A method of making a liner for a shaped charge or an explosively formed projectile may include making a liner substrate using a 3d additive manufacturing process. Stable flight velocity is strongly influenced by liner thickness variability. Improvised explosively formed projectile typical of devices deployed in iraq device construction constructed from 6 to 9 inch diameter steel pipe, one end of which is sealed with a welded. Explosively formed projectiles efps have great potential to cleanly and safely.
The openpoled dished liner is made of a metal more dense than a metal of the cavitation pin. Explosively formed projectiles efps are used as antiarmour warheads, and their use in top attack antiarmour weapons is increasing. Interesting series of infographics about just what is an improvised efp. The explosively formed projectile efp as a standoff. Underwater simulations and experiments were conducted to highlight.
Results of hole diameter d 2 it is obvious from figure 6 that, for different charge diameters, with the increase of standoffs, the variation trend of hole diameter which caused by efp with steel liner or copper liner are nearly the same. Analytical and numerical method of c velocity fields for. Mach wave control in explosively formed projectile warhead. Analytical performance study of explosively formed projectiles. The invention is an explosively formed projectile efp. Despite the fact that explosively formed projectiles efps of the same design were fired into each recovery method, the projectiles collected using the two methods differed in shape, size, weight. Explosively formed penetrator efp and fragmenting warhead us patent 6619210. Surviving an explosivelyformed projectile attack in iraq. The purpose of this paper is to investigate the applicability of the lsdyna software using a lagrangian formulation in the jet formation, flight and penetration of improvised explosively formed projectiles efps. Numerical simulation of penetration by explosively.
Each individual liner forms a separate penetrator, so that the liners are. In order to determine undeformed measurements for the explosively formed projectiles, five projectiles were recovered using a soft. The main concepts of the dclps and image measurement theory are introduced in detail. The explosively formed projectile efp as a standoff sea. Us8434411b2 cluster explosivelyformed penetrator warheads. On detonation of an explosive charge, an explosively formed projectile is formed from two separate metal elements, an openpoled dished liner and a cavitation pin. Study on explosively formed projectiles test system. This model is based on a generic efp with an aspect ratio of 1. There are signs that explosively formed penetrators a type of improved weapon known as a superbomb for its ability to pierce armored vehicles are spreading further in afghanistan. An arrangement for production of explosively formed projectiles consists of casing with explosive contents, a fuse arranged on the base side and a metal insert which covers the explosive contents on the head side, in which case the projectile acquires winglike symmetrical folds on its tail by means of the following. At various laboratories, it was found that the transformation was closely related to extensive plastic flow occurring at high strain rates. Finite elements simulation of improvised explosively. The main objective of an explosively formed projectile designed for underwater applications is. An analytical model for calculating mach wave parameters is presented based on three.
An explosive is used to propel a liner material of low mass at speeds in excess of 5 times the speed of sound. Pdf explosively formed projectile softrecovery force. Research on the skirt tail explosively formed projectile stable. King lost his foot in iraq to an explosively formed projectile, a weapon that can go through armored trucks. Underwater simulations and experiments were conducted to highlight the use of efps.
To be even more precise, explosively formed projectiles efp are weapons of war that, before hitting their target, use high explosives to alter. The effects select physical parameters have on an explosively formed projectiles performance by phillip russell mulligan a thesis presented to the faculty of the graduate school of the missouri university of science and technology in partial fulfillment of the requirements for the degree master of science in explosives engineering 2011. The effects of the flyer plates radius of curvature on the performance of an explosively formed projectile. Explosively formed projectile how is explosively formed projectile abbreviated. The list of acronyms and abbreviations related to efp explosively formed projectile.
To verify and evaluate its design and performance, efp testing is an essential procedure. An explosively formed penetrator efp, also known as an explosively formed projectile, a selfforging warhead, or a selfforging fragment, is a special type of shaped charge designed to penetrate armor effectively at standoff. Explosively formed projectile efp wide angle cones and other liner shapes such as plates or dishes do not jet, but give instead an explosively formed projectile or efp. The law of influenced material of liner is researched by numerical simulation. In order to make quite sure that the projectile shows no asymmetries, a new technique was developed to form projectiles with star.
