A lightweight high-stiffness composite folding wing and method of making the same

Abstract

The application provides a light-weight high-rigidity composite material folding wing, which comprises a wing piece and a joint, the joint comprises an implantation end and a body part, the implantation end and the body part are an integral structure, the implantation end is connected with one side of the wing piece and is arranged in the inside of the wing piece, the material of the joint is metal, the material of the wing piece is a composite material, and the composite material comprises unidirectional carbon fiber prepreg and plain cloth. The application provides a light-weight high-rigidity composite material folding wing, which can be applied to the field of small-sized cylinder missiles and rocket missiles. The application adopts the design of metal joint combined with composite material wing, fully gives the designability and excellent unidirectional performance of the composite material, the weight reduction of the single-piece folding wing reaches more than 40%, and the rigidity requirement of the folding wing is effectively improved. The application adopts the folding wing process positioned through the metal joint, guarantees the symmetry and forming precision of the folding wing, and improves the product quality of the folding wing.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of folding wings, and particularly relates to a light-weight high-rigidity composite folding wing and a preparation method and application thereof. BACKGROUND

[0002] The folding wing is connected to the missile body through a folding mechanism and can be folded in the missile body or on the surface of the missile body before the missile is launched. The folding wing can reduce the lateral size of the missile, facilitate transportation and launching, save the storage and transportation space of the missile, increase the transportation capacity of vehicles or warships, and improve the combat effectiveness. The folding wing is increasingly applied in missile weapons due to its simple structure and small occupied space. The tail wings of rocket missiles are usually folding wings, so that the rocket missiles can be loaded into the launching tube in the smallest volume.

[0003] The small folding wing carried by the traditional tube-loaded missile or shoulder-mounted rocket is an aluminum alloy missile wing, which is unstable in structure. Moreover, with the increase of mission distance and the development of vehicle-mounted universal folding wings, the rigidity, weight and cost of the aluminum alloy missile wing are increasingly difficult to meet the requirements, and therefore, a light-weight high-rigidity composite folding wing is needed. SUMMARY

[0004] The application aims to provide a light-weight high-rigidity composite folding wing, which adopts the design and process of metal joints and composite missile wings and has the advantages of weight reduction, high rigidity and low processing cost.

[0005] In order to achieve the above-mentioned purpose, the application provides the following technical scheme.

[0006] The application provides a light-weight high-rigidity composite folding wing, which comprises a wing piece and a joint, the joint comprises an implantation end and a body part, the implantation end and the body part are of an integrated structure, the implantation end is in the shape of an I-beam, the implantation end is connected to one side of the wing piece and arranged inside the wing piece, the material of the joint is metal, the material of the wing piece is composite material, and the composite material comprises unidirectional carbon fiber prepreg and plain cloth.

[0007] In order to increase the rigidity of the folding wing, preferably, a slope is used between the implantation end and the body end. Further preferably, the wall thickness of the slope gradually changes from 10 mm to 3.9 mm, the slope is about 5-8 degrees, and the thickness of the end of the implantation end is 1.5 mm. The inventors have found that the above-mentioned design scheme can significantly improve the rigidity of the folding wing by synergistic effect.

[0008] Preferably, the laying mode of the composite material is: the inside uses 0 ° unidirectional carbon fiber prepreg layer; the outermost side uses 1 layer of ± 45 ° plain cloth layer. Through the laying mode of the application, the inside uses 0 ° unidirectional carbon fiber prepreg layer 0 °, which can provide maximum stiffness performance, and the outermost side uses 1 layer of ± 45 ° plain cloth layer, which can provide good surface effect, and the combination of the two improves the overall performance of the folding wing.

[0009] The application directly embeds the joint into the wing piece, can improve the stability of the structure between the wing piece and the metal joint, the folding wing structure of the application is simple, ingenious and low in investment, can avoid the instability caused by the joint and the wing piece in the prior art, avoid the stress concentration caused by the hole on the wing piece and the defect that the hole reduces the overall strength of the wing piece, the design of the application improves the overall reliability and the stiffness. The overall of the connecting structure is strong and the stability is higher.

