Preparation method of honeycomb interlayer for radome, radome and preparation method of radome

Abstract

The invention relates to the field of composite material manufacturing and unmanned aerial vehicle component design, in particular to a preparation method of a honeycomb interlayer for a radome, the radome and a preparation method of the radome. The preparation method of the honeycomb interlayer for the radome comprises the following steps that a flattened splice plate is prepared, specifically, the flattened splice plate is prepared according to the appearance of the needed honeycomb interlayer, and a splicing seam of the flattened splice plate in the generatrix direction passes through the maximum curvature change positions of the head and the side wall of the radome; the included angle between the end wall, located on the head of the radome, of the flattening splice plate and the side wall, located on the peripheral wall of the radome, of the flattening splice plate is alpha, and alpha = arc tan (a / b). And assembling the honeycomb interlayer: assembling the flattened splice plates into the honeycomb interlayer in a forming mold. The radome has the advantage of light weight, and the forming process is stable.

Description

Technical Field

[0001] The present application relates to the fields of composite material manufacturing and UAV component design, and more specifically, to a method for preparing a honeycomb interlayer for a radome, a radome and a method for preparing the same. Background Art

[0002] The radome is a key component on the front end of a drone. Its design must strike a balance between protection, electromagnetic performance, aerodynamics, and stealth capabilities. For example, the radome protects the radar system from harsh environmental factors such as rain, hail, dust, and ultraviolet rays, extending the equipment's lifespan. During high-speed flight or collisions (such as bird strikes), the radome absorbs shock and prevents damage to the radar hardware. The radome must also ensure minimal attenuation of electromagnetic waves transmitted and received by the radar, preventing signal distortion. Overall, the radome must possess excellent electromagnetic wave transparency, be lightweight, high strength, and be resistant to environmental corrosion.

[0003] Furthermore, with the increasing demand for low-energy drones, there is also a growing demand for further lightweighting of radomes. In recent years, researchers have often used composite materials to manufacture radomes to reduce their weight. Sandwich structure technology has emerged as the mainstream design for high-performance radomes. Sandwich structures typically consist of high-strength upper and lower panels (skins) and a lightweight core material in the middle. The core principle is to use the core to separate the two panels, forming a mechanical structure similar to an I-beam. This significantly improves the structure's specific stiffness and strength with minimal weight gain.

[0004] However, due to the influence of the shape of the radome, the existing molding process often has instability problems. For example, due to inappropriate process operation, the product has problems such as large porosity and deformation. In particular, the material at the joint position is prone to wrinkles, collapse, voids and other problems. Summary of the Invention

[0005] The present application provides a method for preparing a honeycomb interlayer for a radome, a radome, and a method for preparing the same. The radome of the present application is lightweight, has good mechanical strength, and has a stable molding process, effectively reduces the porosity of the product, and reduces material deformation.

[0006] In a first aspect, the present application provides a method for preparing a honeycomb interlayer for a radome, using the following technical solution:

[0007] A method for preparing a honeycomb interlayer for a radome, comprising the following steps:

[0008] Preparation of flattened splicing panels: According to the desired shape of the honeycomb sandwich, a flattened splicing panel is prepared, wherein the splicing seam of the flattened splicing panel along the generatrix direction passes through the location of the maximum curvature change of the radome head and the side wall, and the angle between the end wall of the flattened splicing panel located at the radome head and the side wall of the flattened splicing panel located at the radome peripheral wall is α, α = arc tan (a / b), where a is the thickness of the honeycomb sandwich, and b is the difference in side length between two symmetrical points on the inner and outer walls of the honeycomb sandwich located at the splicing seam and the vertex of the honeycomb sandwich head;

[0009] Honeycomb sandwich assembly: In the forming mold, the flattened spliced ​​panels are assembled into a honeycomb sandwich.

[0010] By adopting the above-mentioned technical solution, when preparing the flattened honeycomb sandwich panels, in addition to meeting the basic requirements of the required honeycomb sandwich and area, the present application also performs special chamfering on the joint seam position of the flattened panels and the end wall of the flattened panels located on the radar head, and specifies the method for obtaining the size of the angle α. Such chamfering and joint seam positioning can effectively reduce the gap and deformation of the honeycomb sandwich head joint, and can also reduce the amount of foam glue used, thereby reducing its impact on the wave transmission performance of the radome. This ensures that the subsequent radome has good wave transmission and mechanical strength, and the molding process is stable and the manufacturing process is simple.

