Due to the rapid developments in the military field, GMKA Defense continues to develop technologies in many areas related to ballistic protection against ballistic impacts such as ballistic protective clothing, high-strength fabrics, body armor, and air, land and, naval vehicle interiors.
Ballistic protection is one of the main functional features of military textiles. Ballistic protective suits absorb the kinetic energies of bullets and shrapnel fragments to protect the body and vehicles equipped with ballistic technologies.
The main parameters affecting energy absorption in ballistic protective clothing are fiber type, fabric construction, density and weight, and the number of fabric layers used in the clothes. The fibers to be used for this purpose should have high strength, high modulus, and low elasticity. Today, the most preferred fibers in ballistic protective clothing are para-aramid fibers. Besides these, high molecular weight polyethylene fibers have also gained commercial importance. There are also full-aromatic polyester fibers, fibers used for ballistic purposes such as PBO and PIPD. Carbon nanotubes and spider silk fibers are researched intensively and the possibilities of their use for ballistic protection are also promising in this field.
GMKA presents new ballistic protection technologies by examining the ballistic protection mechanism of textile materials, the fibers used in these fabrics and the methods used to compare the ballistic protection performance of textile products.
1. Internal ballistics examining the movement of a bullet or missile at the weapon or in impact area
2. External ballistics examining its movement during flight
3. Terminal ballistics examining the effects on the target
INTERNAL BALLISTICS
It studies the chemical energy source, the expansion of gas, and the control and direction of the resulting energy. Military weapons operate in more extreme conditions in terms of temperature and pressure than non-military weapons. The movement of a projectile in the weapon is related to the effect of the gas on the projectile. During the movement of the bullet, a frictional force arises while pressing against the barrel it is in. The high-temperature gas heats the barrel so much that there is even a chemical reaction between them.
Another aspect of internal ballistics is the spiral-shaped grooves and rifling in the weapon barrel. It allows a long bullet to spin and reach the target while maintaining a stable trajectory. Spiral grooves depend on the curvature of the gun barrel. They can be smooth, denser towards the muzzle, or a combination of these.
EXTERNAL BALLISTICS
If the inertial, gravitational, and aerodynamic forces acting on the projectile or missile are known, calculating trajectories is not a major difficulty. However, determining the aerodynamic forces is quite complex
In order to overcome air resistance and maintain a stable flight, a projectile has to remain in its initial position for the duration of the flight towards the target point. The flight will not end as planned and fall outside its range, if the projectile changes its position or even somersaults. There are two methods to ensure flight stabilization. These are aileron stabilization and rotational stabilization. In aileron stabilization, ailerons mounted on the projectile allow the projectile to travel without rotating on its axis. This is achieved by the aerodynamic forces acting on the ailerons. A projectile with spin stabilization, on the other hand, always continues to move along the initial target direction as a result of its gyroscopic rotational motion. The inertia of this rotational motion does not allow any deviation from the correct axis.
TERMINAL BALLISTICS
Due to the difficulties in obtaining basic information, this branch of ballistics is lags behind the other branches, namely internal ballistics and external ballistics. Rapid developments advances in the field of rradiography and the eraage of high-speed photography have helped in this regard. However, the issue of the reliability of the information received is still questionabledebated. In all known weapon types and target conditions, the destruction of the target occurs with the following physical effects:
• Usually due to fragmentation effect or different differing movements of small particles in cases where bombs, rockets, warheads, grenades are used
• Due to fragmentation as a result of penetration and penetration infiltration of the counter-mass
• Water or air Due to the indignation arising from the sudden release of a large amount of energy in a fluid medium such asDue to impact of the sudden release of a large amount of energy in a fluid medium such as water or air
• Due to the destruction caused by relatively high-speed shocksBy the demolition effect caused by relatively high-velocity quakes
• Due to the heat released generated by the fire or radiation of an explosion
• Due to fire bombs or explosions and resulting fires
• Especially due to the chemical effect of smoke or toxic gases
• Bacteriological effect
• Radiation effect
Fundamentally, armored vehicles are combat systems. They have ballistic protection, mobility and firepower. These features turn into an engineering miracle with a coherent combination. The main design priority is to provide the highest possible level of protection to the crew and the internal components during operation.
