Average armor penetration what. Shells. Penetration rules for HEAT rounds

HOW AND WHY QUESTIONS APPLY TO

PROCESS OF ARMOR PENETRATION

(abbreviated translation)*)

To evaluate the working hypotheses that explain the processes occurring during armor penetration, it is necessary to have a standard, which should be taken as an ideal process armor penetration.

Ideal Process armor penetration occurs when the rate of penetration of the projectile into the armor exceeds the speed of sound propagation in the material of the projectile. In this case, the projectile interacts with the armor only in the area of ​​​​their contact (contact), and therefore no deforming loads are transmitted to the rest of the projectile, since not a single mechanical signal can be transmitted through the medium at a speed greater than the speed of sound in that medium.

The speed of sound in heavy and strong metals is about 4000 m/s. The speed of armor-piercing projectiles of kinetic action is approximately 40 percent of this value, and therefore these projectiles cannot be in ideal conditions armor penetration. On the contrary, the shaped charge affects the armor precisely under ideal conditions, since the speed of the shaped charge jet is several times more speed sound in the metal of the shaped charge lining.

process theory armor penetration is divided into two parts: one (concerning shaped charges) is simple, clear and indisputable, and the other (relating to kinetic armor-piercing projectiles) is still obscure and extremely complex. The latter is due to the fact that when the speed of the projectile is lower than the speed of sound in its material, the projectile is in the process of armor penetration subjected to significant deforming loads. Therefore, the theoretical model armor penetration is clouded by various mathematical models relating to deformations, abrasion and integrity of the projectile and armor. When analyzing the interaction of a kinetic projectile with armor, their behavior must be considered jointly, while armor penetration shaped charges can be analyzed regardless of the armor they are designed to penetrate.

shaped charge

In a shaped charge, the explosive is placed around an empty metal (usually copper) cone (lining). Charge detonation osu-*)

Information about the main design differences between various types of armor-piercing sub-caliber and cumulative projectiles, information about various types of modern tank armor, as well as repetitions available in the article, has been omitted previously published in the Collections of Translations of Articles published by military unit 68064. Note. editor

happensso that the detonation wave propagates from the top of the cladding to its base perpendicular to the generatrix of the cone. When the detonation wave reaches the cladding, the latter begins to deform (compress) at high speed towards its axis, which causes the cladding metal to flow. At the same time, the lining material does not melt, and due to the very high speed and degree of deformation, it passes into a coherent (split at the molecular level) state and behaves like a liquid, remaining a solid body.

According to the physical law of conservation of momentum, the smaller part of the lining, which has more high speed, will flow to the base of the cone, forming a cumulative jet. A larger part of the lining, but with a lower speed, will flow in the opposite direction, forming a core (pestle). The described processes are illustrated in Figures 1 and 2.

Fig. 1. Formation of the core (pestle) and jet during the deformation of the lining caused by the detonation of the charge. The detonation front propagates from the top of the lining to its base, perpendicular to the generatrix of the cone: 1 - explosive; 2 - lining; 3 - jet; 4 - detonation front; 5 - core (pestle)

Rice. 2. Distribution of the cladding metal before and after its deformation by explosion and the formation of a core (pestle) and a jet. The top of the cladding cone creates the head of the jet and the tail of the core (pestle), and the base forms the tail of the jet and the head of the core (pestle)

The distribution of energy between the jet and the core (pestle) depends on the aperture of the lining cone. When the cone aperture is less than 90°, the energy of the jet is greater than the energy of the core, the opposite is true for aperture greater than 90°. Therefore, conventional shaped charges used in projectiles designed to penetrate a thick eyebrow with a shaped charge jet formed by direct contact of the projectile with armor have an aperture of no more than 45 °. Flat shaped charges (such as "shock core"), designed to penetrate relatively thin armor with a core from a significant (up to tens of meters) distance, have an aperture of about 120 °.

The speed of the core (pestle) is lower than the speed of sound in the metal. Therefore, the interaction of the core (pestle) with the armor proceeds as in conventional armor-piercing projectiles of kinetic action.

