A warhead structure using the offset angle of the detonation point to form an inclined tail fin EFP

Abstract

The present invention discloses a warhead that forms an inclined tail fin EFP by utilizing a detonation point offset angle: it comprises a polygonal charge column, a polygonal charge liner, and a shell; the warhead is based on a traditional spherical charge liner, and the charge liner is processed into a polygon. The schematic diagram of the charge structure is shown in FIG1 , and the scheme adopts a same-caliber structure. The warhead adopts multi-point detonation on the charge end face, and the detonation point offset angle α is the angle between the line connecting the charge end face center and the detonation point and the perpendicular line from the charge end face center to one side of the polygon; the detonation radius is Ry. The warhead of the present invention can form an EFP with an inclined tail fin, and the inclined tail fin can generate a reverse torque during flight, thereby greatly improving flight stability and reducing target deviation.

Description

Technical Field

[0001] The invention belongs to the field of ammunition, in particular to a warhead structure which utilizes a detonation point offset angle to form an inclined tail fin EFP. Background Art

[0002] Explosively formed projectiles (EFPs) have high penetration performance and are insensitive to blast height, playing an important role in terminal-sensitive projectile weapon systems. In order to improve the flight stability of explosively formed projectiles (EFPs), tail-fin EFPs have become the focus of EFP research in recent years. Previous research results by some scholars have shown that tilting the tail during flight can generate a reverse torque, causing the EFP to rotate to a certain extent, thereby greatly improving flight stability and reducing target deviation.

[0003] At present, the formation method of straight tail EFP is mainly studied by changing the warhead detonation mode, special-shaped shell structure, setting waveform adjuster, patch on the liner and other technical means, but there are few reports on the method of forming EFP with inclined tail. Therefore, in order to further improve the flight stability of EFP, it is necessary to design a warhead structure that can form EFP with inclined tail. Summary of the invention

[0004] The object of the present invention is to provide a warhead structure which utilizes the offset angle of the detonation point to form an inclined tail fin EFP, so that the tail fin EFP produces a certain rotation, thereby further improving the flight stability and shooting accuracy of the EFP.

[0005] The technical solution to achieve the purpose of the present invention is:

[0006] A warhead structure using a detonation point offset angle to form an inclined tail fin EFP, comprising a shell, a charge, a multi-charge cap and a detonation point, wherein the charge is arranged in the shell, and the detonation point is arranged above the charge;

[0007] The charge column and the multi-charge cover are both polygonal, and the number of detonation points is consistent with the number of sides of the charge column or the multi-charge cover;

[0008] The connection lines of multiple detonation points form a polygonal structure;

[0009] The angle between the line connecting the center of the warhead and the detonation point and the perpendicular line between the center of the warhead end face and the length of the side of the warhead end face constitutes the detonation point offset angle α, which satisfies: 0<α<180° / n, where n is the number of detonation points.

[0010] Compared with the prior art, the present invention has the following significant advantages:

[0011] A six-point detonation method is adopted on the hexagonal molded charge. By changing the detonation offset angle to form an EFP with an inclined tail fin, the flight stability and shooting accuracy of the EFP are further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the hexagonal warhead structure of the present invention; Figure 2 It is a schematic diagram (cross-sectional view) of the hexagonal charge structure of the present invention;

[0013] Figure 3 It is a schematic diagram of the detonation radius and offset angle of six-point detonation;

[0014] Figure 4 This is a schematic diagram of the distribution of CJ detonation wave and Mach wave on the liner surface;

[0015] (a~b) are schematic diagrams of the case without bias angle and the case with bias angle respectively;

[0016] Figure 5 It is a diagram of the forming process of the EFP with inclined tail;

[0017] (a~c) are the front view, rear view and top view respectively. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0019] Combination Figure 1-Figure 4 The warhead structure of the present invention, which forms a tilted tail fin EFP by using a detonation point offset angle, comprises a shell 1, a hexagonal charge column 2, a hexagonal charge liner 3 and six detonation points 4, wherein the tilted tail fin EFP is formed by a six-point detonation method;

[0020] The shell, charge column and charge liner are all hexagonal in shape. The charge column and charge liner have the same caliber structure. The detonation radius R is set on the top end face of the hexagonal charge column. y The warhead is detonated at the same time at six detonation points with an offset angle of α (0<α<30°). After detonation, a spherical detonation wave will be formed inside the charge. Due to the collision of the detonation wave, a Mach wave will be formed. The surface of the charge liner will be subjected to the pressure load of the detonation wave and the Mach wave. The part with high pressure forms the edge of the tail EFP body and the rudder of the tail. Due to the existence of the detonation point offset angle α, the edge of the charge liner will produce a certain rotational angular velocity, that is, the edge of the charge liner will form an oblique tail during the EFP molding process.

