when braking against a ceramic barrier, and determined by the complex wave processes occurring in this case. The degree of core destruction is mainly determined by the time of interaction until the moment of destruction of the ceramic, while the acoustic contact between the layers plays a key role in increasing this time due to the partial transfer of elastic energy to the rear layer, followed by its absorption and dissipation.
A technical solution is known, set forth in US patent No. 6497966 B2, 12/24/2002, which proposes a multilayer composition consisting of a front layer made of ceramic or an alloy with a hardness above 27 HRC, an intermediate layer of alloys with a hardness of less than 27HRC and a back layer of polymer composite material. In this case, all layers are fastened together with a polymeric winding material.
In fact, in this case we are talking about a two-layer composition of the destructive frontal layer, made from materials that differ in hardness. In the recommendations of the authors of this technical solution, it is proposed to use carbon steels in a less hard layer, while questions about the energy exchange of the front and rear layers are not considered, and the proposed class of materials cannot, by its properties, serve as an active participant in the transfer of elastic energy to the rear layer.
The solution to the issues of interaction between the front and rear layers is proposed in the patent of the Russian Federation No. 2329455, 07/20/2008, which, in terms of the totality of common features, is the closest analogue to the proposed invention and is selected as a prototype. The authors propose the use of an intermediate layer in the form of an air gap or an elastic material.
However, the proposed solutions have a number of significant drawbacks. So, at the initial stage of interaction with ceramics, the elastic wave precursor of destruction reaches its rear surface and causes it to move.
When the gap collapses, the impact of the inner surface of the ceramic on the substrate can cause premature destruction of the ceramic and, consequently, accelerated penetration of the ceramic barrier. To avoid this, it is necessary either to significantly increase the thickness of the ceramic, which will lead to an unacceptable increase in the mass of the armor, or to increase the thickness of the gap, which will reduce the protection efficiency due to the separate (stage-by-stage) destruction of individual layers.
In the second version, the authors of the prototype propose to place an elastic layer between the layers, which should protect the ceramics from destruction upon impact with the rear armor. However, due to the low characteristic impedance of the elastic material, the interlayer will not be able to provide acoustic contact between the layers, which will lead to energy localization in brittle ceramics and its early failure.
The problem to be solved by the invention is to increase the armor resistance of the combined armor.
The technical result of the invention is to increase the armor resistance of the combined armor by increasing the density of acoustic contact between the layers.
The disadvantages of the prototype can be eliminated if the intermediate layer is made of a plastic material with certain properties that provides acoustic contact between the layers and the transfer of elastic energy to the rear. The above is achieved if the yield strength of the intermediate layer is 0.05-0.5 of the yield strength of the material of the back layer.
In the presence of an intermediate layer made of a plastic material with a yield strength of 0.05-0.5 of the yield strength of the material of the back layer, in the process of ceramic movement under the action of an elastic wave precursor, leaks and small gaps in the adjacent layers are eliminated due to the plastic deformation of the latter. In addition, under the action of stress waves, its density increases, and hence its characteristic impedance. All this together leads to an increase in the density of acoustic contact between the layers and increases the proportion of energy transmitted and dissipated in the back layer. As a result, due to the presence of an intermediate layer made of a plastic material with a yield strength of 0.05-0.5 of the yield strength of the back layer material, the impact interaction energy is distributed over all layers of the combined armor, while its efficiency increases significantly, since the time of interaction before the destruction of ceramics increases, which, in turn, provides a more complete destruction of the high-hard core.
An intermediate layer with a yield strength of more than 0.5 of the yield strength of the back layer does not have sufficient plasticity and does not lead to the desired result.
Making the intermediate layer of a plastic material with a yield strength of less than 0.05 of the value of the yield strength of the material of the back layer will not lead to the desired result, since its extrusion during the impact interaction is too intense and the effect described above on the mechanics of the interaction processes is not.
