A honeycomb stabilization process, honeycomb core, and sandwich structure

Abstract

The application discloses a honeycomb stabilization treatment method, a honeycomb core and a sandwich structure member, and relates to the technical field of honeycomb core processing. The method comprises the following steps: calculating and cutting a honeycomb mother material according to actual honeycomb size of a product to obtain a to-be-stabilized honeycomb, wherein the upper and lower surface sizes of the to-be-stabilized honeycomb are the same as the actual honeycomb upper and lower surface sizes of the product, and the bevel size of the to-be-stabilized honeycomb is larger than the actual honeycomb bevel size of the product; performing plane stabilization treatment on the upper and lower surfaces of the to-be-stabilized honeycomb to obtain a primary stabilized honeycomb; processing the bevel size of the primary stabilized honeycomb to be the same as the actual honeycomb bevel size of the product to obtain a secondary-processed primary stabilized honeycomb; and performing bevel stabilization treatment on the secondary-processed primary stabilized honeycomb to obtain a stabilized honeycomb. The application solves the problem of insufficient lateral bearing capacity of the honeycomb core, thereby improving the overall bearing capacity of the honeycomb core, and is suitable for low-density honeycombs, and the process is simple and reliable.

Description

Technical Field

[0001] This invention belongs to the field of composite material sandwich molding technology, specifically relating to a honeycomb stabilization treatment method, a honeycomb core, and a sandwich structure. Background Technology

[0002] Weight reduction is a crucial goal in aircraft design and manufacturing, as it can enhance flight performance and fuel economy. However, if sheet metal parts are too thin, they may suffer from insufficient strength and rigidity. To address this issue, adding a lightweight, rigid sandwich material between two panels can effectively control the weight of the part while maintaining its original load-bearing capacity.

[0003] In sandwich structures, there are applications with large-thickness and large-size honeycomb cores. Due to insufficient lateral load-bearing capacity of the honeycomb, deformation and slippage are prone to occur during the skin laying and curing stages, leading to deformation or even scrapping of the final product. Currently, the composite materials industry has developed methods to improve honeycomb strength by stabilizing the top and bottom surfaces of the honeycomb and laterally splicing high-strength honeycombs. However, these methods have limitations in adapting to low-density honeycombs or due to complex manufacturing processes. To improve the manufacturing capability of large-thickness, large-angle honeycomb sandwich components, new honeycomb core processing methods need to be developed. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a honeycomb stabilization treatment method, a honeycomb core, and a sandwich structure, which compensates for the insufficient lateral load-bearing capacity of the honeycomb core, thereby improving the overall load-bearing capacity of the honeycomb core. It is applicable to low-density honeycombs, and the process is simple and reliable.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, a method for stabilizing a honeycomb structure is provided, comprising: calculating and cutting a honeycomb masterbatch according to the actual honeycomb size used in the product to obtain a honeycomb structure to be stabilized, wherein the upper and lower surface dimensions of the honeycomb structure to be stabilized are the same as the upper and lower surface dimensions of the honeycomb structure actually used in the product, and the inclined surface dimension of the honeycomb structure to be stabilized is larger than the inclined surface dimension of the honeycomb structure actually used in the product; performing planar stabilization treatment on the upper and lower surfaces of the honeycomb structure to be stabilized to obtain a preliminary stabilized honeycomb structure; processing the inclined surface dimension of the preliminary stabilized honeycomb structure to be the same as the inclined surface dimension of the honeycomb structure actually used in the product to obtain a secondary processed preliminary stabilized honeycomb structure; and performing inclined surface stabilization treatment on the secondary processed preliminary stabilized honeycomb structure to obtain a stabilized honeycomb structure.

[0007] Furthermore, the honeycomb masterbatch is calculated and cut according to the actual honeycomb size used in the product, including: cutting the upper and lower surfaces of the honeycomb masterbatch according to the actual honeycomb size used in the product; measuring the net size line of the honeycomb by projection or ruler, and obtaining the honeycomb rough processing line by extending it outward by a set distance; performing initial processing of the honeycomb according to the honeycomb rough processing line to obtain the honeycomb to be stabilized.

[0008] Furthermore, the set distance is 20mm~50mm.

[0009] Furthermore, the bottom angle of the cell to be stabilized is 20°~30°.