The speed of the cumulative jet is higher than the speed of sound in metal. Therefore, the interaction of the cumulative jet with the armor proceeds according to the hydrodynamic theory, that is, the cumulative jet and the armor interact as two ideal fluids when they collide.

It follows from the hydrodynamic theory that armor penetration cumulative jet increases in proportion to the length of the jet and the square root of the ratio of the density of the shaped charge lining material to the density of the barrier material. Based on this, it may the theoretical armor-piercing ability of a given shaped charge should be calculated.

However, practice shows that the real armor-piercing ability of shaped charges is higher than the theoretical one. This is explained by the fact that the actual length of the jet turns out to be greater than the calculated one due to the additional elongation of the jet due to the velocity gradient of its head and tail parts.

For the full realization of the potential armor-piercing ability of the shaped charge (taking into account the additional elongation of the shaped charge jet due to the velocity gradient along its length), it is necessary that the detonation of the shaped charge occurs at the optimal focal length from the barrier (Fig. 3). For this purpose, they are used Various types ballistic tips of the appropriate length.

Rice. 3. Change in penetration capacity of a typical shaped charge as a function of change in focal length: 1 - penetration depth (cm); 2 - focal length (cm)

In order to stretch the cumulative jet more and, accordingly, increase its armor-piercing ability, conical linings of shaped charges with two or three angular apertures are used, as well as horn-shaped linings (with a continuously changing angular aperture). When changing the angular aperture (stepwise or continuously), the velocity gradient along the length of the jet increases, which causes its additional elongation and an increase in armor-piercing ability.

Raise armor penetration shaped charges due to the additional stretching of the cumulative jet is possible only if high accuracy in the manufacture of their linings is ensured. Accuracy in the manufacture of linings is a key factor in the effectiveness of shaped charges.

Future developments of shaped charges

Possibility of promotion armor penetration shaped charges due to the additional stretching of the cumulative jet is limited. This is due to the need to correspondingly increase the focal length, which leads to an increase in the length of the projectiles, makes it difficult to stabilize them in flight, increases the requirements for manufacturing accuracy and increases the cost of production. In addition, with an increase in the elongation of the jet, its corresponding thinning reduces the effectiveness of the armor action.

Another way to improve armor penetration cumulative munitions can be the use of tandem-type shaped charges. It's about not about a warhead with two shaped charges in series, designed to overcome reactive armor and not intended to increase armor penetration as such. We are talking about a special design that ensures the targeted use of the energy of two sequentially firing shaped charges precisely to increase the total armor penetration ammunition. At first glance, both concepts look similar, but in reality they completely different. In the first design, the head (with a lower mass) charge fires first, initiating with its cumulative jet the detonation of the protective charge of reactive armor, "clearing the way" for the cumulative jet of the second charge. In the second design, the armor-piercing effect of the cumulative jets of both charges is summed up.

It has been proven that with equal armor-piercing ability, the caliber of a tandem projectile can be less than the caliber of a single-shot projectile. However, a tandem projectile will be longer than a single-shot projectile and more difficult to stabilize in flight. It is very difficult for a tandem projectile and the choice of the optimal Artful distance. It can only be a compromise between ideal values for the first and second charges. There are other difficulties in creating tandem cumulative munitions.

Alternative developments of shaped charges

The rotation of a shaped charge designed to penetrate armor with a cumulative jet reduces its armor-piercing ability. This is due to the fact that the centrifugal force that occurs during rotation breaks and bends the cumulative jet. However, for a shaped charge designed to penetrate armor with a core rather than a jet, the rotation imparted to the core can be useful to increase it. armor penetration similar to how it is with conventional projectiles of kinetic action.

The use of cores formed during the explosion as a penetrating agent is expected in SFF / EFP combat units designed for submunitions scattered by artillery shells and rockets. The core, having a significantly larger diameter compared to the cumulative jet, also has a higher armor damaging effect, but it penetrates a much smaller thickness of armor compared to a cumulative jet, although from a much greater distance. armor penetration the core can be increased by giving it an optimal firmness, which requires a thicker lining than for the formation of a cumulative jet.

