Preparation method of flexible honeycomb core suitable for complex structure curved surface of aircraft

Abstract

The invention discloses a preparation method of a flexible honeycomb core suitable for a complex structure curved surface of an aircraft, a finished product is a multi-layer and multi-column unit structure with hole lattices, and the preparation method comprises the following steps: S1, coating selected aramid paper with an adhesive tape; s2, overlapping the multiple layers of adhesive aramid paper prepared in the step S1; s3, carrying out hot pressing on the aramid paper stacked block material; s4, redundant leftover materials of the hot-pressed aramid paper stacked blocks are cut off; s5, fixing the edge-cut aramid paper stack block on a stretching machine; s6, the positions of the rubber strips of the hole grids are fixed one by one through a clamp; s7, shaping the stretched aramid paper honeycomb core; and S8, the clamp is removed from the shaped aramid paper, and then gum dipping and curing are carried out to obtain complex curved surface flexible aramid paper honeycomb products with different densities. The honeycomb produced by the manufacturing method of the flexible honeycomb has related characteristics of a common hexagonal honeycomb, meanwhile, the obtained product can be bent in a large curvature in a plane, and meanwhile, the stability of the hole grids is kept.

Description

Technical Field

[0001] The invention relates to the technical field of composite polymer materials, and in particular to a method for preparing a flexible honeycomb core suitable for a complex structural curved surface of an aircraft. Background Art

[0002] Honeycomb core material is a representative lightweight and high-strength composite material. It is widely used in the aerospace field due to its light weight, high mechanical strength, good dielectric properties, flame retardancy and other characteristics. Honeycombs are generally stable regular hexagonal flat plate structures, which are difficult to achieve large curvature bending. However, the aircraft structure is complex, and complex curved surface shapes can only be obtained through CNC numerical control processing or preforming processes. However, these two methods have their own advantages and disadvantages: although the products obtained by CNC processing have high precision and regular pores, the honeycomb wall is not perpendicular to the curved surface shape, resulting in large performance differences in all directions; the pores of the preformed honeycomb are perpendicular to the curved surface, and the performance in all directions is more stable, but it is easy to produce pore deformity, cracking, glue flow and other problems, and the process is complicated, and it cannot meet the conformal requirements of large curvature complex structures. Therefore, ordinary hexagonal honeycomb cores are not suitable for complex curved surface structures such as aircraft radomes and curved interiors. At present, most of the overstretched honeycombs with a certain degree of flexibility are used on the market to meet this demand, but it is limited to bending in a single direction, and bending in other directions still causes pore deformation and collapse, so it is not the best choice for complex curved surface structures.

[0003] Chinese patent CN2024100710841, disclosed in the patent, is entitled: A flexible aramid honeycomb core suitable for complex curved surfaces and its manufacturing method. The flexible aramid honeycomb core includes multiple layers of aramid paper adhered to each other, and the single layer of aramid paper of the multi-layer aramid paper is folded into a trapezoidal unit structure whose cross sections are connected in sequence and inverted. The shape of multiple groups of trapezoidal unit structures connected in sequence and inverted is like multiple "B" connected, and the upper bottom of the trapezoidal unit structure is open, and the adjacent trapezoidal unit structures that are inverted in sequence share the waist edge; the adjacent two layers of aramid paper form multiple rectangular through holes with long sides embedded in the cross section. The manufacturing method of the present invention includes S1 preparation of solidified mixed liquid, S2 adsorption of aramid paper solidified mixed liquid, S3 solidification of aramid paper trapezoidal unit structure, S4 demoulding of trapezoidal unit structure aramid paper, S5 glue coating and hot pressing, and S6 molding processing. The flexible aramid honeycomb core manufactured by the present invention can meet the complex curved surfaces with different curvatures and meet the application of ±90 degree curved surfaces.

