Small missile boat. Small rocket ship
At dawn practical use cumulative ammunition, during the Second World War, they were quite officially called “armor-burning”, since in those days the physics of the cumulative effect was unclear. And although in the post-war period it was precisely established that the cumulative effect has nothing to do with “burning through”, echoes of this myth are still found in the philistine environment. But in general, we can assume that the “armor-burning myth” has safely died. However, “a holy place is never empty” and one myth regarding cumulative ammunition was immediately replaced by another...
This time, the production of fantasies about the effects of cumulative ammunition on the crews of armored vehicles was put on stream. The main postulates of dreamers are as follows::
— tank crews are allegedly killed by excess pressure created inside an armored vehicle by cumulative ammunition after penetrating the armor;
— crews who keep the hatches open supposedly stay alive thanks to a “free exit” for excess pressure.
Here are examples of such statements from various forums, websites of “experts” and printed publications (the original spelling has been preserved; among those cited there are very authoritative printed publications):
“- Question for experts. When a tank is hit by cumulative ammunition, what damaging factors affect the crew?
- Excessive pressure first. All other factors are related”;
“Assuming that the cumulative jet itself and fragments of pierced armor rarely affect more than one crew member, I would say that the main damaging factor was the overpressure... caused by the cumulative jet...”;
“It should also be noted that the high destructive power of shaped charges is explained by the fact that when a jet burns through the hull, tank or other vehicle, the jet rushes inside, where it fills the entire space (for example, in a tank) and causes severe damage to people...”;
“The tank commander, Sergeant V. Rusnak, recalled: “It’s very scary when a cumulative projectile hits a tank. “Burns through” armor anywhere. If the hatches in the turret are open, then a huge pressure force throws people out of the tank..."
“...the smaller volume of our tanks does not allow us to reduce the impact of INCREASED PRESSURE (the shock wave factor is not considered) on the crew, and it is the increase in pressure that kills them...”
“What is the calculation made, why actual death should occur, if the drops did not kill, let’s say, a fire did not occur, and the pressure is excessive or it simply tears into pieces in a confined space, or the skull bursts from the inside. There's something tricky about this excess pressure. That’s why they kept the hatch open”;
“Sometimes an open hatch can save you because a blast wave can throw a tanker out through it. A cumulative jet can simply fly through a person’s body, firstly, and secondly, when in a very short time the pressure increases very much + everything around heats up, it is very unlikely to survive. From eyewitness accounts, the tank crews’ turret is torn, their eyes fly out of their sockets”;
“When an armored vehicle is hit by a cumulative grenade, the factors that affect the crew are excess pressure, armor fragments and a cumulative jet. But taking into account the measures taken by the crews to prevent the formation of excess pressure inside the vehicle, such as opening hatches and loopholes, armor fragments and a cumulative jet remain the factors affecting personnel.”.
There are probably enough “horrors of war” presented by both citizens interested in military affairs and the military personnel themselves. Let's get down to business - refuting these misconceptions. First, let's consider whether it is in principle possible for the appearance of supposedly “lethal pressure” inside armored vehicles from the impact of cumulative ammunition. I apologize to knowledgeable readers for the theoretical part, they may miss it.
PHYSICS OF THE CUMULATIVE EFFECT
The principle of operation of cumulative ammunition is based on the physical effect of accumulation (cumulation) of energy in converging detonation waves formed when an explosive charge having a funnel-shaped recess is detonated. As a result, a high-speed flow of explosion products—a cumulative jet—is formed in the direction of the excavation focus. An increase in the armor-piercing effect of a projectile in the presence of a notch in the explosive charge was noted back in the 19th century (Monroe effect, 1888), and in 1914 the first patent for an armor-piercing cumulative projectile was received.
Rice. 1. Tandem cumulative ammunition of the German RPG “Panzerfaust” 3-IT600. 1 – tip; 2 – precharge; 3 – head fuse; 4 – telescopic rod; 5 – main charge with a focusing lens; 6 – bottom fuse.
Rice. 2. Pulsed X-ray image of shaped charge detonation. 1 – armored barrier; 2 – cumulative charge; 3 – cumulative recess (funnel) with metal lining; 4 – charge detonation products; 5 – pestle; 6 – head part of the jet; 7 – removal of barrier material.
The metal lining of the recess in the explosive charge makes it possible to form a high-density cumulative jet from the lining material. The so-called pestle (the tail part of the cumulative jet) is formed from the outer layers of the cladding. The inner layers of the cladding form the head of the jet. A lining made of heavy ductile metals (for example, copper) forms a continuous cumulative jet with a density of 85-90% of the material density, capable of maintaining integrity at high elongation (up to 10 funnel diameters).
The speed of the metal cumulative jet reaches 10-12 km/s at its head. In this case, the speed of movement of parts of the cumulative jet along the axis of symmetry is not the same and amounts to up to 2 km/s in the tail part (the so-called velocity gradient). Under the influence of the velocity gradient, the jet in free flight is stretched in the axial direction with a simultaneous decrease in the cross section. At a distance of more than 10-12 diameters of the shaped charge funnel, the jet begins to disintegrate into fragments and its penetrating effect sharply decreases.
Experiments on trapping a cumulative jet with a porous material without destroying it showed the absence of the recrystallization effect, i.e. the temperature of the metal does not reach the melting point, it is even below the point of first recrystallization. Thus, the cumulative jet is a metal in a liquid state, heated to a relatively low temperatures. The temperature of the metal in the cumulative jet does not exceed 200-400° degrees (some experts estimate the upper limit at 600°).
When meeting an obstacle (armor), the cumulative jet slows down and transfers pressure to the obstacle. The jet material spreads in the direction opposite to its velocity vector. At the boundary between the materials of the jet and the barrier, pressure arises, the magnitude of which (up to 12-15 t/sq.cm) is usually one or two orders of magnitude greater than the tensile strength of the barrier material. Therefore, the barrier material is removed (“washed out”) from the area high pressure in the radial direction.
These processes at the macro level are described by hydrodynamic theory, in particular, the Bernoulli equation is valid for them, as well as that obtained by M.A. Lavrentiev. hydrodynamic equation for shaped charges. At the same time, the calculated depth of penetration of an obstacle does not always agree with experimental data. Therefore, in recent decades, the physics of interaction between a cumulative jet and an obstacle has been studied at the submicrolevel, based on a comparison of the kinetic energy of impact with the energy of breaking interatomic and molecular bonds of the substance. The results obtained are used in the development of new types of both cumulative ammunition and armored barriers.
The armor-protecting effect of cumulative ammunition is ensured by a high-speed cumulative jet that penetrates the barrier and secondary armor fragments. The jet temperature is sufficient to ignite powder charges, fuel vapors and hydraulic fluids. The damaging effect of the cumulative jet and the number of secondary fragments decrease with increasing armor thickness.
HIGH-EXPLOSIVE EFFECT OF CUMULATIVE AMMUNITION
Now let's talk more about excess pressure and shock waves. The cumulative jet itself does not create any significant shock wave due to its small mass. The shock wave is created by the detonation of an explosive charge of ammunition (high-explosive action). A shock wave CANNOT penetrate a thick-armored barrier through a hole pierced by a cumulative jet, because the diameter of such a hole is negligible and it is impossible to transmit any significant impulse through it. Accordingly, excess pressure cannot be created inside the armored object.
Rice. 3. Inlet (A) and outlet (B) holes punched by a cumulative jet in a thick-armored barrier. Source:
The gaseous products formed during the explosion of a shaped charge are under a pressure of 200-250 thousand atmospheres and heated to a temperature of 3500-4000°. Explosion products, expanding at a speed of 7-9 km/s, strike environment, compressing both the environment and the objects in it. The layer of medium adjacent to the charge (for example, air) is instantly compressed. Trying to expand, this compressed layer intensively compresses the next layer, and so on. This process propagates through an elastic medium in the form of a so-called SHOCK WAVE.
The boundary separating the last compressed layer from the normal medium is called the shock wave front. At the front of the shock wave there is a sharp increase in pressure. At the initial moment of formation of the shock wave, the pressure at its front reaches 800-900 atmospheres. When the shock wave breaks away from the detonation products that lose their ability to expand, it continues to independently propagate through the medium. Typically, separation occurs at a distance of 10-12 reduced radii of the charge.
The high-explosive effect of the charge on a person is ensured by the pressure in the front of the shock wave and the specific impulse. The specific impulse is equal to the amount of motion carried by the shock wave per unit area of the wave front. During the short period of action of the shock wave, the human body is affected by the pressure in its front and receives an impulse of movement, which leads to contusions, damage to the outer integument, internal organs and skeleton.
The mechanism for the formation of a shock wave when an explosive charge is detonated on surfaces differs in that, in addition to the main shock wave, a shock wave reflected from the surface is formed, which is combined with the main one. In this case, the pressure in the combined shock wave front almost doubles in some cases. For example, when detonating on a steel surface, the pressure at the front of the shock wave will be 1.8-1.9 compared to the detonation of the same charge in the air. This is exactly the effect that occurs when shaped charges of anti-tank weapons detonate on the armor of tanks and other equipment.
Rice. 4. An example of the area affected by the high-explosive action of a cumulative ammunition with a reduced mass of 2 kg when it hits the center of the right side projection of the turret. The zone of lethal damage is shown in red, and the zone of traumatic damage in yellow. The calculation was carried out according to the generally accepted methodology (without taking into account the effects of the shock wave flowing into the hatch openings).
Rice. 5. The interaction of the shock wave front with a dummy in a helmet during the detonation of a 1.5 kg C4 charge at a distance of three meters is shown. Areas with excess pressure over 3.5 atmospheres are marked in red. Source: NRL's Laboratory for Computational Physics and Fluid Dynamics
Due to the small dimensions of tanks and other armored vehicles, as well as the detonation of shaped charges on the surface of the armor, the high-explosive effect on the crew in the case of OPEN HATCHES of the vehicle is ensured by relatively small charges of shaped ammunition. For example, if it hits the center of the side projection of a tank turret, the path of the shock wave from the point of detonation to the hatch opening will be about a meter; if it hits the front part of the turret, it will be less than 2 m, and if it hits the rear part, it will be less than a meter.
If a cumulative jet hits the dynamic protection elements, secondary detonation and shock waves arise, which can cause additional damage to the crew through the openings of open hatches.
Rice. 6. The damaging effect of the "Panzerfaust" 3-IT600 RPG cumulative ammunition in a multi-purpose version when firing at buildings (structures). Source: Dynamit Nobel GmbH
Rice. 7. M113 armored personnel carrier, destroyed by a Hellfire ATGM hit.
The pressure at the shock wave front at local points can either decrease or increase when interacting with various objects. The interaction of a shock wave even with small objects, for example with the head of a person wearing a helmet, leads to multiple local changes in pressure. Typically, this phenomenon is observed when there is an obstacle in the path of the shock wave and penetration (as they say, “flowing”) of the shock wave into objects through open openings.
Thus, the theory does not confirm the hypothesis about the destructive effect of excess pressure of cumulative ammunition inside the tank. The shock wave of cumulative ammunition is formed when an explosive charge explodes and can penetrate inside the tank only through hatch openings. Therefore, hatches SHOULD BE KEEPED CLOSED. Those who do not do this risk receiving a severe concussion, or even dying from a high-explosive action when a shaped charge is detonated.
Under what circumstances is a dangerous increase in pressure inside closed objects possible? Only in those cases when the cumulative and high-explosive action of an explosive charge makes a hole in the barrier sufficient for the explosion products to flow in and create a shock wave inside. The synergistic effect is achieved by a combination of a cumulative jet and the high-explosive action of a charge on thin-armored and fragile barriers, which leads to structural destruction of the material, ensuring the flow of explosion products behind the barrier. For example, the ammunition of the German Panzerfaust 3-IT600 grenade launcher in a multi-purpose version, when breaking through a reinforced concrete wall, creates an excess pressure of 2-3 bar in the room.
Heavy ATGMs (type 9M120, Hellfire) when hitting a light-class armored fighting vehicle with bulletproof protection, with their synergistic effect, can destroy not only the crew, but also partially or completely destroy the vehicles. On the other hand, the impact of most wearable PTS on armored fighting vehicles is not so sad - here the usual effect of the armor effect of a cumulative jet is observed, and the crew is not damaged by excess pressure.
PRACTICE
We had to fire from 115-mm and 125-mm tank guns with a cumulative projectile, from a cumulative grenade at various targets, including a stone-concrete bunker, self-propelled unit ISU-152 and armored personnel carrier BTR-152. An old armored personnel carrier, full of holes like a sieve, was destroyed by the high-explosive effect of the projectile; in other cases, no allegedly “crushing effect of the shock wave” was detected inside the targets.
Several times I examined damaged tanks and infantry fighting vehicles, mostly damaged by RPGs and LNG. If there is no explosion of fuel or ammunition, the impact of the shock wave is also imperceptible. In addition, no concussion was noted among the surviving crews whose vehicles were damaged by RPGs. There were wounds from shrapnel, deep burns from metal splashes, but there were no concussions from excess pressure.
Rice. 8. Three hits from cumulative RPG shots in an infantry fighting vehicle. Despite the dense grouping of holes, no breaches are observed.
Donkey 18-09-2005 23:11
Dear forum members!
I have long wanted to post this topic, collecting all the information together.
About the cumulative jet (CS), in general, everything is quite clear. It is formed by the collapse of a hemispherical or conical funnel with an acute angle at the apex. A picture emerges that is the opposite of the formation of a sheet during the collision of two jets, described in detail by the hydrodynamic theory of cumulation by M. A. Lavrentiev.
