Composite shell for weight reduction of EFP warhead
By adopting a composite shell structure, combined with high-density restraints and lightweight structural parts, the problem of excessive weight of the EFP warhead is solved, and the effect of significantly reducing the weight of the warhead while maintaining the molding performance unchanged.
Patent Information
- Application Number
- CN202422211138.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-10
- Publication Date
- 2025-07-01
- Estimated Expiration
- 2034-09-10
AI Technical Summary
The existing EFP warhead shell materials are mainly steel No. 45 steel, which causes the shell weight to account for 35% to 70% of the total weight, limiting the weight loss of the warhead, and the use of light metal or thinned shell will affect the molding performance of EFP.
The composite shell structure is adopted, consisting of high-density restraints and lightweight structural parts. The composite shell is threaded and is used to load the EFP warhead with a covered medicine column. The high-density constraints are made of No. 45 steel, and the lightweight structural parts are made of aluminum alloy to ensure the strength and lightweight of the shell.
Without affecting the forming characteristics and power performance of EFP initial speed and compactness, the weight of the EFP warhead is effectively reduced, the shell weight is reduced by about 54%, and the entire EFP warhead is reduced by 36%.
Smart Images
Figure CN223050551U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of warhead of ammunition, and particularly relates to a composite shell for reducing the weight of an EFP warhead. Background Technique
[0002] The structure of a typical Explosively Formed Projectile (EFP) warhead is as Figure 1 shown, and it mainly consists of a pressure screw 1, a liner 2, a charge column 3, a shell 4, a detonating device 5, etc. During operation, the detonating device 5 is detonated, detonating the high-energy explosive charge column 3 loaded in the EFP warhead. The detonation wave causes the liner 2 to turn over and be extruded to form a high-speed and stable flying EFP damage element, whose forming speed is about 1500 - 2500 m / s. It can fly over a long distance to hit and penetrate an armored target, and is suitable for various anti-armor weapon platforms such as missiles, rockets, and guided projectiles. It is the focus of warhead research in various countries around the world. Among them, the shell 4 is an important part of the EFP warhead. A large number of studies at home and abroad have shown that its performance has an important impact on the forming and power of the EFP.
[0003] With the continuous improvement of the lightweight requirement of the weapon system, weight reduction of the warhead has gradually become the focus of warhead design. At present, in order to improve the forming performance such as the initial velocity and density of the EFP, the commonly used shell material is steel such as 45# steel. The shell thickness exceeds 3 mm, and the shell weight accounts for about 35% - 70% of the total weight of the EFP warhead, which restricts the weight reduction of the warhead. If lightweight metals such as aluminum alloy are used as the shell or the shell thickness is further reduced, although the weight of the warhead can be reduced, the forming of the EFP is affected, and it is difficult to obtain a high-speed and dense EFP, which seriously restricts the improvement of the warhead power. For large-caliber and high-overload EFP warheads, this problem is particularly obvious. Content of the Utility Model
[0004] (1) Technical Problems to be Solved
[0005] The technical problem to be solved by the utility model is: how to provide a composite shell for reducing the weight of an EFP warhead, which can effectively reduce the weight of the EFP warhead without affecting the forming characteristics and power performance such as the initial velocity and density of the EFP.
[0006] (2) Technical Solution
[0007] To solve the above technical problems, the utility model provides a composite shell for reducing the weight of an EFP warhead, and the composite shell includes two parts: a high-density restraint member and a lightweight structural member;
[0008] The high-density restraint member and the lightweight structural member are connected to form a composite shell for loading the covered charge column of the EFP warhead.
[0009] Among them, the high-density constraint member and the lightweight structural member are connected by a threaded method.
[0010] Among them, the high density and lightweight in the high-density constraint member and the lightweight structural member are relative to each other, that is, when comparing the high-density constraint member with the lightweight structural member, the material density of the high-density constraint member is higher than that of the lightweight structural member, and the material of the lightweight structural member is lighter than that of the high-density constraint member.
[0011] Among them, the high-density constraint member is a machined circular tubular metal part, and the material is selected as steel with strength and density meeting the requirements of EFP forming;
[0012] Threads are processed at both ends of the high-density constraint member. The external thread at one end is matched with the internal thread of the lightweight structural member, and the internal thread at the other end is matched with the external thread of the pressure screw.
[0013] Among them, the material of the high-density constraint member is selected as 45 steel.
[0014] Among them, the lightweight structural member is a machined quasi-circular tubular metal part, and the material is selected as a lightweight and easy-to-process metal to meet the overall bullet structure strength requirements; the inner and outer diameters are the same as those of the high-density constraint member, and the inner surface of the upper end of the shell is processed with threads to be matched with the external threads of the high-density constraint member.