Based on the square meter and width of the armor material, the mass weight of the backward projection and its resistance to possible threats and the resistance parameter of the material are identified. Rolled armor steel is the most common armor steel. It is produced by the Brinell method. The strength of an ammunition is measured by the thickness of the armor steel it can penetrate.
BRINELL HARDNESS MEASUREMENT METHOD
The Brinell hardness measurement method is applied to iron, steel and non-metallic materials with a tensile stress of less than 150 kg/mm². In this method of hardness measurement, spherical steel balls of different diameters are used.
Ball diameters and weight to be applied are selected according to the type and thickness of the material whose hardness is to be measured. The weight to be applied for thick pieces varies between 187.5 and 3000 kg.
In Brinell hardness measurement, the ratio of the applied weight (P) to the area (A) of the indented part of the spherical steel ball gives the hardness (HB) and is found by the formula below.
HB = P / A
Ball imprint area when the imprint area is written in terms of ball diameter (D) and imprint diameter (d):
When we substitute the area formula in the initial formula:
HB = Brinell hardness, kg/mm²
P = Applied weight (load), kg
A = Surface area of the indented part of the ball, mm²
D = Diameter of the spherical steel ball, mm²
d = Diameter of the imprint made by the ball on the piece, mm
Relationship between piece thickness, ball diameter and applied weight in Brinell hardness measurement
ARMOR PRODUCTION METHODS
Armor production methods are examined under four categories.
1) Mono-block Armor:
It is the method produced by manufacturing the material in one piece. The hull and turret are in one piece. This situation disrupts the integrity of the armor during possible action and the armor may crack.
2) Multi-Block Armor:
A thick layer of welded armor blocks. Since it consists of many layers, it reduces the damage rate of the ammunition in each layer. This provides high ballistic protection.
3) Spaced Multi-Block Armor:
Armor blocks are welded with gaps. After the impacting ammunition penetrates the first block, some of its energy is absorbed by the gaps and the energy is not completely transferred to the other block. This method provides higher ballistic protection than the first two methods.
4) Sloped Spaced Multi-Block Armor:
It is the method of producing armor formed by welding the blocks with a certain angle with gaps. Ammunition has to travel a long way compared to other methods. Due to the inclination, the ammunition may ricochet or the tip may break.
Selection of these production methods is based on a ratio of many different parameters. Threat detection, operational needs and economic conditions determine the production method. Choosing easy production methods and deploying alternative armor on vehicles is also a method of reinforcement.
ARMOR MATERIALS
Armor Steel:
Formerly known as MIL-A-12560, with its new description, the durability of 230 mm rolled steel (density 7.8 t/m³) produced in accordance with MIL-A-46177 standard and Brinell 380 method is accepted as reference by NATO. Brinell 500 and Brinell 600 methods are preferred for higher strength.
Generally, hard steel is applied on the outside, and mild steel is applied on the inside in armoring land vehicles. Thus, the first surface absorbs resistance the second surface absorbs energy. The energy released causes less damage.
Aluminum:
In general, 7020 and AZ5G is the type of aluminum used for ballistic protection. Magnesium is added. It is lighter than steel and the joining process takes place quickly. In vehicles using aluminum, there is no need for a skeleton structure. This advantage is a big factor in lightening the vehicle. Vehicles produced with aluminum are equipped with additional armor.
Titanium:
Partial use is preferred instead of using it in all armored vehicles. It is lighter than steel and has a higher hardness. Titanium, called TA6V, is 1.5 times more durable than steel armor and is much more expensive.
Attenuated Uranium:
It is the material left over from the uranium enrichment process, where the 238 isotopes are used in the manufacture of armor. It has a density of 18.5 t/m³. Its use is not preferred due to its flammability and radiation emission
Composite:
During the penetration of glass hollow-point ammunition used in the first composite laminated armor application, the integrity of the energy-reflecting melt is disrupted. The dispersed melt solidifies and the strength is thus increased by 2.5 times. In addition to glass, nylon, rubber, Teflon, polyurethane, Al203, TiB2, SiC, and B4C are commonly used.