The proposed technical solution was tested in the test center NPO SM, St. Petersburg. The ceramic layer in the prototype 200×200 mm was made of AJI-1 corundum cylinders with a diameter of 14 mm and a height of 9.5 mm. The back layer was made of Ts-85 armor steel (yield strength = 1600 MPa) 3 mm thick. The intermediate layer was made of AMC grade aluminum foil (yield strength = 120 MPa) 0.5 mm thick. The ratio of the yield strengths of the intermediate and back layers is 0.075. Ceramic cylinders and all layers were glued together with a polyurethane-based polymer binder.
The results of field tests showed that the proposed version of the combined armor protection has armor resistance 10-12% higher compared to the prototype, where the intermediate layer is made of an elastic material.
Multilayer combined armor containing a highly hard front layer of a ceramic block or elements connected by a binder into a monolith, a high-strength energy-intensive back layer and an intermediate layer, characterized in that the intermediate layer is made of a plastic material with a yield strength of 0.05-0.5 of the limit back layer fluidity.
Similar patents:
The invention relates to reactive protection systems for the protection of stationary and moving objects from damaging elements. The system is fixed or movably installed or can be installed on the side of the object (1) to be protected facing the striking element (3) and contains at least one protective surface (4) located at a certain angle (2) with respect to the direction of the striking element.
The invention relates to rolling production and can be used in the manufacture of armor plates from (α+β)-titanium alloy. A method for manufacturing armor plates from (α+β)-titanium alloy includes preparing a charge, melting an ingot of the composition, wt.%: 3.0-6.0 Al; 2.8-4.5V; 1.0-2.2 Fe; 0.3-0.7 Mo; 0.2-0.6Cr; 0.12-0.3 O; 0.010-0.045 C;<0,05 N; <0,05 Н;<0,15 Si; <0,8 Ni; остальное - титан.
The group of inventions relates to the field of transport engineering. The method for installing glasses when booking a car according to the first option is that the armored glasses are installed behind the regular ones using a frame connected to the lead-in part of the glass and repeating the shape of the glass, and fasteners.
The invention relates to armored objects, mainly to electrified tanks with dynamic (reactive) armor protection. The armored object contains a protective device of a dynamic type, which includes elements with a body and a cover installed on a part of the outer surface area of the object.
SUBSTANCE: group of inventions relates to the production of multilayer flexible armor materials for personal protective equipment. The method of counteracting the movement of a multi-layered armor of a bullet, a fragment consists in alternating layers of high-modulus fibers with substances that enhance resistance, which are placed in cells formed by layers of high-modulus fibers.
The invention relates to defense technology and is intended for testing facial metal barriers - the basis of heterogeneous protective structures. The method includes firing strikers at a speed greater than the impact speed, determining and measuring the depth of impact penetration of the striker with a diameter d into the metal surface h (cavity depth). In this case, the impact speed is greater or less than the expected minimum speed of continuous penetrations. Determination of the limiting (minimum) speed of continuous penetrations, above which continuous penetrations are obtained, and below - only regular penetrations, against the background of a linear dependence of small values of the cavity depth h on the impact velocity; advantages of quantized impact velocities; single-digit and small two-digit quantum numbers n for all velocities at which penetrations or caverns of increased depth are obtained. EFFECT: determining the presence and advantages of quantized impact velocities, as well as increasing the accuracy of determining the minimum speed of continuous penetrations. 4 ill.
The invention relates to military equipment, in particular to the design of armor protection designed to counter cumulative ammunition. The reactive armor contains a body containing two parallel metal plates, detonators evenly spaced in the gap between the metal plates, sensors for determining the coordinates of a penetrating cumulative jet fixed on the inner surfaces of the plates. In the gap between the metal plates there are vessels filled with liquid, inside the vessels there are rigidly fixed detonators made in the form of controlled electric dischargers, the power electrodes of which are connected by wires to the output of the electric energy storage device, and the ignition electrodes are electrically connected to the output of the ignition pulse generator, the input of which is electrically connected. with sensors for determining the coordinates of the cumulative jet. EFFECT: increased reliability of dynamic protection operation. 1 ill.
