A charge of shaped is the explosive charge formed to focus the effects of explosive energies. Various types are used for cutting and shaping metals, starting nuclear weapons, penetrating armor, and "complete" wells in the oil and gas industry.
A typical modern shaped charge, with metal liners in the load cavity, can penetrate armor steel to a depth of seven or more times the charge diameter (charge diameter, CD), although a depth greater than 10 CDs and above has been achieved.. Contrary to widespread misconceptions (possibly due to the acronym HEAT), the charge is not independent of heating or fusion for its effectiveness; ie, the jet from the shaped charge does not melt its course through the armor, because the effect is purely kinetic in nature.
Video Shaped charge
Munroe Effect
The Munroe or Neumann effect is the focusing of explosive energy by a hollow or empty piece on the surface of the explosive. The earliest mention of hollow accusations occurred in 1792. Franz Xaver von Baader (1765-1841) was a German mining engineer at the time; In the mining journal, he advocated a conical space at the front end of the blast charge to enhance the explosive effect and thus save the powder. This idea was adopted, for the time being, in Norway and in the Harz mountain mine in Germany, although the only explosive available at the time was gunpowder, which was not a high explosive charge and therefore unable to produce shock waves in the form of cost effects.
The first hollow load effect was correctly achieved in 1883, by Max von Foerster (1845-1905), head of the nitrocellulose plant of Wolff & amp; Co. in Walsrode, Germany.
In 1886, Gustav Bloem of DÃÆ'¼sseldorf, Germany had obtained the US span. Patent 342,423 for the metal hemisphere detonator of the brain hemisphere to concentrate the explosive effect in the axial direction. The Munroe Effect was named after Charles E. Munroe, who discovered it in 1888. As a civilian chemist working at the US Naval Torpedo Station in Newport, Rhode Island, he noticed that when a block of explosive guncotton with the manufacturer's name was blown into it next to the metal plate, the writing was cut to the plate. Conversely, if the letters are raised above the explosive surface, then the letters on the plate will also be lifted above the surface. In 1894, Munroe built the first rough-shaped charge:
Among the experiments performed... is one on twenty-nine-inch safe cubes, with walls of four inches and three quarters thick, consisting of iron and steel plates... [W] hen dynamite hollow charge of nine pounds and half weight and not injected detonated on it, a three-inch diameter hole blown clear through the wall... The vacuum cartridge is made by tying the stick of dynamite around the can, the last open mouth placed down.
Although Munroe's discovery of a shaped charge was widely publicized in 1900 in the Popular Science Monthly, the importance of tin can "liner" of hollow loads remain unrecognized for another 44 years. The section of the 1900 article was reprinted in the February 1945 edition of the Popular Science , describing how a charged-work warheads work. It is this article that finally revealed to the general public how the fairy tales of Bazooka actually worked against armored vehicles during World War II.
In 1910, Egon Neumann of Germany discovered that the TNT block, which normally punctures a steel plate, pierces it if the explosive has a cone-shaped curve. The military uses of Munroe and Neumann's work were not appreciated for long. Between world wars, academics in several countries - Myron Yakovlevich Sukharevskii (???????????????) in the Soviet Union, William H. Payments and Donald Whitley Woodhead in England, and Robert Williams Wood in the US - acknowledged that projectiles could be formed during the explosion. However, it was not until 1932 that Franz Rudolf Thomanek, a physics student at the Vienna Technische Hochschule, composed an anti-tank round based on the effect of cavity loading. When the Austrian government showed no interest in pursuing the idea, Thomanek moved to Berlin Technische Hochschule, where he continued his studies under the ballistics expert, Carl Julius Cranz. There in 1935, he and Hellmuth von Huttern developed a prototype anti-tank round. Although the performance of the weapons proved to be disappointing, Thomanek continued his development work, in collaboration with Hubert Schardin at the Waffeninstitut der Luftwaffe (Air Force Arms Institute) in Braunschweig.