[0010] Further, the upper and lower surfaces of the honeycomb to be stabilized undergo planar stabilization treatment, including: dehumidifying the honeycomb to be stabilized; laying a layer of adhesive film and prepreg on the process skin according to the projection, pre-compacting the bag to remove air bubbles, placing the dehumidified honeycomb to be stabilized on the adhesive film according to the projection, and bonding the honeycomb to be stabilized to the adhesive film through bag pre-compacting; then laying another layer of adhesive film and prepreg on the honeycomb to be stabilized, with the upper layer of prepreg and adhesive film overlapping the honeycomb slope to complete the planar stabilization laying of the honeycomb to be stabilized; placing a layer of release film and breathable felt on the honeycomb to be stabilized after the planar stabilization laying is completed, sealing it with vacuum bag film and sealing strip, and then evacuating the vacuum bag film to complete the planar stabilization bag making of the honeycomb to be stabilized; sending the honeycomb to be stabilized after the planar stabilization bag making is completed into an oven, and curing the adhesive film and prepreg according to the stabilization curing regime to obtain the preliminary stabilized honeycomb.

[0011] Furthermore, the dehumidification treatment of the honeycomb to be stabilized includes: first, placing the honeycomb to be stabilized on the process skin according to the projection and fixing it initially; then, placing an isolation film and a breathable felt on the upper surface of the honeycomb to be stabilized, and sealing it with a vacuum bag film and sealing strip; then, evacuating the vacuum bag film to make the honeycomb to be stabilized completely adhere to the process skin; finally, sending it into an oven and completing the dehumidification treatment of the honeycomb to be stabilized according to the honeycomb dehumidification heating procedure.

[0012] Furthermore, the pre-stabilized honeycomb from the secondary processing undergoes a slope stabilization treatment, including: placing the pre-stabilized honeycomb back onto the process skin, and applying a layer of adhesive film and prepreg to the slope of the pre-stabilized honeycomb; then, placing a layer of release film and breathable felt in sequence, sealing it with a vacuum bag film and sealing strip, and then evacuating the vacuum bag film to complete the slope stabilization bag making of the pre-stabilized honeycomb from the secondary processing; finally, sending it into an oven to cure the adhesive film and prepreg according to the stabilization and curing regime to obtain the final stabilized honeycomb.

[0013] In a second aspect, a honeycomb core is provided, which is obtained by stabilizing the honeycomb core using the honeycomb stabilization treatment method described in the first aspect.

[0014] Thirdly, a sandwich structure is provided, wherein the sandwich structure is configured with the honeycomb core described in the second aspect.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0016] (1) This invention compensates for the problem of insufficient lateral load-bearing capacity of the honeycomb core by performing step-by-step processing and step-by-step stabilization treatment on the honeycomb core, thereby improving the overall load-bearing capacity of the honeycomb core and making it suitable for low-density honeycomb. At the same time, the process is simple and reliable.

[0017] (2) This invention improves the strength of the honeycomb slope by stabilizing the honeycomb slope, making the honeycomb a rigid structure. The slope has better compressive strength during the laying and curing process, the honeycomb deformation is small, and the part forming quality is stable. The slope stabilization avoids the problem of slope collapse when the low-density honeycomb slope is not stabilized and formed, so that the low-density honeycomb can be adapted to the manufacturing of sandwich parts with large thickness and large angle, and achieve the goal of product design weight reduction. The process skin simulates the skin shape of the actual honeycomb laying, so that the outline of the honeycomb after stabilization is consistent with the product, ensuring the manufacturing accuracy of the product. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the initial processing of honeycomb masterbatch in an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of honeycomb planar stabilization in an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of honeycomb slope stabilization in an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the honeycomb stabilization bag making process in an embodiment of the present invention;

[0022] Figure 5 This is a physical image of the final product obtained in Embodiment 1 of the present invention;

[0023] Figure 6 This is a radiographic inspection image of a sandwich component;

[0024] In the diagram, 1. honeycomb roughing line; 2. honeycomb to be stabilized; 3. honeycomb net dimension line; 4. adhesive film; 5. prepreg; 6. process skin; 7. release film; 8. breathable felt; 9. vacuum bag film; 10. sealing strip; 11. molding die; 12. stabilized honeycomb. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0026] Example 1

[0027] like Figures 1-4 As shown, a honeycomb stabilization treatment method includes: calculating and cutting honeycomb masterbatch according to the actual honeycomb size used in the product to obtain a honeycomb 2 to be stabilized, wherein the upper and lower surface dimensions of the honeycomb 2 to be stabilized are the same as the upper and lower surface dimensions of the honeycomb actually used in the product, and the inclined surface dimension of the honeycomb 2 to be stabilized is larger than the inclined surface dimension of the honeycomb actually used in the product; performing planar stabilization treatment on the upper and lower surfaces of the honeycomb 2 to obtain a preliminary stabilized honeycomb; processing the inclined surface dimension of the preliminary stabilized honeycomb to be the same as the inclined surface dimension of the honeycomb actually used in the product to obtain a secondary processed preliminary stabilized honeycomb; and performing inclined surface stabilization treatment on the secondary processed preliminary stabilized honeycomb to obtain a stabilized honeycomb 12.