[0010] Preferably, the diameter of the single filament of the unidirectional carbon fiber of the application should be between 5-15 μm, preferably between 7-10 μm. The number of single filaments contained in each bundle of unidirectional carbon fiber should be between 15000-60000.

[0011] Preferably, the plain cloth is epoxy resin prepreg carbon fiber plain cloth, the area density is 200g / m 2 , purchased from Yixing Jiechuang Carbon Fiber Products Co., Ltd., and the product number is 06. The area density of the plain cloth affects the weight and mechanical effect of the product, the application uses epoxy resin prepreg carbon fiber plain cloth, which has good effect in combination with the unidirectional carbon fiber prepreg, the inventor finds that when the area density of the plain cloth is properly selected, not only the weight of the folding wing is reduced compared with the existing product, but also the plain cloth and the unidirectional carbon fiber prepreg use the same system of epoxy resin, which shows excellent applicability, the void of the composite material is less, the stiffness is higher, and the mechanical properties of the composite material are higher.

[0012] Preferably, the material of the joint is aluminum alloy. Further preferably, the aluminum alloy uses 7A04-T6 aluminum alloy, the Rp0.2 yield strength is 410 MPa, and the tensile strength is 480 MPa. The inventor finds that the application of this type of aluminum alloy has the best combination effect with the wing piece material, and the folding wing has the best stiffness effect.

[0013] In order to improve the stiffness of the product, preferably, the preparation method of the carbon fiber prepreg is: heating and melting the resin to impregnate the carbon fiber material to obtain the carbon fiber prepreg, and the mass percentage content of the resin in the prepreg is 55-74 %; the resin includes the following components by weight: 50-80 parts of resin, 5-10 parts of toughening agent, 4-9 parts of filler and 1-3 parts of coupling agent. The unidirectional carbon fiber cloth is purchased from Fosman 9604022.

[0014] Preferably, the resin comprises one or more of unsaturated polyester, vinyl ester resin, epoxy resin, phenolic resin, bismaleimide resin, polyimide resin.

[0015] In order to improve the mechanical properties, preferably, the resin is an epoxy resin. Further preferably, the epoxy resin is a bisphenol A type epoxy resin, available from Merck 31185.

[0016] Preferably, the filler comprises one or more of chromium powder, nickel powder, manganese powder, and one or more of silicon powder, carbon nanotube, silicon carbide, boron carbide, alumina, nano-silica, nano-zinc oxide, nano-titanium dioxide, organic montmorillonite; the coupling agent is one or more of kh550, kh560, kh570; the toughening agent comprises one or more of aliphatic dibasic acid esters, phthalic acid esters, benzene polyacid esters, benzoic acid esters, citric acid esters, polyesters.

[0017] In order to improve the overall performance of the folding wing, preferably, the filler comprises nickel powder, silicon powder and nano-silica, with a weight ratio of 1:1:1; the coupling agent is kh570; the toughening agent is tributyl citrate.

[0018] The second aspect of the present application provides a preparation method of the light high-stiffness composite folding wing. The end process joint is positioned in the mold, the joint is positioned in the mold, the position degree and symmetry degree of the joint in the mold during mold pressing are ensured, the composite material is laid in the mold, the joint and the composite material are subjected to hot pressing treatment of 7-10 MPa in the mold for 2-3 h at constant temperature and pressure, and are cured and formed; finally, the flash of the composite material is removed, the process joint is cut off, and a light high-stiffness composite folding wing is obtained.

[0019] In order to simplify the process and improve the performance of the product, the hot pressing temperature of the present application is less than the melting point of the resin of the unidirectional carbon fiber prepreg, and the reduced temperature range is within 20℃. The melting point is measured by DSC. The adhesion between the layers can be ensured, and the resin can be prevented from melting into a flowing state.

[0020] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0021] (1) The present application provides a kind of lightweight high stiffness composite material folding wing, which can be applied to small-sized barrel missile and rocket shell field.The present application uses the design and process of metal joint combined with composite material missile wing, gives full play to the designability and excellent unidirectional performance of composite material, and the aerodynamic profile is modified using carbon fiber composite material, the weight reduction of single piece folding wing is more than 40%, effectively improves the stiffness requirement of folding wing, and the stiffness is increased by more than 30%.The folding wing process of the present application is positioned by metal joint, which ensures the symmetry and forming precision of folding wing, and improves the quality of folding wing.