In 1937, Shardin believed that the hollow effect was due to the interaction of shock waves. During the test of this idea that, on February 4, 1938, Thomanek devised a charge shaped explosive (or Hohlladungs-Auskleidungseffekt (hollow liner effect)). (Gustav Adolf Thomer who in 1938 was first visualized, with flash radiography, a metallic jet produced by a charge-shaped explosion.) Meanwhile, Henry Hans Mohaupt, a chemical engineer in Switzerland, independently developed a charge ammunition in 1935., which was shown to the Swiss, French, British and US military.
During World War II, shaped ammunition was developed by Germany (Panzerschreck, Panzerfaust, Panzerwurfmine, Mistel), English (PIAT, Beehive charge), Soviet Union (RPG-43, RPG-6), and US (bazooka). The development of payload shaped revolutionized anti-tank warfare. Tanks face serious vulnerabilities from weapons that can be carried by infantry or airplanes.
One of the earliest uses of the shaped charge was by the German glider-borne forces against the Belgian Fort Eben-Emael in 1940. This accusation of destruction - developed by Dr. Wuelfken of the German Ordnance Office - is a striped striped expense and does not produce metal jets like modern HEAT warheads. Due to the lack of metal ships they shook the turret but they did not destroy it, and other air forces were forced to climb the turret and destroy the barrel of the rifle. Maps Shaped charge
Apps
The modern military
The general term in military terminology for the shaped charge warheads is a high explosive anti-tank (HEAT). HEAT warheads are often used in anti-tank missiles, directional rockets, shooting projectiles (either spinning or not), gun grenades, land mines, bombs, torpedoes, and other weapons.
Non-military
In non-military applications it is used in explosive destruction of buildings and structures, especially for cutting metal piles, columns and beams and for boring holes. In the manufacture of steel, small shaped charges are often used to puncture taps that have been plugged with slag. They are also used in excavation, breaking ice, breaking wooden congestion, cutting down trees, and drilling post holes.
Shaped costs are used most widely in the oil and natural gas industry, particularly in the settlement of oil and gas wells, where they are detonated to puncture well metal casing at intervals to receive the entry of oil and gas.
Function
A typical tool consists of a solid explosive cylinder with a metal-coated conical cone at one end and a central detonator, a detonator array, or a detonation wave guide at the other. Explosive energy is released directly from the (normal) surface of the explosive, thus forming the explosive will concentrate the explosive energy into a vacuum. If the hole is properly shaped (usually conically), the large pressure generated by the explosive explosion of the liner drive in the hollow cavity into collapse on its central axis. The resulting collisions form and project a high-speed metal jet forward along the axis. Most of the jet material comes from the innermost part of the liner, a layer of about 10% to 20% of the thickness. The remaining liners form slugs that move more slowly, which, because of their appearance, are sometimes called "carrots".
Because of the variation along the liner in the speed of its collapse, jet velocity also varies along its length, decreasing from the front. This variation in jet velocity extends and eventually leads to its separation into particles. Over time, the particles tend to fall out of alignment, which reduces penetration depth to a long deadlock.
Also, at the top of the cone, which forms the very front of the jet, the liner has no time to fully accelerate before forming its part of the jet. This produces a fraction of the jet projected at a lower speed than the jet formed behind it. As a result, the early part of the jet fused to form a wider end.
Most jets run at hypersonic speed. The tip moves at 7 to 14 km/s, jet tail at lower speeds (1 to 3 km/s), and slugs at lower speeds (less than 1 km/second). The exact speed depends on the configuration and load confinement, the type of explosive, the material used, and the explosive initiation mode. At a typical speed, the penetration process produces enormous pressures that can be considered hydrodynamic; For a good approach, jets and armor can be treated as an inviscid fluid, incompressible (see, for example,), with their material strength ignored.