In SFF / EFP HEAT warheads, it is advisable to use parabolic tantalum liners. Their predecessors, which are flat shaped charges, use conical deep-drawn steel liners. In both cases, the facings have large angular apertures.

Penetration at subsonic speed

All armor-piercing projectiles, the impact velocity of which is less than the speed of sound in the material of the projectile, perceive high pressures and deforming forces when interacting with the armor. In turn, the nature of the resistance of the armor to the penetration of the projectile depends on its shape, material, strength, plasticity and angle of inclination, as well as the velocity, material and shape of the projectile. It is impossible to give a standard comprehensive description of the processes occurring in this case.

Depending on one or another combination of these factors, the main energy of the projectile in the process of interaction with the armor is consumed in different ways, which leads to armor damage of various nature (Fig. 4).In this case, certain types of stresses and deformations arise in the armor: tension, compression, shear, bending. In practice, all these types of deformations appear in a mixed and hardly discernible form, but for each specific combination of conditions for the interaction of a projectile with armor, the determining factors are certain types deformations.

Rice. 4.Some characteristic species damage to armor by kinetic projectiles. From top to bottom: brittle fracture, spalling of armor, shearing of cork, radial cracks, puncture (petal formation) on the back surface

Sub-caliber projectile

top scores armor penetration achieved when firing from cannons large caliber(which ensures that the projectile receives high energy, which increases in proportion to the caliber to the third power) by small diameter projectiles (which reduces the energy required by the armor penetration projectile, proportional to the diameter, of the projectile to the first degree). This determines the widespread use of armor-piercing sub-caliber shells.

armor penetrationsub-caliber projectile is determined by the ratio of its mass and speed, as well as the ratio of its length x diameter (1:d).

Best by armor penetration is the longest projectile that can be made with existing technology. But when stabilized by rotation, 1:d cannot exceed 1:7 (or a little more), because if this limit is exceeded, the projectile becomes unstable in flight.

With a maximum allowable ratio of 1:d to ensure high armor penetration a lighter projectile with a higher velocity than a heavier projectile but with a slower velocity. At a sufficiently high impact velocity of the elongated projectile, the material of the obstacle and impact projectile begins to flow (Fig. 5), which facilitates the process armor penetration. High projectile velocities also contribute to an increase in shooting accuracy.

Fig. 5. Top: X-ray image of an elongated core that hit an armor plate inclined at a large angle (80o) at a speed of 1200 m/s. The snapshot reflects the state 8.5 µs after the impact: the shells of the armor begin to flow together. Left: X-ray of an aluminum plate punching sequence with a copper elongated core at 1200 m/s. It can be seen that the nature of the penetration process approaches the hydrodynamic one: both the barrier material and the core material flow.

The initial velocities of modern armor-piercing sub-caliber projectiles are already close to the maximum achievable in artillery systems, but still some further increase is possible through the use of propellant charges with more energy.

The best armor penetration can be obtained at impact speeds of 2000-2500 m/s. Increasing the impact velocity to 3000 m/s or more does not lead to a further increase armor penetration, since in this case the main part of the projectile energy will be spent on increasing the diameter of the crater. However, the transition to impact velocities equal to (or exceeding) the speed of sound in the material of the projectile (for example, through the use of electromagnetic guns) again increases armor penetration, because the process armor penetration becomes ideal, as when piercing armor with a cumulative jet.

Stabilization by rotation or feathering?

Rotational stabilization is not possible with a ratio of 1:d greater than 8. Stabilization with feathers more difficult, the higher the speed of the projectile, but the solution of this problem is facilitated if the place of attachment of the plumage is located at a sufficient distance from the center of gravity of the projectile. For this purpose, either a heavy core is placed in the head of the projectile, or a cavity is created in the tail of the projectile, or the projectile is simply lengthened. Stabilization with feathers allows you to successfully stabilize projectiles with significantly larger ratio 1:d than this can be provided by rotational stabilization.