The invention relates to means of protecting equipment and crew from bullets, shrapnel and grenade launchers. The protective composite material contains a sandwich that includes at least three layers glued together. The first and second sandwich layers include at least two prepregs and titanium alloy or aluminum alloy corners. The third layer of protective composite has a honeycomb structure and is made of polyurethane. The first and second layers of the sandwich include monoliths formed from an angle profile. Shelves of the angular profile are located at an angle of 45° to the plane of the working surface of the protective composite. The titanium alloy or aluminum alloy corners are interconnected by at least two prepregs. Prepreg fibers contain corundum nanotubes on the surface of a fiber made of polyethylene filament, or glass filament, or basalt filament, or fabric, or tow, or tape. An increase in protective properties is achieved due to the design of the armor. 3 w.p. f-ly, 1 ill.
The invention relates to armored objects, mainly to tanks with dynamic armor protection, and at the same time to means of camouflaging military objects using a camouflage coating fixed on the surface of the object. The protective device of an armored military object contains camouflage square elements-modules with a camouflage pattern in a range of colors and with a choice of one or another individual four-position orientation, removable on the armor sections of the object. The device provides for dynamic protection elements distributed over the surface of the object with removable square covers, and the camouflage elements-modules are made in the form of rigid plates interchangeable with the mentioned covers of dynamic protection elements, with the possibility of quickly changing the camouflage pattern by replacing and / or rearranging two-functional ones, thus , elements-modules between elements of dynamic protection. Efficiency of replacement of camouflage means is achieved by particular application of the principle of multifunctionality of units and parts of machines to elements of dynamic protection and camouflage means. 5 z.p. f-ly, 4 ill.
The invention relates to the field of measurement technology and can be used to control the quality of composite armor barriers. A device for thermal quality control of composite armor barriers based on the analysis of the energy of absorption of the projectile, including a device for firing located between the substrate and the device for firing on the flight path of the projectile, a device for measuring the flight speed of the projectile at the output of the device for firing, a substrate made of plastic material . The device is additionally equipped with a thermal imaging system, a computer system and a device for recording the start of the projectile flight. The thermal imaging system is located in such a way that the field of view of its optical part covers the point of contact between the striking element and the composite armor barrier. The input of the device for recording the beginning of the flight of the projectile is connected to the output of the device for measuring the speed of the projectile at the output of the device for firing. The output of the device for recording the beginning of the flight of the striking element is connected to the input of the thermal imaging system, and the output of the thermal imaging system is connected to the input of the computer system. The technical result is an increase in the information content and reliability of the test results. 9 ill.
The invention relates to the field of transport engineering. The energy-absorbing structure for protecting the bottom of ground vehicles consists of inner and outer layers of protection made of armor and/or structural alloys. Between the layers of protection is a layer. The interlayer is made in the form of two identical rows of U- or W-shaped energy-absorbing profiles mirrored to each other and shifted by half a step relative to each other. The end ribs of the energy-absorbing profiles of one row rest on the end ribs of adjacent energy-absorbing profiles of the opposite row. An increase in the efficiency of energy absorption during detonation is achieved. 3 ill.
The invention relates to the field of measurement technology and can be used to control the quality of composite armor barriers. The method includes installation of an armored barrier in front of a plate of plastic material, directing a striking element at a given speed to the armored barrier. Additionally, the temperature field of the surface of the composite armor barrier having minimal temperature anomalies is recorded, which is taken as anomalous, the spatial resolution is determined for registering the temperature field, based on the detection of temperature anomalies of minimum size with a spatial period determined by the size of the minimum temperature anomaly. After impact on the composite armor barrier by the striking element at a given speed, the temperature field is simultaneously measured in the area of contact of the striking element with the composite armor barrier, starting from the moment of contact of the striking element with the composite armor barrier and from the opposite side, in relation to the side of contact with the striking element, on based on the analysis of the temperature field recorded from two surfaces, the technical state of the composite armor barrier is determined by the vector of characteristics of the armor barrier and its absorption energy by minimizing the functional by the vector of characteristics of the controlled armor plate by solving a system of equations, and based on the analysis of the temperature field, the absorption energy of the composite armor barrier is determined. A device for bench testing of composite armor barriers is disclosed. The technical result is an increase in the information content and reliability of the test results. 2 n. and 3 z.p. f-ly, 3 ill., 1 tab.