[0021] Under the six-point detonation condition, a spherical detonation wave will first be formed inside the charge. Due to the collision of the detonation wave, a Mach wave will be formed. A Mach wave action area 5 and a CJ detonation wave action area 6 will be formed inside the charge. Then, the surface of the liner will be subjected to two different pressure loads. Since the Mach wave pressure is greater than the CJ detonation pressure, the pressure load on the Mach wave action area 5 of the liner is greater than the pressure load on other units of the liner. Therefore, during the entire process of the liner flipping and crushing, the Mach wave action area 5 has the highest crushing speed and is always at the front end, forming the ridge of the tail fin EFP body and the rudder of the tail fin. When there is no detonation point offset angle α, the middle part of the edge of the liner 3 has a faster speed than other parts of the edge. Due to the symmetry of the Mach wave action zone 5 on the liner, a straight tail fin will be formed at the edge of the liner 3 during the EFP molding process; when there is a detonation point offset angle α, the edge part of the liner 3 corresponding to the Mach wave action zone 5 obtains a faster speed than other edge parts. Since the Mach wave action zone 5 is not symmetrical on the liner at this time, the edge part of the liner 3 will produce a certain rotational angular velocity, that is, the edge part of the liner 3 will form an oblique tail fin during the EFP molding process. Figure 4 (a~b) are schematic diagrams of the case without bias angle and the case with bias angle, respectively.

[0022] When the warhead adopts other polygonal structures such as a quadrilateral or octagon, the number of detonation points is consistent with the number of sides of the charge or the liner, and the detonation offset angle α satisfies 0<α<180° / n, an EFP with inclined tail fins can also be formed, and the number of tail fins is consistent with the number of sides of the charge or the liner.

[0023] The ANSYS / LS-DYNA program was used to perform numerical simulation on the tail-stabilized EFP forming. The ALE algorithm was used for calculation, the multi-material Euler algorithm was used for explosives and air, and the Lagrangian algorithm was used for the liner. Fluid-solid coupling was set between the Euler unit and the Lagrangian unit. TrueGrid was used to perform finite element mesh division on the main charge, liner, and shell. In order to accurately simulate the process of the polygonal liner forming the tail-type EFP, a full model was established for simulation; a non-reflective boundary was set on the outer layer of the air to simulate the explosion in an infinite airspace. The unit of the liner would be excessively distorted during the crushing process, and an hourglass was set for the liner PART. In order to prevent unit penetration during the deformation of the liner grid, single-sided automatic contact was set.

[0024] EFP molding process Figure 5As shown, (a~c) are the front view, rear view, and top view, respectively. When the charge is detonated from six points on the top, the detonation wave first collides and then forms a Mach wave and then moves toward the liner. The center of the liner is accelerated first, and the edge of the liner is accelerated later. Due to the effect of the Mach wave, different speeds are obtained at the edge of the liner. At the same time, due to the difference in speed, the edge part will produce a certain rotational angular velocity, as shown in the liner forming result at 40μs; as the liner is continuously crushed and deformed, regular "wrinkles" appear; after t=140μs, the EFP forming is basically maintained, and finally an EFP with an inclined tail is formed.

Claims

1. A warhead structure using a detonation point offset angle to form an inclined tail fin EFP, comprising a shell, a charge, a charge liner and a detonation point, wherein the charge is arranged in the shell, and a detonation point is arranged above the charge; It is characterized in that The charge column and charge liner are both polygonal, and the number of detonation points is consistent with the number of sides of the charge column or charge liner; The connection lines of multiple detonation points form a polygonal structure; The angle between the line connecting the center of the warhead end face and the detonation point and the perpendicular line between the center of the warhead end face and one side of the warhead end face constitutes the detonation point offset angle α, which satisfies: 0°<α<180° / n , n is the number of detonation points.

2. The warhead structure of the EFP using the detonation point offset angle to form an inclined tail fin according to claim 1, characterized in that: The medicine column and medicine liner are both regular polygonal.

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