Jet temperatures vary depending on the type of shaped charge, cone construction, type of explosive filler. A Comp-B shaped load is loaded with a spherical or pointed cone apex with a copper liner having an average temperature of 428 degrees Celsius with a standard deviation of 67 degrees Celsius. Octol-charge pile has an average jet temperature of 537 degrees Celsius with a standard deviation of 40 degrees Celsius. The lead-coating with an average Comp-B charging is 569 degrees Celsius with a standard deviation of 34 degrees Celsius. lead-tin liners also have a slower tip jet speed of 6.3 km/s.
The location of the load relative to its target is essential for optimal penetration for two reasons. If the load is blown too close then there is not enough time for the jet to develop completely. But the jet was destroyed and spread after a relatively short distance, usually under two meters. In such a deadlock, it breaks into particles which tend to fall and drift off the penetrating axis, so that the successive particles tend to widen rather than deepen the hole. At a very long deadlock, speed is lost due to air resistance, decreasing penetration.
The key to the effectiveness of the hollow charge is its diameter. As penetration progresses through the target, the width of the hole decreases leading to a typical "boxing to finger" action, in which the final "finger" size is based on the original "boxing" size. In general, the shaped charge can penetrate the steel plate as thick as 150% to 700% of its diameter, depending on the quality of the charge. The figure is for the base steel plate, not for composite armor, reactive armor, or any other modern armor type.
Liner
The most common form of liner is conical, with an internal apex angle of 40 to 90 degrees. Different apex angles produce different mass distributions and jet velocities. A small apex angle can cause jet bifurcation, or even jet failure to form at all; this is attributed to the speed of the collapse being above a certain threshold, usually slightly higher than the speed of the bulk sound of ship material. Other widely used forms include hemispheres, tulips, trumpets, ellipses, and conic; various forms produce jets with different speeds and mass distributions.
Liners have been made from many materials, including various metals and glass. The deepest penetration is achieved with dense and ductile metals, and a very common option is copper. For some modern anti-armor weapons, molybdenum and pseudo-alloys of tungsten filler and copper binder (9: 1, so density is 18 Mg/m 3 ) has been adopted. Almost every common metal element has been tried, including aluminum, tungsten, tantalum, uranium, tin, lead, cadmium, cobalt, magnesium, titanium, zinc, zirconium, molybdenum, beryllium, nickel, silver, and even gold and platinum. Material selection depends on the target to be penetrated; for example, aluminum has been found profitable for concrete targets.
In early antitank weapons, copper is used as a liner material. Then, in the 1970s, tantalum was found to be superior to copper, due to its much higher density and very high ductility at high strain levels. Other high-density metals and alloys tend to have weaknesses in price, toxicity, radioactivity, or lack of tenacity.
For deepest penetration, pure metals produce the best results, because they show the greatest ductility, which delayed the breakup of jets into particles when stretched. In the case of refueling well, however, it is important that dense snails or "carrots" can not be formed, because it will clog the hole just penetrate and disrupt the influx of oil. In the petroleum industry, therefore, liners are generally made with powder metallurgy, often from pseudo-alloys which, if unsintered, produce jets composed primarily of dispersed fine metal particles.
Cold pressed cold liners, however, are not water resistant and tend to be brittle, which makes them easily damaged during handling. Bimetallic liners, usually zinc-coated copper, can be used; during the formation of the jet the zinc coating evaporates and the snails are not formed; The disadvantage is the increased cost and dependence of jet formation on the quality of the two-layer bond. Low mellow-point alloys (below 500 Â ° C) solder/braze-like (eg, Sn 50 Pb 50 , Zn 97.6 Pb 1.6 , or pure metals such as lead, zinc or cadmium) may be used; this melts before it reaches the well casing, and the molten metal does not block the hole. Other alloys, binary eutectic (eg Pb 88.8 Sb 11.1 , Sn 61.9 Pd 38.1 , or Ag 71.9 Cu 28.1 ), forming a metal-matrix composite material with a ductile matrix with brittle dendrites; such materials reduce the formation of snails but are difficult to form.