Quite a lot is known about the godfather (godfather), thanks to the theory of M. A. Lavrentiev:
Jet radius r:
r=(2*R*x)^0.5*sin(0.5A)
where R is the radius of the charge, x is the thickness of the recess lining, A is the angle between the charge axis and the generatrix of the cone
Jet speed v:
v=u*ctg(0.5A)
where u is the speed of shell collapse (close to the speed of explosion products with thin linings, for hexogen - 2.12 km/s, TG alloy - 1.96 km/s, TEN - 1.83 km/s, tetryl - 1.87 km/s) , A-angle between the charge axis and the generatrix of the cone
Jet length L:
L=R/sinA, where R is the radius of the charge, A is the angle between the charge axis and the generatrix of the cone
Penetration effect:b=L*(Pc/Pп)^0.5
where b is the depth of penetration of the jet into the obstacle, L is the length of the jet, equal to the length of the generatrix of the cumulative recess cone, pc is the density of the jet material, pn is the density of the obstacle. http://www.cultinfo.ru/fulltext/1/001/008/067/408.htm
2 small additions:
a) in modern cumulative ammunition, in order to make the CS longer and increase the penetrating effect, they force the CS to stretch in length, making a funnel of variable curvature http://armor.kiev.ua/ptur/weapon/tank_projectile-70.html
b) The KS does not melt the armor or burn through it, and is not itself molten, but is embedded in the armor, like a liquid stream into a liquid. Everyone seems to know this, but nevertheless it is a very common mistake.
Most members of the forum know all this, and almost everyone has seen the picture of the successive stages of the formation of the CS. What if someone doesn’t know - it will be useful for them.
Squint 18-10-2005 22:05
Greetings to everyone gathered here.
I myself am not an expert in the field at all - rather, I am an interested amateur. But it was always nice to listen to people who knew, and who know the price your knowledge.
I would like to add this information. It would be interesting to compare this information with the time of the first serious work on “directed” ammunition.
I remembered it by chance, from the photographs given. The source is not thematic - a literary processed biography and memoirs of Robert Wood, an American physicist (W. Seabrook. Robert Wood. M.: Nauka, 1980. The original was "Doctor Wood. Modern wizard of the laboratory. by William Seabrook"). Wood's specialty was optics and spectroscopy, but he was also involved in pyrotechnics, which is why he was involved in the investigation of fires and explosions.
One of these cases (with fatal) took place in 1935. It happened at the moment of opening the door of the stove, which was heated with coal and had not yet flared up. The sound "resembled a pistol shot." The main (and correct) assumption about the cause was the accidental entry into the furnace along with coal of a detonator used for blasting in the mine.
Further quotes - first just from the author of the book, then from Wood, whom he quotes (this is pp. 262-264 of the source).
“The autopsy performed by the doctor showed that a large artery had been cut and the internal tissues were severely torn, but no foreign body, no “bullet” could be found at first. Finally, a small opaque object was discovered in the body using X-rays. A new autopsy showed that it is a small metal cap of a strange shape, the size and shape of a grape seed, surrounded by a thin metal "skirt"..."
"The piece of copper removed from the body did not at all resemble any of the parts of the detonator. Here we had a pear-shaped "bullet" of solid copper, the size of a grape seed, surrounded by a thin disk of metal, hanging like a skirt from the middle of the pear - while while the detonator is a thin-walled copper tube about the size of a .22 caliber cartridge, one to two inches long. At the lower end there is a hole in the copper, similar to the one that is pierced by the firing pin of a hunting rifle in the primer. This hole plays a special role and gives
the detonator has its deadly properties. It is filled with mercury fulminate, an easily explosive substance that is “ignited” by electric current in two wires.
We secured the detonator over a solid oak beam about 5 inches on a side and detonated it. A small hole was visible in the surface of the wood, and when we split the block, we found a small copper "bullet" that had penetrated the oak to a depth of 4 inches. The size of the “bullet” resembled that taken out of the body, but it was badly dented when passing through solid wood. I took a few more detonators with me and brought them to my laboratory, where I suspended one of them 2 feet above a large clay pot containing about 5 gallons of water. When the detonator exploded, the pot shattered into pieces from the pressure exerted by the water when a small copper fragment (detonator head) hit it, which flies during the explosion at a speed 3 times higher than the speed of a rifle bullet - just like a jug of water “explodes” " when hit by a bullet from a strong rifle. The small "shard" of copper found among the shards was exactly like the one found during the autopsy, but did not resemble the detonator head in any way.
Further examination of the detonators showed that they did not contain anything resembling such solid “bullets”, and it was clear that they were formed from the thin wall of a copper tube melted by the heat and pressure of the explosion. Such a discovery - it really was a discovery - shows the importance of experiment in any research. Until this time, the formation of such solid “bullets” had not been noticed or described by anyone. Their formation is due to the presence of a depression at the bottom of the copper tube, which, as explosives experts have discovered, increases the force of the dynamite explosion. Why - they didn't know. Now the reason has become clear. A copper bullet penetrates the entire length of a stick of dynamite with a very high initial velocity. If there is no such “bullet”, when the detonator explodes, the dynamite is detonated only at one end.
The question of how exactly a solid bullet was formed was resolved by "firing" detonators charged with varying amounts of explosive into a long cylindrical tube filled with cotton wool, with baffles every 2 inches. The bullet was found between the last pierced and the first intact disk. As the "bullet", ejected at an initial speed of about 6000 feet per second, penetrates the cotton wool, it is enveloped in a dense ball - weaving itself, so to speak, its own "cocoon" and thereby protecting itself from friction with the substance through which it flies "
From the description, although not too technically strict, it is obvious that we're talking about It is about the "impact core", a solid body formed by an explosion, although very miniature, that indicates the mechanism of formation and the role of the form of the explosive.
P.S. And also, if someone is interested, I can take on programming calculations (from time to time such a need slips in here), fortunately it will be in my specialty. Just not too complicated and not very fast, otherwise there will be little time left after work...
Andrei_H 18-10-2005 23:37
Thanks for the material!
Slonyara 19-10-2005 20:03
Really interesting case.
Donkey 20-10-2005 01:52
Hole from the TM-83 mine from the site http://www.warfare.ru/?catid=317&linkid=2471
If I translated correctly, it says that the TM-83 is capable of punching a hole with a diameter of 80 mm in armor 400 (!) mm thick at a distance of 50 m.
On the website http://www.aha.ru/~leokon/rus/ I learned that the initial speed of the FKP "GkNIPAS-a" anti-tank mine is 1700 m/s, the PVR mine's initial speed is 2500 m/s. These figures are similar to the value obtained during experiments for the "grape seed" by Robert Wood - 1830 m/s (6000 feet per second).
But how to calculate it (speed)?
Best regards Donkey
reggae 25-10-2005 16:50
In the Chelyabinsk museum I saw photos of German tanks hit by cumulative shells. very neat and very discreet
Squint 27-10-2005 22:44
And how, by the way, do they generally measure the initial velocities of projectiles, which are only several times, and not orders of magnitude, behind the QW? Unfortunately, I don’t know, although it would be interesting.
I would venture to guess that for Wood’s case, i.e. a small high-speed body, an ordinary ballistic pendulum is perfect, quite light but durable, for example, from the same wooden block.
A larger nucleus will have a lower relative speed and much higher energy. You can probably use high-speed photography. But (very roughly) the shutter speed should be no longer than 1/10000, the interval between frames should be 1/1000. If you use a strobe, you get speeds (also roughly) of the order of 1000 rps. Technically, this was probably solvable for a long time, but it was difficult and expensive. It is possible to record successive impacts of a “projectile” on two targets with a known distance between them using shock sensors, and measure the delay, for example, on a CRT, as in oscilloscopes and radars. But, probably, a pendulum will again be simpler and cheaper, only very heavy and durable. This is if we keep in mind the technology of pre-war times.
Now, probably, non-contact methods for detecting a passing body should work: inductive, optical, radar in a suitable range. And it has become much easier to measure short time intervals.
Donkey 28-10-2005 04:36
quote: Originally posted by Squint:
And how, by the way, do they generally measure the initial velocities of projectiles, which are only several times, and not orders of magnitude, behind the QW? Unfortunately, I don’t know, although it would be interesting...
Dear Squint!
Judging by your further posting, you know everything perfectly well.
This interesting question was discussed here:
Another simple (relatively) way to measure the speed of a projectile or supersonic projectile in a shadow photograph (7th picture from the top in
1st message) --- along the angle of the Mach cone. The speed of the PU in the picture is relatively low --- approximately M = 4.1-4.3 (1.4-1.46 km/s)
Best regards, Donkey
Fireman 28-10-2005 17:29
At one time, when developing high-speed throwing devices, non-contact methods were used to record the initial velocity of a projectile. The method was based on the so-called. "X-ray barrier".
The initial projectile velocities were up to 7500 m/s.
Donkey 28-10-2005 20:41
so-called "X-ray barrier".
Briefly. Two parallel X-ray beams with a known base passed through the path of the projectile in the area of the muzzle. The rays shone into special receiver-detectors. When a moving body crossed the beam, a chronometer was triggered, giving a countdown of time. Simultaneously with the time stamp, radiography of the projectile also took place, giving:
1. The ability to accurately calculate projectile speed, because There were also reference lines in the shooting area
2. The condition of the projectile in the muzzle area.
The latter was extremely important, since when fired, the projectile experienced enormous overloads and did not always maintain its integrity.
The initial projectile velocities were up to 7500 m/s.
Dear Fireman!
A very interesting method, I have not heard about it before.
It is not very clear how RADIOGRAPHY occurs (i.e., photography) if the rays shine constantly. Here either there must be a very fast shutter somewhere, or the flash is very short in order to get an image.
And “The initial velocities of the projectiles were up to 7500 m/s” --- is this, by any chance, not from a light gas cannon?
Best regards, Donkey
Fireman 28-10-2005 22:02
Uv. Donkey!
1. The rays constantly shine right at the barrier itself, i.e. type of standby mode. There is no need to synchronize the registration process with the shot. The radiation is “soft”, close in power to ordinary medical x-rays. But when the receiver is triggered, when the beam is darkened by a flying body, a signal goes to two devices, 1 - a chronometer, 2 - to turn on a powerful X-ray pulse installation. RIU (2 pcs) are located above the emitter beam. Get two more or less high-quality photos, at two points of the trajectory in the area of the muzzle. I don’t remember the radiation parameters from memory, because firstly, it was a long time ago, and secondly, I am more of an expert in what (what) they shoot from. True..., rather it was... This line of work was closed 15 years ago...
I was there. Under a different nickname.
Donkey 28-10-2005 22:41
quote: Originally posted by Fireman:
If you are very interested, you can look for old photos from x-rays.
If anything is unclear, ask.
2. Regarding your link to the forum from two years ago. 7 km/s is from LGP.
I was there. Under a different nickname.
P.S. I wanted to draw a registration diagram, but I don’t know how to insert a picture.
Dear Fireman!
Thank you very much, I think I understood everything.
Insert a picture: there are icons above your message, incl. a piece of paper with a pencil - “editing”. Click on it and the “Editing” button will appear, and below that “Add pictures”. Click "Browse", your "desktop" or your "pictures" will appear, select what you need there, click "open", and then "Add pictures" --- and you're done.
I’m writing in such detail because I had trouble doing it myself before.
Best regards, Donkey
Fireman 28-10-2005 22:48
Uv. Donkey!
Thank you! I will try to satisfy your interest. In 3-4 days.
Donkey 29-10-2005 01:04
Additions about KS and UL.
APPLICATION AND SOME VARIETIES.
Multi-cumulative ammunition.
In Fig. 7a and 7b—ammunition with a circular affected area, forming a set of CS, in Fig. 8---the same, forming a set of LL. (ZVO-2-87, )
It is clear that 7a and 7b have greater penetration ability at a smaller radius, 8 is the opposite.
A very unique variety is ammunition that forms a beam of explosives by crushing the initial projectile plate with a special mesh located in front of it (the plate).
*As is known, during the formation of the UC, the plate “turns out”, in which the center overtakes the edges (see diagram above). When the plate at the stage of formation of the control unit meets the fixed mesh inside each cell, the edges of the plate section are slowed down, and the center of the section moves forward. With further movement, each section breaks away from the plate at the edges and then flies on its own.* I have not seen the mechanism for the formation of small nuclei anywhere, I came up with it myself, so take it with caution.
Mesh Ammo:
grenade for RPG-7
http://www.aha.ru/~leokon/rus/
And the American anti-vehicle mine "Sparta" (ZVO-11-92), size 75 x 55 x 75mm, destruction range 50m (weight not specified)
(sorry for the picture)
As the author of the article, Colonel N. Zhukov, notes, “the directed-action charge has 4 hemispherical recesses with a metal lining, in front of which a metal mesh is placed. During the explosion, the 4 DUs formed from the lining by the mesh are crushed into smaller nuclei, creating a significant damage area.... Such The method, used for the first time, makes it possible to obtain fairly powerful ammunition with a smaller explosive charge and limited dimensions."
Best regards, Donkey
extractor 29-10-2005 10:15
There was such an X-ray installation RINA-1B, developed either by SKB IZAP,
or the Geodesy Research Institute.
Fireman 31-10-2005 19:24
“you can look for old photos from x-rays” Interesting, how!
As promised, a photo of the X-ray “barrier” for measuring the initial velocity of the projectile.
The launcher's barrel is inserted into a special compartment through a hole in the metal partition on the right side of the photo. The direction of the shot is from right to left. Next, two X-ray emitters are installed horizontally. Opposite them, on the other side of the compartment, there are receivers. Above the compartment there are two X-ray pulse installations of the MIRA-1B type, which actually record the projectile. Why is everything tied to x-rays? Everything is forgiven and complicated. At high speeds (>2 km/s), the contact method destroys the projectile, and the high ionization of the propellant gas (powder or hydrogen) in the muzzle area limits the ability to use radiation in the optical range.
Further, all this crap is connected to a vacuum barrel. The shot is fired into a vacuum. The sound of the shot is practically inaudible. All you can hear is the impact of the shell on the obstacle.
Varnas 01-11-2005 05:13
Impressive.
Squint 01-11-2005 20:48
Thanks for the clarification and interesting information.
I really didn't know - I just assumed. As it turned out, it was a little in the wrong direction: towards simpler and older means. But it's nice for the rating.