[0015] Among them, the material of the lightweight structural member is selected as aluminum alloy.
[0016] Among them, the thickness of the composite shell is not less than 3 mm, and the length of the high-density constraint member is not less than 1 / 3 of the total length of the composite shell.
[0017] Among them, the high-density constraint member is selected as 45 steel, with a density of 7.83 g / cm 3 , an inner diameter of 130 mm, a thickness of 6.5 mm, a length of 45 mm, and a threaded end of about 10 mm.
[0018] Among them, the lightweight structural member is selected with an inner diameter of 130 mm, a thickness of 6.5 mm, a length of 45 mm, and a threaded end of 10 mm; the lightweight structural member is made of 2A12 aluminum alloy with a density of 2.71 g / cm 3 , its inner diameter and thickness are the same as those of the high-density constraint member, the length is 85 mm, the threaded end is 10 mm, and the formed composite shell has an inner diameter of 130 mm, a thickness of 6.5 mm, and a height H of 120 mm;
[0019] Correspondingly, the warhead charge is selected as 8701 explosive, the liner is selected as tantalum-tungsten alloy, with a diameter of 130 mm and a height of 100 mm for the charge with the liner; the end-face single-point initiation method is adopted.
[0020] (III) Beneficial effects
[0021] Compared with the prior art, the key points of the present utility model are as follows:
[0022] 1. A composite shell for weight reduction of an EFP warhead, which is composed of two parts: a high-density restraint member and a lightweight structural member. The high-density restraint member and the lightweight structural member are connected by means of threads or the like to form a composite shell for loading the covered charge of the EFP warhead.
[0023] 2. The high-density restraint member is a machined circular tubular metal part, and the material can be selected from steels such as 45# steel, and the strength and density meet the requirements for EFP forming; threads are processed at both ends, one end is matched with the internal thread of the lightweight structural member, and the other end is matched with the external thread of the pressure screw;
[0024] 3. The lightweight structural member is a machined quasi-circular tubular metal part, and the material can be selected from lightweight and easy-to-process metals such as aluminum alloy, meeting the requirements for the overall bullet structure strength; the inner and outer diameters are the same as those of the high-density restraint member, and the inner surface of the upper end of the shell is processed with threads to be matched with the external thread of the high-density restraint member.
[0025] Compared with the prior art, the present utility model has the following advantages and beneficial effects:
[0026] A composite shell for weight reduction of an EFP warhead proposed by the present utility model separates the restraint function and the structural function of the EFP warhead shell. Through the independent design and composite integration of the restraint member and the structural member, the purpose of effectively reducing the weight of the EFP warhead is achieved without affecting the forming characteristics and power performance such as the initial velocity and density of the EFP. The utility model has a simple structure and good processability, and can be applied to EFP warheads of various platforms and different usage environments such as missiles, rockets, gun-launched ammunitions, and loitering ammunitions. Description of the Drawings
[0027] Figure 1 It is a schematic diagram of the structure of a typical EFP warhead.
[0028] Figure 2 It is a schematic diagram of the structure of the weight-reducing composite shell.
[0029] Figure 3 It is a schematic diagram of the division of the effective charge of the EFP warhead.
[0030] Figures 4(a) and 4(b) are schematic diagrams of the comparison of simulation forming results. Among them,
[0031] Figure 4(a) is a traditional all-steel structure shell; Figure 4(b) is a weight-reducing composite shell. Detailed Embodiment
[0032] To make the objectives, contents, and advantages of the present utility model clearer, the following further describes in detail the specific implementation manners of the present utility model with reference to the accompanying drawings and embodiments.
[0033] To solve the above technical problems, the present utility model provides a composite shell for reducing the weight of an EFP warhead, which is characterized in that the composite shell includes two parts: a high-density constraint member and a lightweight structural member;
[0034] The high-density constraint member and the lightweight structural member are connected to form a composite shell for loading the covered charge of the EFP warhead.
[0035] Among them, the high-density constraint member and the lightweight structural member are connected by a threaded method.
[0036] Among them, the high density and lightweight in the high-density constraint member and the lightweight structural member are relative to each other, that is, when comparing the high-density constraint member and the lightweight structural member, the material density of the high-density constraint member is higher than that of the lightweight structural member, and the material of the lightweight structural member is lighter than that of the high-density constraint member.