[0022] (2)The folding wing of the present application has a streamlined aerodynamic shape, and the traditional metal missile wing generally needs to be processed by five-axis machine tool, which has high processing cost.The present application only uses round bar metal for processing at the interface, does not involve complex curved surface processing, limits the cost of folding wing, and the cost is reduced by about 15%.The present application uses the structural design of I-shaped metal joint.The joint avoids the high processing cost of aerodynamic profile, while ensuring the installation interface size and material requirements of folding wing, and can realize low-cost composite material folding wing. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of a kind of lightweight high stiffness composite material folding wing;

[0024] Figure 2 It is a sectional structure schematic diagram of a kind of lightweight high stiffness composite material folding wing;

[0025] Figure 3 It is the schematic diagram of the first joint scheme of the present application, wherein the upper drawing is a plan view, and the lower drawing is an elevation;

[0026] Figure 4 It is the schematic diagram of the second joint scheme of the present application, wherein the upper drawing is a plan view, and the lower drawing is an elevation;

[0027] Figure 5 It is the schematic diagram of the connection between joint and process joint.

[0028] The drawing mark: 1, wing piece, 2, joint, 21, implant end, 22 body part, 3, skin, 4, process joint. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below, obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0030] The present application provides three kinds of joint designs: mainly the transition of the implant end 21 and the body end 22 is different.

[0031] As shown in Figure 3 , the first joint scheme, the connection between the body part 22 and the implant end 21 has no transition, the body part ΦH1 is 10mm directly cliff type transition to the implant end with a thickness H2 of 1.5mm, the transition is in a right angle state, as shown in Figure 3 marked A. Actual test shows that the transition area is the area with the maximum stress. The actual effect is not ideal, 1.5mm is plastic deformation at the cylindrical end.

[0032] As shown in Figure 4 , the second joint scheme, on the basis of the first scheme: the connection between the implant end 21 and the body part 22 is locally thickened, as shown in Figure 4 marked B, the stiffness requirement reaches the stiffness requirement under the same aerodynamic condition of the aluminum alloy folding wing.

[0033] As shown in Figure 2 and Figure 5 , the third joint scheme is an enhanced design of the second joint scheme, the transition section adopts slope transition, the wall thickness gradually changes from φ10mm to a thickness of 3.9mm, through slow transition by slope, the slope is about 5°-8°, as shown in Figure 5 marked C. While ensuring lightweight and processing economy, the stiffness margin is maximized, which is the form used in embodiment 1 of the present application, far exceeding the stiffness requirement of the aluminum alloy folding wing, and the stiffness is improved by more than 30%.

[0034] Embodiment 1

[0035] The present embodiment provides a lightweight high-stiffness composite folding wing, which comprises a wing piece 1 and a joint 2, the wing piece 1 is provided with a skin 3 around, the joint 2 comprises an implant end 21 and a body part 22, the implant end 21 and the body part 22 are integrated structure, the implant end 21 is connected with one side of the wing piece 1 and is arranged inside the wing piece 1; the material of the joint 2 is metal, the material of the wing piece 1 is composite material, the composite material comprises unidirectional carbon fiber prepreg inside and plain cloth outside; the laying mode of the composite material is that 0° unidirectional carbon fiber prepreg layer is used inside; 1 layer of ±45° plain cloth layer is used outside. The joint uses the design of C scheme.

[0036] The material of the joint is 7A04 T6 aluminum alloy.

[0037] The preparation method of the carbon fiber prepreg is that the resin is heated and melted to impregnate the carbon fiber material at 110℃, to obtain the carbon fiber prepreg, the mass percentage content of the resin in the prepreg is 70%; the resin comprises the following components by weight: 72 parts of resin, 6 parts of toughening agent, 5 parts of filler and 2 parts of coupling agent.

[0038] The resin is epoxy resin; the filler includes nickel powder, silicon powder and nano silica in a weight ratio of 1:1:1; the coupling agent is KH570; and the toughening agent is tributyl citrate.