The invention relates to a penetration-resistant article that can be used for the production of protective clothing such as bulletproof vests, helmets, as well as shields or armor elements, as well as to a method for its production. The product contains at least one woven fabric structure (3) having thermoplastic fibers and high strength fibers with a strength of at least 1100 MPa, in accordance with ASTM D-885. The high tenacity fibers are bonded together to form a woven fabric (2) of a woven fabric structure (3), and the thermoplastic fibers have a weight percentage relative to the weight of the woven fabric structure (3) of 5 to 35%. Moreover, the thermoplastic fibers preferably in the form of non-corrugated fabric (6) lie on the woven fabric (2) and are connected to the woven fabric (2) by the main thread and/or weft thread of the woven fabric (2) of high-strength fibers. There are no additional connecting threads or non-textile connecting means for connecting between the woven fabric (2) and the thermoplastic fibres. The penetration resistant article has impact protection and/or anti-ballistic properties. 3 n. and 11 z.p. f-ly, 7 ill.
SUBSTANCE: invention relates to bulletproof composite products, which are characterized by improved resistance to reverse deformation. Bulletproof product contains a vacuum panel, which consists of the first surface, the second surface and the body. The vacuum panel limits at least a part of the internal volume in which the vacuum is created. Bulletproof product contains at least one bulletproof base, which is connected to the first or second surface of the vacuum panel. The ballistic base contains fibers and/or tapes with a specific strength of about 7 g/denier or more and a tensile modulus of about 150 g/denier or more. Also, the bulletproof base is made of a rigid material not based on fibers or tapes. Also proposed is a method for forming a bulletproof article, in which the bulletproof base is positioned so that it is on the outside of the bulletproof article, and the specified vacuum panel is placed behind the specified at least one bulletproof base in order to receive any shock wave that occurs as a result of impact. striking element on the specified bulletproof base. EFFECT: weakening of the impact of shock waves generated as a result of the impact action of the projectile, reduction of the magnitude of the purl deformation, prevention or minimization of injuries from the transcendent action of bullets. 3 n. and 7 z.p. f-ly, 9 ill., 2 tables, 19 pr.
SUBSTANCE: group of inventions relates to the field of measuring technology, namely to a method for quality control of composite armor barriers made of fabric and a device for its implementation. The method includes installing a composite armor barrier in front of a plate made of plastic material, directing the projectile at the armor barrier at a given speed, and determining the absorption energy of the projectile. From the moment of interaction between the armored barrier and the damaging element, two spatial fields are simultaneously recorded on the surface of the armored barrier: the temperature field of the surface of the armored barrier and the field of the video image of the surface. The video image contour is superimposed on the temperature field, a new measured temperature field is formed, and the absorption energy by the composite armor barrier is determined based on the analysis of the new temperature field. Disclosed is a device for quality control of composite armor barriers made of fabric for the implementation of the method. EFFECT: increased informative value and reliability of control results. 2 n. and 1 z.p. f-ly, 5 ill.
The invention relates to the field of development of means of protecting equipment from armor-piercing bullets. Multilayer combined armor contains a highly hard front layer of a ceramic block or elements connected by a binder into a monolith, a high-strength energy-intensive rear layer and an intermediate layer. The intermediate layer is made of a plastic material having a yield strength of 0.05-0.5 of the yield strength of the back layer. An increase in the armor resistance of the combined armor is achieved by increasing the density of acoustic contact between the layers.