[0037] Among them, the high-density constraint member is a machined circular tubular metal part, and the material is selected as steel that meets the EFP forming requirements in terms of strength and density;
[0038] Threads are processed at both ends of the high-density constraint member. The external thread at one end is matched with the internal thread of the lightweight structural member, and the internal thread at the other end is matched with the external thread of the compression screw.
[0039] Among them, the material of the high-density constraint member is selected as 45 steel.
[0040] Among them, the lightweight structural member is a machined quasi-circular tubular metal part, and the material is selected as a lightweight and easily machined metal to meet the overall bullet structure strength requirements; the inner and outer diameters are the same as those of the high-density constraint member, and the inner surface at the upper end of the shell is processed with threads to be matched with the external threads of the high-density constraint member.
[0041] Among them, the material of the lightweight structural member is selected as aluminum alloy.
[0042] Among them, the thickness of the composite shell is not less than 3 mm, and the length of the high-density constraint member is not less than 1 / 3 of the total length of the composite shell.
[0043] Among them, the high-density constraint member is selected as 45 steel, with a density of 7.83 g / cm 3 , an inner diameter of 130 mm, a thickness of 6.5 mm, a length of 45 mm, and about 10 mm at the threaded end.
[0044] Among them, the lightweight structural member is selected with an inner diameter of 130 mm, a thickness of 6.5 mm, a length of 45 mm, and a threaded end of 10 mm; the lightweight structural member is made of 2A12 aluminum alloy with a density of 2.71 g / cm 3 , its inner diameter and thickness are the same as those of the high-density restraint member, with a length of 85 mm and a threaded end of 10 mm. The formed composite shell has an inner diameter of 130 mm, a thickness of 6.5 mm, and a height H of 120 mm;
[0045] Correspondingly, the warhead charge uses 8701 explosive, the liner uses tantalum tungsten alloy, with a diameter of 130 mm and a height of 100 mm for the charge with the liner; the end-face single-point initiation method is adopted.
[0046] Example 1
[0047] A composite shell for reducing the weight of an EFP warhead in this example mainly consists of a high-density restraint member 01 and a lightweight structural member 02.
[0048] Among them, the high-density restraint member 01 is made of 45 steel with a density of about 7.83 g / cm 3 , the inner diameter 2R is 130 mm, the thickness is 6.5 mm, the length is 45 mm, and the threaded end is about 10 mm;
[0049] The lightweight structural member 02 is selected with an inner diameter 2R of 130 mm, a thickness of 6.5 mm, a length of 45 mm, and a threaded end of about 10 mm; the lightweight structural member 02 is made of 2A12 aluminum alloy with a density of about 2.71 g / cm 3 , its inner diameter and thickness are the same as those of the high-density restraint member 01, with a length of 85 mm and a threaded end of about 10 mm. The formed composite shell has an inner diameter 2R of 130 mm, a thickness of 6.5 mm, and a height H of 120 mm. Correspondingly, the warhead charge uses 8701 explosive, the liner uses tantalum tungsten alloy, with a diameter of 130 mm for both, and a height of 100 mm for the charge with the liner; the end-face single-point initiation method is adopted.
[0050] According to the effective charge theory of detonation physics, not all explosive charges will drive the liner to do work after the bottom of the charge is detonated. When the charge is detonated from the bottom, as the detonation wave propagates, rarefaction waves enter both axially and radially, causing the detonation products to scatter backward and laterally. Since the curvature radius of the liner in the EFP warhead is relatively large and the crown height is very small, the liner can be approximately considered as a flat liner. Let the radial rarefaction wave velocity be V and the time to reach the central axis be t. Then t = R / V = L / D, where R is the charge radius, L is the limit effective charge length, and D is the explosive detonation velocity. We can obtain: L = DR / V. Through a large number of experiments, it is measured that the propagation velocity of the radial rarefaction wave towards the charge axis is half of the explosive detonation velocity, that is, V = D / 2. Thus, L = 2R can be obtained. According to the geometric relationship, the angle κ between the effective charge line at the non-detonating end and the charge side line is 26.6°. When the charge has a casing, the formula for calculating the effective charge is as follows:
[0051]
[0052] In the formula: N / C represents the mass ratio of the casing to the explosive per unit length.
[0053] Considering the end effect at the detonating end, it is equivalent to digging out a cone at the end of the charge, and the height of the cone is equal to the charge radius R. According to the geometric relationship, the angle κ between the effective charge line at the detonating end and the charge side line is 45°. Thus, the division of the effective charge amount of the EFP warhead under the traditional all-steel structure casing and the weight-reducing composite casing is as Figure 3 shown. Among them, the solid line area is the effective charge of the EFP warhead under the all-steel structure casing, and the dotted line area is the effective charge of the EFP warhead under the weight-reducing composite casing.