[0004] However, in practical applications, such as Figure 1 As shown in the figure, due to the inward depression in the middle of the honeycomb core cells, when applied to complex curved surfaces with different curvatures, the cells cannot always be perpendicular to the structural surface, and part of the structure collapses; within a certain range, as the surface curvature increases, the honeycomb strength decreases instead of increasing, and it cannot be fully applied to complex curved surface structural parts of aircraft, and does not have good conformability. Figure 1 It can be clearly seen that the above invention curls horizontally. Due to the concave structure of the pores, although it meets the function of adapting to large curvature bending, as the take-up rate increases, the concave structure in the middle of the pores reaches its extreme. Figure 2 As shown, this will cause the structure to collapse.

[0005] The defects are as follows: 1. The grid is an "I"-shaped concave structure, which can easily lead to grid collapse in complex curved surface applications (especially when the curvature increases); 2. The mechanical properties decrease as the curvature increases, and cannot meet the high dynamic load requirements of the aircraft. Summary of the invention

[0006] To this end, the present invention provides a method for preparing a flexible honeycomb core suitable for complex structural surfaces of aircraft. This article invents a manufacturing process for a new type of flexible honeycomb with plasticity in all directions within a certain thickness range. The honeycomb produced according to the present invention not only has the relevant characteristics of a hexagonal honeycomb, but also can realize the shaping of any complex curved surface, and plays a role in keeping the cells always perpendicular to the structural surface without collapse. At the same time, the honeycomb strength does not decrease but increases with the increase of surface curvature within a certain range. It is suitable for complex curved surface structural parts of aircraft and has good conformability.

[0007] To achieve the above object, the present invention provides a method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft, wherein the finished product is a multi-layer, multi-row unit structure with pores, wherein the finished product is a multi-layer honeycomb core unit structure, wherein the unit structure is a bow-tie structure composed of an inverted symmetrical trapezoid; each layer comprises a plurality of unit structures, and two adjacent unit structures are highly adhered by a glue strip staggered by half the bow-tie structure, and the preparation method is as follows: S1. Use the selected aramid paper to coat the strip, wherein the strip width is related to the cell size of the honeycomb core. Assuming the strip width is a, the cell side length is b, then the pitch is a+2b, where the pitch is the distance between two adjacent strips, and the above dimensions must satisfy a<b<2a; S2. The multi-layer aramid paper with adhesive prepared by S1 is stacked, wherein the adhesive strip of the upper aramid paper with adhesive and the adhesive strip of the lower aramid paper with adhesive are staggered by a spacing of b, and the above steps are repeated to stack the multi-layer aramid paper with adhesive to obtain an aramid paper stack; S3. Hot pressing the aramid paper stack material; S4. Cutting off the excess scraps of the aramid paper stack after hot pressing; S5. Fix the cut aramid paper block to a stretching machine, start the stretching machine and stretch it at a specified speed until the honeycomb is rectangular; S6. Fix the position of the rubber strips of the cells one by one with a fixture, apply a certain external force to prevent rebound, and adjust the force in real time as the cell shape changes until the cell is in a bow-tie shape, wherein the honeycomb cell angle is 75±5°, thereby obtaining an aramid paper honeycomb core; S7. shaping the stretched aramid paper honeycomb core; S8. Remove the fixture from the shaped aramid paper, then perform dipping and curing, and repeat the dipping and curing process to obtain a complex curved flexible aramid paper honeycomb product with different densities.

[0008] Preferably, in the step S1, the aramid paper is any one of quartz fiber cloth, carbon fiber, and glass cloth, and the corresponding finished product is a quartz fiber cloth honeycomb core, a carbon fiber honeycomb core, and a glass cloth honeycomb core.

[0009] Preferably, the aramid paper and the carbon fiber or quartz fiber cloth are alternately laminated in a mass ratio of 1:1 to 1:3, and the staggered spacing of each layer of laminated rubber strips is 0.8b-1.2b.

[0010] Preferably, the width of the clamp is equal to the width a of the rubber strip, and the structure thereof is a two-layer structure, with one side being embedded in the position of the rubber strip of the honeycomb cell wall.

[0011] Preferably, the rubber strip a=0.5-1.2mm, and the grid side length b=1.0-2.0mm.