Projectile stabilization by rotation is possible only when firing from rifled guns, and stabilization by plumage is possible when firing from both rifled and smoothbore guns. Otherwise, from rifled guns it is possible to fire shells stabilized both by rotation and plumage, and from smooth-bore guns - only by stabilized plumage. In this regard, the British decision to use rifled guns for their tanks seems justified.

The use of feather stabilization opens up the possibility of a significant increase in the 1:d ratio, however, on the other hand, these possibilities are limited by the strength of the projectile, since excessively long and thin projectiles will break when they hit the armor, especially when they hit at a large angle from the normal to the armor surface. The intended use of 1:d=20 in the design of APFSDS-type projectiles made from an alloy of depleted uranium ("Stabella") can only be explained by the very high strength of this alloy. Such strength can be obtained if the projectile is a single-crystal body, since the mechanical strength of a single crystal is much higher than the strength of a polycrystalline body.

Armor

With the same thickness, a denser material has a higher anticumulative durability compared to less dense material. However, the limitation for booking mobile vehicles is not the thickness of the armor as such, but the mass of the armor. With an equal mass, a less dense material (due to greater thickness) will have a higher anticumulative durability compared to denser material. This implies the expediency of using for anticumulative lung protection durable materials(aluminum alloys, Kevlar, etc.).

However, light materials provide poor protection against kinetic projectiles. Therefore, to protect against these projectiles, it is necessary to place strong steel armor outside and behind the layer of light material. This is the basic concept of composite (combined) armor, specific composition which can be quite complex is kept secret.

Recent advances in armor are reactive armor, first used on Israeli tanks and also used on American tank M-1A1 armor, including single crystals based on depleted uranium. The latter has high protective properties against cumulative and armor-piercing sub-caliber projectiles, as well as from gamma radiation from a nuclear explosion. However, depleted uranium can be easily split by fast neutrons (yield between 2 and 4), which will enhance the neutron component. This can increase the radius of lethal damage to tank crew members by a neutron flux during a nuclear explosion by 1.25-1.6 times. Is it worth considering? The answer may not come from weapons experts, but only from strategy experts.

GIORGIO FERRARI

THE "HOWS" AMD "WHYS" OF ARMOR PENETRATION.

MILITARY TECHNOLOGY, 1988, No10, p. 81-82, 85, 86, 90-94, 96

Gun penetration in World of Tanks is one of the main parameters of a gun. It doesn't matter what accuracy or rate of fire the gun has. If the armor penetration of the projectile is low, the gun is useless. The low penetration of the cannon is most noticeable in battle with a heavily armored enemy. Many players are wondering: "What is the most penetrating gun in WoT?"

True, before giving an answer, you need to understand that there are about three hundred tanks of ten levels in the game, each of which has its own penetrating cannon. At the same time, each gun has its own types of shells. However, all shells are classified into armor-piercing, sub-caliber, cumulative, high-explosive fragmentation.

The most penetrating weapons

So, the owner of the penetrating gun is FV215 (183). The average penetration of a 183 mm gun by an armor-piercing projectile is 310 mm. This absolute indicator penetration among all armor-piercing shells in the game.

However, british tank destroyer is also a record holder in penetration by a high-explosive fragmentation projectile. True, this projectile belongs to the category of "gold". The "Golden Landmine" penetrates an average armor thickness of 275 millimeters.

We offer you to watch a video guide about this killer tank destroyer:

Among the tanks whose guns are capable of firing cumulatives, the champion in armor penetration is german tank destroyer JgPzE100 with a colossal penetration of 420 millimeters. Such a penetration is enough to flash Mouse even into a gun mask.

Although before the great "artonerf" the record for penetration of the cannon belonged to the Soviet Object 268 - 450 millimeters. But the developers have lowered this figure to 395 mm.

Other levels, other tanks

Undoubtedly, the higher the level of the tank, the higher the armor penetration rate. But also for more low levels there are steel monsters with lethal weapons. So, for example, at the first level, the nomination "The most penetrating gun in World of Tanks" belongs to the Soviet MS-1 with a penetration rate of 88 mm with a gold shell. At the second level, the American-made T18 tank destroyer with a two-pounder gun (121 mm) stands out.