Donkey 01-11-2005 22:49
quote: Originally posted by Fireman:
Below is a photo from an X-ray image of a projectile fired from a 34 mm caliber LGP. The speed is something like 6.2 km/s. The projectile consists of a plastic tray and a ball made of residence permit. Also, I think the public will be interested in evaluating the effect of plastic blanks fired from the LGP with a caliber of 34 mm, weighing 40 g, onto a 120 mm armor plate (400x400 mm)
Dear Fireman, thank you very much, I knew that such “space” things existed, but until now I had only seen diagrams. Interesting.
"plastic blanks fired from the LGP with a caliber of 34 mm, weighing 40 g onto a 120 mm armor plate" -- no traces of the balls are visible. Do they disperse after the shot or did they shoot with an empty pallet?
Best regards Donkey
Donkey 14-11-2005 22:07
I am posting the remnants of my meager information on the topic.
Everyone already knows the use of short circuits.
Everyone also knows the use of CU, but nevertheless:
1. Mines (lots of anti-aircraft mines, except TM-83)
Some of them:
Flying (in whole or in part) anti-tank anti-roof mines: http://www.fas.org/man/dod-101/sys/land/m93.htm
http://www.aha.ru/~leokon/rus/
2. High-precision combat elements for rocket and cannon field artillery http://www.army-technology.com/contractors/ammunition/bofors7/
3. In combat units, ATGMs to hit a tank from above (photo and diagram from the website of uv. Andrey N http://btvt.narod.ru/index.html)
4. In cannon tank shells (it seems that it did not go into production)
Here's about it ---Smart Target Activated Fire and Forget (STAFF) http://www.fas.org/man/dod-101/sys/land/m943.htm
These are the areas of application for now, but then new ones will probably appear. I wonder if I forgot anything?
Donkey 14-11-2005 23:50
Misconceptions and beliefs found on the Internet (and the media) regarding CS and UL.
who knows (or has a book)
Best regards, Donkey
Methanol 15-11-2005 17:14
quote: Originally posted by Donkey:
Misconceptions and beliefs found on the Internet (and the media) regarding CS and UL.1. The KS burns (or melts) the armor due to its high temperature. This belief appeared at the beginning of the Second World War, when cumulative shells were called “armor-burning” shells. Regarding the state in which the metal of the cumulative jet is: soon after the Second World War an experiment was carried out (by Lavrentyev or Pokrovsky or one of their employees). A cumulative funnel was made from a sheet of metal, then it was inserted into the charge and the charge was detonated, and the cumulative jet was caught by a thick porous barrier. Then, metallographic methods were used to compare the crystal structure of the jet fragments and the original sheet. Thus, it was proven that recrystallization of the metal does not occur, i.e. the metal does not melt when the funnel collapses. See at the beginning in the topics.
2. The cumulative effect and its mechanism have not yet been solved by science. For almost 70 years, like the ancient Babylonians, they have been using a galvanic element, but they do not know. how it works. The belief is quite stable.
3. UL is a plasmoid, i.e. something like ball lightning. I even saw this belief in a newspaper article!
4. When the short circuit and ammunition are detonated from the control unit, nuclear reactions. The belief at first glance is quite funny, but during laboratory studies of the compression of matter with special multi-stage shaped charges (which have no resemblance to ammunition), hard radiation actually occurs, indicating an impact, if not on the nuclei of atoms, then on the internal electronic shells.
That's all my meager knowledge.
I cry again with a voice crying (I hope not in the desert):
who knows (or has a book)
ANALYTICAL EXPRESSION FOR THE SPEED OF THE CHARGE DEPENDING ON THE INITIAL PARAMETERS (parameters at the beginning) OF THE CHARGE?
Please respond, I will be very grateful
Best regards, Donkey
Well, the Kuma jet is liquid, even though the metal is not heated to melting, the temperature of the copper jet is 500-600C, which is far from melting ~1000C, the pressure kind of rules
but I’ve never seen anything about the physical basis of impact nuclei with formulas, try to find a description of focusing lenses in the chum, you’ll find horseradish, but a more well-known and more studied thing is either hidden well, or pure empirics
extractor 15-11-2005 20:10
These questions are reflected, IMHO, in the “hydrodynamic theory”, which considers the penetration of an obstacle by a projectile as the interaction of two pseudo-fluids. We must look!
Methanol 15-11-2005 20:50
Donkey 15-11-2005 23:53
quote: Originally posted by extractor:
These questions are reflected, IMHO, in the “hydrodynamic theory”, which considers the penetration of an obstacle by a projectile as the interaction of two pseudo-fluids. We must look!
Dear extractor!
With classical hydrodynamic theory everything is quite simple,
I have a good book (from which I gave expressions for the parameters of the CS at the beginning of the topic), although it is not thick, all the formulas for the “problem of two colliding jets” are derived in detail in it, if you are interested, I can scan it.
Unfortunately, when considering the CU and its formation, the “problem of two colliding jets” cannot help in any way, because in it the lining of a cumulative funnel is considered as a veil of an ideal (without strength and viscosity) liquid, and what kind of liquid will turn inside out, like a sock?
I tried to approach it from the other end: to consider the DU funnel as a shell of a flat charge thrown by an explosion and used formula 17.8 on page 33 from the book that you kindly posted (thanks again!) in the topic “Determining the lethal effect of METHODOLOGY ammunition?” With a charge of hexogen d=h=12cm, with a copper funnel 6mm thick with an angle of 120 degrees, it turned out to be 2078m/s ---it seems quite similar to what is written in different places about the speed of the UC.
However, it is confusing that there are nuclei with speeds of 2.5 and even more than 3 km/s, and in form 17.8 the speed of the projectile shell cannot be greater than the speed of the explosion products (i.e., 1/4 of the detonation speed). But there are no explosives with detonation speeds of 10-12 or more km/s. Something is wrong here, i.e. the model of the shell of a flat charge is incorrect.
I searched the Internet more than once, but to no avail.
Now I'm trying to get hold of the book "Physics of Explosion", but I haven't succeeded yet.
Or maybe nimi will appear on the forum? For some reason it seems to me that he is privy to this great secret.
Best regards, Donkey
Donkey 16-11-2005 12:17
but about the focusing lenses that form the desired shape shock wave front in cum, no data available anywhere
red lenses in an explosive charge, serve to form a flat or concave waveform, without them it is convex
Dear Metanol!
It seemed to me before that there is nothing particularly complicated in detonation lenses, if they consist of explosives - the wave front obeys the same laws, regardless of which wave - EM (for simplicity, light) or detonation, so you can feel free to open physics for 10th grade. in the section on geometric optics and use it (the ratio of the detonation speeds of the charge and the lens will play the role of the refractive index). However, I’m not used to trusting my amateurish hypotheses, I decided to check it out, and, wow, I found confirmation from smart people: http://iate.obninsk.ru/press/journal/archive/2000_1.html
A.G.Karabash
"Refraction of detonation waves and increasing the directional effect of an explosion using collecting lenses of explosives"
“The article describes the phenomenon of refraction of detonation waves, first established in 1945, which manifests itself in the cumulative effect of collecting “explosive lenses” in systems of condensed explosives (HE) having different detonation velocities.
Based on a large number of experiments, in a simplified theoretical model, the main pattern of phenomena during detonation is shown - an analogy with general laws propagation of directed wave processes (Snell's law, etc.).
Experimental data and new principles for increasing the directional action of the explosion were taken into account in basic research when creating RDS - 1." RDS - 1 --- a serious thing: http://wsyachina.narod.ru/history/chronicle.html
But this is the case if the lens consists of explosives.
And if it is made of an inert material, and even porous (a package of cardboard gaskets), where not only is there no detonation, but also the speed of sound is somehow indefinite
then “pure empirics” is probably more useful here.
Best regards, Donkey
Methanol 16-11-2005 01:01
the lenses are inert, but not made of cardboard but made of foamed plastics, and you described the effect of the lenses when using two explosives with different speeds, which are used in nuclear weapons
Donkey 21-11-2005 20:09
quote: Originally posted by Metanol:
the lenses are inert, but not made of cardboard but made of foamed plastics, and you described the effect of the lenses when using two explosives with different speeds, which are used in nuclear weaponsand in the cum they no longer work as lenses but as obstacles, the detonation front cannot pass through the lens, since the soft material extinguishes it, but passes along the explosive along the perimeter around the lens, and while the wave after the lens reaches the center of the charge, it lags behind periphery, it turns out to be a flat or concave shape, but different shapes are used in the charges, this can be seen in the photo that I attached above, the precharge has a lens in the form of a cone with the base towards the funnel, and the main one has a double cone
Perhaps I subconsciously guessed about this.
When a detonator explodes, “the detonation front cannot pass through the lens, since the soft material extinguishes it, but passes along the explosive along the perimeter around the lens,” and the annular gap around the disk becomes a secondary source of a wave (according to Huygens’ principle), the front of which takes the form inner surface torus (almost a cone).
Why is it necessary for the shape of the detonation front to coincide with the shape of the cum. funnels? Most likely, this is with Pokrovsky’s scheme, according to which the specific energy of the explosion products in the direction of propagation of the detonation wave is 4 times greater than in the opposite direction.
The position of the front from the left edge of the annular gap is depicted at various subsequent moments in time with thin black lines (well, I don’t have normal circles --- I hope so far).
A zone of “detonation shadow” (purple color) forms behind the disk --- the explosive there, of course, will detonate, but a little later, when the front of the main wave approaches the walls of the funnel.
It is possible that the detonation of the “shadow” section of the charge with a long funnel in modern ammunition disrupts the regularity of the main wave front and has a detrimental effect on the formation of the jet. To do this, it is replaced by an inert cone --- a continuation of the disk (circled in the figure with a black line).
It turns out that these are all guesses and assumptions based on purely geometric-wave considerations.
And why the precharge has a “lens” in the shape of an inverse truncated cone, I can’t yet come up with an explanation.
Best regards, Donkey
Donkey 21-11-2005 20:54
I found a plate of self-aiming combat elements from UY (American and European). The numbers in pencil are the estimated mass of the actual UU, but these numbers do not inspire confidence in me.
But here is Russian ammunition of this type: http://www.airwar.ru/weapon/ab/rbk500.html
“A copper bar with a diameter of 173 mm and a weight of 1 kg, accelerated to a speed of 2000 m/s, is capable of penetrating up to 70 mm of armor at an angle of 30? to the normal.”
Methanol 28-11-2005 02:46
At the airbase you figure out the theory
it seems that the conical lens causes the wave to follow its shape, and arrive at the funnel at a right angle, to increase the pressure on it
Donkey 28-11-2005 22:22
quote: Originally posted by Metanol:
1) At the airbase you figure out the theory2) it seems that the conical lens causes the wave to repeat its shape and arrive at the funnel at a right angle, to increase the pressure on it
http://forums.airbase.ru/index.php?s=b0f9f1a5feea5f7482914d1e89545dea&act=Attach&type=post&id=21755
Foma 29-11-2005 09:28
quote: Originally posted by Donkey:
Yesterday I forgot one more important difference between the CS and the YU - not all of the metal of the funnel turns into the CS, a significant part of it goes into the pestle:
m=2*M*sin^2(0.5A),
where m is the mass of the jet, M is the mass of the funnel, A is the angle between the charge axis and the generatrix of the cone
Thus, if the angle at the top of the funnel is 60 degrees, then only 13.4 percent will go into the stream. metal, and the remaining 86.6 percent. will remain in the pestle.
100 percent goes to UY. funnel lining.Here are a few more pictures of UY from English. Institute:
Methanol 29-11-2005 10:43
quote: Originally posted by Donkey:1) wanted to know one thing, but found out another, but also interesting http://forums.airbase.ru/index.php?s=b0f9f1a5feea5f7482914d1e89545dea&act=Attach&type=post&id=21755
Oh, if only I had a Book (FV2002 or at least FV1975)
2) “the lens forces the wave to repeat its shape” --- if it were made of explosives, then it would be possible to imagine, but if it were inert, it would be difficult.
Donkey 29-11-2005 16:05
Bro! where were you before... that was the topic of my diploma....
KS or UY?
Best regards, Donkey
Donkey 29-11-2005 20:51
quote: Originally posted by Metanol:well, how could it be otherwise, a wave for maximum pressure should fall normal to the funnel, this is approximately exactly the shape of the head part of the wave should repeat the shape of the lens, otherwise geometrically it won’t work
This is probably true, but why a cone and, for example, not a disk? I have some ideas, but they are very unverified; I’ll at least have to draw a diagram in my spare time and see if it fits.
I also noticed an interesting fact - such “lenses” are made in grenades for RPGs, ATGM warheads, but not in artillery shells.
At first I thought that the “lens” could not withstand overloads, but then I realized that this was not the case.
Thick walls of the projectile (having significant mass, strength is unimportant here) reflect the detonation wave, and its front becomes converging (concave). I wonder if this is really true?
Foma 01-12-2005 10:39
quote: Originally posted by Donkey:Dear Foma, I wonder what the topic was---
KS or UY?
If YA, then you probably know the answer to the question about the speed of a self-forming projectile and how it can outpace the products of the explosion.
Best regards, Donkey
The topic was just a self-aiming combat element with a missile launcher. I need to look somewhere I had literature at home. To be honest, I forgot something.
Donkey 01-12-2005 22:31
quote: Originally posted by Foma:The topic was just a self-aiming combat element with a missile launcher. I need to look somewhere I had literature at home.
Filled with bright hopes. If you find it, I'll be very grateful in advance.
Best regards, Donkey
Donkey 11-03-2006 01:11
Until now I thought that the UYA was a weapon of modern times, but suddenly I discovered the following information in the “Corner of the Sky” http://www.airwar.ru/enc/bww2/ki167.html:
“The bomber was equipped with a special 2900 kg directional charge “Sakuradan”, which was based on German developments. Apparently, the charge resembled the warhead of the German Mistels. The data for it was delivered to Japan at the end of 1942 on a German submarine. Tests "Sakuradan" was carried out at a training ground in Manchuria, where it was established that with the help of this warhead it was possible to destroy a medium tank from 300 meters. The warhead "Sakuradan" had a diameter of 1.6 m. It was placed on the aircraft so that the shock core of the explosion was directed at a slight downward angle. To do this, the bomb had to be installed at the center of gravity of the aircraft so that it would rise 0.5 m above the fuselage. At the same time, the bomber acquired a large fairing behind the cockpit, covering the Sakuradan. "
If this is indeed the case, then the duration of combat use of the explosive device is not inferior to the shaped charge. However, it is very strange
that there is no information about the post-war use of nuclear weapons.