Aluminum Composite Armor
Ettore di Russo
Professor Di Russo is the scientific director of the company "Aluminia", which is part of the Italian MCS group of the EFIM consortium.
Alumina, part of the Italian MCS group, has developed a new type of composite armor plate suitable for use on light armored combat vehicles (AFV). It consists of three main layers of aluminum alloys of different composition and mechanical properties, joined together into one plate by means of hot rolling. This composite armor provides better ballistic protection than any standard monolithic aluminum alloy armor currently in use: aluminium-magnesium (5XXX series) or aluminium-zinc-magnesium (7XXX series).
This armor provides a combination of hardness, toughness and strength, which provides high resistance to ballistic penetration of kinetic projectiles, as well as resistance to the formation of armor spalls from the rear surface in the area of impact. It can also be welded using conventional inert gas arc welding techniques, making it suitable for the manufacture of elements of armored combat vehicles.
The central layer of this armor is made of aluminum-zinc-magnesium-copper alloy (Al-Zn-Mg-Cu), which has high mechanical strength. The front and back layers are made of a weldable high-impact Al-Zn-Mg alloy. Thin layers of commercially pure aluminum (99.5% Al) are added between the two internal contact surfaces. They provide better adhesion and increase the ballistic properties of the composite board.
Such a composite structure made it possible for the first time to use a very strong Al-Zn-Mg-Cu alloy in a welded armor structure. Alloys of this type are commonly used in aircraft construction.
The first lightweight material widely used as armor protection in the design of armored personnel carriers, for example, M-113, is the non-heat treatable Al-Mg alloy 5083. Three-component Al-Zn-Mg alloys 7020, 7039 and 7017 represent the second generation of light armor materials . Typical examples of the use of these alloys are: English cars "Scorpio", "Fox", MCV-80 and "Ferret-80" (alloy 7017), French AMX-10R (alloy 7020), American "Bradley" (alloys 7039+ 5083) and Spanish BMR -3560 (alloy 7017).
The strength of Al-Zn-Mg alloys obtained after heat treatment is much higher than the strength of Al-Mg alloys (for example, alloy 5083), which cannot be heat treated. In addition, the ability of Al-Zn-Mg alloys, unlike Al-Mg alloys, to precipitation hardening at room temperature makes it possible to largely restore the strength that they can lose when heated during welding.
However, the higher penetration resistance of Al-Zn-Mg alloys is accompanied by their increased tendency to armor spalling due to lower impact strength.
A composite three-layer board, due to the presence of layers with different mechanical properties in its composition, is an example of an optimal combination of hardness, strength and impact strength. It has the commercial designation Tristrato and is patented in Europe, USA, Canada, Japan, Israel and South Africa..
Fig.1.
Right: Tristrato armor plate sample;
left: cross section showing the Brinell hardness (HB) of each layer.
Ballistic performance
Plates have been tested at several military training grounds in Italy and abroad Tristrato thickness from 20 to 50 mm by shelling with various types of ammunition (various types of 7.62-, 12.7-, and 14.5-mm armor-piercing bullets and 20-mm armor-piercing projectiles).
During the tests, the following indicators were determined:
at various fixed impact velocities, the values of the meeting angles corresponding to the penetration frequencies of 0.50 and 0.95 were determined;
at various fixed angles of impact, impact velocities were determined corresponding to a penetration frequency of 0.5.
For comparison, parallel tests were carried out on monolithic control plates made of alloys 5083, 7020, 7039 and 7017. The test results showed that the armor plate Tristrato provides increased resistance to penetration by selected armor-piercing weapons with a caliber of up to 20 mm. This allows a significant reduction in weight per unit of protected area compared to traditional monolithic slabs while maintaining the same resistance. For the case of shelling with 7.62-mm armor-piercing bullets at a meeting angle of 0 °, the following reduction in mass is provided, which is necessary to ensure equal durability:
by 32% compared to alloy 5083
by 21% compared to alloy 7020
by 14% compared to alloy 7039
by 10% compared to alloy 7017
At a meeting angle of 0 o, the impact velocity corresponding to a penetration frequency of 0.5 increases by 4 ... -but effective against 20mm projectiles FSP , when shelled by which the specified characteristic increases by 21%.