At the third level in the armor penetration rating is the French-made UE57 tank destroyer with a penetration of 180 mm. Moreover, this tank is the smallest and lightest in WoT (3 tons). The fourth level is represented by the Soviet anti-tank self-propelled guns SU-85B. The ZIS-2 gun of 57 mm caliber penetrates an average armor thickness of 189 mm.

At the fifth level, the battle for the title of the most penetrating gun is entered by heavy tanks. But tank destroyers still win, and the podium is occupied by Pz. Sfl. IVc with a penetration of 237 mm. The sixth place belongs to the French ARL V39 and ARL 44. Both tanks are equipped with a 90 mm gun that can penetrate 259 mm of gold armor.

AMX AC mle.46 rightfully occupies the seventh place in the armor penetration rating of guns with a 263 mm gold shell. Eighth place unconditionally belongs to the ISU-152 (Fri-Sau of the USSR). The BL-10 gun terrifies all opponents, has a colossal damage of 750 units and penetration of 329 mm.

The ninth place is immediately occupied by 2 German tank destroyers (WT auf PZ.IV and JagdTiger) with a 12.8 cm Kanone L / 61 gun. As for tier 10 tanks with piercing barrels, they were discussed at the beginning of the article.

As a matter of fact, if you want to break through everyone in the game, then develop branches of tank destroyers in each of the nations. by the most penetrating guns possess anti-tank self-propelled guns Germans, French and USSR.

Process calculation of armor penetration very complex, ambiguous and depends on many factors. Among them are the thickness of the armor, the penetration of the projectile, the penetration of the gun, the angle of the armor plate, etc.

Calculate the probability of armor penetration, and even more so exact amount inflicted damage, on its own is almost impossible. There are also miss and rebound probabilities programmed in. Do not forget to take into account that many values ​​in the descriptions are not indicated as maximum or minimum, but as averages.

Below are the criteria by which an approximate calculation of armor penetration.

Calculation of armor penetration

1. The sight circumference is the circular deflection at the moment the projectile hits the target/obstacle. In other words, even if the target overlaps the circle, the projectile can hit the edge (the junction of armor sheets) or pass tangentially to the armor.
2. Calculate the energy reduction of the projectile depending on the range.
3. The projectile flies along a ballistic trajectory. This condition applies to all implements. But for anti-tank ones, the muzzle velocity is quite high, so the trajectory is close to a straight line. The trajectory of the projectile is not straight, and therefore deviations are possible. The sight takes this into account, showing the calculated area of ​​impact.
4. The projectile hits the target. First, its position at the moment of impact is calculated - for the possibility of a rebound. If there is a ricochet, then a new trajectory is taken and recalculated. If not, armor penetration is calculated.
   In this situation, the penetration probability is determined from the calculated armor thickness(this takes into account the angle and inclination) and the armor penetration of the projectile, and is + -30% of the standard armor penetration. Normalization is also taken into account.
5. If the shell has pierced the armor, then it removes the number of hit points of the tank specified in its parameters (Relevant only for armor-piercing, sub-caliber and HEAT shells). Moreover, there is a possibility, when hitting some modules (cannon mask, caterpillar), they can completely or partially absorb the damage of the projectile, while receiving critical damage, depending on the area where the projectile hit. There is no absorption when armor is pierced by an armor-piercing projectile. In cases with high-explosive fragmentation shells, there is absorption (slightly different algorithms are used for them). The damage of a high-explosive shell upon penetration is the same as that of an armor-piercing one. In case of non-penetration, it is calculated according to the formula:
   Half the damage of a high-explosive projectile is (armor thickness in mm * armor absorption coefficient). The coefficient of absorption of armor is approximately equal to 1.3, if the "Anti-fragmentation lining" module is installed, then 1.3 * 1.15
6. The projectile inside the tank "moves" in a straight line, hitting and "piercing" modules (equipment and tankers), each of the objects has its own number of hit points. Damage dealt (proportional to energy from item 5) - divided by damage directly to the tank - and critical damage to modules. The number of hit points removed is the total, so the more one-time critical damage, the less hit points are removed from the tank. And everywhere there is a probability of + - 30%. For different armor-piercing shells- different coefficients are used in the formulas. If the caliber of the projectile is 3 or more times the thickness of the armor at the point of impact, then the ricochet is excluded by a special rule.
7. When passing through modules and causing critical damage to them, the projectile spends energy, and in the process completely loses it. Through penetration of the tank, the game is not provided. But there is a module getting critical damage by a chain reaction caused by a damaged module (gas tank, engine) if it catches fire and starts to damage other modules, or explodes (ammunition rack), completely removing the tank’s hit points. Some places in the tank are recalculated separately. For example, the caterpillar and the mask of the gun only take critical damage, without taking hit points from the tank, if armor-piercing projectile did not go further. Or the optics and the driver's hatch - in some tanks they are "weak points".

