EP2921813A1 - Switchable charge variants with hole pattern inserts - Google Patents

Abstract

A reversible cylindrical active charge of a warhead with a tubular support is designed so that it has openings through the holder, that their preferred direction is approximately perpendicular to the inner or outer surface of the holder and the apertures have an opening width in the range of 3 mm to 10 mm, wherein the holder is disposed between an inner part and an outer part of the explosive charge.

Description

1. State of the art

1. 1. Umschaltbare Ladung (Pellet-Methode, EP 2312259, 19.04.2007 )
2. 2. Zylindrische Wirkladung (mehrere Zündketten, DE 102006048299, 12.10.2006 )
3. 3. Umschaltbare Wirkladung (Sintermaterialien, DE 102010048570, 18.10.2010 )

From earlier applications, controllable and / or switchable splinter charges are already known:

1. 1. Switchable charge (pellet method, EP 2312259, 19.04.2007 )
2. 2. Cylindrical active charge (several ignition chains, DE 102006048299, 12.10.2006 )
3. 3. Switchable Wirkladung (sintered materials, DE 102010048570, 18.10.2010 )

Based on these EMs, novel ideas and concepts are introduced, which find their way into extended effective charges.

2nd problem

• "Pellet-Methode" mit vereinfachter Technologie
• "Pellet-Methode" zur Splitter-Subzerlegung
• Einbeziehung Reaktiver Struktur-Materialien (RSM)
• Kombination: Umschaltbarkeit mit Skalierbarkeit

The already known methods for the target-adapted switchability of the fragment effects should be extended, regarding:

• "Pellet method" with simplified technology
• "Pellet method" for splinter sub-decomposition
• Inclusion of Reactive Structure Materials (RSM)
• Combination: switchability with scalability

These new opportunities and technologies did not come from "desk thinking" but required additional numerical simulations or re-attempts to validate those ideas.

3rd solution

The mentioned extensions and innovations are presented and described below.

3.1 "Air Pellet Method" for controlled fragmentation

The pellet method explained in (1) above (see FIG. illustration 1 ) requires a plastic hollow cylinder with holes (holes) filled with explosive charge (HE = High Explosive) pellets ("standard technology"). If a central ignition chain is ignited ( Fig. 1 , not sketched), so the detonation front passes unhindered through these HE pellets. In the plastic cylinder itself, the detonation wave is transformed into a slower shock wave. As a result, numerous detonation sources (in the same number of existing pellets) are produced after the cylindrical pellet holder (multi-point initiation, MPI). These multiple detonation fronts are superimposed, resulting in high voltage spikes, extremely localized at the location of the overlays. In this way, certain patterns of stress concentrations result, which eventually scores the outer cargo envelope. The notches in turn act as predetermined breaking points in the subsequent expansion of the metallic charge envelope. As a result, this decomposes into controlled splinters.

Numerical simulations and experiments have shown, however, that the explosive charge filling of the pellet alternatively also omitted, ie instead can be filled with "air"("newtechnology"). It was not clear from the outset that this was possible. The functionality changes "globally", so in the end not, "local" but already: Namely no detonation front can run through the HE pellets. Instead, at the location of the holes fast dense particle-rays form from the explosive charge swaths, whose velocity lies in the same order of magnitude as the detonation velocity. In this way manages to initiate the explosive charge on the opposite side of the hole. It also results in a multi-point initiation with the same consequences, as if the holes were filled with HE.

Of course, the design parameters have to be adapted to the new situation. So the functionality goes back, if the hole size has fallen below a certain critical threshold. Typical hole sizes are about 5 mm, but this also depends on the outer explosive charge: initiation sensitivity and mechanical strength. In general, it can be said that (as with the HE pellets), the entire initiator system now has to be parametrically matched to one another for the "air pellets".

The big advantage of the new method is that you no longer need to fill the holes with explosive charge, which saves time and money.