Numerical results dealing with different properties of the efps have been validated with a significant number of field tests. Penetration evaluation of explosively formed projectiles. The explosively formed projectile efp is an important type of warhead technology. Det developed and built such a device for rapidly cutting through metal hedgehog obstacles, as might be encountered on a beach protected from amphibious assault. Investigation on interaction of explosively formed. Multiple explosively formed projectiles mefp forming process is numerically simulated with different liner material,such as copper, aluminum, iron and so on. Pdf the ultimate goal of weapon system employing an explosively formed penetrator efp is to defeat a target at the longest standoff. Numerical solution techniques have advanced to the point where calculations of explosively. Thus, an explosively formed projectile efp, due to its configuration. Bomb attacks killed nine american troops yesterday, north of baghdad. The subsequent projectile is capable of penetrating the steel of armoured vehicles and inflicting significant injury to any enclosed personnel.
Explosively formed projectile efp is a new branch of the shaped charge technology. Results, however, depend to a very large extent on the experience of the code user and familiarity with the capabilities and eccentricities of. Explosively formed projectiles efps have great potential to cleanly and safely defuse underwater ammunition. Shaped charges sc have been used in high explosive antitank heat munitions and the mining industry since world war ii. The cavitation pin lies on the openpoled dished liner longitudinal axis and in. As the name suggests, the effect of the explosive charge.
There are many methods that can be used for the clearance of underwater ammunition. Efp warhead consists of synchronous threepoint explosive circuit and main charge, as shown in fig. It is developed as an antisolid target technology in recent decades. The ultimate goal of weapon system employing an explosively formed penetrator efp is to defeat a target at the longest standoff. Explosive devices, and in particular cluster explosivelyformed penetrator warhead devices. An explosively formed penetrator efp, also known as an explosively formed projectile, a selfforging warhead, or a selfforging fragment, is a special type of shaped charge designed to penetrate armor effectively. The law that the formation parameters of mefp such as velocity, lengthdiameter ratio and radial dispersion angle,influenced by the density and ductility of. Results of an experimental and computational investigation on the effects of the shape of an explosively formed projectile on the penetration into various targets are presented. Segmented kinetic energy explosively formed penetrator assembly abstract a segmented, kinetic energy projectile is formed by stacking several liners in a single warhead, for effectively producing a longer penetrator capable of greatly enhancing penetration. Modelling the formation of explosively formed projectiles. The explosively formed projectile efp as a standoff sea mine neutralization device, journal of. Projectile efp affect its performance is crucial in determining what. Research and development in the area of explosively formed.
The effects select physical parameters have on an explosively. Segmented kinetic energy explosively formed penetrator. In the present paper the authors propose and describe a finite element based numerical model of a medium calibre explosively formed projectile efp device. Aip conference proceedings proceedings of the 17th biennial international conference of the aps topical group on shock compression of condensed matter. Us9482499b1 explosively formed projectile efp with. Thus, to avoid breakage at the efp nose, the pressure behind the mach wave should be controlled. Explosively formed projectile efp protection module. Identifying how changes in the physical parameters of an explosively formed. In this paper, theory of the exploding forming effects of.
An explosively formed penetrator efp, also known as an explosively formed projectile, a selfforging warhead, or a selfforging fragment, is a special type of. Its not known, yet, whether these weapons responsible were explosively formed projectiles the socalled superbombs. The projectile forms by dynamic plastic flow and has a velocity of kmsl. In all such techniques, the primary aim is to defuse underwater ammunition without detonation. Armatec provides lightweight efp shields designed to stop explosively formed projectiles, and deliver enhanced protection to the vehicle and crew. Authors model the formation process of explosively formed projectiles. Investigation on interaction of explosively formed projectile with multilayer medium targets 3. Any time of the day sometimes at night arterial routes the triggerman needs to see his target coming so he can arm the efp urban streets are less suitable for attack placement may be interrupted and higher risk of collateral overt military and security. Numerical and experimental study on the formation and dispersion. Pdf formation of explosively formed penetrator with fins and its. If one thinks of the hammer blow of an oldtime, brawnyshouldered blacksmith on a glowing piece of iron, one gets a mental image of explosive forming, rather than of a fine machinist using a precise machine to turn screw threads on a part of a gun. This paper will address the experimental results of the impact of 101. Influence of liner material on formation of multiple. Explosively formed penetrators for dummies interesting series of infographics about just what is an improvised efp.