[0054] According to the formula for calculating the effective charge, reducing the weight of the casing per unit length will increase the angle κ, thereby reducing the effective charge amount and affecting the collapse velocity of the liner microelement. According to the law of the detonation-driven liner microelement ejection motion, the change in the mass at the bottom of the charge has a significant impact on the liner collapse mechanism. From Figure 3 it can be seen that by controlling the mass of the casing at the bottom of the charge, the charge amount at the bottom of the effective charge can be ensured, and then the collapse state of the liner can be ensured, and the forming velocity and density of the EFP can be ensured. Calculating the effective charge amount of the implementation example, the effective charge at the bottom of the two casings is exactly the same, and the difference in the entire effective charge amount is less than 10%.
[0055] Verified by numerical simulation, the EFPs formed by detonation driving under the traditional all-steel structure shell and the weight-reducing composite shell with the same structure are shown in Fig. 4(a) and Fig. 4(b). The tail diameter of the EFP formed under the weight-reducing composite shell is slightly larger, but the overall configuration is similar. The forming speeds of both reach 1750 m / s. Compared with the weight of 5.48 kg of the traditional all-steel structure shell, the weight of the weight-reducing composite shell is only 2.51 kg. Without affecting the forming characteristics and power performance such as the initial velocity and density of the EFP, the weight of the shell is reduced by about 54%, and the weight of the entire EFP warhead is reduced by 36%.
[0056] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.
Claims
1. A composite shell for reducing the weight of an EFP warhead, characterized in that: The composite shell includes two parts: a high-density restraining part and a light-weight structural part; The high-density restraint member and the light-weight structural member are connected to form a composite shell for loading the EFP warhead shrouded charge.
2. The composite shell for reducing the weight of an EFP warhead according to claim 1, characterized in that: The high-density restraining member and the light-weight structural member are connected by threads.
3. The composite shell for reducing the weight of an EFP warhead according to claim 1, characterized in that: The high density and light weight in the high-density constraint parts and lightweight structural parts are relative to each other, that is, when comparing the high-density constraint parts with the lightweight structural parts, the material density of the high-density constraint parts is higher than that of the lightweight structural parts, and the material of the lightweight structural parts is lighter than that of the high-density constraint parts.
4. The composite shell for reducing the weight of an EFP warhead according to claim 1, characterized in that: The high-density restraint is a machined tubular metal part, made of steel with strength and density that meet the EFP forming requirements; The high-density restraint member is processed with threads at both ends, the external thread at one end cooperates with the internal thread of the lightweight structural member, and the internal thread at the other end cooperates with the external thread of the pressing screw.
5. The composite shell for reducing the weight of an EFP warhead according to claim 4, characterized in that: The material of the high-density restraint is 45 steel.
6. The composite shell for reducing the weight of an EFP warhead according to claim 1, characterized in that: The lightweight structural part is a machined quasi-circular tubular metal part, made of lightweight and easy-to-process metal that meets the full-elastic structure strength requirements; the inner and outer diameters are consistent with the high-density restraint part, and the inner surface of the upper end of the shell is processed with threads that match the external threads of the high-density restraint part.
7. The composite shell for reducing the weight of an EFP warhead according to claim 6, characterized in that: The lightweight structural member is made of aluminum alloy.
8. The composite shell for reducing the weight of an EFP warhead according to claim 6, characterized in that: The thickness of the composite shell is not less than 3 mm, and the length of the high-density restraint is not less than 1 / 3 of the total length of the composite shell.
9. The composite shell for reducing the weight of an EFP warhead according to claim 8, characterized in that: The high-density restraint is made of 45# steel with a density of 7.83 g / cm 3 , inner diameter is 130mm, thickness is 6.5mm, length is 45mm, and the threaded end is about 10mm.
10. The composite shell for reducing the weight of an EFP warhead according to claim 9, characterized in that: The lightweight structural part has an inner diameter of 130 mm, a thickness of 6.5 mm, a length of 45 mm, and a threaded end of 10 mm; the lightweight structural part is made of 2A12 aluminum alloy with a density of 2.71 g / cm 3 , whose inner diameter and thickness are consistent with the high-density restraint, the length is 85mm, the thread end is 10mm, and the composite shell formed has an inner diameter of 130mm, a thickness of 6.5mm, and a height H of 120mm; Accordingly, the warhead charge is made of 8701 explosive, the charge cap is made of tantalum-tungsten alloy, the diameter is 130mm, and the charge height with cap is 100mm; the end face single-point detonation method is adopted.