Best regards, Donkey
Laborant 11-03-2006 06:09
2900 kg charge against one tank? Even if from 300 meters....
Kind 26-03-2006 09:18
If necessary, I can post scans from a book on the topic, it’s 14 pages long and in English, there’s not much theory there, but at a qualitative level it’s quite informative.
Slonyara 26-03-2006 12:54
Post it, I think many will be interested.
Novgorodets 23-08-2006 23:06
I really need help. When did work on cumulative ammunition begin and who was at the origins of the work. Several versions of primacy contradict each other - it depends on who is writing. I found that research began in 1880 with the work of the American physicist Charles Edward Monroe, and continued in the 1930s. Swiss emigrant Henry Mohopton worked for the US Department of Defense. He achieved success and even created the first cumulative anti-tank grenade before the war, but it turned out to be too heavy (then the M9 rifle was made based on it). The Germans were working on cumulative ammunition at the same time, and judging by the VPGS-41, we were not lagging behind.
Best regards, Novgorodets
Donkey 24-08-2006 01:43
Dear Novgorodian, you may still not know the truth, because regarding priorities, everyone pulls the blanket over themselves.
In the scientific literature, explosive cumulation is usually called the “Monroe effect,” but in almost all Soviet and Russian books we read that it was discovered by M.M. Boreskov.
Maybe it will be useful to you
From the book by V.V. Mayer “Cumulative effect in simple experiments” M. “Nauka” 1989
Best regards, Donkey
Donkey 26-08-2006 12:38
Interesting article about war options (4.54 Mb) www.dtic.mil/ndia/2004armaments/DayII/SessionI/02_Fong_Multi_Mode_War_Heads.pdf
In my opinion, here http://www.vpk-news.ru/article.asp?pr_sign=archive.2005.105.articles.defence_02#
Novgorodets 26-08-2006 19:45
***You may still not know the truth, because when it comes to priorities, everyone pulls the blanket over themselves.***
Thanks, that's pretty much what I thought. "Truth" depends on the author. And the truth about the cumulative grenade is that it really was the first, or America is again the “homeland of elephants.” I found the M9, but it was difficult with the M10, but it was probably the same only bigger.
Best regards, Novgorodets.
Donkey 26-08-2006 22:56
Dear Novgorodian, do you know how to correctly spell “Henry Mohopton” in English?
In Russian transcription, the search returned 1 single link ----Your post!
And I also became interested about the godfather. pre-war grenade.
Best regards, Donkey
Novgorodets 28-08-2006 22:55
Dear Donkey. I'm sorry, but it probably reads differently
Wrong. Written in English - Henry Mohaupt.
Best regards, Novgorodets.
Donkey 29-08-2006 12:42
Dear Novgorodian, thank you, I looked at Henry Mohaupt and immediately found SOMETHING
Have you seen this? http://armor.kiev.ua/ptur/first/SC_history.html
"Many foreign works refer to the priority of the discovery of the cumulative effect (cavity effect) by F.X. Von Baader in 1792 (!!!). He was interested in the practical improvement of mines and proposed a conical and mushroom-shaped notch in the explosive to INCREASE the explosive effect and saving gunpowder"
I wonder what was the use of black powder? It doesn't detonate at all.
However, what a visionary this same Von Baader is!
Never heard of him before. But to the sons of the creator of this projectile
You can probably trust him in this matter.
Best regards, Donkey
Alhim 29-08-2006 14:42
Good day, gentlemen. First of all, I will provide a link to more detailed literature: http://my-lair.narod.ru/news.htm
cumulatively there are large chapters in the “physics of explosion” by Orlenko and the “action of weapons and ammunition” by Balagansky and Merzhievsky - everything is considered in great detail. Moreover, the speed of the impact core can be considered, to a first approximation, as the speed of a plate being thrown by a normally falling flat object. wave, something like this:
u/D =h/2*(1-h)
where u is the speed of the explosive device D is the detonation speed h= 16/27*m/M where m is the mass of the explosive layer per unit. plate area M - mass units of plate area. In fact, the speed of the blast will be somewhat less than the calculated one due to the non-flatness of the front and failure to take into account wave phenomena in the thrown plate. Then the lenses in the cumulative - as already mentioned - serve to form a converging detonation front. But the increase in pressure on the shell has nothing to do with it - the lens is needed to increase the velocity gradient along the jet - this leads to its (the jet) stretching and an increase in armor penetration.
Donkey 29-08-2006 20:37
Dear Alhim, thank you very much. However, there are some additional questions.
1. In "The Porcupine's Lair" books load only 1-2 pages, and do not go further. What's the matter? Please tell me how to copy "Physics of Explosion". This book is my long-time dream, especially the section dedicated to throwing plates and various objects, because... I had several. ideas about fragmentation ammunition, which I would like to check with a serious source.
2. In the formula you provided, if you substitute m/M = 1 (for example, a copper layer of 0.5 cm and a layer of TNT of about 2.8 cm), you get u = 833 m/s (somehow not enough for a control unit, you need a charge increase to get the desired 2000 m/s) And if you increase the thickness of the explosive to 4.725 cm, then h becomes one, and u --- becomes 0. Or did I read the formula incorrectly?
By the way, I have “The Effects of Weapons and Ammunition” by Balagansky and Merzhievsky, but nothing is written there about finding the speed of the weapon.
Thanks in advance for your answer.
Best regards, Donkey
Alhim 29-08-2006 22:26
Good day.
Regarding 1) It’s better to download books first and then open them, it’s just that there are glitches when opening them. If it doesn’t work, let me know, I’ll try to wash it, but I won’t be able to wash it until Monday.
Regarding 2) I’m very sorry for the mistake - I looked in the wrong place (I didn’t pay attention that it was displayed for large M/m). For small values, integrate it there (Physics of Explosion, volume 2, pp. 31-34). It will be correct to calculate using the following formulas:
v=D*r*(3/((k^2-1)*(r^2+5*r+4)))^0.5 where k-index of the PD polytrope r=q0*d0/(q1* d1) the ratio of the masses of the thrown body and the explosive q0 - the density of the explosive q1 - the density of the liner d0 - the thickness of the explosive layer d1 - the thickness of the shell, with a polytropic index of 3 (most high-density high-density explosives fit here with sufficient accuracy) the speed will be:
v=D*((1+32/27*r)^0.5-1)/((1+32/27*r)^0.5+1) Both formulas are obtained from the Garni throwing model in a one-dimensional scheme ( A.A. Deribas Physics of hardening and welding by explosion ed. Nauka 1980), why Balagansky cites them when describing the throwing of sliding parts. wave (pp. 123-124) is not entirely clear to me.
Donkey 30-08-2006 22:13
Dear Alhim, thank you again. I looked at all 3 formulas, I liked them because for different r (from 0.1 to 10) they give a spread of v values of no more than 12-13 percent.
How I missed them before, when reading Balagansky’s book, I don’t understand.
I wonder what's the matter?
Formulas for throwing a plate show at r=5-10 v values of more than 3-3.5 km/s. This surprised me somewhat, because the speed of the explosion products is in the range of 1.75-2.12 km/s (for TNT or hexogen). It turned out that “the sailboat goes faster than the wind.” However, it turns out that this happens: http://www.membrana.ru/articles/technic/2004/07/20/221200.html
Best regards, Donkey
Novgorodets 30-08-2006 23:15
Interesting, but not complete.
Best regards, Novgorodets.
Alhim 31-08-2006 02:29
quote: Originally posted by Donkey:
Good day.
Where should I try to send it? If something happens in Moscow, I might send a blank. The speed of dispersion of detonation products into the air is much higher than 1.7-2.12 km/sec (perhaps you mean mass speed in the Far East, but that will be a completely different story). About sines-cosines, I’m sorry, I didn’t quite understand, please clarify what you meant (I’m also not good at mathematics, by the way, but I had a specialist in detonation, so let’s try to figure it out together if there’s any interest).
Donkey 31-08-2006 21:09
quote:
Interesting, but not complete.
Not a word about LMG and VPGS-41, which is a pity.Best regards, Novgorodets.
Dear Novgorodian, what are LMG and VPGS-41?
Donkey 31-08-2006 21:55
Best regards, Donkey
Alhim 31-08-2006 23:05
quote: Originally posted by Donkey:
Dear Alhim, send it by e-mail in your profile, it seems to work fine.
What is a "blank"? (I'm not good at computers).
I don’t really understand what mass velocity is. Is this the speed of transfer of gas mass to a certain area perpendicular to the direction of flow? Then why is it in kms and not in kgs?
Or does it have something to do with the speed of gas molecules?
In various books I came across the ratio u=0.25*D, where u is the speed of explosion products, D is the speed of detonation. I thought that the blast was blown out by something like wind, only it was blowing only a few miles away. diameter of the charge (rapidly decreasing), its density is approximately equal to the initial density of the explosive, and the pressure reaches 18.9 GPa (for TNT). This “wind” picks up and disperses fragments of the shell, GPE, etc. But it seems that everything turns out to be somewhat more complicated...
Regarding sin-cos --- with oblique blowing, the speed of the blown body may seem to be greater than the flow speed, like that of a sail-wing, but I don’t know what the relationship is yet.
Best regards, Donkey
Good day.
I sent the first part of the second volume (it’s about cumulative and throwing), try downloading and open, about the results write back as soon as possible. A disc is a CD. Mass velocity is the speed of movement of the substance behind the front of the shock wave (as opposed to the speed of the wave itself) and it is precisely its formula that you wrote, but the fact is that this is the speed of the substance IN THE DIRECTION OF THE DETONATION FRONT and has nothing to do with the expansion of the PD. The formula for the speed of PD expiration into the air is somewhat more complicated; I haven’t fully understood the calculations, but it’s about 6-7 km/sec.
Novgorodets 31-08-2006 23:05
VPGS-41 http://www.weltkrieg.ru/ammunition/VPGS-41/
LMG http://tewton.narod.ru/mines-3/lgm.html
Best regards, Novgorodets.
Donkey 01-09-2006 12:18
Eat! It's opened!
Dear Alhim, A HUGE THANK YOU!
I'm running to work, I'll look into it tomorrow.
Karstjager 01-09-2006 12:16
quote: Originally posted by Novgorodets:
Dear Donkey. LMG and VPGS-41 are proof that we have not lagged behind in the development of cumulative ammunition.
VPGS-41 http://www.weltkrieg.ru/ammunition/VPGS-41/
LMG http://tewton.narod.ru/mines-3/lgm.html
Best regards, Novgorodets.
LMG - late 41 developments
VPGS - sample 40 did not have a notch
current 41 notches appeared
accordingly, after familiarization with German cumulative ammunition.
tramp 01-09-2006 21:27
quote: Originally posted by Donkey:Dear tramp, thank you, I looked at your link (though it didn’t open right away), it’s very interesting pictures. It seems that UL is developing and new varieties are appearing.
In my opinion, here http://www.vpk-news.ru/article.asp?pr_sign=archive.2005.105.articles.defence_02#
translation (not very good) of this article, but without pictures.
The most interesting thing in the link is the development of the control unit, both in the direction of improving a single control unit to increase armor penetration, and multi-control unit, to destroy manpower and lightly armored targets, modification of the warhead of a system like this with the ability to change the reconfiguration of the control unit for the type of target - mono or multi and upper /lower hemisphere http://tewton.narod.ru/mines/m93.html http://www.popularmechanics.ru/part/?articleid=289&rubricid=7 allows it to be used to destroy a wide range of targets - from infantry to helicopters. (IMHO)
Novgorodets 02-09-2006 23:45
Dear Karstjager. Do you have a description of VPGS-40?
VPGS-41 was put into service on October 13, 1941. And when did the Germans use kuma? There was no time for copying.
LMG - appeared at the end of 1941 - the first half of 1942. German developments could have influenced the LMG and ours, now there are no solutions, but if work was going on on the godfather before the war, then there were clearly their own developments.
Best regards, Novgorodets.
Karstjager 04-09-2006 11:19
Dear Novgorodian!
I have small description on English language.
Here:
V.P.G.S. 40 It is not certain if this grenade used a chaped charge or if it was a chemical designed thermide grenade to burn its way through armor plate. The former is more likely, and its relatively poor performance may be explained by the poor quality of Soviet explosives.
Let us remember the experiments with thermite shells.
In addition, the logic is not entirely clear - if there were developments, why were they not embodied in artillery shells, but in weapons such as LMGs and VPGS?
opolchenec 04-09-2006 13:30
Balagansky I.A., Merzhievsky L.A. Effect of weapons and ammunition. Novosibirsk, NSTU, 2004 http://my-lair.narod.ru/Balaganskii.djvu
virus 06-09-2006 14:27
Dear experts, I have long been tormented by the question of what are the minimum values for the diameter of a projectile and explosive explosive.
Alhim 06-09-2006 18:59
The diameter of the charge is practically limited, in principle, only by the region of stable detonation of explosives (i.e., in principle, it is possible to create a cumulative charge a couple of millimeters in diameter - but what is the use of it). And brisance is generally not very useful here - we must consider the speed of shell throwing according to the known characteristics of explosives.
Donkey 08-09-2006 01:15
DUs also come in very small diameters, see the crime story on page 1 at the beginning of the topic, given by uv. member of Squint. This story, investigated with the participation of physicist Robert Wood, featured a detonator that was “a thin-walled copper tube approximately the size of a 22-caliber cartridge.”
Thus, reducing the size for the formation of CS and UC is not a hindrance.
Best regards, Donkey
Alhim 10-09-2006 01:31
Good day.
Donkey, I washed the books, did you get them?
Novgorodets 10-09-2006 18:28
Dear Karstjager! What source is this passage from?
The use of a high-explosive charge in the first sample is understandable - everyone went through it. But termite is highly doubtful.
