Polyimide fiber composite stealth sandwich structure and method of making same

Abstract

The application provides a polyimide fiber composite stealth sandwich structure and a manufacturing method thereof, and belongs to the field of fiber reinforced composite structure design and manufacturing. The sandwich structure comprises a high-transmission polyimide wave-transparent skin, a wave-absorbing honeycomb as a core layer, a carbon fiber reflection plate as a reflection layer, and a carbon fiber end rib, wherein the reflection layer adopts an angle adjusting structure with low-frequency wave-absorbing effect. During processing, the edge of the wave-transparent skin is first processed to a net size and then solidified and formed, then the solidified and formed carbon fiber reflection plate and the carbon fiber end rib are combined with the wave-absorbing honeycomb to form a whole, the outer shape of the wave-absorbing honeycomb is then processed, and finally, the polyimide wave-transparent skin is glued to form an integral structure. The application optimizes the stealth characteristics, structural weight reduction and manufacturing precision, has novel design, low manufacturing risk, simple assembly and maintenance, strong universality, and can be widely applied to the wing-body leading edge and vertical-horizontal tail leading edge structures of various stealth aircrafts.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fiber-reinforced composite material structure design and manufacturing, and relates to a polyimide fiber composite material stealth sandwich structure and a manufacturing method thereof, in particular to a fiber-reinforced composite material stealth sandwich structure design and manufacturing for the wing leading edge, inlet lip, horizontal tail leading edge and vertical tail leading edge of a radar stealth aircraft, which is mainly used to reduce the radar cross section (RCS) of the edge structure of the stealth aircraft. BACKGROUND

[0002] The fiber-reinforced composite material stealth sandwich structure has excellent properties such as wave absorption, light weight, high strength, corrosion resistance, fatigue resistance and strong designability, and the stealth sandwich structure composite material is a kind of structure-function integrated composite material with radar wave absorption and mechanical bearing. The structure wave-absorbing composite material has the characteristics of strong designability, wide absorption frequency band and high absorption rate, and generally uses multiple wave-transparent, wave-absorbing and reflecting materials to realize function and mechanical structure design, but the structure design often faces the problems of overweight and excessive deformation in manufacturing, so it is very important to find a stealth structure that meets the requirements of high stealth, low weight and high-precision manufacturing.

[0003] The present application takes the matching of the thermal expansion coefficient of high-performance fibers and the stealth functionality as the innovative concept, solves the problems of high-stealth, low-weight structure-function integrated design and manufacturing stress caused by the inconsistent thermal expansion coefficient of fibers in the autoclave process, and improves the technical level of stealth structure function / bearing design and manufacturing integration. SUMMARY

[0004] The present application aims to solve the technical problems of multi-objective mutual contradiction in the design of stealth function and bearing structure such as high electromagnetic wave absorption, high mechanical bearing and high manufacturing precision, and provides a polyimide fiber composite material stealth sandwich structure and a manufacturing method thereof. Based on the thermal expansion coefficient matching and stealth functionality of multi-variety fiber laminated structure, a stealth sandwich structure is proposed, which uses high-transparency polyimide fiber-reinforced composite material as the wave-transparent skin, wave-absorbing honeycomb as the core layer, and carbon fiber composite material as the reflecting layer. The polyimide fiber and carbon fiber laminated structure reduces the bonding stress and structure weight, improves the manufacturing precision of large-aspect-ratio leading edge structure, and reduces the overall weight of the structure. The carbon fiber composite material reflecting plate adopts an angle adjustment structure with low-frequency wave-absorbing effect. To solve the problem of difficult processing of polyimide fibers, the edge processing method of the polyimide fiber composite material sandwich structure is improved, which can greatly improve the edge processing quality and processing efficiency of similar structures.

[0005] The technical scheme adopted by the present application is as follows:

[0006] The application discloses a polyimide fiber composite stealth sandwich structure, which comprises a wave-transparent skin, a core layer and a reflection layer, and specifically comprises a polyimide wave-transparent skin 1, a wave-absorbing honeycomb 2, a carbon fiber reflection plate 3, a carbon fiber end rib 4, a core film 9, a plate film 10 and foaming glue 11.

