RU2274818C1 - Dynamic protection component(modifications) - Google Patents

Abstract

FIELD: defensive equipment, in particular, components of protection against shaped-charge projectiles.

SUBSTANCE: the dynamic protection component is made in the form of a multilayer plate with outer layers of an inert high-density substance, and an inner layer of an explosive, whose thickness is smaller than the critical thickness of detonation propagation, initiated at a pressure of a shock wave exceeding the preset level. As a modification of the offered construction is the dynamic protection component made in the form of a multilayer plate with outer layers of n inert high-density substance, and inner layers a part of which is made of layers of an explosive initiated at a pressure of a shock wave exceeding the preset level, whose thickness is smaller than the critical thickness of detonation propagation, and the other part - of chemically inert materials, if the number of the explosive layers exceeds two, layers of a chemically inert material are positioned between them.

EFFECT: reduced level of explosion action of the dynamic protection component on the protected object.

4 cl, 4 dwg

Description

The invention relates to defense technology and can be used in the development of devices for protection against the effects of shells with cumulative charges, in particular from cumulative warheads of the tandem type.

Known protective devices containing an inner layer of explosive, lined with two outer layers of inert material of high density, in particular metal, referred to as "dynamic protection" or "reactive armor", providing protection against the action of cumulative jets formed when the cumulative charges are fired or from kinetic shells (see, for example, the FRG patent No. 2008156, dated 02.21.1970; the French patent No. 2436361, dated 13.03.1974; the UK patent No. 1581125 dated 01/01/1925 dated 01/01/1974). The specified "dynamic protection" in the form of containers called "dynamic protection elements" (EDZ) (see, for example, Dynamic anti-cumulative protection / BV Voytsekhovsky, VL Istomin // Combustion and Explosion Physics, 2000, v. 36 , No. 6, pp. 87-90; or the monograph “Explosion Physics” under the editorship of L.P. Orlenko, vol. 3, T.2, M. - FIZMATLIT, 2002) is used as a part of devices for protecting obstacles from various shells, especially cumulative shells and mines, by installing an EDZ at an angle of about 30-60 ° to the expected direction of movement of the cumulative jet (CS). The cumulative jet generated when the cumulative charge is triggered initiates an explosive placed between the inert layers, causing them to throw almost in the direction normal to the EDZ surface. Moreover, due to the presence of an angle between the direction of movement of the EDZ wall and the CS, their interaction occurs, leading to the destruction of all or most of the CS, which reduces the damage ability of these cumulative shells and mines.

It is also known to place several layers between the walls of the EDZ, some of which are layers of explosive, and some are layers of chemically inert materials (see Combination of Inert and Energetic Materials in Reactive armor Against Shaped Charge Jets / A. Holzwarth, K.Weimann // Proc. 19 ^th International Symposium on Ballistics, 7-11 May 2001, Interlaken, Switzerland / - p. 1523-1530).

Non-explosive anti-cumulative dynamic protection constructions are known in which instead of an explosive layer, an inner layer of a chemically inert material called a “filler”, such as plastic, rubber, paraffin, or a mixture based on them, is placed between the outer inert layers of a material with high density . When a CS penetrates through such an “non-explosive” EDZ, a diverging shock wave (HC) is formed in the filler, under the influence of which the material of the outer layers surrounding the CS penetration site is accelerated. Due to the rapid decrease in pressure in the shock wave (shock wave attenuation), the acceleration of the outer layers is localized near the point where the CS reaches the element of non-explosive remote sensing. Despite the limited size of the zone in which the accelerated movement of the outer layers of the EDZ with an inert filler occurs, the decrease in the depth of the armor-piercing action due to the destruction of the high-speed part of the CS can reach 65-70% (see. Explosive anti-cumulative dynamic protection / S.A. Bodrov, V .A. Grigoryan, N.S. Dorokhov, I.F. Kobylkin, D.A. Rototaev // In the collection of reports of the II scientific conference of the Volga regional center RARAN "Modern methods of designing and development of missile and artillery weapons." - Sarov, RFNC-VNIIEF, 2003. - p.3 73-382). It is believed that the use of non-explosive EDZ is most promising when creating devices against the effects of cumulative charges placed in containers for transporting radioactive materials, cars and other structures - where the own reservation of the structure or its contents prevent the use of a large number of explosive EDZ in the protection, which are nothing more than explosive charges, the group operation of which can lead to destruction of the protected structure, greater than what will be produced and one shaped charge effect.

Known devices for protecting barriers from shells (see, for example, US patent No. 5070754 from 10.12.91), which combined EDZ containing explosives, and EDZ containing an inert filler.