[0012] Preferably, in step S3, the glue strips are aligned up and down and the paper is flat; in step S4, the glue strip edges are perpendicular to the horizontal edges and parallel to the longitudinal edges; in step S7, the aramid paper honeycomb core forming temperature is 100-180°C, the forming time is 3-5h, and the cooling rate is 20-30°C / min.

[0013] Preferably, the dipping in step S8 needs to be carried out in a specific dipping mechanism, the glue solution is formulated according to different materials, and after dipping, it is cured in a special oven, the curing temperature is 120-230° C., and the curing time is 1-2 hours.

[0014] Preferably, the aramid paper honeycomb core is composited with the skin to obtain a flexible honeycomb core structural member with a complex structural surface of an aircraft.

[0015] Preferably, the flexible honeycomb core structural member of the aircraft's complex structural curved surface is made of a composite of a quartz fiber cloth honeycomb core, a carbon fiber honeycomb core, a glass cloth honeycomb core and a skin.

[0016] Preferably, the skin is made of carbon fiber reinforced epoxy resin composite material, and the composite process adopts a vacuum bag curing method, the curing pressure is 0.2-0.4 MPa, and the curing temperature is 120-150°C.

[0017] The core innovation of the present invention lies in: 1. Innovation in the honeycomb core cell structure prepared by the present invention, bow-shaped cell design: By reversing symmetric trapezoidal units to form a bow structure, ensuring the vertical stability (angle 75 ± 5°) of the cells during stretching or compression, and avoiding collapse; Multi-directional adaptability: The cells can be locally indented (compressed) or protruded (stretched) to achieve large-curvature bending in any in-plane direction (±75° without collapse).

[0018] 2. Process optimization, control of rubber strip parameters: The width (a) of the rubber strip and the side length (b) of the cell satisfy a < b < 2a, and the pitch is a + 2b, optimizing the balance between bonding strength and flexibility.

[0019] Fixture shaping technology: Upper and lower layer fixtures with the same width as the rubber strip are embedded in the cell walls, and the external force is adjusted in real time to stabilize the bow shape and reduce rebound.

[0020] Dipping in glue and step-by-step curing: By repeating dipping in glue and curing at different temperature segments (120 - 230°C / 1 - 2h), the density and mechanical properties of the honeycomb core are improved.

[0021] 3. Mechanical advantages of the bow shape with an angle of 75 ± 5°, stress distribution uniformity, 3.1 Geometric symmetry: During the stretching and compression processes of the bow-shaped cell with an angle of 75 ± 5°, the inclination angles of the cell walls can form a symmetric stress transfer path, enabling the load to be evenly dispersed between the honeycomb walls.

[0022] 3.2 Node optimization: At this angle, the bending radius of the cell connection nodes is relatively large, avoiding stress concentration caused by sharp corners. Through finite element simulation, the maximum stress value of the cell with a 75° angle is reduced by about 25% compared to that with a 60° angle, and the distribution is more uniform than that with a 90° angle.

[0023] 3.3 Critical curvature improvement: When the angle is 75°, the honeycomb core can adapt to bending with a curvature of ±75° while the cells still remain vertical; if the angle is 60°, the cells start to tilt at a curvature of ±50°; when the angle is 90°, although the compressive strength is slightly higher, the curvature limit is only ±60°.

[0024] The beneficial effects of the present invention are: Compared with the prior art, the flexible aramid honeycomb core manufactured by the present invention has the following advantages: 1. The honeycomb produced by the manufacturing method of the flexible honeycomb of the present invention not only has the relevant characteristics of a general hexagonal honeycomb, but also the obtained product can achieve large-curvature bending in the plane and at the same time maintain the stability of the cells.

[0025] 2. The flexible honeycomb of the present invention is suitable for concave, convex or irregular complex curved surfaces, including concave, convex and irregular surfaces, which reduces the collapse caused by the honeycomb splicing process, ensures the integrity of the honeycomb structure, and improves its stress strength.

[0026] 3. The present invention is applicable to complex curved surfaces to avoid damage and collapse of honeycomb cells, thereby reducing the uncertainty of nondestructive testing of honeycomb structures and reducing the risks of use.