[0007] The polyimide wave-transparent skin 1 is a variable-thickness thin-walled laminated plate structure, is shaped as a U-shaped or V-shaped structure, adopts a polyimide fiber composite material with low dielectric constant and high mechanical bearing capacity, and can effectively improve the wave-transparent performance; the polyimide wave-transparent skin 1 is provided with the carbon fiber end rib 4 on both sides and is shaped as a half-open box structure, and adopts a carbon fiber layer with a wave-absorbing prepreg on the surface; the carbon fiber reflection plate 3 is shaped as a V-shaped angle pyramid or an oblique cutting angle pyramid structure, adopts a carbon fiber composite material, is arranged at a rear end opening of the polyimide wave-transparent skin 1 as a reflection layer, and forms a closed space in combination with the polyimide wave-transparent skin 1 and the carbon fiber end rib 4 on both sides, thereby serving as a filling cavity of the wave-absorbing honeycomb 2, and the low-frequency effect can be improved by adjusting the shape or angle of the carbon fiber reflection plate 3; the wave-absorbing honeycomb 2 is a homogeneous or gradient wave-absorbing honeycomb, and is arranged in the filling cavity as a core layer.

[0008] The core film 9 is used for bonding between the wave-absorbing honeycomb 2 and the laminated plate area of the polyimide wave-transparent skin 1; the plate film 10 is used for bonding between the polyimide wave-transparent skin 1 and the carbon fiber reflection plate 3 and the carbon fiber end rib 4; and the foaming glue 11 or a film is used for bonding between the wave-absorbing honeycomb 2 and the carbon fiber reflection plate 3 and the carbon fiber end rib 4.

[0009] The polyimide wave-transparent skin 1 adopts a polyimide fiber reinforced prepreg, has a dielectric constant similar to that of a quartz wave-transparent prepreg, meanwhile, the carbon fiber reflection plate 3 and the carbon fiber end rib 4 are both made of carbon fiber materials, can effectively utilize the mechanical properties of the carbon fiber to reduce weight, and utilize the electric conductivity of the carbon fiber to reflect electromagnetic waves, so as to achieve multiple targets of wave-absorbing function, structure weight reduction and high-precision manufacturing. In addition, the polyimide wave-transparent skin 1, the wave-absorbing honeycomb 2 and the carbon fiber reflection plate 3 have good temperature matching, fully utilize the negative thermal expansion coefficient of the polyimide fiber and the carbon fiber, keep the consistency of thermal expansion during the bonding and curing process of the three, reduce the thermal stress during bonding to the minimum, avoid stress deformation caused by fiber thermal expansion, and improve the manufacturing precision of the part.

[0010] Further, according to the temperature requirement of the working condition of the stealth sandwich structure, one or two of epoxy resin, bismaleimide resin and cyanate resin is selected as a matrix for the polyimide wave-transparent skin 1.

[0011] Further, the core film 9 and the plate film 10 are matched with the temperature resistance requirement of the stealth sandwich structure.

[0012] A manufacturing method of a polyimide fiber composite stealth sandwich structure, the manufacturing method comprising the following steps:

[0013] Step 1, the edge of the polyimide wave-transparent skin 1 is processed to the net size to avoid edge processing after curing; the polyimide wave-transparent skin 1 with completed edge processing is cured and formed by using polyimide fiber reinforced prepreg; the carbon fiber reflective plate 3 is cured and formed by using carbon fiber prepreg; the carbon fiber end rib 4 is cured and formed by using polyimide wave-transparent fiber reinforced wave-absorbing prepreg and carbon fiber prepreg.

[0014] Among them, since the polyimide wave-transparent skin 1 is difficult to edge process, different edge processing schemes are adopted according to the structural characteristics of different polyimide wave-transparent skins 1: (1) for the no allowance assembly area, the edge is formed to the net size by using a mold; (2) for the chamfering area of the variable curvature edge, numerical control milling is used for forming; (3) for features such as drainage holes and reference holes, pulse laser processing is used for forming.

[0015] Step 2, the wave-absorbing honeycomb 2 is formed by numerical control processing, and a secondary processing allowance is left in the contact area of the wave-absorbing honeycomb 2 and the polyimide wave-transparent skin 1. In order to improve the shape accuracy of the wave-absorbing honeycomb 2, a five-axis numerical control machining center is used for processing.

[0016] Step 3, the carbon fiber reflective plate 3 and the carbon fiber end rib 4 cured and formed in step 1 are fixed and positioned by a combination mold to form a combination structure with the wave-absorbing honeycomb 2, and the combination structure is formed by a secondary gluing process using foaming glue 11 or glue film. After the whole combination structure is formed, the gluing surface is non-destructively detected; after the combination structure is formed, the outer shape of the wave-absorbing honeycomb 2 is processed, and after processing, the gap between the combination structure and the polyimide wave-transparent skin 1 is checked by a honeycomb checking film 6. After the checking meets the gluing quality condition, the next step is carried out.