[0039] This invention provides a method for preparing a lightweight, high-rigidity composite folding wing. The method involves positioning the connector 2 within a mold using a process connector 4 at the end, ensuring the positional accuracy and symmetry of the connector 2 within the mold during molding. The composite material is then laid within the mold, and the connector 2 and the composite material are subjected to a hot-pressing treatment at 91℃ / 8MPa for 2.5 hours to cure and solidify. Finally, the excess burrs from the composite material are removed, and the process connector 4 is cut off to obtain a lightweight, high-rigidity composite folding wing.

[0040] Example 2

[0041] The difference between this embodiment and Embodiment 1 is that the composite material is laid in the following way: the inner layer is a 0° unidirectional carbon fiber prepreg layer; the outermost layer is a 0° plain weave fabric layer.

[0042] Example 3

[0043] The difference between this embodiment and Embodiment 1 is that the aluminum alloy used is aluminum alloy 1050, which was purchased from Chengrui Group.

[0044] Example 4

[0045] The difference between this embodiment and Embodiment 1 is that the carbon fiber prepreg is prepared by heating and melting resin to impregnate carbon fiber material to obtain carbon fiber prepreg, wherein the resin content in the prepreg is 66% by weight; the resin comprises the following components by weight: 72 parts resin, 5 parts filler, and 2 parts coupling agent. The resin is phenolic resin, purchased from Hebei Zetian Chemical 2123-1T; the filler includes nickel powder; and the coupling agent is KH570.

[0046] Example 5

[0047] The difference between this embodiment and Embodiment 1 is that the connector uses the second design scheme.

[0048] Performance testing

[0049] The deflection of Examples 1 to 5 was measured. Here, stiffness refers to the distance the wingtip descends when a certain load is applied to a certain position on the aerodynamic profile of the fixed metal joint part. This stiffness can also be called deflection.

[0050] Table 1 Performance Test Results

[0051] Item Deflection (mm) Example 1 35 Example 2 43 Example 3 40 Example 4 47 Example 5 48

[0052] As can be seen from the embodiments, the lightweight and high-rigidity composite material folding wing provided by the present invention is lightweight and has high rigidity.

[0053] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A lightweight, high-rigidity composite material folding wing, characterized in that, The device includes a wing and a connector. The connector includes an implantation end and a body, which are integral structures. The implantation end is I-shaped and is connected to one side of the wing and located inside the wing. The connector is made of metal, and the wing is made of a composite material, which includes unidirectional carbon fiber prepreg and plain weave fabric. A ramp transition is used between the implant end and the body end; the wall thickness of the ramp gradually changes from φ10mm to 3.9mm, the slope is 5° to 8°, and the thickness of the implant end is 1.5mm. The composite material is laid out as follows: the inner layer is a 0° unidirectional carbon fiber prepreg; the outermost layer is a 1-layer ±45° plain weave fabric. The method for preparing the carbon fiber prepreg is as follows: heating and melting resin to impregnate carbon fiber material to obtain carbon fiber prepreg, wherein the resin content in the prepreg is 55-74% by weight; the resin includes the following components by weight fraction: 50-80 parts resin, 5-10 parts toughening agent, 4-9 parts filler and 1-3 parts coupling agent. The resin is epoxy resin; the filler includes nickel powder, silicon powder and nano silica in a weight ratio of 1:1:1; the coupling agent is KH570; and the toughening agent is tributyl citrate.

2. The lightweight, high-rigidity composite folding wing according to claim 1, characterized in that, The joint is made of 7A04-T6 aluminum alloy with a yield strength of 410MPa and a tensile strength of 480MPa.

3. A method for preparing a lightweight, high-stiffness composite folding wing according to any one of claims 1-2, characterized in that, The joint is positioned in the mold by the process connector at the end to ensure the position and symmetry of the joint in the mold during molding. The composite material is laid in the mold, and the joint and the composite material are subjected to hot pressing treatment of 7-10 MPa in the mold for 2-3 hours to cure and form. Finally, the flash of the composite material is removed and the process connector is cut off to obtain a lightweight and high-rigidity composite material folding wing.

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