Closest to the claimed solution on the technical nature and the achieved result is a protective device from shells, especially from cumulative charges, according to US patent No. 4368660 from 01/18/1983. The design of the dynamic protection element according to this patent is made in the form of a flat element formed by a layer of explosive, which is coated on the front and back with layers of inert high-density substance. Explosive for EDZ is selected from the condition of being capable of initiating detonation in it by a shock wave of a given intensity, but should be resistant to open fire fire, bullets, small fragments and other "weak" sources of a shock wave. In particular, in the said patent description it is proposed to use explosive compositions with a detonation velocity of more than 2000 m / s containing hexogen, octogen, tetryl, ten, TNT or their mixtures capable of initiating when exposed to a shock wave with a pressure of 10 kbar .

It is known (see K.K.Andreev, A.F. Belyaev. Theory of explosives. - M .: State Scientific and Technical Publishing House OBORONGIZ, 1960, pp. 193-210) that detonation is a self-sustaining exothermic reaction propagating through an explosive substance with a supersonic constant speed. The process of the occurrence of detonation is determined by the fulfillment of a number of necessary initial conditions, such as, for example, the level of the acting shock, charge temperature, the value of the initial density, the amount of impurities, etc. One of these necessary initial conditions is the pressure level of the initiating shock wave used in the prototype patent.

However, providing only the required pressure level of the initiating shock wave does not guarantee the occurrence of a detonation wave propagating through the explosive. It is necessary that a number of conditions are satisfied that ensure the propagation of a self-sustaining exothermic reaction. In particular, on the basis of a large number of experimental studies of the detonation of explosives (see Explosion Physics, monograph, under the editorship of K.P. Stanyukovich, 2nd ed., Revised. - M.: Chief ed. Mat. literature of the Nauka publishing house. - pp. 212-235) it can be considered established that a cylindrical charge of any explosive substance has a certain limit size (critical diameter d _cr ), exceeding which guarantees the propagation of detonation in charge with constant speed.

In charges, the diameter of which is less than d _{cr, the} propagation of detonation in charge is impossible under any influence of the pressure of the initiating shock wave. The value of d _cr for a given explosive is not constant and depends on the charge density, characteristics of the shell material and its thickness, as well as the amount of inert impurities.

For flat explosive charges, there is also the concept of “critical thickness”, above which detonation propagation conditions are ensured throughout the layer. The critical thickness of a plane charge, as well as the critical diameter of cylindrical charges, depends on the chemical nature of the explosive, the presence and thickness of the outer layers, and also on the characteristics of the material of the outer layers.

The value of the critical diameter (critical thickness) is determined experimentally for specific conditions for the placement of the explosive in the developed design by determining the place where the detonation process stops in the charge, the diameter (thickness) of which continuously or steps decreases in the direction from the initiation site.

Minimum critical diameters known from the literature are primary explosives, such as lead azide (0.01-0.02 mm), maximum explosive mixtures, such as, for example, mixtures of TNT with ammonium nitrate (12-15 mm). Moreover, the introduction of inert additives into the explosive composition can lead to a significant change in the value of the critical diameter (critical thickness).

The technical solution described in US patent No. 4368660, as the closest to the claimed technical essence and the achieved technical result, is selected as the prototype.

Signs of the prototype, common with the claimed design: the element of dynamic protection is made in the form of a multilayer plate with the outer layers of an inert high-density substance and the middle layer of explosive, initiated when the pressure of the shock wave exceeds a predetermined level.

The specified prototype has several disadvantages that lead to a decrease in its effectiveness. In particular, a significant drawback of the design of the prototype is the need to select requirements for the properties of explosives, providing, when the conditions for initiation of detonation are met, the propagation of detonation throughout the explosive of the dynamic protection element. This leads to an increase in the level of explosive effects of EDZ on the protected object and to a decrease in the level of protection against the breakdown action of cumulative ammunition of the tandem type.

The technical task of eliminating the above drawback is to reduce the level of explosive effects of EDZ on the protected object and to increase the level of protection against the breakdown action of cumulative ammunition of the tandem type.

Indeed, if under the influence of a cumulative jet or other high-speed projectile in accordance with the EDZ performed in accordance with the prototype patent, the conditions for initiating detonation of the middle layer of explosives are fulfilled, then the detonation propagates throughout the middle layer. In this case, the inert walls of the EDZ are ejected from the protected zone and the container containing the EDZ is destroyed. As a result, in no more than a millisecond, the protective ability of the device in the area of the indicated EDZ is neutralized. This disadvantage of the prototype patent is taken into account when developing tandem-type ammunition containing two successively cumulative charges - the leading and the main. The action of these ammunition is based on the ability of the cumulative jet of the leading charge to produce the EDZ neutralization process described above, and the ability of the cumulative jet of the main charge to defeat an obstacle that has lost its protection in the area where the neutralized EDZ is located.