[0011] Furthermore, each of the flattened splicing panels includes an upper panel and a lower panel, and the upper panel and the lower panel are spliced ​​relative to each other along the busbar direction of the radome, and the splicing seam is located at a position between one-third and one-half of the distance from the head end of the radome along the height direction of the radome.

[0012] Furthermore, in the honeycomb sandwich assembly step, a film is pasted in the forming mold, a flattened splicing plate is attached to the film at a specified position, and then an adhesive is placed at the splicing end, and the next flattened splicing plate is attached to the film at a specified position and bonded to the splicing end of the previous flattened splicing plate until the splicing is completed, and then a film is pasted on the spliced ​​flattened splicing plate and placed in an oven for pre-forming.

[0013] Furthermore, the temperature of the oven is 60-150°C and the drying time is 1-4 hours.

[0014] Furthermore, the adhesive is a modified epoxy film-like foaming adhesive.

[0015] In a second aspect, the present application provides a method for preparing a radome, which adopts the following technical solution:

[0016] A method for preparing a radome using the honeycomb sandwich layer comprises the following steps:

[0017] Outer skin laying: laying the outer skin prepreg in the mold;

[0018] Honeycomb sandwich laying: laying the preformed honeycomb sandwich on the outer skin prepreg;

[0019] Inner skin laying: laying inner skin prepreg on the inner wall of honeycomb sandwich;

[0020] The product is obtained by heating and curing, and cooling.

[0021] Furthermore, a vacuum bag is used, and the curing temperature is (127±5)° C. and the curing pressure is 0.31±0.035 MPa. The curing is carried out for 90 to 240 minutes, and the temperature is lowered to obtain the product.

[0022] Furthermore, in the step of laying the outer skin and the inner skin, the prepreg is laid in multiple layers, and the laying seams between different layers are staggered. Furthermore, the laying seams here refer to lap seams and butt seams.

[0023] Furthermore, the prepreg is epoxy glass fiber prepreg, wherein the reinforcing material glass fiber accounts for 60%-70%, the epoxy resin material accounts for 30%-40%, the overlapped part of the prepreg is 10-20mm wide, and the butt joint is ≤2mm.

[0024] In a third aspect, the present application provides a radome, which adopts the following technical solution:

[0025] A radome, which is a glass fiber skin honeycomb sandwich structure, the honeycomb sandwich of the radome is the above-mentioned honeycomb sandwich, and lightning protection aluminum strips are installed on the outer side walls of the radome.

[0026] In summary, this application has the following beneficial effects:

[0027] This application uses high-strength and lightweight composite materials to achieve lightweighting. During the preparation process of the honeycomb sandwich, the flattened splicing plates of the honeycomb sandwich are specially treated, so that the obtained honeycomb sandwich can be used in the preparation of the radar cover to achieve lightweighting, good mechanical strength and wave transmittance, and the molding process is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a plan view schematically showing the depth of the honeycomb interlayer required for the radar cover in the embodiment of the present application.

[0029] Figure 2 It is a planar schematic diagram showing the major and minor axes of the honeycomb sandwich required for the radar cover in the embodiment of the present application.

[0030] Figure 3 It is a planar schematic diagram to illustrate the angles in the flattened spliced ​​plate in the embodiment of the present application.

[0031] Figure 4It is a planar schematic diagram to reflect the side length of the honeycomb sandwich required for the radar cover in the embodiment of the present application.

[0032] Figure 5 It is a planar schematic diagram to illustrate the shape of the flattened splicing plate in Example 1 of the present application.

[0033] Figure 6 It is a planar schematic diagram to illustrate the shape of the flattened splicing plate in Example 2 of the present application.

[0034] Figure 7 This is a physical picture of Example 4 of the present application.

[0035] Explanation of the accompanying reference numerals: 1. honeycomb interlayer; 2. flattened splicing board; 3. upper display board; 4. lower display board. DETAILED DESCRIPTION

[0036] The present application is further described in detail below with reference to the accompanying drawings and examples.

[0037] Example

[0038] In the embodiment of the present application, the prepreg used may be epoxy glass fiber prepreg, wherein the mass proportion of the reinforcing material glass fiber is 60%-70%, and the mass proportion of the epoxy resin material is 30%-40%.

[0039] Glass fibers are available as continuous unidirectional cloth, woven cloth, or chopped strands.

[0040] Epoxy resin materials are composed of a matrix, a curing agent, an accelerator and functional additives.

[0041] The matrix can be bisphenol A (DGEBA), multifunctional epoxy (such as TGDDM), etc.