[0027] 4. The present invention meets the quality requirements of lightweight: it has excellent mechanical properties in all directions and meets the needs of lightweight. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram in the prior art; Figure 2 It is a schematic diagram of a structure adapted to a large curvature limit in the prior art; Figure 3 It is a schematic diagram of the structure of the present invention; Figure 4 It is a schematic diagram of the use of the clamp of the present invention; Figure 5 It is a schematic diagram of the structure of the present invention when it is compressed; Figure 6 It is a schematic diagram of the structure of the present invention during stretching; Figure 7 This is a schematic diagram of the actual finished product of the present invention; In the figure, 1-honeycomb cell angle; 2-honeycomb wall; 3-clamp. DETAILED DESCRIPTION

[0029] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0031] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0032] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Embodiment 1, as Figure 3-Figure 7 As shown, a method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft, wherein the finished product is a multi-layer honeycomb core unit structure, wherein the unit structure is a bow-tie structure composed of inverted symmetrical trapezoids; each layer comprises a plurality of unit structures, and two adjacent unit structures are highly adhered by adhesive strips staggered by half of the bow-tie structure, and the multiple layers are adhered by adhesive strips to form a multi-layer honeycomb core, and the preparation method thereof is as follows: S1. Use the selected aramid paper to coat the strip, wherein the strip width is related to the cell size of the honeycomb core. Assuming the strip width is a, the cell side length is b, then the pitch is a+2b, where the pitch is the distance between two adjacent strips, and the above dimensions must satisfy a<b<2a; S2. The multi-layer adhesive aramid paper obtained by S1 is stacked, wherein the adhesive strip of the upper layer of adhesive aramid paper and the adhesive strip of the lower layer of adhesive aramid paper are staggered by a spacing of b, and the adhesive strips are aligned up and down and the paper is flat, and the above steps are repeated to stack the multi-layer adhesive aramid paper to obtain an aramid paper stack; S3. The aramid paper stack material is hot pressed, and the pressure parameters are adjusted according to the thickness of the aramid paper stack and the performance of the aramid paper, wherein the pressure range is 5-10kgf / cm2, and the curing temperature of the rubber strip is controlled at 150-200℃ / 3-5h; S4. Cut off the excess scraps of the aramid paper block after heat pressing, ensure that the edge of the rubber strip is perpendicular to the horizontal edge line, and the edge of the rubber strip is parallel to the longitudinal edge line, and cut the size of the aramid paper block after heat pressing according to production requirements; S5. Fix the cut aramid paper block to a stretching machine, start the stretching machine and stretch it at a specified speed until the honeycomb is rectangular; S6. Fix the position of the rubber strip of each cell with a clamp 3, wherein the width of the clamp is equal to the width a of the rubber strip, and the structure is a two-layer structure, wherein one side is embedded in the position of the rubber strip of the honeycomb cell honeycomb wall 2, and a certain external force is applied to prevent rebound, and the force is adjusted in real time as the cell shape changes until the cell is in a bow-tie shape, wherein the honeycomb cell angle 1 is 75±5°, thereby obtaining an aramid paper honeycomb core; S7. The stretched aramid paper honeycomb core is shaped, the aramid paper honeycomb core shaping temperature is 100-180°C, the shaping time is 3-5h, and the cooling rate is 20-30°C / min; S8. Remove the fixture from the shaped aramid paper, and then carry out dipping and curing. The dipping needs to be carried out in a specific dipping mechanism. The glue is formulated according to different materials. After dipping, it is cured in a special oven. The curing temperature is 120-230°C and the curing time is 1-2h. Repeat the dipping and curing process to obtain complex curved flexible aramid paper honeycomb products with different densities.

[0034] Example 2 is basically the same as Example 1, except that the aramid paper in Example 1 is replaced with quartz fiber cloth, thereby preparing a quartz fiber cloth honeycomb product.

[0035] Example 3 is basically the same as Example 1, except that the aramid paper in Example 1 is replaced with carbon fiber, thereby preparing a carbon fiber honeycomb product.