In contrast to the well-known dynamic protection element, made in the form of a multilayer plate with the outer layers of an inert high-density material and the middle layer of explosive, initiated when the shock wave pressure exceeds a predetermined level, in the proposed embodiment 1 dynamic protection element: the explosive layer is made of a thickness less than the critical thickness of the propagation of detonation, and in the proposed option 2, the element of dynamic protection is made of a set of internal alternating layers of explosive eschestva and inert material, the layers of explosive disposed between layers of chemically inert material and each explosive layer is formed in thickness less than the critical thickness of detonation propagation.

Technical solutions containing features that distinguish the claimed solutions from the prototype are not known and do not follow explicitly from the prior art. This allows us to consider that the claimed solutions are new and have a sufficient inventive step.

The essence of the proposed technical solutions is illustrated by graphic images on which:

figure 1 schematically depicts an element of dynamic protection made according to the invention (option 1) at the moment of operation of the leading charge of the cumulative ammunition of the tandem type;

figure 2 illustrates the element of dynamic protection made according to the invention (option 1) at the time of operation of the main charge of the cumulative ammunition of the tandem type;

figure 3 illustrates an embodiment 2 of a dynamic protection element;

4 illustrates an embodiment 1 of a dynamic protection element.

The dynamic protection element (figure 1), made according to option 1 of the proposed invention, contains an inner layer of explosives 1, the thickness of which is less than the critical thickness at which detonation propagates through this explosive. On the front and back sides, the inner layer of explosive 1 is covered with layers of an inert high-density substance 2, 3. The cumulative jet formed when the leading charge 4 of the cumulative tandem type ammunition is triggered, moves in the direction of the axis 5 of the ammunition, directed at an angle of attack of 6 to the path of its movement 7. Upon collision with the EDZ, the cumulative jet of the leading charge 4 creates a shock wave 9 in the internal layer of explosive 1, the pressure of which in region 10 exceeds the explosive initiation pressure, which causes explosive energy release in layer 1 and the image vanie gaseous products of the explosion.

The composition of the cumulative ammunition of the tandem type includes the main charge 8, detonated after a few hundred microseconds after the operation of the leading charge 5 (figure 2). By the moment of undermining the main charge 8, the ammunition is displaced along the trajectory 7 by a distance equal to the product of the speed of movement by the time of the delayed operation. The cumulative jet 11 formed when the main charge 8 is triggered moves along a new trajectory 12 and acts on the part of the EDZ, which was not subjected to shock-wave loading when the leading charge was triggered and did not receive local destruction of layer 13 of explosive 1 and inert outer layers 2 and 3.

Embodiments of the proposed EDZ are possible with placement of a multilayer inner layer consisting of several layers between the outer layers of high-density materials, some of which are explosive layers having a thickness less than the critical detonation propagation thickness, and some are chemically inert layers. Moreover, if there are more than two layers of explosive, layers of chemically inert materials are located between them. In particular, FIG. 3 illustrates the embodiment of the dynamic protection element according to embodiment 2, wherein the inner layer contains two layers of explosive 1 and 14, each of which has a thickness less than the critical thickness of the detonation propagation, separated by a layer of chemically inert material 15. Image of FIG. .4 shows the embodiment of the dynamic protection element according to option 1, in which the inner layer contains one layer of explosive 1 and two surrounding layers 16 and 17 of chemically inert materials.

The differences in the response of the proposed EDZ from the prototype are based on the features of the response to the initiating effect of the shock wave of the explosive charge, the size of which is less than critical. If a shock wave with a pressure above the pressure necessary to initiate detonation is affected by a explosive with a diameter (thickness) less than critical to a local region of the charge, then all explosives in this region will experience explosive transformation. However, for any arbitrarily large pressure value in the indicated zone, the process of detonation propagation along the charge will stop as soon as the pressure in the shock wave becomes less than that required for initiation.

The proposed element of dynamic protection works as follows.