Metal-matrix composites with discrete inclusions of low melting agents are another option; the inclusions either melt before the jet reaches either the casing, the weakening of the material, or serves as a crack nucleation site, and the snail ruptures on the impact. Second phase dispersions can also be achieved with castable alloys (eg copper) with low melting copper metal melting points, such as bismuth, 1-5% lithium, or up to 50% (usually 15-30%) lead; the size of the inclusions can be adjusted by heat treatment. Non-homogeneous inclusion distribution can also be achieved. Other additives may modify the alloying properties; tin (4-8%), nickel (up to 30% and often together with tin), up to 8% aluminum, phosphorus (forming brittle phosphorus) or 1-5% silicon forming a brittle inclusion that acts as the initiation site of the crack. Up to 30% zinc can be added to lower material costs and to form additional brittle phases.
Oxide glass liners produce low-density jets, resulting in fewer penetration depths. Double-layer liners, with a less dense but pyrophoric metal layer (eg aluminum or magnesium), can be used to enhance the burner effect after armor-piercing action; explosive welding can be used to make them, because then the interfaces of the metals are homogeneous, do not contain significant intermetallic amounts, and have no adverse effect on jet formation.
The penetration depth is proportional to the maximum length of the jet, which is the product of the jet tip velocity and time for the particles. The speed of the jet tip depends on the speed of bulk sound in the liner material, the time for the particles depends on the ductility of the material. The maximum jet speed that can be achieved is approximately 2.34 times the speed of sound in the material. Speed ​​can reach 10 km/sec, peaking about 40 microseconds after blasting; the cone tip is subjected to an acceleration of about 25 million g. Jet tail reaches about 2-5 km/sec. The pressure between the jet tip and the target can reach one terapascal. Extremely large pressures make the metal flow fluid, although x-ray diffraction shows the metal remains solid; one theory that explains this behavior proposes a liquid core and a jet-dense sheath. The best materials are cubic metal centered on the face, as they are the most ductile, but even graphite and zero-ductility ceramic cones show significant penetration.
Explosive charges
For optimal penetration, high explosive with high detonation speed and pressure is usually selected. The most common explosives used in high performance anti-armor warheads are HMX (octogen), although never in pure form, as it would be too sensitive. This is usually compounded by several percent of some types of plastic binders, such as in LX-14 polymer binder (PBX), or with other less sensitive explosives, such as TNT, which form Octol. Another common high-performance explosive is the RDX-based composition, again either as a PBX or a mixture with TNT (to form Composition B and Cyclotol) or wax (Cyclonites). Some explosives incorporate aluminum powders to increase the temperature of the explosion and detonation, but this addition generally results in a decrease in the performance of the shaped charge. There have been studies in using high-performance but CL-20 sensitive explosives in charged warheads, but, today, due to their sensitivity, this has been in the form of a compound of PBX LX-19 (CL-20 and Estane binder).
Other features
'Waveshaper' is the body (usually a disc or cylindrical block) of inert material (usually solid or foam plastic, but sometimes metal, probably hollow) inserted into the explosive for the purpose of changing the detonation wave path. The effect is to modify the cone collapse and produce jet formation, with the intention of improving penetration performance. Waveshaper is often used to save space; a shorter charge with a waveshaper can achieve the same performance with longer charging without a waveshaper.
Another useful design feature is sub-calibration , the use of liners that have a smaller diameter (caliber) than the explosive charge. In an ordinary charge, the explosives near the bottom of the cone are so thin that they can not accelerate adjacent liners at speeds sufficient to form effective jets. In the sub-calibrated charge, this part of the device is effectively disconnected, resulting in a shorter load with the same performance.
Defense
During World War II, the precision of the charge construction and the detonation mode were equally inferior with modern warheads. This lower accuracy causes the jet to warp and break at a previous time and hence at a shorter distance. The resulting dispersion lowers the penetration depth for the given cone diameter and also shortens the optimum deadlock distance. Because the allegations were less effective in the larger impasse, the sides and turret skirts (known as Schaarben) were fitted to several German tanks to protect against common anti-tank rifles that were accidentally discovered to provide jet space to disperse and thereby also reducing HEAT penetration.