The increased resistance of the Tristrato plate is explained by the combination of high resistance to the penetration of a bullet (projectile) due to the presence of a solid central element with the ability to hold fragments that occur when the central layer is pierced with a plastic back layer, which itself does not give fragments.
Plastic layer on the back Tristrato plays an important role in preventing armor spalling. This effect is enhanced by the possibility of delamination of the plastic back layer and its plastic deformation over a large area in the area of impact.
It is an important mechanism for resisting slab penetration. Tristrato . The peeling process absorbs energy, and the void formed between the core and back member can trap the projectile and fragments generated when the highly hard core material breaks. Likewise, delamination at the interface between the front (face) element and the center layer can contribute to the destruction of the projectile or direct the projectile and fragments along the interface.
Fig.2.
Left: Schematic showing the chipping resistance mechanism of a Tristrate plate brow;
right: the results of a blow with a blunt-nosed armor-piercing
projectile on a thick Tristrato slab;
Production properties
Tristrato slabs can be welded using the same methods that are used to join traditional monolithic slabs of Al-Zn-Mg alloys (methods TIG and MIG ). The structure of the composite plate still requires that some specific measures be taken, determined by the chemical composition of the central layer, which should be considered as a "not good for welding" material, in contrast to the front and back elements. Therefore, when developing a welded joint, one should take into account the fact that the main contribution to the mechanical strength of the joint should be made by the outer and back elements of the plate.
The geometry of welded joints should localize welding stresses along the boundary and in the fusion zone of the deposited and base metals. This is important for solving the problems of corrosion cracking of the outer and back layers of the slab, which is sometimes found in Al-Zn-Mg alloys. The central element, due to its high copper content, exhibits high resistance to stress corrosion cracking.
Rrof. ETTORE DI RUSSO
ALUMINUM COMPOSITE ARMOR.
INTERNATIONAL DEFENSE REVIEW, 1988, No12, p.1657-1658
You can often hear how armor compared according to the thickness of steel plates 1000, 800mm. Or, for example, that a certain projectile can break through some "n"-number of mm armor. The fact is that now these calculations are not objective. Modern armor cannot be described as equivalent to any thickness of homogeneous steel.
There are currently two types of threats: kinetic energy projectile and chemical energy. By kinetic threat is meant armor-piercing projectile or, more simply, a blank with great kinetic energy. In this case, it is impossible to calculate the protective properties armor based on the thickness of the steel plate. So, shells with depleted uranium or tungsten carbide pass through steel like a knife through butter and the thickness of any modern armor, if it were homogeneous steel, it would not withstand the impact of such shells. There is no armor 300mm thick, which is equivalent to 1200mm steel, and therefore capable of stopping projectile, which will get stuck and stick out in the thickness armored sheet. Success protection from armor-piercing shells lies in changing the vector of its impact on the surface armor.
If you're lucky, then when you hit there will be only a small dent, and if you're not lucky, then projectile will sew all armor regardless of whether it is thick or thin. Simply put, armor plates are relatively thin and hard, and the damaging effect largely depends on the nature of the interaction with projectile. In the American army to increase hardness armor used depleted uranium, in other countries Wolfram carbide, which is actually more solid. About 80% of tank armor's ability to stop shells-blanks fall on the first 10-20 mm of modern armor.
Now consider chemical impact of warheads.
Chemical energy is represented by two types: HESH (anti-tank armor-piercing high-explosive) and HEAT ( HEAT projectile).