Why was kuma originally used in a grenade, and not in a projectile? IMHO, creating a shaped charge for a rifle grenade is easier.
Best regards, Novgorodets.
Alhim 10-09-2006 20:15
And also because the armor penetration of the CS is extremely adversely affected by the rotation of the projectile (especially with low precision in its manufacture).
Donkey 10-09-2006 20:30
quote: Originally posted by Alhim:
Good day.
Donkey, I washed the books, did you get them?
Dear Alhim, thank you very much again!!!
The books have arrived and open beautifully.
At first I didn’t notice the 2nd part, it fell into the “buns”, and I only discovered it now, having seen the word “books” in plural. number.
Of course, it's a solid read, not an easy one. I’m gradually figuring it out, skipping overly complex derivations of formulas and looking straight into the result.
If I’m lucky and I find confirmation of my intuitive assumptions here, I’ll post the result HERE (there’s no point in submitting an application anyway, you’ll pay the money and then get a big bang).
With respect and gratitude, Donkey
Alhim 10-09-2006 21:11
Hmm... there should be only 4 parts. You write about two, some are missing, or I misunderstand something.
Donkey 10-09-2006 22:32
Found 2 --- one is about 7.5, and the other is 5.5 MB
Alhim 11-09-2006 01:14
So not everything got through. Write down the names of the received files.
Donkey 11-09-2006 17:59
This is what they look like:
Inbox
den Simonov Thu Aug 31, 2006 7506k Second part of volume 2.___2_____302_644.djvu (5.5MB)
Page 302-644
Bulk
den Simonov Thu Aug 31, 2006 8120k Volume two, part one.___2_____1_301.djvu (5.9MB) Page. 1-302
At first they did not open, showing Error #6: We didn't understand your request,
but then one opened and downloaded, and about the second I thought that it was the same thing, only it had arrived a second time, and I discovered my mistake only yesterday, after reading your message.
Best regards, Donkey
Novgorodets 11-09-2006 22:58
Dear Karstjager
The LMG mine began to be used in the summer of 1941.
Best regards, Novgorodets.
GorkaM5 05-05-2007 23:15
Originally posted by Squint:
[B]And how, by the way, do they generally measure the initial velocities of projectiles, which are only several times, and not orders of magnitude, behind the QW? Unfortunately, I don’t know, although it would be interesting.
2-angle X-ray filming
Doppler locator
shooting speed 1,000,000 frames/sec
According to TM-83. It has a large recess angle, which leads to the formation of a core, after which the lining can be turned out. Simplified, of course, but described in detail in the works of Titov. A similar phenomenon is used in ODAB. That is, in modern ODB.
Util 06-05-2007 01:18
quote: mixture of ammonium nitrate with peat, finely dispersed at
0.9 g/cm3 per cubic meter 10.0 - 12.0
What if there is sawdust instead of peat? Will this recipe work?
Util 06-05-2007 01:33
That's right:
"2-angle X-ray filming
5-angle X-ray filming
Doppler locator
electrocontact time-of-flight recording
shooting speed 1,000,000 frames/sec"
Used:
-electrocontact time-of-flight recording
usually in the initial section (target frames and solenoids):
-photo-contact recording of time of flight (photo-blocking, no need to wind the frames, no need to magnetize the projectiles. But if it is not coarse, then it also works against a fly.
- Doppler locator at large elevation angles (ABS, Luch, LUCH-SM devices)
-2-angle X-ray filming - when leaving the barrel and
when armor is penetrated - X-ray pulse installations.
- filming speed 1,000,000 frames/sec." This is to record the penetration process. Ultra-high-speed filming with the SSKS-producer Karl-Zeis-Jena camera.
Best regards, Util
Donkey 04-08-2007 23:43
Dear forum users, with some delay I am posting those formulas (the approximate speed of the firing device depending on the charge parameters) that I unsuccessfully searched for at the beginning of the topic.
The formulas are approximate (based on the model of a thrown plate), but seem to be reliable (their convergence with each other is decent). uv helped to find them. Alhim http://talks.guns.ru/forum/show_profile/00034370?username=Alhim
Donkey 04-10-2007 01:43
Fig.1. Diagram of the formation of a projectile formed by an explosion from a metal liner.
Fig.2. Type of elongated projectiles with feathers according to numerical modeling(first two columns), after stamping and softly caught.
Donkey 10-03-2008 23:41
Dear tramp, thank you very much!
Nguyen Minh Thuan wrote an interesting dissertation, although some things from it were known before, but many interesting conclusions follow from his work.
For example, if a charge with a diameter of 7mm (5mm funnel) penetrates 15mm armor, then it is possible to create ammunition for a low-power pocket pistol that penetrates NIB up to class 4.
It is also possible to create a cluster (from many miniature cumulus charges that scatter like shrapnel at a given distance from the target) ammunition for an anti-tank grenade launcher. This cluster grenade will successfully initiate dynamic protection over a large area and ensure that the second grenade penetrates the main armor.
tramp 11-03-2008 12:09
quote: if a charge with a diameter of 7mm (5mm --- funnel) penetrates 15mm armor, then it is possible to create ammunition for a low-power pocket pistol that penetrates NIB up to class 4.Well, as far as I can guess, taking into account R&D, this is more likely to be suitable for special forces, especially if the cartridge is of a large caliber, such as .45AKP
quote: It is also possible to create a cluster (from many miniature cumulus charges that scatter like shrapnel at a given distance from the target) ammunition for an anti-tank grenade launcher. This cluster grenade will successfully initiate dynamic protection over a large area and ensure that the second grenade penetrates the main armor.
Probably not only a grenade launcher, but also for cluster warheads in general, such as hand grenades or low-ballistic gun shots, such as the 2A70.
As it appears, modern works according to the physics of explosions, they are increasingly giving more scope in ammunition - convertible impact cores, ultra-small shaped charges, etc.
NORDBAGGER 11-03-2008 12:34
quote: Originally posted by tramp:
Well, as far as I can guess, taking into account R&D, this is more likely to be suitable for special forces, especially if the cartridge is of a large caliber, such as .45AKP
NORDBAGGER 11-03-2008 12:35
quote: Originally posted by Donkey:
It is also possible to create a cluster (from many miniature cumulus charges that scatter like shrapnel at a given distance from the target) ammunition for an anti-tank grenade launcher. This cluster grenade will successfully initiate dynamic protection over a large area and ensure that the second grenade penetrates the main armor.
IMHO the protection will not detonate.
tramp 11-03-2008 02:09
IMHO this is of no use for CO cartridges and is very expensive.
It is quite possible as an option for working on BZ.
NORDBAGGER 11-03-2008 13:43
quote: Originally posted by tramp:
It is quite possible as an option for working on BZ.
So it's possible. What for? There must be clear advantages over conventional ammunition and an acceptable price - which is not the case and IMHO is unlikely to happen in the foreseeable future.
tramp 11-03-2008 20:41
quote: There must be clear advantages over conventional ammunition and an acceptable price - which is not the case and IMHO is unlikely to happen in the foreseeable future.But what a drink! In general, the question, IMHO, is not so clear-cut, especially for low-velocity ammunition. Another thing is interesting - how will they go legally - explosive or armor-piercing?
NORDBAGGER 11-03-2008 20:50
quote: Originally posted by tramp:
In general, the question, IMHO, is not so clear-cut, especially for low-velocity ammunition.
Ceramics or combi rule.
quote: Originally posted by tramp:
Another thing is interesting - how will they go legally - explosive or armor-piercing?
It doesn't matter to police officers.
Donkey 12-03-2008 01:36
quote: Originally posted by tramp:
But what a drink! In general, the question, IMHO, is not so clear-cut, especially for low-velocity ammunition. Another thing is interesting - how will they go legally - explosive or armor-piercing?
Why explosive? They explode OUTSIDE the target. Sighting-armor-piercing --- quite a decent name
tramp 12-03-2008 09:28
quote: Originally posted by NORDBAGER:
Ceramics or combi rule.
but they charge dearly
quote: Originally posted by NORDBAGER:
It doesn't matter to police officers.
I'm talking about the military
quote: Originally posted by Donkey:
Why explosive? They explode OUTSIDE the target. Sighting-armor-piercing --- quite a decent name
So for people it is hidden by targeting conventions; for the police this does not matter, but for the military it does.
NORDBAGGER 12-03-2008 13:57
quote: Originally posted by tramp:
but they charge dearly
tramp 12-03-2008 22:33
quote: Originally posted by NORDBAGER:So Westerners in armor are more focused on ceramics.
We will fire a burst from KRISS V
PS I don’t insist, especially since our pistol caliber is smaller
Varnas 15-03-2008 01:30
quote: For example, if a charge with a diameter of 7mm (5mm --- funnel) penetrates 15mm armor, then it is possible to create ammunition for a low-power pocket pistol that penetrates NIB up to class 4.
I thought about this 10 years ago, but even then the main question was: what is the armor effect? For example, it penetrates 30 mm. Let's say a bulletproof vest is equivalent to 15 mm of steel. After all, the weight of the cumulative jet is small compared to the lining and will quickly pass through the body armor, etc.... won’t there simply be severe damage to a depth of 3-4 cm? This may not be enough.
tramp 15-03-2008 12:38
R&D must be carried out, experiments on the BZ, if the business fails, then you understand...
Varnas 15-03-2008 21:59
WHO WILL CONDUCT? Unless some kind of enthusiast...
tramp 15-03-2008 22:18
WHO WILL CONDUCT? Unless some kind of enthusiast...
Why, exactly, an enthusiast? Such developments are of interest to manufacturers of small arms cartridges, but we still have them, and if it is really possible to implement the ultra-small diameter short-circuits mentioned in the dissertation, which opens up prospects for a new type of ammunition, then the interest in conducting experiments may well be material.
Varnas 15-03-2008 23:08
Well, well, what new cartridges have been developed in Russia over the past 10 years?
tramp 16-03-2008 12:12
quote: Originally posted by Varnas:
Well, well, what new cartridges have been developed in Russia over the past 10 years?
A line of cartridges with increased penetration for small arms 5.45; 7.62; 12.7; sniper 12.7; all sorts of special cartridges.
In general, remember the situation in the military-industrial complex at that time, what kind of R&D?
Varnas 16-03-2008 15:45
Developed based on Soviet experience. But where, for example, are the high-precision cartridges? Based on the current Soviet experience, you won’t get far. For example, cumulative heads are being improved. But for example, there are no means of hitting a tank from above. Like the Bill complex or the Javelin. China and the Czech Republic are developing cartridges for PDV sales. But for Russia it is either too expensive or too difficult. And this can continue ad infinitum...
tramp 16-03-2008 18:26
I expected something like this... The question is desire, not opportunity.
Varnas 16-03-2008 22:25
quote: The question is desire
The question is the desire of the right people. In the meantime, they are looking to get more into their paw and think/work less
tramp 16-03-2008 22:35
quote: Originally posted by Varnas:
The question is the desire of the right people. In the meantime, they are looking to get more into their paw and think/work less
In many ways this is exactly the case.
Medvedko 23-04-2008 04:01
Uv. Donkey you provided a scanned page from the book: V.V. Mayer “Cumulative effect in simple experiments”
Do you happen to have this book in your email? option? Thanks in advance.
Fath 24-04-2008 16:24
Somehow, the use of ultra-small CVs as bullets for small arms is very doubtful. Very good difficult and expensive, but the effectiveness will not exceed the actions of special ones. cartridges SP-3, SP-5 or SP-6, although used. But with the defeat of dynamic protection, the idea is interesting, but I deeply doubt that if hit by such a small charge, it will detonate (practice shows that even a defeat by sub-caliber artillery ammunition does not always lead to the detonation of the ERA charge).
Donkey 25-04-2008 01:39
1) The use of ultra-small short-circuits as bullets for small arms is very doubtful. Very good difficult and expensive, but the effectiveness will not exceed the actions of special ones. cartridges SP-3, SP-5 or SP-6, although used. 2) But with the defeat of dynamic protection, the idea is interesting, but I deeply doubt that if hit by such a small charge, it will detonate (practice shows that even a defeat by sub-caliber artillery ammunition does not always lead to the detonation of the ERA charge).
http://ww1.iatp.org.ua/sbullet.htm
http://www.niistali.ru/ it will be successfully solved.
Grandfather 25-04-2008 03:55
quote: Originally posted by Donkey:
It is even possible that over time, in some institution like this http://www.niistali.ru/ it will be successfully solved.
Theoretically and at the research level, we solved it back in Soviet times. The neighboring department was drinking away bonuses right before May 9th. Then the money ran out and the institute fell apart and folded. And ammunition with bouquet cumulative warheads, by the way, existed in 1990 even at the level of the first R&D stage, and in testing them to me (then to the young boss sector) had a chance to take part. By the way, it could have been a good thing. It was not easy to defend against them.
Fath 25-04-2008 12:41
quote: Originally posted by Donkey:Dear Fath, regarding point (1) earlier I already provided a link to the uv website somewhere. Student-a http://ww1.iatp.org.ua/sbullet.htm, what kind of bullets were made in the First World War, and then they didn't seem complicated or too expensive. By now, technology has advanced significantly. Regarding their comparison in terms of effectiveness with conventional armor-piercing bullets of kinetic action, I don’t know, here I need to make a calculation (I can do this later) and for the final answer, experience, and more than one (but here, alas, I can’t do anything ).
2) In fact, the sensitivity of the explosive dynamic protection is SPECIALLY SELECTED SO that it detonates from a CUMULATIVE JET and does not detonate from the INTRODUCTION OF KINETIC AMMUNITION. But I don’t know whether explosives in plates are capable of distinguishing between large and small cumulative jets... It seems to me that “teaching” explosives to distinguish cumulative jets with similar size parameters is not an easy task.
However, if such cluster cumulative grenades do appear, then the developers of dynamic grenades will be faced with this task. It is even possible that over time, in some institution like this http://www.niistali.ru/ it will be successfully solved.
1) Well, many people have been making explosive (sighting) bullets for a long time, but it is very difficult to execute a shaped charge in the format of a regular bullet, because with the required safety margin of the case, the explosive charge and the diameter of the funnel will be very tiny.