[0028] The specific processing steps of the cellular stabilization treatment method of the present invention are as follows.

[0029] S1. Transfer the molding mold 11 to the mold preparation area. Use a cloth dampened with acetone to clean the stains on the surface of the molding mold 11. After the molding mold 11 is processed, place the process skin 6 on the molding mold 11 and fix the process skin 6 on the molding mold 11 using positioning pins and pressure-sensitive tape.

[0030] A piece of honeycomb master material is calculated and divided according to the actual honeycomb size used in the product. The honeycomb master material has a size of 1220×2440mm, a thickness of 46.5mm, and a honeycomb density of 48Kg / m³. This yields honeycomb 2 to be stabilized, which has a size of 1220×605mm, a thickness of 46.5mm, and a honeycomb density of 48Kg / m³. The upper and lower surface dimensions of honeycomb 2 to be stabilized are the same as those of the actual honeycomb used in the product, while the inclined surface dimension of honeycomb 2 to be stabilized is larger than that of the actual honeycomb used in the product.

[0031] S2. According to the actual dimensions of the upper and lower surfaces of the honeycomb material used in the product, cut the upper and lower surfaces of the honeycomb masterbatch using a utility knife. The masterbatch should be approximately 100mm wider than the net dimensions of the honeycomb. Measure the net dimensions of the honeycomb (line 3) by projection, and extend it by 20mm to obtain the honeycomb rough processing line 1. Perform initial honeycomb processing according to the honeycomb rough processing line 1, controlling the bottom angle of the honeycomb to be stabilized (line 2) to 25°, thus obtaining the honeycomb to be stabilized (line 2). When obtaining the honeycomb rough processing line 1 by extension, the extension dimension can be set to 20mm~50mm depending on the actual situation. The bottom angle of the honeycomb to be stabilized (line 2) can be controlled between 20° and 30° depending on the actual situation.

[0032] The upper and lower surfaces of the cell 2 to be stabilized are subjected to planar stabilization treatment to obtain a preliminary stabilized cell.

[0033] S3. Place the honeycomb 2 to be stabilized onto the process skin 6 according to the projection, and fix it with pressure-sensitive tape. Press the honeycomb 2 to be stabilized onto the process skin 6 by hand to complete the initial shaping.

[0034] S4. Place a layer of isolation film 7 and breathable felt 8 on the upper surface of the honeycomb 2 to be stabilized, and seal it with vacuum bag film 9 and sealing strip 10. Apply a vacuum of more than 800mbar to the vacuum bag film 9 through the vacuum connector so that the honeycomb 2 to be stabilized is completely attached to the process skin 6.

[0035] S5. Place the honeycomb 2 to be stabilized into an oven and heat it to 121°C at a rate of 2.5°C / min. When the hysteresis thermocouple reaches 116°C, hold it at that temperature for 90 minutes. After holding, cool it down to below 60°C at a rate of 1.5°C / min to complete the dehumidification treatment of the honeycomb. After dehumidification, remove the auxiliary materials on the surface of the honeycomb and remove the honeycomb from the process skin surface.

[0036] S6. Following the projection, lay a layer of adhesive film 4 and prepreg 5 on the process skin 6. Pre-compact the bag to remove air bubbles, ensuring a vacuum of at least 600 mbar and a pre-compaction time of at least 5 minutes. Place the dehumidified honeycomb 2 to be stabilized onto the adhesive film 4 according to the projection. Pre-compact the bag to be stabilized onto the lower adhesive film 4, ensuring a vacuum of at least 600 mbar and a pre-compaction time of at least 5 minutes. Then, lay another layer of adhesive film 4 and prepreg 5 on the honeycomb 2, overlapping the upper prepreg 5 and adhesive film 4 by 15 mm onto the honeycomb slope, completing the planar stabilization laying of the honeycomb 2. The overlap of the upper prepreg 5 and adhesive film 4 onto the honeycomb slope can be set according to actual conditions, generally 10~20 mm.

[0037] S7. Place a layer of isolation film 7 and a breathable felt 8 on the surface of the honeycomb 2 to be stabilized after the planar stabilization has been completed. Use a vacuum bag film 9 and a sealing strip 10 for sealing. Apply a vacuum of more than 800 mbar to the vacuum bag film 9 through a vacuum connector to complete the planar stabilization bag making of the honeycomb 2 to be stabilized.