HEAT - more common today, and has nothing to do with high temperatures. HEAT uses the principle of focusing the energy of an explosion into a very narrow jet. A jet is formed when a geometrically regular cone is surrounded on the outside explosives. During detonation, 1/3 of the energy of the explosion is used to form a jet. Due to high pressure (not temperature), it penetrates through armor. The simplest protection against this type of energy is a layer set aside half a meter from the body. armor, thus dissipating the energy of the jet. This technique was used during the Second World War, when Russian soldiers surrounded the body tank netting from the beds. Israelis are doing the same now. tank Merkava, they are for protection ATGM feeds and RPG grenades use steel balls hanging from chains. For the same purposes, a large aft niche is installed on the tower, to which they are attached.
Other method protection is the use dynamic or reactive armor. It is also possible to use combined dynamic and ceramic armor(such as Chobham). When a jet of molten metal comes into contact with reactive armor the detonation of the latter occurs, the resulting shock wave defocuses the jet, eliminating its damaging effect. Chobham Armor works in a similar way, but in this case, at the moment of the explosion, pieces of ceramics fly off, turning into a cloud of dense dust, which completely neutralizes the energy of the cumulative jet.
HESH (anti-tank armor-piercing high-explosive) - the warhead works as follows: after the explosion, it flows around armor like clay and transmits a huge momentum through the metal. Further, like billiard balls, the particles armor collide with each other and thus the protective plates are destroyed. Material booking capable of flying into small shrapnel, injuring the crew. Protection from such armor similar to the one described above for HEAT.
Summarizing the above, I would like to note that protection from kinetic impact projectile reduced to a few centimeters of metallized armor, it depends protection from HEAT and HESH is to create a delayed armor, dynamic protection, as well as some materials (ceramics).
Common types of armor that are used in tanks:
1. Steel armor. It's cheap and easy to make. It can be a monolithic bar or soldered from several plates. armor. The elevated temperature treatment increases the elasticity of the steel and improves the reflectivity against kinetic attack. Classic tanks M48 and T55 used this armor type.
2. Perforated steel armor. This is sophisticated steel armor in which perpendicular holes are drilled. Holes are drilled at the rate of no more than 0.5 of the expected diameter. projectile. It is clear that the weight is reduced. armor by 40-50%, but the efficiency also drops by 30%. It does armor more porous, which to some extent protects against HEAT and HESH. Advanced types of this armor include solid cylindrical fillers in the holes, made, for example, of ceramics. Besides, perforated armor placed on the tank in such a way that projectile fell perpendicular to the course of the drilled cylinders. Contrary to popular belief, initially the Leopard-2 tanks did not use Chobham armor type(type of dynamic armor with ceramics), and perforated steel.
3. Ceramic layered (Chobham type). Represents a combined armor from alternating metal and ceramic layers. The type of ceramic used is usually a mystery, but usually it is alumina (aluminum salts and sapphire), boron carbide (the simplest hard ceramic), and similar materials. Sometimes synthetic fibers are used to hold metal and ceramic plates together. Lately in layered armor ceramic matrix connections are used. Ceramic layered armor protects very well from a cumulative jet (due to defocusing of a dense metal jet), but also resists kinetic effects well. The layering also makes it possible to effectively resist modern tandem projectiles. The only problem with ceramic plates is that they cannot be bent, so the layered armor built from squares.
Alloys are used in ceramic laminate to increase its density. . This is a common technology by today's standards. The main material used is tungsten alloy or, in the case of 0.75% titanium alloy with depleted uranium. The problem here is that depleted uranium is extremely poisonous when inhaled.
4. dynamic armor. This is a cheap and relatively easy way to defend against HEAT rounds. It is a high explosive, squeezed between two steel plates. When hit by a warhead, explosives detonate. The disadvantage is the uselessness in the event of a kinetic impact projectile, as well as tandem projectile. However, such armor is lightweight, modular and simple. It can be seen, in particular, on Soviet and Chinese tanks. dynamic armor usually used instead advanced layered ceramic armor.
5. Abandoned armor. One of the tricks of design thought. In this case, at a certain distance from the main armor set aside light barriers. Effective only against a cumulative jet.
6. Modern combined armor. Most of the best tanks equipped with this armor type. In fact, a combination of the above types is used here.
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Translation from English.
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