2) I’m afraid that the sensitivity of the explosive sensing device is not so high, and I doubt that a short circuit jet of such a small size will be able to pierce several plates of the sensing device and reach the explosive charge.
Medvedko 25-04-2008 18:21
Uv. Donkey, if it didn’t bother you:
Chapter 4, paragraph 2: "collapse of conical and hemispherical recesses"
Chapter 5, everything is desirable, but the hydrodynamic mechanism and if there are calculations of the cumulative jet are enough.
soap: [email protected]
Thank you very much in advance, otherwise there is practically no information on this issue on the internet...
ZY I’m preparing a problem for the Youth Physicists Tournament (tournament of young physicists), the problem is specifically on the phenomenon of cumulation in a falling test tube.
and once again a huge thank you!
tramp 25-04-2008 22:16
quote: By the way, it could have been a good thing. It was not easy to defend against them.
Grandfather 26-04-2008 04:18
quote: Originally posted by tramp:
hurray, then my guess was correct.
The most interesting thing began then. None of our people could understand why this (a bouquet of shaped charges) was needed? After all, for thin armor, the good old impact core and the usual cumulative pestle and their combination would be suitable... And against them, within the given limitations, it was also not easy to make reliable protection
For example, you can’t hang classic “reactive” armor (or reactive armor) on the sides of armored personnel carriers and infantry fighting vehicles. She will break these sides.
tramp 26-04-2008 13:40
quote: For example, you can’t hang classic “reactive” armor (or reactive armor) on the sides of armored personnel carriers and infantry fighting vehicles. She will break these sides.
Grandfather 26-04-2008 15:49
quote: Originally posted by tramp:
But now they’ve done it and hung it, although it’s not a simple one, but they’ve hung it.
Yes, they could have hanged her even then. Only the price! In 1990, the price of remote protection for the BTR-80 was comparable to the price of the BTR-80 itself.
quote: Originally posted by tramp:
I actually assumed that the point of using such a “bouquet” was to remove the remote sensing from the largest possible area on a heavy-class armored vehicle.
Then they saw great prospects in the creation of a tandem warhead. It turned out to be more reliable from the point of view of the fact that it removes remote sensing precisely in the target area of the main charge. Roughly speaking, the efficiency is higher.
Donkey 14-10-2008 03:38
"The Czech anti-aircraft mine PT Mi-RK is a battery of five charges installed in a row<ударное кумулятивное ядро», выстреливающую по сигналу от обрывного или натяжного датчика."
http://mobiparse.ru/?showimg=0&showjs=0&showflash=0&url=www.vokrugsveta.ru/vs/article/6123/
http://artofwar.ru/img/w/waleckij_o_w/hummanitariandeminingpart3/index.shtml
Valetsky’s illustrations say: “Weight 10.1 kg (explosive charge 8.5 kg hexolite). Range 30 meters.” If the total charge is like this, then each one turns out to be 1.7 kg
IMHO, a mine of this design has 2 advantages
1) High probability of damage (one of the cores will hit a weak spot of the tank!)
2) Greater reliability of hitting the fastest vehicles with reduced requirements for fuse speed
NORDBAGGER 14-10-2008 11:47
Anti-vehicle mine - up to 20 mm of armor at a distance of 30 m. And it seems to be called PD Mi-PK vz.86. And for some reason it seems to me that, due to the chosen method of destruction, 5 charges are intended to increase the area and guarantee, and not the probability, of defeat. IMHO of course.
Donkey 15-10-2008 12:08
quote: Originally posted by NORDBAGER:
Anti-vehicle mine - up to 20 mm of armor at a distance of 30 m. And it seems to be called PD Mi-PK vz.86. And for some reason it seems to me that, due to the chosen method of destruction, 5 charges are intended to increase the area and guarantee, and not the probability, of defeat. IMHO of course.
The mine is especially suitable against luxury armored cars with important people rushing at high speed - a chain of holes is highly likely to cross the main object.
NORDBAGGER 15-10-2008 12:41
quote: Originally posted by Donkey:
Dear NORDBADGER, it seems that you know more about PD Mi-PK vz.86 than I was able to find. Do you know whether the mines are directed parallel or with a dissolution angle?
Perhaps 20 mm of armor at a range of 30 m is rather weak for a charge of 1.7 kg. Probably, they use the very first generation UU, which quickly loses speed in flight.
The mine is especially suitable against luxury armored cars with important people rushing at high speed - a chain of holes is highly likely to cross the main object.
Dear Donkey, unfortunately I am only aware of the existence of this item.
tramp 15-10-2008 12:51
quote: Originally posted by Donkey:
Here's an interesting mine I found based on the UYA principle
“The Czech anti-aircraft mine PT Mi-RK is a battery of five charges of the “impact cumulative core” type installed in a row, firing upon a signal from a break or tension sensor.”
Found (with difficulty) in ru. Information here http://mobiparse.ru/?showimg=0&showjs=0&showflash=0&url=www.vokrugsveta.ru/vs/article/6123/
and the only picture is from here: http://artofwar.ru/img/w/waleckij_o_w/hummanitariandeminingpart3/index.shtml
What are they doing in Iraq http://www.iran.org/news/mnfi-qodsforce.pdf http://www.qando.net/details.aspx?Entry=7210 http://www.nytimes.com/2007/ 03/27/world/middleeast/27weapons.html?pagewanted=3&_r=1&ref=worldspecial
Donkey 15-10-2008 16:05
Dear NORDBADGER and tramp, thank you.
“the hexotol charge is placed in a metal casing and has five hemispherical sections arranged in a row, covered with metal linings” --- it turns out that there is one charge, and 5 funnels, i.e. the charge is multicumulative.
As far as I understand from uv.tramp’s links, the ammunition from the UYA has already moved from the high-tech category to the handicraft guerrilla (I wonder, do the Arabs make copper plates for such ammunition themselves or do they get them from somewhere?)
NORDBAGGER 15-10-2008 18:58
quote: Originally posted by Donkey:
(I wonder, do the Arabs make copper plates for such ammunition themselves or do they get them from somewhere?)
SRL 15-10-2008 19:23
Dear Donkey, what they say about the lids is correct.. :-), You haven’t been out to the shopping malls for a long time, for example, the street where tourists are taken to Golgotha.
The Arabs made copper riveted teapots, hookahs, chikats, plates and other rubbish... all for the last 1000 years. Since they don’t know how to do anything else, copper plates are not a problem for them.... :-)
tramp 15-10-2008 23:20
quote: Originally posted by NORDBAGER:They added a lid to the kettle and that was it. In the East, objects of any shape or form from copper (or alloys) have been sculpted by hand from time immemorial, if we abstract from the presence of industry and educated personnel - of which there are plenty. The parameters can also be selected experimentally.
No, not from a teapot, but specially made, according to instructions from Iran. It’s quite an established production, fortunately it’s not a problem to make a template for the desired shape of the UY funnel. http://en.wikipedia.org/wiki/Explosively_formed_penetrator
NORDBAGGER 15-10-2008 23:47
quote: Originally posted by tramp:
No, not from a teapot, but specially made, according to instructions from Iran.
tramp 16-10-2008 12:19
quote: Originally posted by NORDBAGER:Well, that’s how it all started well.
So this is international cooperation.
bomb_squad 23-10-2008 02:52
and ultra-small short circuits (most likely UY, since the optimal distance to the target is more than 10 crater diameters) are currently widely used in explosive device destroyers, for example "Typhoon" http://www.bnti.ru/des.asp?itm= 1836&tbl=04.01.03. (yellow foam box in photo)
Donkey 23-10-2008 02:59
quote: Originally posted by bomb_squad:
I wonder why no one here remembered about PTM-1 and PTM-3, they are also built on the principle of the UYA, only the so-called destructive element. "knives"
A dark matter about the UYA, here in the article: “Anti-tank mine PTM-3” Veremeev writes: “Enemy vehicles are defeated by destroying their chassis, piercing the bottom with a CUMULATIVE JET when a mine charge explodes when the vehicle is above the mine.” http://tewton.narod.ru/mines/ptm-3.html
Anti-tank mine PTM-1 http://tewton.narod.ru/mines/ptm-1.html, it seems to be anti-track “Defeat to enemy vehicles is caused by the destruction of 1-3 caterpillar tracks at the moment the tank hits a mine,” and it seems generally high explosive.
bomb_squad 23-10-2008 03:26
oh, sorry, about PTM -1 I said something wrong (I corrected the post), but about PTM-3, the already respected Veremeev Yu.G. (if you wrote it yourself) where will the cumulative jet come from in it, and its fuse is non-contact, magnetic
bomb_squad 23-10-2008 03:33
“When a tank mine hits a mine as a result of exposure to a magnetic field, the fuse is triggered and causes an explosion of the detonating device and the mine charge. The destructive element formed during the explosion, acting in the direction of the bottom, pierces it, hitting the tank crew and disabling its units. When the mine is triggered, under the chassis of the military equipment defeats it due to the high-explosive effect of the explosion" - this would be more correct;-)
ASK 28-10-2008 22:08
This topic is also interesting to me, and I was doing a good job of it until I was noticed in the library and the “conversation” was interrupted.
Donkey 29-10-2008 01:13
quote: Originally posted by ASK:
Sorry for joining the topic late. Until now, no one has explained the beginnings of the mathematics of the cumulative effect. I wrote it here. A plastic plate falls onto an incompressible plate. maybe it will be useful.
This topic is also interesting to me, and I was doing a good job of it until I was noticed in the library and the “conversation” was interrupted.
Dear ASK, look at the beginning of the topic, there is a hydrodynamic model of M. A. Lavrentiev
ASK 29-10-2008 23:14
I'm talking about the same thing. That the mat model does not have any radii or velocities of propagation of the shock wave in the explosive.
tramp 10-01-2009 02:06
quote: Originally posted by Grandfather:
Then they saw great prospects in the creation of a tandem warhead. It turned out to be more reliable from the point of view of the fact that it removes remote sensing precisely in the target area of the main charge. Roughly speaking, the efficiency is higher.
This is for the case of using a tandem warhead in one ammunition, but the option of repeated exposure to ammunition with a lower armor-penetrating warhead is also possible; cleaning a larger protected remote sensing area is valuable here + an increased likelihood of damage to the heads of the sighting system.
SR-71 08-06-2009 19:30
Old thread, but interesting...
I came across this video, maybe someone saw it:
z.y. The first video, apparently with a show-off, doesn’t work here for some reason, then watch the link directly: http://www.youtube.com/watch?v=mXp5czdufoQ&NR=1
It also has a name like “that volcano”
It turns out that from a distance of 15-20m in an inch metal plate there is a good hole from this “homemade adult device”...
lexey 30-06-2009 13:40
I'm interested in this question.
The American CBU-97/105 cluster bomb uses submunitions with an impact core. These same ammunitions have the original form of metal lining. Along the circumference of this lining there are (what should we call them?) depressions. Why was this done, for what reasons?
And the video I found:
http://www.youtube.com/watch?v=ua3nLmE7Kow
SR-71 30-06-2009 14:07
Maybe additional destructive elements for manpower surrounding or located on the armored target...
lexey 30-06-2009 14:14
Quite possibly, I didn’t think about it. Since the attack is carried out on a concentration of equipment, and where there is equipment, there are people. By the way, in the video (though in a hand-drawn version) you can see that in addition to the pestle of the impact core, a circle is formed from smaller elements.
Grinya 30-06-2009 14:33
for dense coverage of any significant area around armored vehicles, 20 destructive elements are very few, and to defeat infantry you don’t need a weapon, especially of such mass.
Using weight this way is not effective, and the high-explosive effect of an explosive charge on unsheltered infantry will be stronger.
25 seconds into the video they appear to be flying off to the side
Most likely, these notches are for the correct symmetrical formation of the UU.
due to the large area of the plate, stamping defects affect the accuracy, and how often it is easier to introduce previously known disturbances than to then deal with those that arise, it is not clear what natural ones
as a version
tramp 01-07-2009 23:52
Look at this topic first, PDFs on these warheads have been posted there.
Irben 24-03-2010 14:03
Maybe someone can shed some light on this issue.
SR-71 24-03-2010 19:29
I was puzzled by the issue of destroying old mines at the bottom of the Baltic. The method used today by all navies of the Baltic countries is to detect a mine at the bottom, deliver a demolition charge to it (either by a submersible vehicle or a demolition diver) and detonate this charge. The demolition charge is usually from 10 to 50 kg of explosive.
But there was information about the use of shaped charges to detonate old mines. The weight of explosives is naturally several times less. But the question arises - how effective is the action of a cumulative jet under water, what are the features of using a demolition charge in this case.
And nah, there is a godfather, then you need...? Their body doesn't seem to be thick-walled...
If its (mine) explosive is still “alive”, then it is not even close to the body of a regular TG-500... Why is there 10-50kg, then?
Fath 24-03-2010 20:09
Their bodies are just not sickly. I remember watching the disposal of sea mines (admittedly more modern, but I don’t think the design has changed much in this regard) - a steel cylinder with a wall thickness of a couple of centimeters. And it’s dying... So that it detonates inside during an external explosion, we had to try hard. There, however, they detonated on land and blew it up more easily - almost routinely, and then they began to burn it completely (when houses within a radius of 10 km cracked).
I think there should be no problems with a shaped charge: it is, after all, explosive and is applied close to the body of the mine, i.e. the jet spreads first in the body of the charge itself, and then passes directly into the body of the mine.
Danishin 24-03-2010 21:50
quote: Originally posted by Irben:
I was puzzled by the issue of destroying old mines at the bottom of the Baltic. The method used today by all navies of the Baltic countries is to detect a mine at the bottom, deliver a demolition charge to it (either by a submersible vehicle or a demolition diver) and detonate this charge. The demolition charge is usually from 10 to 50 kg of explosive.
But there was information about the use of shaped charges to detonate old mines. The weight of explosives is naturally several times less. But the question arises - how effective is the action of a cumulative jet under water, what are the features of using a demolition charge in this case.
Maybe someone can shed some light on this issue.
I think I can enlighten you.