[0038] S8. The honeycomb 2 to be stabilized after the planar stabilization bag making is sent into the oven and heated to 121°C at a rate of 3°C / min. When the hysteresis thermocouple reaches 116°C, it is kept at this temperature for 120 minutes. After the holding time is completed, it is cooled to below 60°C at a rate of 2°C / min to complete the curing of the film and prepreg. After curing, the auxiliary materials on the honeycomb surface are removed to obtain the preliminary stabilized honeycomb.

[0039] The bevel dimensions of the initially stabilized honeycomb are processed to be the same as the bevel dimensions of the honeycomb actually used in the product, resulting in a second-processed initially stabilized honeycomb.

[0040] S9. Using a five-axis CNC machine, the preliminary stabilized honeycomb is processed and chamfered according to the honeycomb net dimension line 3, so that the bevel size of the preliminary stabilized honeycomb is the same as the bevel size of the honeycomb actually used in the product, thus obtaining the preliminary stabilized honeycomb after secondary processing.

[0041] The pre-stabilized honeycomb from the secondary processing was subjected to sloping stabilization treatment to obtain stabilized honeycomb 12.

[0042] S10. Place the pre-stabilized honeycomb from the secondary processing back onto the process skin 6, and lay a layer of adhesive film 4 and prepreg 5 on the inclined surface of the pre-stabilized honeycomb from the secondary processing.

[0043] S11. Place a layer of isolation film 7 and a breathable felt 8 on the inclined surface of the pre-stabilized honeycomb after secondary processing. Use vacuum bag film 9 and sealing strip 10 for sealing treatment. Apply a vacuum of more than 800mbar to the vacuum bag film 9 through the vacuum connector to complete the inclined surface stabilization bag making of the pre-stabilized honeycomb after secondary processing.

[0044] S12. The honeycomb bag with the slanted stabilized shape is sent into the oven and heated to 121°C at a rate of 3°C / min. When the hysteresis thermocouple reaches 116°C, it is kept at this temperature for 120 minutes. After the temperature is kept at this temperature, it is cooled to below 60°C at a rate of 2°C / min to complete the curing of the adhesive film 4 and the prepreg 5, and the finally cured stabilized honeycomb 12 is obtained.

[0045] This invention aims to improve the adaptability of honeycomb stabilization to various honeycomb types and shorten the stabilization process. The honeycomb masterbatch is calculated and segmented according to the actual honeycomb size used in the product. The masterbatch size is 1220×2440mm, thickness is 46.5mm, and honeycomb density is 48Kg / m³. The masterbatch is approximately 100mm wider than the net honeycomb size, and a chamfer is applied to a 20mm area outside the net honeycomb size line. The roughly machined honeycomb is placed on a process skin for positioning, heat-set, and dried. After completion, a layer of adhesive film and prepreg are applied to the upper and lower planar areas of the honeycomb. After bagging, it is placed in an oven or autoclave for planar stabilization. The demolded honeycomb is then machined to the net size, and a layer of adhesive film and prepreg are applied to the chamfered areas. After bagging, it is placed in a curing oven for chamfered stabilization. Finally, it is demolded to obtain a fully stabilized honeycomb. This invention provides a method adaptable to honeycomb cores of all densities and chamfers, particularly suitable for stabilizing thick, large-chamfer honeycomb, thus improving the manufacturability of honeycomb sandwich components.

[0046] Without stabilization treatment, honeycomb cells shrink during the component placement stage, rendering the product unmanufacturing. In this embodiment, honeycomb cells stabilized on the upper and lower surfaces and at an angle exhibit shrinkage of <1mm in an autoclave at 3 bar pressure and 120°C curing temperature. The final product has a wrinkle-free outer surface, as shown in the image. Figure 5 As shown; no non-destructive defects were found inside the part, such as Figure 6 As shown, the product meets the requirements for delivery and use.

[0047] Example 2

[0048] Based on the cellular stabilization treatment method described in Embodiment 1, this embodiment provides a cellular core, which is obtained by stabilizing the cellular core using the cellular stabilization treatment method described in Embodiment 1.

[0049] Example 3

[0050] Based on the honeycomb core described in Embodiment 2, this embodiment provides a sandwich structure, wherein the sandwich structure is configured with the honeycomb core described in Embodiment 2.