Figure 2 shows a sketch (cross section) of a possible charge design with an integrated shadow mask. The two indicated ignition chains (ZK1 and ZK2) allow the above-mentioned switchability. The various explosive charges (HE for booster, transformer plate, outer explosive charge layer and inner main charge) can be identical, depending on the requirement and choice of design parameters, or else (as indicated) may be different.

• Kontrollierte vs. natürliche Splitter, bei einer kontinuierlichen Ladungs-Metallhülle
• Große vs. kleine (zerlegte) Splitter, bei einer Ladungs-Belegung mit großen vorgeformten Splittern (Konstruktionssplitter)

The basic functionality with the two ignition chains is in Figure 3 outlined. Is the central ignition chain ZK2 initiated ( Fig. 3 left), the detonation front runs towards the shadow mask. This results in particle flows in the holes, with a subsequent multi-point initiation. Upon ignition of the front-side ignition chain ZK1 ( Fig. 3 right), the detonation front is forced to run around the integrated detonation waveguide. It results relative to the shadow mask a grazing detonation front. This is not able to form particle beams. There is no multi-point initiation. So you can switch back and forth with this shadow mask method between a structured detonation front, with a pattern of voltage peaks, and a smooth detonation front, without such voltage spikes (dashed lines in the illustrations indicated). Accordingly, this splitter charge can be switched between the splitter modes in a targeted manner:

• Controlled vs. natural splinters, in a continuous charge metal shell
• Great vs. Vs. small (disassembled) fragments, with a charge occupancy with large preformed splinters (construction splitter)

The switchability can still be realized by another possibility. Figure 4 shows sections of the shadow mask and at the same sketchy sketch indicates the rotation or displacement of the two hollow cylinders relative to each other, whose functionality is now described.

The above-described hollow cylinder with the drilled holes was supplemented by another. One of the two hollow cylinders is provided with a rotating and / or sliding mechanism, so that both cylinders can be rotated relative to one another peripherally or axially displaced.

• Kontrollierte vs. natürliche Splitter, bei einer kontinuierlichen Ladungs-Metallhülle
• Große vs. kleine kontrollierte Splitter, bei einer kontinuierlichen Ladungs-Metallhülle
• Große vs. kleine (zerlegte) Splitter bei einer Ladungs-Belegung mit großen vorgeformten Konstruktions-Splitter

The hole patterns in the two hollow cylinders determine the later pattern of controlled fragmentation. Although these hole patterns can now be configured as desired, they should be harmonized relative to one another in such a way that either all holes can be opened or closed (by rotation / displacement), or only part of them can be closed, the rest remains open. In this way, you can (mechanically) switch between the splitter modes:

• Controlled vs. natural splinters, in a continuous charge metal shell
• Great vs. Vs. small controlled splinters, in a continuous charge metal shell
• Great vs. Vs. small (disassembled) chips at a charge occupancy with large preformed construction splitter

Experiments with the method of "air pellets" have shown that, depending on the choice of the parameters for the external explosive charge such as: initiation sensitivity / strength / mechanical properties, etc., this explosive charge from the swath flow can also be purely mechanically perforated, without the it comes to an immediate point-like initiation. This then takes place at a later date (but possibly too late). Such a punctiform initiation is roughly comparable to the initiation by a shaped charge sting. In such a situation, one can then either adjust these HE parameters (unless other requirements prohibit this), or alternatively the hole design in the shadow mask.

Figure 5 indicates such a possibility. The holes taper from the larger diameter D towards the outer explosive charge, to the smaller diameter d. The swath flow is now slowed down and mitigated. Depending on the diameter ratio D / d, this reduction is different and can thus be adapted to the sensitivity of the explosive charge.

Another possible embodiment is, if one closes the holes with webs / "grafting" at the end of the channel, as in Figure 6 outlined as an example. Then the swath flow is stopped and transferred into a shock wave through this web. On the other hand, then the explosive is initiated by this shock wave. The bar can be integrated directly into the pellet holder and made of the same material. But it can also be made of denser material (eg metals such as steel) and then by the higher impedance (density multiplied by shock wave velocity) the point-like initiation facilitate. The "plug" can also be designed as a flying plate, the hole then serves as an acceleration tube. Further embodiments of this method are conceivable, but should not be further elaborated here.