Tank armor penetration also depends on his level. The higher the level of the tank, the more difficult it is to break through. Top tanks have maximum protection and minimum armor penetration.

Dear players!

On June 18, testing of the updated concept of armor penetration for both conventional and premium ammunition began. The new concept implies changes in the performance characteristics of a number of high-level vehicles.

The changes will affect most of the "top" tank destroyers and medium tanks, as well as some heavy tanks.

The main reasons for the revision:

• Excessive armor penetration in Tier VIII–X battles: The ratio of successful shots to non-penetration exceeds similar indicators at medium and low levels.
• The need to increase the role of armor in high-level battles: as the analysis of these battles shows, excessive armor penetration reduces the role of heavily and medium armored vehicles.

Armor penetration values ​​on the test server are not final. Changes in the performance characteristics of vehicles will be finalized only after a thorough study of the statistics collected on the basis of the tests. Other parameter changes will also be determined to improve the playability of the test vehicles (aiming time, stabilization while moving, reloading, etc.).

The results of mass testing are one of the key factors for making decisions about such changes. The more developers receive feedback and suggestions, the more objective the conclusions and changes will be.

Participation in testing

• Download a special installer (4.47 MB).
• Run the installer, which will download and install a special test version of the client: 5.94 GB for the SD version and 3.33 GB for the HD version. When you run the installer, it will automatically offer to install the test client in a separate folder on your computer; you can also specify the installation directory yourself.
• Run the installed test version.
• Only those players who registered in World of Tanks before 23:59 (UTC) on June 3, 2015 can take part in the general test.

general information

• The general test will last approximately until June 25 - stay tuned.
• Due to the large number of players on the test server, there is a limit on user login. All new players who wish to take part in the testing of the update will be placed in a waiting queue and will be able to enter the server as it becomes available.
• If a user changed their password after June 3, 2015 11:59 PM UTC, authorization on the test server will only be available with the password that was used before the specified time.

Peculiarities

• Payments for test server are not produced.
• From the very beginning of testing, the account will be credited one-time: 200,000 , 7 days of Premium Account, 500 , as well as all equipment and crew skills.
• In this testing, the earnings of experience and credits do not increase.
• Achievements on the test server will not be transferred to the main server.

We would also like to inform you that during testing, scheduled maintenance will be carried out on the test server - at 07:00 (Moscow time) daily. The average duration of work is 25 minutes.

• Note! The test server is subject to the same rules as the main game server, and therefore, there are penalties for violating these rules in accordance with the User Agreement.
• The User Support Center does not review applications related to the Common Test.
• We remind you: the most reliable way to download the World of Tanks client, as well as its test versions and updates, is in

Before the start of the battle, shells must be loaded into the tank. Without them, the tank will not be able to shoot and, accordingly, will be useless. The number of shells that can be loaded into a tank depends on the type of tanks in WoT, or rather on the type of gun (caliber) and turret. Different types projectiles have different properties.

Regular projectiles

Armor-piercing (AP) shells

Sub-caliber (BP) shells

Improved Projectiles

Sub-caliber (BP) shells

Cumulative (CC) projectiles

A detailed device of the cumulative projectile is presented on Wikipedia.

High-explosive (HE) projectiles

Armor-piercing (AP) shells