The use of excess armor skirts on armored vehicles may have the opposite effect and actually increase the penetration of the shaped charge warheads. Due to constraints in the length of the projectile/missile, the built-in stand-off on many warheads is less than the optimal distance. In such cases, skirting effectively increases the distance between the armor and the target, and the warhead blows closer to its optimum impasse. Skirting should not be confused with the armor cage used to damage the projector's RPG-7 fuse system. Armor works by altering the inner and outer oval shapes and shortening the firing circuit between the piezoelectric nose rocket probe and the rear fuse assembly. Armor cage can also cause the projectile to rise or fall on the impact, extending the penetration path for a charge-shaped charge penetration stream. If the nose probe strikes one of the armor cage blades, the warhead will function as usual.
Variant
There are different forms of payload.
Claim in linear form
A linear charge (LSC) has layers with a V-shaped profile and variable length. The layer is surrounded by explosives, the explosives are then encased in a suitable material that serves to protect the explosives and to confine (condense) the blasting. "At the time of detonation, explosive high-pressure wave displacement due to an incident on the side wall causes the LSC metal liner to shrink-create a cutting force." Detonation projects into layers, to form continuous jets, such as blades (planar). The jet cuts any material in its path, to a depth depending on the size and material used in the load. To bypass the complex geometry, there is also a flexible version of the linear charge, this with a coating of lead or high-density foam and flexural material, which also often leads. LSC is commonly used in rolling steel beams (RSJ) and other structural targets, such as in the dismantling of controlled buildings. LSC is also used to separate multistage rocket stages.
Explosively form the penetrator
The explosive penetrator (EFP) is also known as self-forging fragment (SFF), explosively formed projectile (EFP), self-forging projectiles (SEFOP), plate loads, and Misznay-Schardin (MS) loads. EFP uses explosive detonation wave action (and to a lesser extent the driving effect of its detonation product) to project and destroy ductile metal plate or plate (such as copper, iron, or tantalum) into projectile velocities, commonly called snails. This snail is projected toward a target of about two kilometers per second. The main advantage of EFP over conventional shaped charges (eg conical) is its effectiveness at enormous impasse, equal to hundreds of times the diameter of the load (perhaps a hundred meters for practical devices).
EFP is relatively unaffected by first generation reactive armor and can travel up to maybe 1000 charge diameter (CD) before its speed becomes ineffective in penetrating armor due to aerodynamic obstacles, or achieving a target becomes a problem. The impact of EFP ball or slug usually causes large diameter but relatively shallow, at most, multiple CD holes. If EFP punctures armor, spalling and extensively behind the armor effect (BAE, also called behind armor damage, BAD) will occur. BAE is primarily caused by high-speed, high-speed armor and slug injected into the interior space and overpressure explosions caused by these debris. The more modern version of EFP warheads, through the use of advanced initiation modes, can also produce long bars (stretched slicks), multi-slug, and stem/bullet projectiles. Long rods are able to penetrate much larger armor depths, at some BAE losses, multi-slugs are better at defeating light targets or areas and finned projectiles are much more accurate.
The use of this warhead type is mainly limited to light armored areas of major battle tanks (MBT) such as the upper, abdomen and armored backs. Very suitable for non-protected armored fighters (AFV) attacks and in violation of material targets (buildings, bunkers, supporting bridges, etc.). Newer stem projectors may be effective against heavier armored MBT areas. Weapons using EFP principles have been used in combat; "clever" submissions in CBU-97 cluster bombs used by the US Air Force and Navy in the 2003 Iraq war used this principle, and the US Army reportedly experimented with precision-guided artillery shells under the SADARM Project (Search and Destroy Relics). There are also other projectiles (BONUS, DM 642) and rocket submunitions (Motiv-3M, DM 642) and mines (MIFF, TMRP-6) using EFP principles. Examples of EFP warheads are US patent 5038683 and US6606951.