Figure 7 Finally, shows a sketch (cross-section) of a further charge design with an integrated shadow mask, but this time with asymmetric holes relative to the detonation front. The second middle detonation chain has been replaced by a second front detonation chain. The direction of the detonation front can now be selected via the ignition of ZK1 or ZK2. The different functionality of the holes depending on the direction of the detonation front is in Figure 8 discussed.

In Figure 8 on the left comes the detonation front from above. The swaths flow into the asymmetrical holes and initiate punctiform the outer explosive charge. It forms a structured detonation front. Ignite the other CC, the detonation front comes from below. The swaths would now have to flow around almost 180 ° around the hole edges. However, the shadow mask material is chosen so that the holes are plastically deformed by the pressure fronts (arrows) and thereby closed. The swath flow is therefore prevented and only the shock wave propagating through the shadow mask material initiates an unstructured detonation front in the outer explosive charge.

Of course, this method can also be combined with the asymmetrical holes with the tapering of the holes discussed above or with the bridge method.

The methods with the shadow masks are described here in radial charge configurations with cylindrical metal sheaths. However, they can also be used in axial charge configurations with metal assignments (disk-shaped). The procedure for the axial application is analogous to the radial application discussed in detail herein, and therefore will not be discussed further.

3.2 "Air Pellet Method" for splinter subdivision

Instead, as explained above, to use the fast particle beams for explosive charge initiation, they can also be used for splitter sub-decomposition. For this purpose, the hole cylinder is enlarged in diameter and brought directly into contact with the outer metal shell ( Figure 9 ). This consists not now of a continuous metal shell, but rather of individual preformed splinters. The number and pattern of the preformed construction splitter (K-splitter) of the charge jacket harmonize with those of the holes in the shadow mask, so that each individual splitter is acted upon by a particle beam.

The material quality of these K-splitters is matched to the intensity of the particle beams, so that a direct application of the "hard" particle beam completely subdivides the K-splitters. Experiments have shown that this sintered metals are particularly well suited. The sintering can be adjusted so ("weak") that the cohesion of the sintered particles is not sufficient to survive such aggressive radiation (see. Fig. 10 left: at central initiation with ZK2).

• Intakte vs. subzerlegte vorgeformte Konstruktions-Splitter

However, the detonation front does not come head-on, but grazing (sh. Fig. 10 right: at the front side ignition with ZK1), so no particle beams (or at least only those of lesser intensity) are formed, which are not sufficient to change the K-splinters in their integrity, ie they fly away as whole undivided fragments. So you can switch back and forth between two splitter modes:

• Intact Vs. subdivided preformed construction splitter

Very small splinters have a large surface / volume ratio and are therefore slowed down in the air very quickly, whereas large K-splinters largely unchecked and thus fly very far. That You can switch the effective radius in large limits (for example, 100 m vs. 2000 m).

Another embodiment of this design is in Figure 11 outlined. This time, the design of the holes in the shadow mask is not symmetrical, but asymmetrical with respect to the directions of the two detonation fronts. The central ignition chain was replaced by an opposite frontal ignition chain.

Figure 12 shows sections of the shadow mask of Figure 11 and outlines the different mode of action of the holes, depending on which ZK was ignited, ie from which direction the detonation fronts come (dashed, whose propagation is indicated by numbers).

If ZK1 is ignited, the particle beams from the detonation front can flow into the holes facing the front ( Fig. 12 Left). The brittle and porous splinter material does not withstand this load, it disassembles. On ignition of ZK2, however ( Fig. 12 right), the particle beam would have to flow around corners of almost 180 °, which is not possible. Rather, the pressure load on the shadow mask in the region of the holes is so large that the mask material (plastics or low-strength metals) flows away and closes the holes. There is no high radiation load due to the swath particles and the fragment remains integer and flies away as a whole.