Using a short circuit underwater is not a simple matter. The effect of the cumulative effect under water drops to almost zero already at a distance of seven times the diameter of the cumulative funnel. These are not my speculations, but calculations that were made by Pokrovsky back in 1944.
The short circuit must be placed on the mine as tightly and stably as possible on the object being undermined, i.e. in this case mine. The Soviet KZ-6 charge has a nozzle specifically for use under water, which allows the formation of a cumulative jet under water. It is also equipped with a weighting agent so that it sinks when using the nozzle.
So, in order to use short circuit underwater, you need to try very hard.
In my opinion, only a person can do a fairly good job of installing a short circuit, because... a robot cannot do this. More precisely, he will place the charge himself, but will not really secure it, etc. Well, the minus for the diver is that not all depths are within his control, and an appropriate profile is needed, and not many people have it. So at great depths, concentrated charges of large mass will most likely be used.
Fath 25-03-2010 12:10
Yes, it will be quite difficult for a robot there. And if you consider that mines are usually also covered with all sorts of nautical crap, then the installation problem can be problematic for humans as well. Apparently this is one of the reasons why short circuits are not used.
tramp 26-03-2010 10:51
quote: Originally posted by Fath:
Yes, it will be quite difficult for a robot there. And if you consider that mines are usually also covered with all sorts of nautical crap, then the installation problem can be problematic for humans as well. Apparently this is one of the reasons why short circuits are not used.
yep http://www.lockheedmartin.com/data/assets/886.pdf
www.imtp.febras.ru/journal/31-39.pdf
Donkey 21-02-2011 22:57
In the old “Technology for Youth”, it seems, from the late 80s, there was a small article called “Copper Spit”. It described a kind of self-propelled anti-tank mine with remote control
The note indicated the parameters of the impact core (now it is clear to us that it was not a KZ, but it was an SFZ or an EFP): mass 10 kg, tank destruction range approx. 500m
In the Institute there was a video about this self-propelled mine http://www.youtube.com/watch?v=syuu_g7svoE, lasting 23 seconds (that’s where the picture comes from), but no more information about it was found, not even a name. It was probably a prototype that was later rejected.
Based on the mass, you can roughly estimate the diameter of the UYA --- approximately 28-30 cm
abc55 22-02-2011 01:58
the wheels are so good
Donkey 22-02-2011 03:18
quote: Originally posted by abc55:
and the machine becomes unusable after a shot - a little expensive
the wheels are so good
Dear abc55, IMHO, in comparison with a tank costing from 2.5 (old) to 8-10 (new) million dollars, it may be inexpensive, and even the wheels are not so bad.
oldcolony 22-02-2011 12:30
I also remember this bullshit. I don't mind the wheels, I think it's different here. Its speed along the intersection is unlikely to be more than 15 km/h. She won’t catch up with the tank, they’ll shoot a current in the forehead, and then they’ll stupidly shoot her with a machine gun—they won’t even waste a shell. Like a mine, it’s expensive, you can make a dozen TM-82s for that money, and why the wheels? the soldier will bring it. As an active means of destruction, the Pturs at the same price is incomparable in terms of capabilities. In short, a toy for nerds from the military-industrial complex; they didn’t play enough with cars when they were kids.
Donkey 23-02-2011 15:24
Dear oldcolony, IMHO, such a machine is still not complete garbage.
In front of the TM-83 mine http://www.saper.etel.ru/mines/tm-83.html and even in front of the M93 HORNET mine http://www.saper.etel.ru/mines/m93.html it has an important advantage --- it can be quickly moved from one tank-hazardous direction to another and meet the tank exactly where it goes. Its use is precisely an anti-tank ambush, as shown, by the way, in the video on YouTube. It is not at all necessary to go out onto the road in front of the tank and reveal yourself to it, just as it is not necessary to hit the tank in the frontal armor (although a 10 kg weapon at close range will probably not withstand every tank even in the forehead)
oldcolony 23-02-2011 16:55
Where you need to quickly move anti-tank weapons, you need helicopters, tanks, ATGM installations on wheeled chassis, remote mining - and not an electric stroller. When will she get there again, if she doesn’t get stuck on the way? And as for the anti-tank ambush, no sane commander would climb headlong onto a road that is invisible from right to left for 400 m (they write up to 500, which means, in reality, 400).
oldcolony 23-02-2011 17:01
The Hornet is a really interesting thing, at least it can be camouflaged in a well, and it will be impossible for a tank to notice it. I'd buy a couple of these
Donkey 25-02-2011 18:27
The M93Hornet mine is a really interesting thing, although it costs 52.4 thousand. Doll.
http://www.globalsecurity.org/military/systems/munitions/m93.htm
According to Yu.G. Veremeev, “as a means of attempting to assassinate high-ranking officials (presidents, heads of government, etc.), this ammunition is ideal.”
But I also had one consideration in favor of a car on wheels:
an infantryman with a grenade launcher has an intersection speed of much less than 15 km/h, and he must take a significant lead on a moving tank (at a distance of 500 m, 9-17 vysirels are needed to hit a tank), but for a UYA lead is not required.
However, the infantryman can emerge victorious, albeit at a very high cost.
The machine has a much greater chance of winning, and the operator does not have to sacrifice his life.
IMHO, a good improvement to the machine would be control via fiber-optic communication lines (and the radio channel is a duplicate one).
oldcolony 25-02-2011 21:10
Well, everything is the same with regard to the ATGM, only the distance from which it can reach the tank is much greater. Actually, life has already judged us - there is nothing like this in the arsenal of any of the armies.
Donkey 26-02-2011 02:41
quote: Originally posted by oldcolony:
1) Well, everything is the same with regard to the ATGM, only the distance from which it will reach the tank is much greater. 2) Actually, life has already judged us - there is nothing like this in the arsenal of any of the armies.
1) ATGM, especially heavy --- this, IMHO, is a further frontier of anti-tank missiles.
2) Whether or not there is such an army is not always the criterion for how successful a given technical solution is. The Germans released Goliath in fair quantities and used it quite widely, but this did not make it any more successful, although the performance was not bad. It’s just that in those days there were no technical means to implement it.
Nowadays, these means (primarily cheap television cameras) have been around for a long time.
Why didn’t the AMERICANS (they tested it, according to TM) need the machine? IMHO, they are not planning DEFENSIVE actions, especially against large masses of tanks. If the enemy has developed ground forces, they will simply bomb him from the air (in the near future and from space) until the last tank is set on fire.
Varnas 26-02-2011 13:57
not necessarily the tank itself. Without the support of infantry, transporters of fuel and ammunition, without reconnaissance on tanks, you won’t fight much...
Two 26-02-2011 15:35
Why not attach a couple of propellers to this mine and let it fly?
Donkey 26-02-2011 23:29
quote: Originally posted by Two:
Why not attach a couple of propellers to this mine and let it fly?
It flies beautifully, but not on propellers, but on small parachutes
http://en.wikipedia.org/wiki/Sense_and_Destroy_ARMor or on the wings
z.y. Maybe I’m interested, I don’t have all the T-M magazines, but some are even from 1976...
Donkey 04-03-2011 19:36
quote: Originally posted by SR-71
:
z.y. Maybe I’m interested, I don’t have all the T-M magazines, but some are even from 1976...
Thank you very much, I just came across the archive from 1933
http://technica-molodezhi.ru/
SR-71 04-03-2011 19:44
Well, what’s the point of storing this waste paper now...
Varnas 04-03-2011 20:04
Well, isn’t it interesting what happened before? And often the new is the well-forgotten old. Now he is patenting a bunch of new engines... Both piston and all sorts of rotary ones... And the funny thing is that all these designs already existed a hundred years ago - in steam versions. Not in series, but they were. and some were even in the internal combustion engine version. But the technology and materials were not suitable then..
Fireman2 04-03-2011 20:30
But personally, I am tormented by vague doubts about the effectiveness of the UU. I can’t understand how the declared armor penetration is achieved? How much do they promise, 100 mm, I think, right?
Well, the speed is, of course, quite high. 2 - 2.5 km/s. But you also need mass! And the mass of the formed striker does not seem to be very large. By the way, will anyone clarify within what limits it varies? I think that in any case this is several times smaller than a BPS core of similar caliber. This is the time.
Second. At such impact speeds, the material and shape of the striker still play a large role in armor penetration. And the UYA, as I understand it, is something in the form of a droplet shape and consists of soft and ductile alloys, such as copper. Somehow this is far from a specially shaped tungsten core..
knkd 04-03-2011 20:35
quote: Originally posted by Fireman2:
and consists of soft and ductile alloys, such as copper
At such deformation rates, armor steel is also a liquid alloy
Fireman2 04-03-2011 20:39
quote: At such deformation rates, armor steel is also a liquid alloy
Well, don't tell me. The armor will be thin after 4-5 km/s
Varnas 04-03-2011 20:59
quote: Well, the speed, of course, is quite high. 2 - 2.5 km/s. But you also need mass! And the mass of the formed striker does not seem to be very large. By the way, will anyone clarify within what limits it varies? I think that in any case this is several times smaller than a BPS core of similar caliber. This is the time.
The mass is there And since the mass is several times less than the mass of a normally armor-piercing core of the same caliber, then the armor penetration is several times less.
Fireman2 04-03-2011 21:08
quote: And since the mass is several times less than the mass of a normally armor-piercing core of the same caliber, the armor penetration is several times less.
So how many grams are there in UA?
I can say from my own experience that a copper bar with a caliber of 40 mm and a mass of about 450 g, when impacted at a speed of about 2000 m/s, cannot penetrate a steel plate 100 mm thick.
Varnas 04-03-2011 21:14
Why not? The Jacob de Marre formula gives a penetration of about 150 mm. Yes, it is not for such speeds and not for copper projectiles... On the other hand, you can recall Gerlich’s experiments and penetration of 12-15 mm armor plates with a 7 mm caliber bullet with a lead core. I don’t see any contradictions here.
Donkey 04-03-2011 21:33
Exactly!
a “soft” (not armor-piercing) bullet of the specified weight pierced through the armor of chromium-nickel steel 15 mm thick (mechanical properties of steel: elastic limit 61 kg/mm2, elongation 13.5%), and a plug with a diameter of 18-20 mm was knocked out in the armor and spalling occurred armor on the opposite side with a diameter of about 40 mm; pieces of armor received such living force that they went deep into the pine boards behind the armor to a depth of about 30 mm;
http://www.guns.ru/library/Blagonravov/6.html
Fireman2 04-03-2011 21:48
quote: Why not? The Jacob de Marre formula gives a penetration of about 150 mm. Yes, it is not for such speeds and not for copper projectiles... On the other hand, you can recall Gerlich’s experiments and penetration of 12-15 mm armor plates with a 7 mm caliber bullet with a lead core. I don’t see any contradictions here.
Here is a photo of a copper bar hitting a steel plate. V= 2000 m/s
Fireman2 04-03-2011 21:54
quote: a “soft” (not armor-piercing) bullet of the specified weight pierced through 15 mm thick chromium-nickel steel armor
Yeah... and for some reason the cores of armor-piercing shells continue to be made from tungsten.
And I even know why.
This photo shows the same slab, pierced through with a core from a residence permit at the same speed
Fireman2 05-03-2011 06:45
quote: Originally posted by Varnas:
Blank 40 mm 450 grams?
40mm x40mm.
450grams
quote: Originally posted by Varnas:
naturally. If the Gerlich bullet had a tungsten core, it would have pierced all 30.
Hmm... a bullet with a tungsten core will weigh significantly more. How do you propose to maintain the initial speed of the bullet?
quote: Originally posted by Varnas:
Already in the 80-90s, experiments were underway with linings made of tantalum-based alloys, etc.
I don’t think that this would fundamentally change the mechanism and depth of armor penetration of such a weapon. So, at the level of a dozen or two percent.
SR-71 05-03-2011 11:03
quote: Originally posted by Varnas:
Well, isn’t it interesting what happened before? And often the new is the well-forgotten old. Now he is patenting a bunch of new engines... Both piston and all sorts of rotary ones... And the funny thing is that all these designs already existed a hundred years ago - in steam versions. Not in series, but they were. and some were even in the internal combustion engine version. But the technology and materials were not suitable then..
Yes, I’m not talking about this Varnas. Those stacks of magazines that I have now, as you can see, are all in electronic form and will fit on one CD... And now you don’t need to go to the library, everything is on the Internet...
Donkey 06-03-2011 02:26
To rejoice that I found the TM archive, I decided to post fragments of another small article, “The KAZ Dynasty is working for peace” (issue 7, 1974, of course, then everything worked only for peace, even nuclear charges --- after all, the USSR was the most peace-loving country )
According to the bottom picture.
Hellish pressures act on the electrons rotating around the nucleus, causing radiation - this is fantastic!
saad 13-04-2011 13:33
SRL 13-04-2011 14:36
Varnas 13-04-2011 16:51
Is there any work that proves that with reverse cumulation the jet velocity is greater than with cylindrical lining?
abc55 13-04-2011 18:12
and I believe TM for 74g
SR-71 13-04-2011 18:57
quote: Originally posted by SRL:
posted 13-4-2011 14:36Regarding the output of hard radiation during inverse conical cumulation.
I have not found a single serious work proving the output of hard radiation during obath-conical cumulation. Maybe someone has a link?
Why do you need a link? Maybe it’s “New”... which hasn’t been “studied” yet..
Varnas 13-04-2011 23:10
quote: and I believe TM for 74g
But not me
Donkey 15-04-2011 03:02
IMHO, the article should be understood in such a way that ultra-high pressures and temperatures (1 million atm and 300 thousand degrees) arise not in an inverse conical funnel, but in a charge with a cavity in the shape of a body of rotation of a logarithmic spiral, and at this point where the products rush explosion, high-temperature plasma appears.
At 300000K, according to Wien’s rule (I don’t know if it can be applied here), the maximum emission length should be about 10 nm, i.e. on the border between ultraviolet and x-rays.
Principle of Education
The impact core is formed during the explosion of any shaped charge with a metal lining, but its mass and energy depend on the angle of the lining. To form full-fledged impact nuclei, linings with an opening angle of over 100° or a spherical shape are used, with a lining thickness significantly greater than that of a shaped charge for action with a cumulative jet.