Pdf the explosively formed projectile efp as a standoff sea. Study influence of materials liner, he and detonation parameters. West point cadets create bionic foot rockets that are fired on us and on the iraqis that are made in iran as recently as 2008. Arrangement for production of explosively formed projectiles. The surface finished portion may be electroplated with a metal to form a multilayer liner. Introduction nowadays, the efp warheads are present in many systems that expect appropriate modernization andor optimization. Explosively formed projectiles efps have great potential to cleanly. A model is presented to help in the design of a softcatch device for safely recovering explosively formed penetrators efps. Multiple explosively formed penetrator mefp warhead technologies have a very. Impact effects of explosively formed projectiles on normal. A linear explosively formed penetrator lefp, a counterpart to a linear shaped charge, is capable of projecting a massive wide metal blade instead of a narrow jet or compact slug. Explosively formed projectile softrecovery force analysis laurin bookout a 1, phillip mulligan b, jason bairdd b a applied research associates, 2760 eisenhower ave.
Aspects of dynamic recrystallization in shaped charge and. An explosively formed penetrator efp, also known as an explosively formed projectile, a selfforging warhead, or a selfforging fragment, is a special type of shaped charge designed to penetrate armour effectively at standoff distances. Formation of explosively formed penetrator with fins and. Under a shock wave, a shaped charge sc liner or an explosively formed projectile efp device transforms into a jet and a slug. The simulation studies of explosively formed projectiles.
Along with the shape transformation, there is evidence of changes in hardness, strength, grain configuration, microstructure. At least a portion of the surface of the liner substrate may be surface finished. Explosively formed projectile encyclopedia article. Era generally consists of an era sandwich and an outer steel cover to protect it from unintended initiation.
Arshad, design and simulate explosively formed projectiles efps, ms thesis. Cluster explosivelyformed penetrator warheads download pdf. Research on the skirt tail explosively formed projectile stable shaping technology. As one of the toughest projectiles to defeat, efps act as a serious threat to force survivability. It is very important to research the velocity and morphology change of efp in their movements to improve its performance. Lsdyna theoretical manual, livermore software technology corporation. Results of experimental investigations of the influence of charge length and confinement on the velocity, form and terminal ballistic performance of explosively formed projectiles are presented. Numerical results had successfully described the formation process and. This work applies a newly developed dualcolor laser photographic system dclps to diagnose the efp in a flight. In order to do this, an efp must be aerodynamically stable so as to strike the target at a small angle of obliquity, and the decay velocity per. Five projectiles were recovered using a soft recovery system to determine the average mass and nose shape of the projectiles. Explosive reactive armour era is used to protect the armoured vehicles against chemical energy warheads and longrod penetrators. Velocity of efp changes quickly with the change of efp shape. Explosively formed projectile softrecovery force analysis laurin bookouta1, phillip mulliganb, jason bairddb aapplied research associates, 2760 eisenhower ave.
Formation of explosively formed penetrator with fins and its flight. Roxana delgado became a caregiver when her husband, army sgt. An explosively formed penetrator efp, also known as an explosively formed projectile, a selfforging warhead, or a selfforging fragment, is a special type of shaped charge designed to penetrate armor effectively at standoff distances. This research is intended to expand the available data on explosively formed projectile impacts and determine which, if any, of the existing equations can be used or slightly modified to predict penetration depths. Improvised explosively formed projectile typical of devices deployed in iraq formation of the projectile the heat and shock wave from the detonation of the explosive projects the steel copper.
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