[0017] Step 4, after the combination structure is positioned, the polyimide wave-transparent skin 1 is glued to the combination structure as a whole structure, wherein the polyimide wave-transparent skin 1 and the carbon fiber reflective plate 3 and the carbon fiber end rib 4 are bonded by using a plate film 10, and the wave-absorbing honeycomb 2 and the polyimide wave-transparent skin 1 are bonded by using a plate core film 9; after gluing and curing are completed, non-destructive testing is carried out.

[0018] Step 5, a digital measuring instrument is used to detect the shape of the final structure, and a detection report is provided.

[0019] Wherein, the carbon fiber reflecting plate 3 and the carbon fiber end rib 4 are combined with the wave-absorbing honeycomb 2 after curing, and then the wave-absorbing honeycomb 2 is secondarily processed to improve the bonding quality with the polyimide wave-transparent skin 1, which is the first innovation point of the manufacturing method. The edge size of the polyimide wave-transparent skin 1 is ensured to be a net size before curing, so that the edge processing after curing can be avoided, and the manufacturing cost is reduced, which is the second innovation point of the manufacturing method.

[0020] Further, the carbon fiber reflecting plate 3 is manufactured by adopting a negative mold forming of a carbon fiber unidirectional tape or fabric prepreg, so as to ensure the assembly precision of the nested surface.

[0021] Further, the carbon fiber end rib 4 is manufactured by adopting a carbon fiber fabric prepreg and a positive mold forming, so as to be a box-shaped structure.

[0022] Further, for the polyimide wave-transparent skin 1 with large curvature, a positive mold and a uniform pressing cover plate are adopted for forming; and for the polyimide wave-transparent skin 1 with small curvature, a negative mold is adopted for forming, so as to ensure the surface quality of the polyimide wave-transparent skin 1.

[0023] The beneficial effects of the present application are as follows:

[0024] 1. The stealth structure uses the good wave-transparent performance and mechanical bearing performance of the polyimide fiber, realizes the design target of high stealth performance and low structure weight, and effectively reduces the curing stress and improves the shape manufacturing precision by using the matching characteristics of the polyimide fiber and the carbon fiber thermal expansion coefficient, so as to realize the design and manufacturing integration of multiple targets of function / bearing / precision.

[0025] 2. The stealth structure skillfully uses polyimide fiber, carbon fiber, wave-absorbing honeycomb, wave-absorbing prepreg, structural adhesive film and other materials, so that the electromagnetic wave is greatly attenuated after being absorbed by the wave-absorbing honeycomb and the wave-absorbing prepreg, and the low-frequency effect is improved by adjusting the structure shape or angle of the reflecting plate.

[0026] 3. The manufacturing process adopts a honeycomb structure one-time bonding combined with a secondary combination process and a net size edge processing technology, so that the thermal stress caused by the mismatch of the thermal expansion coefficient is effectively controlled, the manufacturing precision of the structure is greatly improved, and the full-size stealth structure with wave-absorbing function, low weight and high precision is realized.

[0027] 4. A reasonable processing scheme is adopted for the edge processing of the polyimide fiber composite material, which can process edges and holes in different situations, improve the roughness of the processing surface, and can be widely applied to the wing or horizontal and vertical tail leading edge structure of various stealth aircrafts. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1It is a structure exploded view of a typical polyimide fiber composite stealth sandwich structure.

[0029] Figure 2 It is a wave absorption principle diagram of a typical polyimide fiber composite stealth sandwich structure.

[0030] Figure 3 It is a schematic diagram of the combination of wave absorption honeycomb and carbon fiber reflection plate and carbon fiber end rib glue.

[0031] Figure 4 It is a schematic diagram of the combination of wave absorption honeycomb and carbon fiber reflection plate and carbon fiber end rib glue.

[0032] Figure 5 It is a schematic diagram of the combination of wave absorption honeycomb and carbon fiber reflection plate and carbon fiber end rib glue.

[0033] Figure 6 It is a schematic diagram of the combination of wave absorption honeycomb and carbon fiber reflection plate and carbon fiber end rib glue.