[0042] The curing agent (accounting for 1%-5% in the epoxy resin material) can be anhydrides, amines and latent curing agents. Further, the anhydride curing agent can be methyltetrahydrophthalic anhydride, MTHPA, amines such as DDS, 4,4'-diaminodiphenyl sulfone, dicyandiamide, DICY; the accelerator (accounting for 0.5%-2% by mass in the epoxy resin material) can be 2-methylimidazole (2-MI), benzyldimethylamine (BDMA), etc.; the functional additive (accounting for 2%-10% by mass in the epoxy resin material) can be a toughening agent, a flame retardant, etc. The toughening agent can be end-carboxyl nitrile rubber, and the flame retardant can be aluminum hydroxide, phosphorus compounds, etc.

[0043] Specifically, the prepreg ratio used in this embodiment is as follows:

[0044] Prepreg composition: glass fiber reinforcement accounts for 65%, and epoxy resin material accounts for 35%. The glass fiber in this embodiment is all woven fabric.

[0045] The curing agent is methyltetrahydrophthalic anhydride, which accounts for 4% of the epoxy resin material; the accelerator is benzyldimethylamine (BDMA), which accounts for 1% by mass of the epoxy resin material; the toughening agent is carboxyl-terminated nitrile rubber, which accounts for 6% by mass of the epoxy resin material; and the flame retardant is aluminum hydroxide, which accounts for 5% by mass of the epoxy resin material.

[0046] The foaming adhesive used in this embodiment is modified epoxy film foaming adhesive MF9010.

[0047] It should also be noted that the relevant parameters involved in the embodiments of this application are explained as follows:

[0048] Regarding the radome, the radome prepared in the embodiment of the present application is a radome for drones, and its shape is similar to a bird's beak, such as Figure 1 and Figure 2 As shown, in the honeycomb interlayer 1 corresponding to the radar cover, the depth is h, the major axis direction is m, and the minor axis is n.

[0049] Regarding flattening splice plates, Figure 3 and Figure 4 As shown, the thickness of the flattened splice plate 1 is a, i.e., the thickness of the honeycomb interlayer. When the flattened splice plate is located at the splice seam, the honeycomb interlayer of the desired radome shape corresponds to the length difference between two symmetrical points on the inner and outer walls and the corresponding apex of the honeycomb interlayer of the desired radome shape: b, i.e., b = b1 - b2. The two symmetrical points on the inner and outer walls are opposite each other, with parallel tangent lines at these points.

[0050] The angle α between the end wall of the flattened splicing plate located at the head of the radome and the side wall of the flattened splicing plate located at the outer peripheral wall of the radome is α=arc tan(a / b).

[0051] The following is an explanation through specific examples.

[0052] Example 1

[0053] The radome prepared in this embodiment is a radome for unmanned aerial vehicles, with a depth of 478 mm and an end portion having a length of 1008 mm in the long axis direction and a length of 924 mm in the short axis direction.

[0054] This embodiment first provides a method for preparing a honeycomb interlayer for a radome, comprising the following steps:

[0055] The required honeycomb interlayer is an aramid honeycomb interlayer with the following dimensions: thickness a is 15 cm, and the side length difference b of the honeycomb interlayer of the required shape of the corresponding radome is 5.5 cm.

[0056] Preparation of flattened splicing plate: According to the required shape of honeycomb sandwich, prepare flattened splicing plate, and the splicing seam along the generatrix direction of the flattened splicing plate passes through the maximum curvature change of the radome head and side wall, such as Figure 5 As shown, there are two flattened splicing plates 1 in this embodiment.

[0057] The included angle between the end wall of the flattened splicing plate located at the head of the radome and the side wall of the flattened splicing plate located at the outer peripheral wall of the radome is α, α=arc tan(a / b)=70°.

[0058] Honeycomb sandwich assembly: In the forming mold, the flattened spliced ​​panels are assembled into a honeycomb sandwich.

[0059] Specifically, the assembly process of the honeycomb sandwich includes the following steps:

[0060] A layer of adhesive film is pasted on the mold tooling and pre-compacted (vacuum degree ≥-0.06MPa, time ≥5min); after applying a foam film to the bonding surface of a flattened splicing plate to be spliced, the flattened splicing plate is positioned on the tool according to the shape of the required radar cover; another flattened splicing plate is positioned at the specified position of the mold; then the two flattened splicing plates are tightly compacted for assembly; at the half of the tail end wall of the spliced ​​honeycomb sandwich close to the outside, a potting glue is poured into the honeycomb of the honeycomb sandwich and a layer of adhesive film is pasted to strengthen the strength here, and then it is placed in an oven for pre-forming. The oven temperature is 127±5° and the drying time is 3 hours.