[0036] Example 4 is basically the same as Example 1, except that the aramid paper in Example 1 is replaced with glass cloth, thereby preparing a glass cloth honeycomb product.

[0037] Example 5, a flexible honeycomb core structural component suitable for aircraft with complex structural curved surfaces, which is obtained by compounding the aramid paper honeycomb core and skin of Example 1 to obtain a flexible honeycomb core structural component for aircraft with complex structural curved surfaces.

[0038] Example 6, a flexible honeycomb core structural component suitable for aircraft with complex structural curved surfaces, which is obtained by compounding the quartz fiber cloth honeycomb and skin of Example 2 to obtain a honeycomb core structural component for aircraft with complex structural curved surfaces.

[0039] Example 7, a flexible honeycomb core structural component suitable for aircraft complex structural curved surfaces, which is obtained by compounding the carbon fiber cloth honeycomb and skin of Example 2 to obtain a honeycomb core structural component for aircraft complex structural curved surfaces.

[0040] Example 8, a flexible honeycomb core structural component suitable for aircraft with complex structural curved surfaces, which is obtained by compounding the glass cloth honeycomb and skin of Example 2 to obtain a honeycomb core structural component for aircraft with complex structural curved surfaces.

[0041] The honeycomb products prepared by Examples 1-4 and the honeycomb core structural parts prepared by Examples 5-8 have performance parameters as shown in Table 1 based on the data of Comparative Example 1 of CN2024100710841: Table 1 L-axis shear strength (MPa) W-axis shear strength (MPa) Plane compressive strength (MPa) Applicable to large curvature ±75° collapse Example 1 2.36 1.89 6.53 none Example 2 2.08 1.88 6.46 none Example 3 2.19 1.70 6.36 none Example 4 2.28 1.79 6.40 none Example 5 2.52 1.98 6.72 none Example 6 2.26 1.96 6.65 none Example 7 2.34 1.78 6.57 none Example 8 2.45 1.87 6.60 none Comparative Example 1.50 1.20 4.80 ±45° has collapse It can be seen from Table 1 that the honeycomb products and honeycomb core structural parts manufactured by the present invention have good mechanical properties and can adapt to complex curved surfaces. They will not collapse when used on large curvatures. After composite skinning of Examples 1-4, honeycomb core structural parts are obtained, and the mechanical properties are enhanced.

[0042] The comparison between the finite element simulation and the experiment for the bow-tie shape angle of the present invention is shown in Table 2 below: Table 2 Angle Maximum stress (MPa) Critical collapse curvature (±°) In-plane shear strength (MPa) 60° 85.6 50 1.72 75° 63．2 75 1.89 90° 70.5 60 1.65 From Table 2, we can conclude that the 75° angle has the best comprehensive performance, the lowest stress value and the strongest curvature adaptability. The process adaptability and manufacturing feasibility of the angle. The bow-tie shape of the 75° angle can be precisely controlled by the fixture during the stretching process, while the 60° angle is prone to tearing of the aramid paper due to severe deformation, and the 90° angle requires a higher tensile force, which increases the equipment load. The process tolerance of ±5° can cover slight deviations in manufacturing and ensure the stability of the honeycomb core performance. If the angle deviation exceeds ±8°, the critical curvature will drop below ±60°.

[0043] The basic principle of the present invention is to design the honeycomb cells into a bow-tie shape, so that the honeycomb cells have instability, stretchability and flexibility in all directions, ensuring that the honeycomb can fit any complex structural surface and has excellent free deformation ability within a certain thickness range. Figure 3 The flexible honeycomb of the present invention is suitable for composite materials with complex curved surfaces and has good conformability. When used, the cells can be kept perpendicular to the surface of the structure without collapse. Figure 4 As shown, within a certain range, the honeycomb strength increases instead of decreases as the surface curvature increases.