[0034] In the figure: 1 polyimide wave-transparent skin; 2 wave-absorbing honeycomb; 3 carbon fiber reflection plate; 4 carbon fiber end rib; 5 honeycomb milling cutter; 6 honeycomb calibration film; 7 polyimide fiber composite milling cutter; 8 pulse laser processing cutter; 9 plate core glue film; 10 plate plate glue film; 11 foaming glue. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present application clearer and more intelligible, the present application will be described in detail below with reference to the accompanying drawings.

[0036] Example 1

[0037] A leading edge structure of a polyimide fiber composite stealth sandwich structure, comprising a leading edge using a high wave-transparent polyimide wave-transparent skin 1, a wave-absorbing honeycomb 2, a carbon fiber reflection plate 3, a carbon fiber end rib 4, a plate core glue film 9, a plate plate glue film 10 and foaming glue 11, and the structure exploded view is as shown in Figure 1 .

[0038] The polyimide wave-transparent skin 1 is a variable-thickness thin-walled laminated plate structure, which is in the shape of U or V, and uses epoxy resin as the matrix, which can effectively improve its wave-transparent performance; the polyimide wave-transparent skin 1 is provided with carbon fiber end ribs 4 on both sides, which is a half-open box structure, and uses carbon fiber layers with wave-absorbing prepreg on the surface; the carbon fiber reflection plate 3 is a V-shaped pyramid structure, which is made of carbon fiber composite material, and is arranged at the rear end opening of the polyimide wave-transparent skin 1 as a reflection layer, and forms a closed space after being combined with the polyimide wave-transparent skin 1 and the carbon fiber end ribs 4 on both sides, which is a filling cavity of the wave-absorbing honeycomb 2, and the low-frequency effect is improved by adjusting the shape or angle of the carbon fiber reflection plate 3; the wave-absorbing honeycomb 2 is a gradient wave-absorbing honeycomb, which is arranged in the filling cavity as a core layer.

[0039] The wave-absorbing honeycomb 2 and the lamination plate area of the polyimide wave-transparent skin 1 are bonded by using a plate core adhesive film 9; the polyimide wave-transparent skin 1 and the carbon fiber reflection plate 3 and the carbon fiber end rib 4 are bonded by using a plate-to-plate adhesive film 10; the wave-absorbing honeycomb 2 and the carbon fiber reflection plate 3 and the carbon fiber end rib 4 are glued and formed by using foaming glue 11, as shown in the figure. Figure 6

[0040] As shown in the figure, Figure 2 The wave-absorbing principle diagram of the stealth sandwich structure, the carbon fiber reflection plate 3 is made of carbon fiber material and constitutes a reflection surface of electromagnetic waves, so that the electromagnetic waves are greatly attenuated after being doubly absorbed by the multi-layer penetration loss and the wave-absorbing layer (i.e. the core layer composed of the wave-absorbing honeycomb 2), and at the same time, the reflection angle of the carbon fiber reflection plate 3 can be adjusted to effectively improve the absorption effect of low-frequency radar waves.

[0041] The scheme of the application optimizes the three targets of stealth characteristics, structure weight reduction and manufacturing precision through ingenious material combination and structure design, is novel and creative. The leading edge typical structure has low manufacturing risk, simple assembly and maintenance, strong universality, and can be widely applied to the leading edge and vertical and horizontal tail leading edge structures of various stealth aircrafts.

[0042] A manufacturing method of a polyimide fiber composite stealth sandwich structure, the manufacturing method comprising the following steps:

[0043] Step 1: forming the polyimide wave-transparent skin 1 by using a male die and a uniform pressure cover plate; forming and manufacturing the carbon fiber reflection plate 3 by using a fabric prepreg female die; forming the carbon fiber end rib 4 by using carbon fiber fabric prepreg through a male die; processing the edges of the polyimide wave-transparent skin 1 to a net size by using a polyimide fiber composite milling cutter 7 and a pulse laser processing cutter 8 to avoid edge processing after solidification, as shown in the figure; curing and forming the polyimide wave-transparent skin 1 with completed edge processing by using polyimide fiber reinforced prepreg; curing and forming the carbon fiber reflection plate 3 by using carbon fiber prepreg; curing and forming the carbon fiber end rib 4 by using polyimide wave-transparent fiber reinforced wave-absorbing prepreg and carbon fiber prepreg. Figure 5

[0044] Step 2: forming the wave-absorbing honeycomb 2 by using numerical control processing through a honeycomb milling cutter 5, as shown in the figure, wherein a secondary processing allowance is left in the contact area of the wave-absorbing honeycomb 2 and the polyimide wave-transparent skin 1. In order to improve the shape precision of the wave-absorbing honeycomb 2, a five-axis numerical control machining center is used for processing. Figure 3