[0061] This embodiment also discloses a method for preparing a radome, comprising the following steps:

[0062] Outer skin laying: laying the outer skin prepreg in the mold. The specific operations are as follows:

[0063] The outer skin includes three layers of prepreg and one layer of film. After the first layer of prepreg and the fourth layer of film are laid, they are vacuum compacted with a vacuum degree of ≥-0.06MPa and a time of ≥5min.

[0064] If there is an overlap between each layer of prepreg, the overlap should be 10-20mm. If there is no overlap, the joint should be ≤2mm. The overlap or joints between each layer should be staggered.

[0065] Honeycomb sandwich laying: laying the preformed honeycomb sandwich on the outer skin prepreg;

[0066] Inner skin laying: Lay the inner skin prepreg on the inner wall of the honeycomb sandwich; the specific operation is:

[0067] The inner skin has nine layers of prepreg. After the first, seventh and eighth layers of prepreg are laid, they are vacuum compacted with a vacuum degree of ≥-0.06MPa and a time of ≥5min.

[0068] If there is an overlap between each layer of prepreg, the overlap should be 10-20mm. If there is no overlap, the joint should be ≤2mm. The overlap or joints between each layer should be staggered.

[0069] Heat up to solidify, and cool down to obtain the product. The specific operation is as follows:

[0070] The product S1 was obtained by curing the product in a vacuum bag at a curing temperature of (127±5)°C and a curing pressure of 0.31±0.035 MPa for 150 minutes, followed by cooling. The curing temperature was increased at a rate of (0.5-1.5)°C / min, and the cooling rate was not more than 3°C / min or the product was cooled naturally.

[0071] Example 2

[0072] The difference between Example 2 and Example 1 is that:

[0073] Preparation of flattened splicing plates: According to the desired shape of the honeycomb sandwich, flattened splicing plates are prepared. The splicing seams of the flattened splicing plates along the generatrix direction pass through the maximum curvature change of the radome head and side walls. There are two groups of flattened splicing plates in this embodiment, such as Figure 6 As shown, each set of flattened panels 2 consists of an upper panel 3 and a lower panel 4. The upper and lower panels are joined together along the radome's generatrix, with flat surfaces. The joint seam is located one-third of the way from the radome's head, meaning there are four panels to be joined. During the honeycomb sandwich assembly process, the two panels near the radome's head are assembled first, followed by the two panels near the radome's tail. This results in product S2.

[0074] Example 3

[0075] The difference between Example 3 and Example 1 is that:

[0076] The radome prepared in this embodiment is a radome for unmanned aerial vehicles, with a depth of 478 mm and an end portion with a length of 988 mm in the long axis direction and a length of 824 mm in the short axis direction.

[0077] This embodiment first provides a method for preparing a honeycomb interlayer for a radome, comprising the following steps:

[0078] The required honeycomb interlayer is an aramid honeycomb interlayer with the following dimensions: thickness a is 14 cm, and the side length difference b of the honeycomb interlayer of the required shape of the corresponding radome is 4 cm.

[0079] This embodiment first provides a method for preparing a honeycomb interlayer for a radome, comprising the following steps:

[0080] The honeycomb sandwich required is an aramid honeycomb sandwich, and the angle α between the flattened splicing plate located at the end wall of the radome head and the flattened splicing plate located at the side wall of the radome outer peripheral wall is α = arc tan (a / b) = 74°.

[0081] Example 4

[0082] The difference between Example 4 and Example 1 is that Figure 6 As shown, six lightning protection aluminum strips are evenly installed on the outer side wall of the radome of Example 4; countersunk blind rivets are installed in the corresponding area of ​​the honeycomb interlayer. Using the wet installation method, the operator applies adhesive 9394 on both sides of the rivet rod, under the rivet head, and at the place where the lightning protection aluminum strip and the workpiece are to be glued, and then rivets are riveted using a rivet gun. Product S4 is obtained. The finished product of Example 4 is as shown. Figure 7 shown.

[0083] Comparative Example

[0084] Comparative Example 1

[0085] The difference between Comparative Example 1 and Example 1 is that the splicing seam along the generatrix direction of the flattened splicing plate passes through the symmetric surface of the honeycomb sandwich required for the radome, thereby obtaining product D1.

