The most important thing required for the construction of armor systems is the ammunition that will threaten the armored system. The type, type, characteristics, and qualities of the ammunition are the determining factors in this regard. These range from hand-held assault weapons such as piercing, cutting, ripping knives, skewers, chisels, and similar weapons, low-velocity grenade fragments, and projectiles, to rocket-propelled weapons, long and heavy alloy kinetic energy penetrates, and other ammunition. Let us examine these munitions.
Kinetic Energy Ammunition
- Knife, skewer type weapons for cutting, piercing, stabbing.
Hand tools such as knives, skewers, drills, and chisels are serious threats that can be used by hand. They can cause fatal wounds with the high pressure they apply to the surface with their pointed ends. They can tear especially knitted polymer-type armor materials. They can also penetrate metallic armor. The speed of these attack tools is related to how fast they can swing the human arm. In general, impact speeds vary between 7-10 m/sec. Due to the off-axis forces and torsional torque during the attack, the impact cannot be measured precisely. We will continue with an example of simulation studies with these tools.
Knife and steel armor are tested by the ANSYS. Knife made from stainless steel. This simulation provided penetration capability of knife against to metal armor.
Low-Caliber Kinetic Energy Projectiles
Low-caliber projectiles generally consist of cores and fragment up to 7.62 mm in size, with velocities below 1000 m/sec. They are generally made of high-strength materials (steel, tungsten carbide, lead, or tungsten alloys). The reason why lead is generally used for this type of projectile is due to the lightness of the core due to its density. For this reason, the lightness of the bullet core can give the core higher velocities depending on the gunpowder ratio. For a body without armor systems, this would already be enough to cause a lethal impact. Different bullet designs have also been developed to achieve this effect. For armor-piercing bullets, bullets made of high-strength materials with a pointed or blunt core tip are generally used. The kinetic energy of these projectiles can be several kilojoules.
- 9 mm metal-plated, rounded type. This type of ammo is most popular handgun projectile in the world. Therefore, it has a good range and penetration for its mass. According to IIA Standard, it has 124 gr. projectile mass, and 341 m/sec impact velocity.
- 40 S&W metal-plated, blunt-end type. This type of ammo is more dangerous than 9 mm, because it can apply more pressure to bone. Thus, bones can form fragment effect inside the body. According to IIA Standard, it has 180 gr, projectile mass, and 322 m/sec impact velocity.
- .357 Magnum soft point bullet type. This type of ammo is examined with standard of II, because it has 158 gr. projectile mass, and 436 m/sec impact velocity. With its speed and mass, adiabatic shear is observed as the soft tip is embedded on the armor surface during the impact.
- .44 Magnum semi-enveloped hollow point bullet type. This type of projectile contains high-strength metal cores with high penetration power. It has high mass ratios with high-strength metal cores. If we consider low caliber bullets, they can be extremely lethal and penetrating. According to standard IIIA, it has 240 gr. projectile mass, and 436 m/sec impact velocity. In addition to this information, bullets defined as long 9 mm is also analyzed in this class. Their velocity is 436 m/sec and their mass is defined as 124 gr.
Medium and High-Caliber Kinetic Energy Projectiles
Medium and High-Caliber projectiles are classified between 20-140 mm as length, and they are used with 1300 m/sec between 1600 m/sec for heavily armored structure. Cores of projectiles are made from high density metals. Therefore, resilience of core must be enough to protect your rigidity during damping. High-Caliber projectiles have high megajoules (10^6 J) impact energy. That mechanism is important for ability of penetration. Every shell has its penetration capability. The main shell type used by most guns and vehicles is the armor piercing type. These shells fly quickly, but their penetration capability slightly reduces with distance. Their penetration capability also reduces when they hit a destructible object like a fence or a vehicle. The APCR shell is faster than AP shell. APCR shells can go through fences too but with distance they lose their penetration capacity more than AP. When I consider rolled homogeneous armor, high hardness armor, ultra high hardness armor, and armored steel, two parameters are very important. These parameters are shell penetration capability, and mechanical behavior of armor . Shell penetration capability depends on shell type, velocity, materials of projectile, and angle of arrival. Mechanical behavior of armor depends on hardness, grain orientation, ultimate tensile strength, and resilience of armor. These parameters will examine on next articles with details. Nowadays, The most effectively used projectile is the APFDS. Modern sabots are made of tungsten heavy alloys and depleted uranium. These materials are extremely superior in terms of their high density and mechanical properties. However, depleted uranium is highly toxic due to its radioactivity in the event of a collision, and uranium dust (UO2) can be dispersed. The main use of this munition is due to the high energy of the impact and the enormous explosive energy it generates. This projectile generally has a length-to-diameter ratio of 15-20/1. This ratio is 30/1 in experimental projectiles. As the diameter decreases, the penetration capability also increases. The reason for this is the reduction of friction and lightness as the diameter decreases. However, in this case, since the stresses on small diameters will increase, a fracture is possible. M256 120 mm ammunition reaches speeds of approximately 1650 m/s after being fired from the M1A1 and M1A2 launchers. Fin stabilization is used to prevent wobbling during flight. The flight path and ballistic condition are extremely important. With the angle it will form with the armor, it can lose 80% of its penetrating power. The critical angle value for APFDS ammunition is a degree of inclination of the armor plate of approximately 83 degrees or more. For AP and APCR rounds, the value is related to the tangent angle and the thickness of the armor too, and the angles are much smaller than for APFDS ammunition. An APFDS round fired from the 130 mm main gun of Rheinmetall’s newly introduced the KF51 tank can reach a range of 12 kilometers. Today’s modern armor technologies produce ceramic metallic composites to stop these munitions. These ceramics include boron carbide, alumina, silicon carbide, and titanium diboride. I will discuss the details of these materials and ammunition in other articles.