[0051] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for stabilizing a honeycomb structure, characterized in that, include: The honeycomb master material is calculated and cut according to the actual honeycomb size used in the product to obtain the honeycomb to be stabilized (2). The upper and lower surface dimensions of the honeycomb to be stabilized (2) are the same as the upper and lower surface dimensions of the honeycomb actually used in the product, and the inclined surface dimension of the honeycomb to be stabilized (2) is larger than the inclined surface dimension of the honeycomb actually used in the product. The upper and lower surfaces of the honeycomb to be stabilized (2) are subjected to planar stabilization treatment to obtain a preliminary stabilized honeycomb; The bevel dimensions of the initially stabilized honeycomb are processed to be the same as the bevel dimensions of the honeycomb actually used in the product, resulting in a second-processed initially stabilized honeycomb. The pre-stabilized honeycomb from the secondary processing was subjected to sloping stabilization treatment to obtain stabilized honeycomb (12).

2. The cell stabilization treatment method according to claim 1, characterized in that, Calculate and cut the honeycomb masterbatch according to the actual honeycomb size used in the product, including: Cut the upper and lower surfaces of the honeycomb masterbatch according to the actual dimensions of the honeycomb surface used in the product. The net dimension line of the honeycomb is measured by projection or ruler (3), and the honeycomb rough processing line (1) is obtained by extending it outward by a set distance. The honeycomb is initially processed according to the honeycomb rough processing line (1) to obtain the honeycomb to be stabilized (2).

3. The cell stabilization treatment method according to claim 2, characterized in that, The set distance is 20mm~50mm.

4. The cell stabilization treatment method according to claim 2, characterized in that, The bottom angle of the cell (2) to be stabilized is 20°~30°.

5. The cell stabilization treatment method according to claim 1, characterized in that, The upper and lower surfaces of the cell (2) to be stabilized are subjected to planar stabilization treatment, including: The honeycomb to be stabilized (2) is subjected to dehumidification treatment; According to the projection, a layer of adhesive film (4) and prepreg (5) are laid on the process skin (6). The bag is pre-compressed to remove air bubbles. The honeycomb (2) to be stabilized after dehumidification treatment is placed on the adhesive film (4) according to the projection. The honeycomb (2) to be stabilized is bonded to the adhesive film (4) by bag pre-compressing. Then, a layer of adhesive film (4) and prepreg (5) are laid on the honeycomb (2) to be stabilized. The upper layer of prepreg (5) and adhesive film (4) are overlapped on the honeycomb slope to complete the planar stabilization laying of the honeycomb (2). A layer of isolation film (7) and breathable felt (8) are placed on the honeycomb (2) to be stabilized after the planar stabilization is completed. Vacuum bag film (9) and sealing strip (10) are used for sealing treatment. Then, vacuum bag film (9) is vacuumed to complete the planar stabilization bag making of the honeycomb (2) to be stabilized. The honeycomb (2) to be stabilized after the planar stabilization bag making is sent into the oven and the film and prepreg are cured according to the stabilization curing system to obtain the preliminary stabilized honeycomb.

6. The cell stabilization treatment method according to claim 5, characterized in that, The process of dehumidifying the honeycomb (2) to be stabilized includes: first, placing the honeycomb (2) to be stabilized on the process skin (6) according to the projection and fixing it initially; then, placing the isolation film (7) and the breathable felt (8) on the upper surface of the honeycomb (2) to be stabilized, and sealing it with vacuum bag film (9) and sealing strip (10); then, evacuating the vacuum bag film (9) so that the honeycomb (2) to be stabilized is completely attached to the process skin (6); finally, sending it into the oven and completing the dehumidification process of the honeycomb (2) according to the honeycomb dehumidification heating procedure.

7. The cell stabilization treatment method according to claim 1, characterized in that, The preliminary stabilized honeycomb of the secondary processing is subjected to sloping stabilization treatment, including: placing the preliminary stabilized honeycomb of the secondary processing back onto the process skin (6), and laying a layer of adhesive film (4) and prepreg (5) on the sloping surface of the preliminary stabilized honeycomb of the secondary processing; then, placing a layer of isolation film (7) and breathable felt (8) in sequence, using vacuum bag film (9) and sealing strip (10) for sealing treatment, and then evacuating the vacuum bag film (9) to complete the sloping stabilization bag making of the preliminary stabilized honeycomb of the secondary processing; finally, sending it into the oven, and completing the curing of adhesive film (4) and prepreg (5) according to the stabilization curing system to obtain the final stabilized honeycomb (12).

8. A honeycomb core, characterized in that, The honeycomb core is obtained by stabilizing the honeycomb core using the honeycomb stabilization treatment method according to any one of claims 1 to 7.

9. A sandwich structure component, characterized in that, The sandwich structure is configured with the honeycomb core as described in claim 8.

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