The principle of the action of a shaped charge.
The principle of the action of a shaped charge.
- When the cumulative charge is undermined, the energy of the explosion is directed to the center of the funnel and tends forwards. The so-called Monro effect is observed, the mechanism of which has not yet been fully explained. A powerful jet of explosion gases strikes the obstacle at a speed of about 8000 meters per second and breakdown pressure of 10.000.000 kg per square centimeter (according to other sources - 12.000.000 kg per square centimeter). The effect could be further strengthened by installing a metal sleeve on the inner surface of the funnel. During the explosion, the metal bushing instantly melted, and the liquid metal mixed with the gases of the explosion. The resulting jet is often called "plasma" jets. For maximum efficiency, the cumulative projectile must be eroded at the correct distance from the target. If the detonation occurs too close to the target, the "plasma" jet else will not have time to fully form until the projectile comes into contact with the armor, and the impact will decrease. If the detonation occurs too far from the target, then by the time of contact with the armor, the "plasma" jet will lose its focus and some of the energy (this version of the blasting is applied against the cellular armor (see below)).
Due to the fact that the cumulative effect does not depend on the kinetic energy of the projectile, it does not matter how the cumulative charge will be delivered to the target. The distance to the target and the power of the gun also does not matter, the cumulative projectile can simply be put on the armor, and will still maintain its burning effect. The only parameters affecting the efficiency of the shaped charge are the type of explosive used, the shape of the funnel, and the distance from the target at which the charge is eroded.
Now from myself: protective measures against cumulative ammunition are specific shields (serve to increase the distance from the point of charge initiation to the armor). As screens, thin sheets of metal are usually used. In Berlin, our tankmen often attached metal nets to beds, in Chechnya our tankmen used a simple mesh netting.
The second way is the system of "dynamic protection" used in the last 2-3 decades, it is also an "active armor", it is also a "reactive armor" - hanging or built-in containers with explosives that, when undermined, break the cumulative jet and nullify the damaging the effect of this type of ammunition.
- The cumulative charge (the charge of a directed explosion) is a charge of an explosive in a sturdy body, the front covered with a funnel (top inward) of soft metal. When the charge is blown, the gas jet of the directed explosion crushes and melts the "funnel" and even very thick armor breaks through e kinetic energy. Actually, armor breaks not with the impact of the projectile but with a powerful impact of the molten metal stream.
From this, the old name of the cumulative projectiles occurred: "armor-burners"
Shells with a shaped charge punched even very thick (up to 0,5 meter) ship's armor, but leaving holes with a thickness of a pencil.
In modern weapons such charges are used in anti-tank grenades, grenades and rockets.
More less reduces the damage from such charges - dynamic armor - thin metal boxes with plastids (the explosion of such a box can weaken a directional explosion).
- Principle - directional explosion.
All the energy of the explosion, due to the design, is directed to one point,
- The most common mistake is that cumulative charges are attributed to the armored SPECIALER. What is not true. Here is an excerpt from my book.
The specificity of the cumulative action of an explosive charge is illustrated by such examples. If the cylindrical checker of the blasting explosive is put on the unplit and undermined, having a detonator in the middle of the checker, then the energy of the explosion will spread equally in all directions, and only a small dent will form on the armor. But if in the same explosive charge the detonator is placed in the upper end of the checker, then the action of the explosion will be stronger in the direction of the plate, and accordingly the dent on it after the explosion will be of greater depth. However, in both cases, the scattering of the explosion products occurs in all directions. If, however, the charge has an axial or spherical recess on the plate facing the plate, then as a result of the explosion a deeper dent in the form of a crater forms in the plate. The presence of a notch in the explosive charge leads to the fact that the direction of the flow of the products of the explosion is concentrated along the axis of the notch, and does not dissipate in all directions. A jet of explosive explosives is formed in the form of a narrow beam of gases with a beam of light. The speed of the jet in focus reaches 15 km / s. But the greatest effect on the plate is achieved when the wall of the cavity in the charge is covered with a metal lining. When blasting a charge with the lining of a copper or steel funnel, the armored plate even penetrates through a considerable thickness. It happens this way. When the detonator, located in the upper end of the checker, is triggered, the detonation wave propagates in the explosive substance in the direction of the notch. The detonation velocity of explosives used in cumulative charges is 7-9 km / s.
A detonation wave at such a speed exerts a tremendous pressure on a metal lining up to 800 thousands of atmospheres. As a result, the cladding metal collapses and stretches along the recess axis in the form of a cumulative jet. The metal that makes up the cumulative jet does not melt, although it heats up to 400-600 degrees. Recall that the melting point of copper is about 1100 degrees, and steel 1300-1400 degrees. The metal jet with a diameter of 3-4 mm gains speed up to 10 km / s and puts pressure on armor for about one million atmospheres. The state of metal in a cumulative jet is defined by science as an ideally incompressible fluid. With such a huge pressure, the material of the barrier armor, concrete, etc. in the place of the impact of the cumulative jet flows, that is, just like the jet itself, acquires the properties of a perfectly incompressible fluid. A hole appears in the barrier, the edges of which have an indirect appearance. This led, in its time, to the incorrect definition of cumulative dream-rows as armor-burning. Even after overcoming the obstacle, the high energy of the residual elements of the jet, causing the destruction of equipment, the detonation of ammunition, the destruction of people, is still preserved.
Thus, the highly efficient action of a cumulative projectile is the result of the fact that the energy of a charge with a notch and a metal lining of its surface during an explosion propagates in one direction along the axis of the notch, and not in all directions, as if an ordinary charge exploded. This concentration of energy leads to the formation of a metal jet with a speed of up to 10 km / s on the order of 1-th cosmic velocity and creates pressure on the obstacle of millions of atmospheres. This is where the name of the cumulation phenomenon originated, from the Latin word cumulatio accumulation, concentration.