[0045] ​​​Step 3, the carbon fiber reflector plate 3 and the carbon fiber end rib 4 are fixed and positioned by the combined mold, and the wave-absorbing honeycomb 2 is combined and formed, the foaming glue 11 is used for gluing and forming by secondary gluing process, and the overall combined structure is made, and the gluing surface is non-destructively detected, as shown in Figure 3 After the combined structure is formed, the outer shape of the honeycomb is processed, and the gap between the combined structure and the polyimide wave-transparent skin 1 is checked by the honeycomb checking film 6, and the checking satisfies the gluing quality condition, and the next step is performed, as shown in Figure 4 .

[0046] Step 4, after the combined structure is positioned, the polyimide wave-transparent skin 1 is glued to the combined structure as a whole structure, wherein the polyimide wave-transparent skin 1 and the carbon fiber reflector plate 3 and the carbon fiber end rib 4 are adhered by the plate film 10, and the wave-absorbing honeycomb 2 and the polyimide wave-transparent skin 1 are adhered by the plate core film 9. After the gluing and curing are completed, non-destructive detection is performed.

[0047] Step 5, a digital measuring instrument is used to detect the shape of the final structure, and a detection report is provided.

[0048] Example 2

[0049] This embodiment is basically the same as example 1, the difference is that:

[0050] The polyimide wave-transparent skin 1 uses bismaleimide and cyanate resin as the matrix, the carbon fiber reflector plate 3 is a bevelled corner cone structure, and the wave-absorbing honeycomb 2 is a homogeneous wave-absorbing honeycomb.

[0051] In step 2, the wave-absorbing honeycomb 2 is machined after blank splicing, the splicing area is glued with wave-transparent foaming glue material, and no machining allowance is reserved during shape processing.

[0052] In step 3, the carbon fiber reflector plate 3 and the carbon fiber end rib 4, the wave-absorbing honeycomb 2 and the skin 1 are first checked and combined, and the whole combined structure is glued and cured after the checking satisfies the gluing quality condition.

[0053] According to the stiffness of the wave-absorbing honeycomb 2, two gluing combination schemes can be used, when the stiffness is low, the stealth sandwich structure manufacturing method in example 1 is selected; when the stiffness is high, the stealth sandwich structure manufacturing method in example 2 is selected. In order to facilitate non-destructive testing and improve the internal quality of gluing, the method in example 1 is generally selected; when the quality requirement is not high, the method in example 2 can be selected.

[0054] The above embodiments only express the implementation ways of the present application, and cannot be understood as the limitation to the scope of the present application patent. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A polyimide fiber composite stealth sandwich structure, characterized by, The stealth sandwich structure comprises a wave-transparent skin, a core layer and a reflection layer, and specifically comprises a polyimide wave-transparent skin (1), a wave-absorbing honeycomb (2), a carbon fiber reflection plate (3), a carbon fiber end rib (4), a core film (9), a plate film (10) and foaming glue (11). The polyimide wave-transparent skin (1) is a variable-thickness thin-walled laminated plate structure, is in the shape of U or V, is made of polyimide fiber composite material, and can effectively improve the wave-transparent performance; the polyimide wave-transparent skin (1) is provided with carbon fiber end ribs (4) on both sides and is in a half-open box structure, and is made of a carbon fiber layer with wave-absorbing prepreg on the surface; the carbon fiber reflection plate (3) is in the shape of a V-shaped pyramid or an oblique cutting pyramid structure, is made of carbon fiber composite material, is arranged at the rear end opening of the polyimide wave-transparent skin (1) as a reflection layer, and forms a closed space after being combined with the polyimide wave-transparent skin (1) and the carbon fiber end ribs (4) on both sides, and serves as a filling cavity of the wave-absorbing honeycomb (2); the wave-absorbing honeycomb (2) is homogeneous or gradient wave-absorbing honeycomb, and is arranged in the filling cavity as a core layer. The wave-absorbing honeycomb (2) and the polyimide wave-transparent skin (1) are bonded by using the core film (9); the polyimide wave-transparent skin (1) and the carbon fiber reflection plate (3) and the carbon fiber end rib (4) are bonded by using the plate film (10); and the wave-absorbing honeycomb (2) and the carbon fiber reflection plate (3) and the carbon fiber end rib (4) are bonded by using the foaming glue (11) or the film. The polyimide wave-transparent skin (1), the wave-absorbing honeycomb (2) and the carbon fiber reflection plate (3) utilize the negative thermal expansion coefficient of polyimide fiber and carbon fiber to keep the consistency of thermal expansion during the bonding and curing process.