Tandem warhead
Some modern anti-tank rockets (RPG-27, RPG-29) and missiles (TOW 2B, ERYX, HOT, MILAN) use a tandem-shaped warhead, consisting of two separate charges, one in front of another, usually with multiple the distance between them. TOW-2A was the first to use tandem warheads in the mid-1980s, an aspect of the arms that the US Army must disclose under the news media and Congressional pressure resulting from concerns that NATO's anti-tank missiles are ineffective against Soviet-installed tanks New era. The Army revealed that 40 mm of warhead-shaped warheads were mounted on the TOW-2B folded probe tip. Typically, the front load is somewhat smaller than the rear, as it is intended primarily to interfere with ERA boxes or tiles. Examples of tandem warheads are US patent 7363862 and US 5561261. The US Hellfire anti-rudor missile is one of the few that has accomplished the intricate engineering feat of having two charge shaped in the same diameter stacked in one warhead. Recently, a Russian arms company reveals a 125mm round tank gun with two equal diameter shapes one behind the other, but with the rear one offset so that the penetration flow will not interfere with the forward charge charge penetration flow. The reason behind both Hellfire and Russian 125 mm munitions has the same diameter warhead tandem not to increase penetration, but to enhance the outer-armor effect.
Voitenko Compressor
In 1964 a Russian scientist proposed that a shaped charge originally developed to puncture a thick steel armor adapted to the task of accelerating the shock wave. The resulting device, looking a bit like a wind tunnel, is called a Voitenko compressor. The Voitenko compressor initially separates the test gas from the shaped charge with a soft steel plate. When the charge is in the form of a blast, most of its energy is focused on the steel plate, pushing it forward and pushing the test gas in front of it. Ames translates this idea into a self-destructive shock tube. A 66 pound shaped charge accelerated gas in 3-cm glass-walled tube 2 meters in length. The shock wave speed generated is 220,000 feet per second (67 km/sec). The equipment hit by the explosion is completely destroyed, but not before the useful data is extracted. In a typical Voitenko compressor, the shaped charge accelerates the hydrogen gas which in turn accelerates the thin disk to about 40 km/s. A slight modification to the Voitenko compressor concept is super-compressed detonation, a tool that uses compressible fluid or solid fuel in steel compression chambers instead of traditional gas mixtures. A further extension of this technology is the explosive diamond anvil cell, utilizing several opposite charge charges projected on a single encapsulated steel material, such as hydrogen. The fuel used in this device, together with secondary combustion reactions and long blast impulses, produces conditions similar to those found in air-fuel and explosive explosives.
Nuclear bills
The proposed Project Orion nuclear propulsion system will require the development of a nuclear charge for the acceleration of the spacecraft's reaction. The charge-shaped effect driven by nuclear explosions has been speculatively discussed, but is unknown to have been produced in fact. For example, the original nuclear arms designer Ted Taylor was quoted as saying, in the context of a shaped charge, "A one-kiloton fission device, properly formed, can create a hole with a diameter of ten feet a thousand feet into solid rock." Also, a nuclear-driven explosive penetrator appears to be proposed for ballistic missile defense of terminals in the 1960s.
Example in media
- The Future Weapon program of the Discovery channel features Krakatau, a simple shaped weapons system designed by Alford Technologies for the deployment of special operations. The weapon consists of simple plastic outer skin, copper cone, and plastic explosive volume. This device effectively penetrates steel plate 1 inch (25 mm) thick with a distance of several meters.
See also
- Explosive lens
- High explosive explosive head
References
Further reading
External links
- https://www.youtube.com/watch?v=3ZnUZQCeEWw the
- 1945 Popular Science article which finally reveals the secrets of charge shaped weapons; the article also includes a reprint of 1900 Popular Science Professor Munroe's experimental images with roughly shaped content
- Fisix Weapon Elements
- Bomb shaped enlarge Iraqi attack
- Cost Shaping Through the Heaviest Target
- Development of the first Hollow load by Germany in World War II
- Use of shaped pay and protection against them in World War II
Source of the article : Wikipedia
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