Another possibility to realize a switchover consists in the application of the above-mentioned double shadow mask, consisting of relatively movable double cylinders (sections of the double shadow mask and their functionality in Fig. 13 ). Again, you can by relative Rotation and / or displacement of the two shadow masks to each other (advantageously the inner relative to the outer), either all, or only a part of the holes close or leave open, depending on the design and harmonization of the two hole pattern.

• Intakte vs. subzerlegte vorgeformte Konstruktions-Splitter
• Teilweise intakte vs. teilweise subzerlegte vorgeformte Konstruktions-Splitter

You can switch back and forth between splitter modes using this method:

• Intact Vs. subdivided preformed construction splitter
• Partially intact vs. partially subdivided preformed construction splitter

3.3 "Air Pellet Method" with Reactive Structure Materials (RSM)

In addition to explosive charges as fast energy suppliers, metallically inert but chemically reactive materials have increasingly gained in importance for use in active systems. These materials, because of their mostly high strength and density, can also be used as (reactive) structural materials (RSM, e.g., as charge hulls).

• Inter-Metalle (z.B. Ni/Al)
• Metastabile Intermolekulare Verbindungen oder Thermite (z.B. FeO₂/Al)
• Verbindungen von Metall-Halogeniden (z.B. Mo/Ti & Teflon)
• Poröse, reaktive Sintermetalle (z.B. Mo, WSM)

The following reactive materials can be distinguished:

• Inter-metals (eg Ni / Al)
• Metastable Intermolecular Compounds or Thermites (eg FeO ₂ / Al)
• Compounds of metal halides (eg Mo / Ti & Teflon)
• Porous, reactive sintered metals (eg Mo, WSM)

So it is mostly about metal compounds, which either as explosive charges, their oxygen (general oxidizer) carry along (at least parts thereof), or to those who need the oxygen of the air. The former must be triggered by the shockwave generated by the detonation front (so-called shock-induced reaction). The latter will heated and subdivided by the shock wave only to then react with the oxygen of the air.

This offers further variations with the technologies presented above:

Shock-induced reaction

• Streifende, unstrukturierte Detonationsfront, die Stoßwellen geringerer Amplituden erzeugt
• Frontale, strukturierte und aggressive Detonationsfront, die entsprechend harte (zumeist lokal wirkende) Stoßwellen mit Spannungsspitzen hoher Amplituden erzeugt

The above-mentioned various switchability technologies provide opportunities (see especially Section 3.2) to switch between two detonation fronts:

• Striking, unstructured detonation front that generates shock waves of lesser amplitudes
• Frontal, structured and aggressive detonation front that generates correspondingly hard (mostly local) shock waves with high amplitude voltage peaks

• Stoßwellen-induziert reagierender Splitter, der im Nahabstand Blast-Energie liefert, im Fernabstand keine Wirkung hat, da er abreagiert ist.
• Nicht zur Reaktion getriggerter Splitter, der im Nah- und Fernabstand wie ein normaler mechanischer Splitter wirkt.

If one harmonizes the reactive material in such a way that a hard shock wave triggers the reaction (shock wave-induced), whereas a weak grazing one does not harmonize, then one can switch back and forth between the splitter modes:

• Shock-induced reacting splitter, which provides near-distance blast energy, has no effect at a distance because it is reacted.
• Non-responsive splitter that acts as a normal mechanical splitter at near and far distances.

Sub-decomposition and subsequent reaction with atmospheric oxygen

The various switchable technologies mentioned above (see in particular section 3.2) provide possibilities for leaving intact or subdividing sintered splinters. Here is, for example, the possibility discussed above with particle beams. The splitter will now turn off Reactive material sintered so that it is subzero by the activated particle beam, or in closed hole pattern, this particle beam is not exposed and therefore remains intact. A thorough sub-decomposition is necessary, if you want to let the generated reactive metal particles with the Luftsaurestoff abreact. The shock wave heats up the material to the extent that the reaction is triggered with the oxygen.