2. The polyimide fiber composite stealth sandwich structure of claim 1, wherein The carbon fiber reflection plate (3) improves the low-frequency effect by adjusting the shape or angle.

3. The polyimide fiber composite stealth sandwich structure of claim 1, wherein The polyimide wave-transparent skin (1) selects one or two of epoxy resin, bismaleimide resin and cyanate resin as the matrix.

4. The polyimide fiber composite stealth sandwich structure of claim 1, wherein The core film (9) and the plate film (10) are matched with the temperature resistance requirement of the stealth sandwich structure.

5. A method of manufacturing the polyimide fiber composite stealth sandwich structure according to any one of claims 1 to 4, characterized in that, The manufacturing method comprises the following steps: Step 1: after the edges of the polyimide wave-transparent skin (1) are processed to the net size, the polyimide fiber reinforced prepreg is cured and formed; the carbon fiber reflection plate (3) is cured and formed by using carbon fiber prepreg; and the carbon fiber end rib (4) is cured and formed by using the wave-absorbing prepreg with polyimide wave-transparent fiber reinforcement and carbon fiber prepreg; Step 2: the wave-absorbing honeycomb (2) is formed by numerical control processing, and a secondary processing allowance is left in the contact area of the wave-absorbing honeycomb (2) and the polyimide wave-transparent skin (1); Step 3: the carbon fiber reflection plate (3) and the carbon fiber end rib (4) cured and formed in step 1 and the wave-absorbing honeycomb (2) are bonded and formed by using the foaming glue (11) or the film, the bonding surface is detected after the combined structure is formed, the outer shape of the wave-absorbing honeycomb (2) is processed after the combined structure is formed, and the gap between the combined structure and the polyimide wave-transparent skin (1) is checked by using the honeycomb checking film (6). Step 4, after positioning the combined structure, the polyimide wave-transparent skin (1) is glued to the combined structure as an integral structure, wherein the polyimide wave-transparent skin (1) and the carbon fiber reflective plate (3) and the carbon fiber end rib (4) are bonded by using a plate-to-plate adhesive film (10), and the wave-absorbing honeycomb (2) and the polyimide wave-transparent skin (1) are bonded by using a plate-to-core adhesive film (9); After the gluing and curing is completed, non-destructive testing is performed; Step 5, the final structure is subjected to shape detection.

6. The method of manufacturing a polyimide fiber composite stealth sandwich structure according to claim 5, wherein In step 1, different edge processing schemes are adopted according to the structural characteristics of different polyimide wave-transparent skins (1): ① for the no excess assembly area, a mold is used to form the edge to the net size; ② for the chamfering area of the variable curvature edge, numerical control milling is used for forming; ③ for the drainage hole and reference hole features, pulse laser processing is used for forming.

7. The method of manufacturing a polyimide fiber composite stealth sandwich structure according to any one of claims 5-6, wherein When the wave-absorbing honeycomb (2) has high stiffness or the quality requirement of the stealth sandwich structure is not high, the manufacturing method is replaced by: Step 1, after the edge of the polyimide wave-transparent skin (1) is processed to the net size, polyimide fiber reinforced prepreg is used for curing and forming; the carbon fiber reflective plate (3) is cured and formed by using carbon fiber prepreg; the carbon fiber end rib (4) is cured and formed by using polyimide wave-transparent fiber reinforced wave-absorbing prepreg and carbon fiber prepreg; Step 2, the wave-absorbing honeycomb (2) is formed by numerical control processing, and the outer shape surface does not have a processing allowance; Step 3, the carbon fiber reflective plate (3) and the carbon fiber end rib (4), the wave-absorbing honeycomb (2) and the skin 1 are first combined and checked, and after the checking meets the gluing quality condition, the integral combination is glued and cured at one time, wherein the polyimide wave-transparent skin (1) and the carbon fiber reflective plate (3) and the carbon fiber end rib (4) are bonded by using a plate-to-plate adhesive film (10), and the wave-absorbing honeycomb (2) and the polyimide wave-transparent skin (1) are bonded by using a plate-to-core adhesive film (9); after the gluing and curing is completed, non-destructive testing is performed; Step 4, the final structure is subjected to shape detection.

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