[0086] Comparative Example 2

[0087] The difference between Comparative Example 2 and Example 1 is that the end wall of the flattened splicing plate at the head of the radome is a straight end wall. The length of the flattened splicing plate is equal to the outer length of the honeycomb sandwich required for the radome, and product D2 is obtained.

[0088] Comparative Example 3

[0089] The difference between Comparative Example 3 and Example 1 is that α is 45°, and product D3 is obtained.

[0090] Performance testing

[0091] For the products obtained in the examples and comparative examples, the performance of the radomes was tested as follows:

[0092] 1. Appearance quality-visual inspection

[0093] Tests were performed on S1, S2, S3 and D1, D2, D3.

[0094] 1.1 The surface of the composite material part should be smooth and flat, the fabric fibers should be clearly visible, the surface fibers should be evenly covered with resin, and no obvious resin accumulation is allowed.

[0095] 1.2 No cracks are allowed on the surface of the workpiece.

[0096] 1.3 Severe bruises, scratches and bumps on the surface of the workpiece are not allowed.

[0097] 1.4 No other defects that would significantly affect the overall strength of the component are allowed to appear on the surface of the component.

[0098] Judgment: qualified, unqualified.

[0099] 2. Internal quality - light transmission inspection

[0100] Tests were performed on S1, S2, S3 and D1, D2, D3.

[0101] 2.1 Maximum allowable defect size

[0102] 2.1.1 Delamination, voids, or disbonding defects shall be controlled according to Class C. The maximum allowable defect size shall not be greater than 2Z = X + Y, where Z is 19 mm, and X and Y are the maximum length and width of the defect, respectively.

[0103] 2.1.2 The minimum distance between the edges of two or more defective areas should be greater than 100mm.

[0104] 2.1.3 For diffuse defects (such as pores, loose areas, fat-rich areas, etc.) that are grouped together, if they exceed the specified value (per 155cm 2 When the maximum cumulative defect is ≤25%, it is judged as unqualified.

[0105] 3. Internal quality of honeycomb sandwich structure - light transmission inspection

[0106] For S1, S2, S3 and D1, D2, D3, the quality of the honeycomb sandwich structure was further observed.

[0107] 3.1 Degumming

[0108] The scope of debonding is not allowed to exceed the provisions of 2.1.1 and 2.1.2.

[0109] 3.2 Panel-core air holes

[0110] The scope of the defect is not allowed to exceed the provisions of 2.1.1 and 2.1.2.

[0111] 3.3 Honeycomb Defects

[0112] a) The cumulative area of ​​defects such as honeycomb deformation and honeycomb wrinkling shall not exceed 3cm within any 30cm×30cm area. 2 , and the edge spacing of the defective area shall not be less than 200mm, and the distance from the edge of the normal sandwich shall not be less than 100mm.

[0113] b) Within any Ø254mm range, the number of completely or partially separated nodes shall not exceed 10. Partial node separation means that more than half of the nodes are separated.

[0114] c) Honeycomb splicing does not allow 4 or more sandwich walls to be unbonded within any 150mm length.

[0115] e) After curing, the single-side shrinkage of the honeycomb interlayer of the product shall not exceed 5mm.

[0116] 4. Mechanical Strength Testing: The accompanying parts of Examples 1-3 and the comparative example were tested for performance, including interlaminar shear strength, flexural strength, and roller peel strength of the honeycomb panels. Interlaminar shear strength was tested according to ASTM D2344 (Test Method for Short Beam Strength of Polymer Matrix), flexural strength was tested according to ASTM D790 (Standard Test Method for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials), and roller peel was tested according to ASTM D1781 (Standard Test Method for Roller Peeling of Adhesives).

[0117] The test results are shown in Table 1

[0118] Table 1 Performance test results of examples and comparative examples

[0119]

[0120] Performance tests in the examples show that the radome furnace components prepared in this application have good mechanical strength and, due to the use of composite materials, are lightweight. Furthermore, the molding process employed in this application results in a high product qualification rate and a stable process.