• Subzerlegung des Splitters mit anschließender Nachverbrennung mit Luftsauerstoff
• Keine Subzerlegung; Splitter wirkt wie normaler inerter vorgeformter Splitter.

So you can switch back and forth between the splitter modes:

• Sub-decomposition of the splitter with subsequent afterburning with atmospheric oxygen
• No sub-decomposition; Sliver looks like normal inert preformed splinter.

• Splitterhülle von ausschließlich inertem, ausschließlich reaktivem bzw. Mischungen zwischen beiden. Vorgeformte Splitter bzw. kontinuierliche Metallhülle

mit den Möglichkeiten der Sprengladungs-Beeinflussungen andererseits:

• Detonationsfronten / Stoßwellenfronten mit oben genannten Technologien

eine enorme Erweiterung des Spektrums der Umschaltbarkeit der Splitterwirkungen.In summary, therefore, the possibilities of combining material on the one hand:

• Splinter shell of exclusively inert, exclusively reactive or mixtures between the two. Preformed splinters or continuous metal shell

with the possibilities of the explosive charge influences on the other hand:

• Detonation fronts / shockwave fronts with the above technologies

a tremendous expansion of the spectrum of switchability of fragmentation effects.

Another combination option should now be mentioned in the last point.

3.4 Combination of switchability and scalability

Figure 14 outlined (exemplarily for all other possible combinations) an action system that combines the switchability with the shadow mask method (as described in Section 3.2), with the scalability already known from the art, using an integrated detonation cord.

It can be assumed that an integrated, for example, central detonation cord as in Figure 14 implied, can implement a blasting charge deflagrativ with low energy release rate, without causing a detonation. The second technology outlined here is the switchable subdivision by particle beams.

But it can just as well be used the multi-point initiation shadow mask described above, so as to cause a superposition of detonation fronts with controlled disassembly of the shell. It is up to the resourceful designer to use any other combination of the technologies presented to extend the range of adaptability and switchability.

At this point only one possibility is described, as exemplarily in Figure 14 shown.

• Die stirnseitige ZK1 initiiert eine streifende Detonationsfront. Sie bildet keine Partikelströmung in den Löchern und beschleunigt nur die vorgeformten Splitter
• Die mittige ZK2 initiiert eine mittige Detonationsfront, die frontal zur Außenhülle läuft. In den Löchern entstehen Partikelströmungen, die die entsprechend schwach gesinterten vorgeformten Splitter subzerlegen.
• Alternativ: Bei Einsatz einer inneren Lochmaske entsteht eine Multi-Punkt-Initiierung, welche eine kontinuierliche Metallhülle kontrolliert zerlegen würde.
• Die gegenüberliegende ZK3 initiiert schließlich die Detonationsschnur, die die Sprengladung deflagrativ umsetzt, die vorgeformten Splitter integer lässt, und sie auf weitaus geringere Geschwindigkeit beschleunigt.
• Weitere Kombinationsmöglichkeiten bieten sich durch den (optional gemischten) Einsatz von vorgeformten Splittern aus Reaktivem Material (optional gemischt mit Inertem Material).

You have here three ignition chains (ZK):

• The frontal ZK1 initiates a grazing detonation front. It does not form any particle flow in the holes and only accelerates the preformed fragments
• The central ZK2 initiates a central detonation front, which runs frontally to the outer shell. In the holes arise particle flows, which subdroplate the corresponding weakly sintered preformed splinters.
• Alternatively: When using an inner shadow mask, a multi-point initiation occurs, which would disperse a continuous metal shell in a controlled manner.
• The opposing ZK3 finally initiates the detonation cord that deflagrates the explosive charge, allowing the preformed splitter to be integer, and accelerating it to much lower velocity.
• Further combination possibilities are offered by the (optionally mixed) use of preformed splitters made of reactive material (optionally mixed with inert material).

Further possibilities arise with ignition of two (or all) ignition chains with corresponding relative time delays.