ARMOR TYPES
Spall Liner:
The armor placed on the interior of the vehicles prevents shrapnel from damaging the personnel and interior parts in the event of a puncture. Composite armor is preferred due to its light weight and thinness.
Liquid Armor:
The gel, which is produced using nanotechnology, is in liquid form between two steel blocks and becomes solid upon contact with the ammunition. Its lightness is remarkable compared to other materials.
Explosive Reactive Armor:
An armor consisting of explosives placed in steel boxes is placed on the outer surface of the chassis by a riveting method. Activated upon contact with the ammunition, the explosive detonates in the opposite direction and reduces the impact. This armor provides the same resistance as steel armor, which is ten times heavier than itself.
Additional Grid and Mesh Armors:
Developed after shaped-charge ammunition, additional grid armors ensure the ammunition explodes before it reaches the main body. These armors have low weight, are very cheap, and can be quickly replaced when damaged, are one of the best solutions against ammunition.
GMKA continues to develop ballistic protection technologies. Materials that are successful in the laboratory environment must be able to be processed and shaped in terms of manufacturing. They should be suitable for mass production, withstand any wear and tear caused by weather conditions, absorb the tensile – tensile forces to be imposed on them during the operation, and not be deformed. One of the most important considerations for armors is the way they are manufactured. Manufacturing techniques, engineering knowledge, quality workmanship and experience are among the criteria taken into consideration in determining the production method.
GMKA continues to develop ballistic protection technologies. Materials that are successful in the laboratory environment must be able to be processed and shaped in terms of manufacturing. They should be suitable for mass production, withstand any wear and tear caused by weather conditions, absorb the tensile – tensile forces to be imposed on them during the operation, and not be deformed. Materials that are successful in the laboratory environment; In terms of manufacturing, it should be able to take shape by processing, be suitable for mass production, withstand every wear caused by weather conditions, absorb the tensile-tensile forces that will be on it during the operation and not be deformed. One of the most important issues considerations for armors is the way they are manufactured. Manufacturing techniques, engineering knowledge, quality workmanship and experience are one amongof the criteria taken into consideration for how to producein determining the production method.
Ceramic materials are preferred in effective armor systems due to their low density, high stiffness, and hardness. When ceramics are used for ballistic purposes, a ductile plate should be placed on the back surface to prevent damage to the surface to be protected and to absorb the residual kinetic energy of the projectile. The material of this plate can be metal or fiber-reinforced polymer composites. The ceramic layer used as the top layer in the composite armor system causes the projectile to wear and shatter, while the back plate reacts against the dulled projectile, holding the broken ceramic pieces and absorbing the kinetic energy. When the bullet hits the ceramic front surface, the ceramic surface is shattered due to the high kinetic energy of the bullet. These damages occur as tensile damage, transverse cracks, pulverization, and shear plug. In composite armor systems produced in this way, even if the armor is penetrated, the impact of the projectile is significantly reduced. Commonly used ceramic types in ceramic composite armor systems are Alumina (Al2O3), Silicon Carbide (SiC), and Boron Carbide (B4C).
BALLISTIC PROTECTION LEVELS
The most effective target penetration and destruction are achieved with armor-piercing kinetic energy projectiles and shaped-charge projectiles. Kinetic energy projectiles contain no explosive materials. The tip of the projectile is sintered from a high-density material such as tungsten or uranium. The penetrating effect of these projectiles on the target depends on the projectile diameter, the energy of the projectile, the angle of impact of the projectile on the armor, and the metallurgical structure of the projectile and the armor material. Ballistic protection is concerned with body armor and levels of protection. Ballistic requirements for military and police armor are generally defined by international standards.
FACTORS AFFECTING BALLISTICS
Caliber: Cartridge dimensions expressed in millimeters (mm) in metric systems.
Rifling marks (Rayyür): The weapon-specific imprints on the cartridge bullet of the sets extending parallel to each other in the form of a helix inside the barrel.
Pitch: The distance traveled by the cartridge inside the barrel while rotating around its axis once.
Diameter: The distance between two sets opposite each other.