If in a conventional shaped charge about 75% of the lining mass is converted into a pestle, then in a charge with an impact core - up to 95%. Unlike a cumulative jet, which maintains relative armor penetration over a length of tens of initial charge diameters, the impact core maintains its speed at a distance of the order of a thousand initial charge diameters.
After compression (collapse of the lining), the pestle has a diameter of approximately a quarter of the diameter of the original charge and a length of about one diameter (that is, it has an elongated shape). The speed of the impact core is about 2.5 km/s (in some designs 3.5-5.0 km/s), significantly exceeding the speed of the BOPS. At the same time, the armor penetration of the impact core is maintained at distances of tens of meters. The armor penetration of the impact core against steel armor can reach values of 0.4-0.6 at these distances from the initial diameter of the lining (about the diameter (caliber) of the shaped charge). According to empirical relationships, the armor penetration of the impact core, determined by the thickness of the steel armor, is half the diameter of the charge for a copper or iron lining, and the full diameter of the charge for a tantalum lining. In this case, the armor penetration of a typical shaped charge is at least six charge diameters.
The impact core's effective destruction velocity drops quickly, so the impact core is delivered by a carrier and can also be used as a mine or destructive charge.
Story
Ammunition with a percussion core was first designed in Germany during the Second World War under the leadership of ballistician Hubert Schardin.
A group of scientists from the Institute of Ballistics of the Air Force Technical Academy ( Technischen Akademie der Luftwaffe), starting in 1939, studied the processes of detonation and cumulation using an X-ray pulse installation. A fundamental difference in the results of detonation of profiled charges with conical and hemispherical linings was revealed. Detonation of a charge with a hemispherical lining actually did not result in the formation of a cumulative jet, however, it was discovered that the hemispherical lining of the charge was turned outward with the formation of a pestle in the form of a compact fragment, which, after formation, could maintain its integrity. The pestle speed was about 5000 m/s. At the same time, Shardin, based on X-ray pulse survey data, completely distinguished between the mechanisms of penetration of armor by a cumulative jet and a compact pestle fragment, rightly equating the latter in its mechanism of action to a projectile accelerated to a speed of 5000 m/s. The result of these studies was the discovery of the so-called Mizhnei-Shardin effect ( Misznay-Schardin effect).
In our time, this principle has been put into practice in the United States, starting in the 1970s, where in the technical documentation, ammunition with impact cores is divided into two groups:
- Effective at short ranges, a “self-forming fragment” SFF) with armor penetration of at least 100 mm at ranges up to 10 m, and
- An “explosively formed projectile”, effective at extended ranges, EFP) with armor penetration of at least 100 mm at a distance of at least 200 m.
In our country, charges with impact nuclei can be designated by the abbreviation "SFZ", that is, a projectile-forming charge. In Germany, a similar designation for the projectile-forming charge has been adopted - projektilbildende Ladung.
In August 1987, the State Research and Production Enterprise "Basalt" created a disposable bomb cluster RBK-500SPBE with high-precision self-aiming anti-tank combat elements (SPBE). The SPBE warhead is made on the basis of a projectile-forming charge.
Because percussion core ammunition is a shaped charge with a special lining, it is sometimes confused with classic shaped charges that act as a metal stream. But unlike classic shaped charges, charges with an impact core, quite similar in design to cumulative charges, actually act like conventional kinetic ammunition (armor-piercing shells and BOPS).
Links
Literature
- Gook M. The Science of High Explosives N,Y.: Reinhold Publishing Cjrp, 1958,
Categories:
- Military equipment
- Weapon
- Ammunition
- Explosives
- Artillery ammunition
- Anti-tank weapons
- Improvised explosive devices
Wikimedia Foundation. 2010.
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What is the cumulative effect, and how does it help penetrate the thick armor of modern tanks.
Installation for producing a cumulative jet High-voltage generator with voltage up to 10 kV High-voltage capacitor (6.3 kV) with a capacity of 0.5 μF Static voltmeter (up to 7.5 kV) High-voltage spark gap made of coaxial cable Plastic capillary with a paper insert Distilled water Set of thick gelatin bars from 1 to 5 cm
Dmitry Mamontov Alexander Prishchepenko
In 1941, Soviet tank crews encountered an unpleasant surprise - German cumulative shells, which left holes in the armor with melted edges. They were called armor-piercing (the Germans used the term Hohlladungsgeschoss, “a projectile with a notch in the charge”). However, the German monopoly did not last long; already in 1942, the Soviet analogue of the BP-350A, built using the “reverse engineering” method (disassembling and studying captured German shells), was adopted for service - an “armor-burning” shell for 76-mm guns. However, in fact, the effect of the shells was not associated with burning through the armor, but with a completely different effect.
Disputes about priorities
The term “cumulation” (Latin cumulatio - accumulation, summation) means the strengthening of any action due to addition (accumulation). During cumulation, due to a special charge configuration, part of the energy of the explosion products is concentrated in one direction. Several people who discovered it independently of each other claim priority in the discovery of the cumulative effect. In Russia - a military engineer, Lieutenant General Mikhail Boreskov, who used a charge with a recess for sapper work in 1864, and Captain Dmitry Andrievsky, who in 1865 developed a detonator charge for detonating dynamite from a cardboard sleeve filled with gunpowder with a recess filled with sawdust. In the USA - chemist Charles Munro, who in 1888, as legend has it, exploded a charge of pyroxylin with letters embossed on it next to a steel plate, and then drew attention to the same letters, mirrored “reflected” on the plate; in Europe - Max von Forster (1883).
At the beginning of the 20th century, cumulation was studied on both sides of the ocean - in Great Britain, Arthur Marshall, the author of a book dedicated to this effect, published in 1915, did this. In the 1920s, the famous explosives researcher Professor M.Ya. studied explosive charges with a notch (albeit without metal lining) in the USSR. Sukharevsky. However, the Germans were the first to put the cumulative effect into the service of the military machine, who began the targeted development of cumulative armor-piercing shells in the mid-1930s under the leadership of Franz Tomanek.
Around the same time, Henry Mohaupt was doing the same thing in the United States. It is he who is considered in the West to be the author of the idea of metal lining a recess in an explosive charge. As a result, by the 1940s, the Germans already had such shells in service.
Deadly Funnel
How does the cumulative effect work? The idea is very simple. In the head of the ammunition there is a recess in the form of a funnel lined with a millimeter (or so) layer of metal with an acute angle at the apex (socket towards the target). The detonation of the explosive begins from the side closest to the top of the crater. The detonation wave “collapses” the funnel towards the axis of the projectile, and since the pressure of the explosion products (almost half a million atmospheres) exceeds the limit of plastic deformation of the lining, the latter begins to behave as a quasi-liquid. This process has nothing to do with melting; it is precisely the “cold” flow of the material. A very fast cumulative jet is squeezed out of the collapsing funnel, and the rest (pestle) flies from the point of explosion more slowly. The distribution of energy between the jet and the pestle depends on the angle at the top of the funnel: at an angle of less than 90 degrees, the energy of the jet is higher, at an angle of more than 90 degrees, the energy of the pestle is higher. Of course, this is a very simplified explanation - the mechanism of jet formation depends on the explosive used, on the shape and thickness of the lining.
One of the varieties of cumulative effect. To form an impact core, the cumulative notch has an obtuse angle at the apex (or a spherical shape). When exposed to a detonation wave, due to the shape and variable thickness of the walls (thicker towards the edges), the lining does not “collapse”, but is turned “inside out”. The resulting projectile with a diameter of a quarter and a length of one caliber (the original diameter of the notch) accelerates to 2.5 km/s. The armor penetration of the core is less than that of a cumulative jet, but it is maintained over almost a thousand recess diameters. Unlike a cumulative jet, which “takes away” only 15% of its mass from the pestle, the impact core is formed from the entire lining.
When the funnel collapses, a thin (comparable to the shell thickness) jet accelerates to speeds on the order of the explosive detonation speed (and sometimes higher), that is, about 10 km/s or more. This jet does not burn through the armor, but penetrates it, just as a jet of water under pressure erodes sand. However, during the formation of the jet, its different parts acquire different speeds (the rear parts are slower), so the cumulative jet cannot fly far - it begins to stretch and disintegrate, losing its ability to penetrate armor. The maximum effect of the jet is achieved at a certain distance from the charge (it is called focal). Structurally, the optimal armor penetration mode is ensured by the gap between the notch in the charge and the projectile head.
Liquid projectile, liquid armor
The speed of the cumulative jet significantly exceeds the speed of sound propagation in the armor material (about 4 km/s). Therefore, the interaction of the jet and the armor occurs according to the laws of hydrodynamics, that is, they behave like liquids. Theoretically, the depth of penetration of the jet into the armor is proportional to the length of the jet and the square root of the ratio of the densities of the lining material and the armor. In practice, armor penetration is usually even higher than theoretically calculated values, since the jet becomes longer due to the difference in the speeds of its head and rear parts. Typically, the thickness of the armor that a shaped charge can penetrate is 6-8 of its calibers, and for charges with linings made of materials such as depleted uranium, this value can reach 10. Is it possible to increase armor penetration by increasing the length of the jet? Yes, but often this does not make much sense: the jet becomes too thin and its armoring effect is reduced.
Pros and cons
HEAT ammunition has its advantages and disadvantages. The advantages include the fact that, unlike sub-caliber shells, their armor penetration does not depend on the speed of the projectile itself: cumulative ones can be fired even from light guns that are not capable of accelerating a projectile to high speed, and such charges can also be used in rocket-propelled grenades.
By the way, it is precisely the “artillery” use of cumulation that is fraught with difficulties. The fact is that most projectiles are stabilized in flight by rotation, and this has an extremely negative effect on the formation of the cumulative jet - it bends and destroys it. Designers achieve a reduction in the rotation effect in various ways - for example, by using a special cladding texture (but at the same time, armor penetration is reduced to 2-3 calibers).
Another solution is used in French shells - only the body rotates, and the shaped charge mounted on bearings practically does not rotate. However, such shells are difficult to manufacture, and besides, they do not fully utilize the capabilities of the caliber (and armor penetration is directly related to the caliber).
The installation we assembled does not at all look like an analogue of the formidable weapon and mortal enemy of tanks - cumulative armor-piercing shells. Nevertheless, it represents a fairly accurate model of a cumulative jet. Of course, on a scale, the speed of sound in water is less than the speed of detonation, and the density of water is less than the density of the lining, and the caliber of real projectiles is larger. Our setup is excellent for demonstrating phenomena such as jet focusing.
It would seem that projectiles fired at high speed from smoothbore guns do not rotate - their flight is stabilized by the tail, but even in this case there are problems: at high speeds when the projectile hits the armor, the jet does not have time to focus. Therefore, shaped charges are most effective in low-velocity or generally stationary ammunition: shells for light guns, rocket-propelled grenades, ATGMs, and mines.
Another drawback is related to the fact that the cumulative jet is destroyed by explosive dynamic protection, as well as when passing through several relatively thin layers of armor. To overcome dynamic protection, a tandem ammunition has been developed: the first charge undermines its explosives, and the second pierces the main armor.
Water instead of explosives
In order to simulate the cumulative effect, it is not necessary to use explosives. We used ordinary distilled water for this purpose. Instead of an explosion, we will create a shock wave using a high-voltage discharge in water. We made the arrester from a piece of television cable RK-50 or RK-75 with an outer diameter of 10 mm. A copper washer with a 3 mm hole (coaxial with the central core) was soldered to the braid. The other end of the cable was stripped to a length of 6-7 cm and the central (high-voltage) core was connected to the capacitor.
If the jet is well focused, the channel punched in the gelatin is almost invisible, but with a defocused jet it looks like in the photo on the right. Nevertheless, “armor penetration” in this case is about 3-4 calibers. In the photograph, a gelatin block 1 cm thick is pierced with a cumulative jet “through and through”.
The role of the funnel in our experiment is played by the meniscus - it is this concave shape that the surface of the water takes in a capillary (thin tube). A large depth of the “funnel” is desirable, which means that the walls of the tube must be well wetted. Glass will not work - water hammer during discharge destroys it. Polymer tubes do not wet well, but we solved this problem by using a paper liner.
Tap water is not good - it conducts current well, which will pass through the entire volume. We will use distilled water (for example, from injection ampoules), which does not contain dissolved salts. In this case, all the discharge energy will be released in the breakdown region. Voltage is about 7 kV, discharge energy is about 10 J.
Gelatin armor
Let's connect the spark gap and the capillary with a piece of elastic tube. Water should be poured inside using a syringe: there should be no bubbles in the capillary - they will distort the “collapse” picture. Having made sure that the meniscus has formed at a distance of about 1 cm from the spark gap, we charge the capacitor and close the circuit with a conductor tied to the insulating rod. In the area of the breakdown, high pressure will develop, a shock wave (SW) will be formed, which will “run” towards the meniscus and “collapse” it.
You can detect a cumulative jet by its poke into your palm, extended at a height of half a meter to a meter above the installation, or by spreading drops of water on the ceiling. It is very difficult to see a thin and fast cumulative jet with the naked eye, so we armed ourselves with special equipment, namely the CASIO Exilim Pro EX-F1 camera. This camera is very convenient for filming fast-paced processes - it allows you to shoot video at up to 1200 frames per second. The first test shootings showed that it is almost impossible to film the formation of the jet itself - the discharge spark “blinds” the camera.
But you can film “armor penetration”. It will not be possible to penetrate the foil - the speed of the water jet is too low to liquefy aluminum. Therefore, we decided to use gelatin as armor. With a capillary diameter of 8 mm, we were able to achieve “armor penetration” of more than 30 mm, that is, 4 calibers. Most likely, with a little experimentation with focusing the jet, we could achieve more and even, perhaps, penetrate two-layer gelatin armor. So the next time the editorial office is attacked by an army of gelatin tanks, we will be ready to give a worthy rebuff.
We thank the CASIO representative office for providing the CASIO Exilim Pro EX-F1 camera for filming the experiment.