• Zündung von ZK3 und nach einer Zeitverzögerung von ZK1: Ein unterer Teil der Ladung deflagriert und der obere detoniert: Kombination von langsamen und schnellen vorgeformten Splittern. Die Zeitverzögerung bestimmt das Mischungsverhältnis.
• Zündung von ZK3 und nach einer Zeitverzögerung von ZK2: Ein unterer Teil der Ladung deflagriert und der obere detoniert: Kombination von langsamen vorgeformten Splittern und schnellen subzerlegten Splittern (die nachreagieren könnten, bei Einsatz von RSM). Die Zeitverzögerung bestimmt das Mischungsverhältnis.

Examples:

• Ignition of ZK3 and after a time delay of ZK1: Deflagration of a lower part of the charge and detonation of the upper one: Combination of slow and fast preformed splinters. The time delay determines the mixing ratio.
• Ignition of ZK3 and after a time delay of ZK2: Deflagration of a lower part of the charge and detonation of the upper one: Combination of slow preformed splinters and fast subdivided splinters (which could react after using RSM). The time delay determines the mixing ratio.

reference numeral

A

Recess, breakthrough

d, D

Transverse dimension of A

H

bracket

HE1, HE2

Parts of the explosive charge

HE3

distributed charge

HU

shell

L

longitudinal axis

O

Surface of the holder

T

Transverse web (e)

T1, T2

Parts of the bracket

ZK1, ZK2, ZK3

ignition devices

α

Inclination angle of the breakthroughs

Claims (10)

Switchable cylindrical active charge of a warhead comprising a tubular and at least one part holder (H) with a plurality of recesses (A), wherein holder (H) within a fragment-forming sheath (HU) of the warhead is arranged, wherein the holder of a the Detonationsfront strongly damping material, and wherein in the effective charge at least two ignition devices (ZK1, ZK2) in the region of the longitudinal axis (L) of the active charge are arranged,
characterized in that the recesses (A) are designed as apertures through the holder (H) whose preferred direction is approximately perpendicular to the inner or outer surface (O) of the holder, and which have an opening width in the range of 3 mm to 10 mm, and wherein the holder (H) between an inner part (HE1) and an outer part (HE2) of the explosive charge is arranged. Switchable cylindrical active charge according to claim 1, characterized in that the openings (A) have a tapering from the inner to the outer surface of the holder transverse dimension (D, D)). Switchable cylindrical active charge according to claim 1, characterized in that the openings (A) in the region of the outer surface (O) of the holder (H) arranged transverse webs (T). Switchable cylindrical active charge according to claim 3, characterized in that the transverse webs (T) consist of metal. Switchable cylindrical active charge according to claim 1, characterized in that the preferred direction of the apertures (A) with respect to the perpendicular to the inner or outer surface (O) of the holder (H) has an acute angle (α). Switchable cylindrical active charge of a warhead comprising a tubular and at least one part holder (H) with a plurality of recesses (A), wherein holder (H) is disposed within a fragment-forming shell (HU) of the warhead, wherein the holder (H) consists of a material strongly attenuating the detonation front, and wherein in the active charge at least two ignition devices (ZK1, ZK2) are arranged in the region of the longitudinal axis (L) of the active charge,
characterized in that the recesses (A) are designed as apertures (A) through the holder (H) whose preferred direction is approximately perpendicular to the inner or outer surface (O) of the holder, and which has an opening width in the range of 3 mm to 10 mm, and wherein the holder (H) on the inside of the shell (HU) rests positively. Switchable cylindrical active charge according to claim 6, characterized in that the sheath (HU) consists of sintered material. Switchable cylindrical active charge according to claim 1 or 6, characterized in that the holder (H) of two nested and mutually repositionable parts (T1, T2) and each of the parts (T1, T2) has a plurality of openings (A). Switchable cylindrical active charge according to claim 8, characterized in that in at least a part (T1, T2) of the holder (H), the openings (A) have a tapered from the inner to the outer surface of the holder transverse dimension (d, D). Switchable cylindrical active charge according to claim 8, characterized in that the local distribution of the openings (A) on the repositionable parts (T1, T2) of the holder (H) is the same or different.

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