[0044] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft, wherein the finished product is a multi-layer, multi-row unit structure with cells, characterized in that: The finished product is a multi-layer honeycomb core unit structure, wherein the unit structure is a bow-tie structure composed of an inverted symmetrical trapezoid; each layer comprises a plurality of unit structures, and two adjacent unit structures are highly adhered by a half-staggered bow-tie structure through a glue strip, and the preparation method is as follows: S1. Use the selected aramid paper to coat the strip, wherein the strip width is related to the cell size of the honeycomb core. Assuming the strip width is a, the cell side length is b, then the pitch is a+2b, where the pitch is the distance between two adjacent strips, and the above dimensions must satisfy a<b<2a; S2. The multi-layer aramid paper with adhesive prepared by S1 is stacked, wherein the adhesive strip of the upper aramid paper with adhesive and the adhesive strip of the lower aramid paper with adhesive are staggered by a spacing of b, and the above steps are repeated to stack the multi-layer aramid paper with adhesive to obtain an aramid paper stack; S3. Hot pressing the aramid paper stack material; S4. Cutting off the excess scraps of the aramid paper stack after hot pressing; S5. Fix the cut aramid paper block to a stretching machine, start the stretching machine and stretch it at a specified speed until the honeycomb is rectangular; S6. Fix the position of the rubber strips of the cells one by one with a fixture, apply a certain external force to prevent rebound, and adjust the force in real time as the cell shape changes until the cell is in a bow-tie shape, wherein the honeycomb cell angle is 75±5°, thereby obtaining an aramid paper honeycomb core; S7. shaping the stretched aramid paper honeycomb core; S8. Remove the fixture from the shaped aramid paper, then perform dipping and curing, and repeat the dipping and curing process to obtain a complex curved flexible aramid paper honeycomb product with different densities.

2. The method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft according to claim 1, characterized in that: In the step S1, the aramid paper may be any one of quartz fiber cloth, carbon fiber, and glass cloth, and the corresponding finished product is a quartz fiber cloth honeycomb core, a carbon fiber honeycomb core, or a glass cloth honeycomb core.

3. The method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft according to claim 2, characterized in that: The aramid paper and the carbon fiber or quartz fiber cloth are alternately stacked in a mass ratio of 1:1 to 1:3, and the staggered spacing of each layer of stacked rubber strips is 0.8b-1.2b.

4. The method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft according to claim 1, characterized in that: The width of the clamp is equal to the width a of the rubber strip, and the structure thereof is a two-layer structure, and the rubber strip position is embedded in the honeycomb cell honeycomb wall through one side.

5. The method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft according to claim 1, characterized in that: The rubber strip a is 0.5-1.2 mm, and the grid side length b is 1.0-2.0 mm.

6. The method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft according to claim 1, characterized in that: In step S3, ensure that the rubber strip is aligned up and down and the paper is flat; in step S4, ensure that the edge of the rubber strip is perpendicular to the horizontal edge line and parallel to the longitudinal edge line; in step S7, the aramid paper honeycomb core is set at a temperature of 100-180°C, a setting time of 3-5h, and a cooling rate of 20-30°C / min.

7. The method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft according to claim 1, characterized in that: In step S8, the dipping process needs to be carried out in a specific dipping mechanism, and the glue solution is prepared according to different materials. After dipping, the dipping process is cured in a special oven at a curing temperature of 120-230° C. and a curing time of 1-2 hours.

8. The method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft according to claim 1, characterized in that: A flexible honeycomb core structural component with complex structural surface of aircraft is obtained by compounding aramid paper honeycomb core and skin.

9. The method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft according to claim 8, characterized in that: The flexible honeycomb core structural component of the aircraft's complex structural curved surface is made of a composite of a quartz fiber cloth honeycomb core, a carbon fiber honeycomb core, a glass cloth honeycomb core and a skin.

10. The method for preparing a flexible honeycomb core suitable for complex structural curved surfaces of aircraft according to claim 8, characterized in that: The skin is made of carbon fiber reinforced epoxy resin composite material, and the composite process adopts a vacuum bag curing method, the curing pressure is 0.2-0.4MPa, and the curing temperature is 120-150°C.

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