[0121] Furthermore, in the preparation process of the honeycomb interlayer, analysis of the performance of Comparative Examples 1 and 2 shows that in the finished product of Comparative Example 1, after the honeycomb interlayer contacts the outer skin at the point where the curvature changes the most, the honeycomb cells are deformed or unable to contact, resulting in voids and other phenomena. The appearance quality, internal quality, and internal quality of the honeycomb interlayer structure are all unqualified. In the finished product of Comparative Example 2, the inner side of the honeycomb interlayer end face contacts first at the splicing point, resulting in a lack of contact on the outer side, forming a sharp-angled gap at the splicing position. The appearance quality, internal quality, and internal quality of the honeycomb interlayer structure are all unqualified. Although Comparative Example 3 uses chamfering, the determination of its angle does not meet the technical requirements of this application, resulting in pores on the inner side of the splicing end of the honeycomb interlayer after splicing, requiring additional foam filling. The appearance quality, internal quality, and internal quality of the honeycomb interlayer structure are all unqualified, and the wave transmission of the product is also affected.

[0122] This application describes a special chamfering treatment of the joint seams of the flattened panels and the end walls of the flattened panels located on the radar head, and specifies a method for determining the angle α. This chamfering and joint seam positioning effectively reduces gaps and deformation in the honeycomb sandwich head joints, reduces the amount of foam used, and thereby reduces its impact on the radome's wave transmission performance. This results in a subsequent radome with excellent wave transmission and mechanical strength, and a stable and simple molding process.

[0123] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for preparing a honeycomb interlayer for a radome, characterized in that: The following steps are involved: Preparation of flattened splicing panels: According to the desired shape of the honeycomb sandwich, a flattened splicing panel is prepared, wherein the splicing seam of the flattened splicing panel along the generatrix direction passes through the location of the maximum curvature change of the radome head and the side wall, and the angle between the end wall of the flattened splicing panel located at the radome head and the side wall of the flattened splicing panel located at the radome peripheral wall is α, α = arc tan (a / b), where a is the thickness of the honeycomb sandwich, and b is the difference in side length between two symmetrical points on the inner and outer walls of the honeycomb sandwich located at the splicing seam and the vertex of the honeycomb sandwich head; Honeycomb sandwich assembly: In the forming mold, the flattened spliced ​​panels are assembled into a honeycomb sandwich.

2. The method for preparing a honeycomb interlayer for a radome according to claim 1, characterized in that: Each of the flattened splicing panels includes an upper panel and a lower panel, which are spliced ​​relative to each other along the direction of the radome busbar, and the splicing seam is located at a position between one-third and one-half of the distance from the head end of the radome along the height direction of the radome.

3. The method for preparing a honeycomb interlayer for a radome according to claim 1, characterized in that: In the honeycomb sandwich assembly step, adhesive film is pasted in the forming mold, a flattened splicing plate is attached to the adhesive film at a specified position, and then adhesive is placed on the splicing end. The next flattened splicing plate is attached to the adhesive film at a specified position and adhered to the splicing end of the previous flattened splicing plate until the splicing is completed. Then, adhesive film is pasted on the spliced ​​flattened splicing plate and placed in an oven for pre-forming.

4. The method for preparing a honeycomb interlayer for a radome according to claim 3, characterized in that: The temperature of the oven is 60-150°C and the drying time is 1-4 hours.

5. The method for preparing a honeycomb interlayer for a radome according to claim 3, characterized in that: The adhesive is a modified epoxy film-like foaming adhesive.

6. A method for preparing a radome using the honeycomb sandwich according to any one of claims 1 to 5, characterized in that: The following steps are involved: Outer skin laying: laying the outer skin prepreg in the mold; Honeycomb sandwich laying: laying the preformed honeycomb sandwich on the outer skin prepreg; Inner skin laying: laying inner skin prepreg on the inner wall of honeycomb sandwich; The product is obtained by heating and curing, and cooling.

7. The method for preparing a radome according to claim 6, characterized in that: During the temperature-raising curing process, a vacuum bag was used, and the curing temperature was (127±5)° C. and the curing pressure was 0.31±0.035 MPa. The curing was carried out for 90 to 240 minutes, and the temperature was lowered to obtain the product.

8. The method for preparing a radome according to claim 6, characterized in that: In the paving step of the outer skin and the inner skin, the prepreg is paved in multiple layers, and the paving seams between different layers are staggered.

9. The method for preparing a radome according to claim 7, characterized in that: The prepreg is epoxy glass fiber prepreg, wherein the reinforcing material glass fiber accounts for 60%-70%, the epoxy resin material accounts for 30%-40%, the overlap part of the prepreg is 10-20mm wide, and the butt joint is ≤2mm.

10. A radome using the honeycomb sandwich according to any one of claims 1 to 5, characterized in that: The radome is a glass fiber skin honeycomb sandwich structure, the honeycomb sandwich of the radome is the above-mentioned honeycomb sandwich, and the outer side wall of the radome is provided with lightning protection aluminum strips.

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