Option 1. When hit (figure 1) in the element of dynamic protection of the cumulative jet formed by the leading cumulative charge 4 of the tandem type of ammunition in the local area where the impact is carried out, shock waves 9 diverging from the point of impact are formed in the explosive, the pressure in which exceeds pressure required to initiate detonation. When a shock wave moves in an explosive, the pressure in which exceeds the detonation initiation pressure, an explosive energy release process is realized in the explosive, which leads to the movement of inert layers 2 and 3 in directions close to the normal to the EDZ surface. The inert layers of the EDZ interact with high-speed sections of the CS of the leading charge 4. In this case, the interaction process proceeds more intensively and in a larger region than in the case of using EDZ, the middle layer of which is made of inert material, which provides greater protective ability than those known from the description analogues of the proposed device. Due to the fact that the explosive layer thickness is chosen less than the critical detonation propagation thickness, a detonation wave is not formed. When the initiating shock wave moves over the charge, the pressure behind it quickly decreases to values lower than the detonation initiation pressure, and therefore the detonation process stops or goes into the combustion process, the propagation velocity of which is several millimeters per second. The size of the region of detonation transformation 10 is several thicknesses of the explosive layer 1. The rest of the EDZ, which is outside the zone of detonation transformation 10, contains the explosive in a healthy state. In the event that after a time of the order of several hundred microseconds in this part of the EDZ, the action of the cumulative jet 11 of the main cumulative charge 8 creates a new shock wave, the pressure in which will also exceed the initiation pressure, this will lead to a repeated process of the operation of the same EDZ and a decrease in breakdown ability of the main charge of 8 and the entire tandem cumulative ammunition in general.

The above description of the process of interaction of the cumulative ammunition of the tandem type with the proposed EDZ is realized under the dynamic conditions of the approach of the ammunition to the surface of the object protected by the dynamic protection element, since in order to fulfill the conditions of a stable flight, the ammunition needs to move with a certain angle of attack of 6, which is usually several degrees. This turns out to be sufficient so that, at the aforementioned level, the response time of the leading and main charges of the tandem-type cumulative ammunition (several hundred microseconds), the point of contact with the main charge is shifted relative to the point of contact with the leading charge by a distance of several tens of millimeters. In this case, the condition is ensured that the CS of the main charge falls into a part of the explosive layer that has not experienced detonation transformation, which, in comparison with the EDZ prototype, leads to the repeated operation of the proposed EDZ and a decrease in the breakdown ability of the tandem-type cumulative ammunition.

Option 2. The implementation of the EDZ according to option 2 provides the possibility of varying the speed of throwing the walls of the container and, thereby, allows you to additionally change the level of explosive impact on the protected object. So, when the dynamic protection element, a cumulative jet formed by the leading cumulative charge 4 of the tandem type of ammunition, similar to option 1, gets into the local area where the impact occurs, shock waves will form in the layers of explosive 1, shown in figure 3, pressure in which exceeds the pressure that initiates detonation. In this case, an energy release process takes place in the explosive of each layer, which leads to the throwing of layers 2 and 3, in directions close to the normal to the surface of the EDZ with velocities higher than option 1, since in comparison with it the energy of the explosive transformation is released two times more. The inert layers of the EDZ 2 and 3 interact with the high-speed sections of the CS of the leading charge 4. In this case, the interaction process proceeds more intensively, and therefore most of the cumulative jet of the leading charge 4 is destroyed. In this case, the presence of an inert layer in the chemical layer between explosive layers 1 and 14 with respect to the material 15 provides separate flow in these layers of the explosive process, which (similar to option 1) prevents the development of the detonation process outside the area where the pressure of the shock waves 9 created by the cumulative effect trui leading charge 4, higher than the pressure required to initiate detonation.

The implementation of the inner multilayer layer according to figure 4, when the outer layers of inert high-density material 2 and 3 are separated from the explosive layer 1 by layers 16 and 17 of chemically inert material, respectively, provides the ability to reduce to the required level the values of the throwing speed of the external inert layers of the EDZ and, thereby, reduces the level of explosive impact on the protected object.

A similar reduction in the level of impact on the protected object can be achieved by placing a layer of chemically inert material on one side of the explosive layer and by orienting the dynamic protection element with the indicated side in the direction of the protected object.

It is possible to produce an inner layer from a larger number of alternating layers of explosive and layers of a chemically inert material.

Thus, the use of the proposed design variants of the EDZ leads to an increase in the level of protection against the damaging effects of cumulative ammunition of the tandem type while reducing the explosive effect on the protected barrier.

Claims (4)

1. The element of dynamic protection, made in the form of a multilayer plate with the outer layers of an inert high-density substance and the inner layer of explosives, initiated when the pressure of the shock wave exceeds a predetermined level, characterized in that the explosive layer is made less than the critical thickness of the propagation of detonation . 2. The element according to claim 1, characterized in that on both sides of the explosive layer are layers of chemically inert materials that are adjacent to it. 3. The element according to claim 1, characterized in that on one side of the explosive layer is a layer of chemically inert material that is adjacent to it. 4. The element of dynamic protection, made in the form of a multilayer plate with the outer layers of an inert high-density substance and an inner layer of explosive, initiated when the pressure of the shock wave exceeds a predetermined level, characterized in that it is equipped with additional inner layers of explosive, between the layers of explosive are layers of a chemically inert material, and the layers of explosive are made with a thickness less than the critical propagation thickness d detonation of.

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