Preparation method of grid-shaped composite material prepreg and composite material honeycomb core

Abstract

A preparation method of a grid-like composite material prepreg and a composite material honeycomb core relate to the field of composite material prepreg preparation. Currently, the internal interconnection of the composite material core is achieved by secondary processing drilling after the core is solidified and formed. The processing is time-consuming and labor-intensive, and is prone to internal damage. The preparation process of the present invention is as follows: a release paper is pasted to an arrangement machine, a first layer of pre-impregnated resin fiber filaments is laid on the release paper and heated and cured, so that the first layer of pre-impregnated resin fiber filaments adheres to the release paper; the release paper adhered to the pre-impregnated resin fiber filaments is removed from the arrangement machine, the release paper is rotated and pasted to the arrangement machine again; a second layer of pre-impregnated resin fiber filaments is laid on the release paper and heated and cured, so that the second layer of pre-impregnated resin fiber filaments adheres to the release paper; the release paper adhered to the upper and lower layers of pre-impregnated resin fiber filaments is removed from the arrangement machine to obtain a grid-like composite material prepreg. The present invention is mainly used for the preparation of grid-like composite material prepreg.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material prepreg preparation, in particular to a preparation method of a grid-shaped composite material prepreg and a composite material honeycomb core. Background Art

[0002] Composite materials and sandwich structures made from them offer excellent properties such as light weight and high strength and stiffness, and are widely used in the aerospace field. However, the cells within the honeycomb core are not interconnected. After the upper and lower panels are bonded together, each honeycomb pore is independently sealed. When affected by ambient temperature fluctuations or pressure differences after ground assembly and launch into space, the air pressure within the honeycomb core can change, potentially causing damage to the sandwich structure panels or debonding of the core. Therefore, through-holes are typically opened within the honeycomb core to avoid these problems. Furthermore, through-holes within the core allow wiring and other equipment to be routed within the sandwich structure, saving space.

[0003] Currently, the primary method for achieving internal interconnectivity within composite cores is through secondary drilling after the core has solidified. However, for larger composite cores, secondary machining is time-consuming and labor-intensive, and cannot precisely control the quality of the work. Furthermore, secondary machining can easily damage the composite core and cause fiber breakage, impacting the core's performance. Summary of the Invention

[0004] In view of this, the present invention provides a method for preparing a grid-shaped composite material prepreg and a composite material honeycomb core, wherein upper and lower layers of pre-impregnated resin fiber filaments are laid on release paper and cured to form a grid-shaped composite material prepreg.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A method for preparing a grid-shaped composite material prepreg, the specific preparation process is as follows:

[0007] S1, the release paper is attached to the arrangement machine, and the first layer of pre-impregnated resin fiber filaments is laid on the release paper and heated and cured so that the first layer of pre-impregnated resin fiber filaments adheres to the release paper;

[0008] S2, removing the release paper with the pre-impregnated resin fiber filaments from the layout machine, rotating the release paper and sticking it back to the layout machine;

[0009] S3, laying a second layer of pre-impregnated resin fiber filaments on the release paper and heating and curing the second layer of pre-impregnated resin fiber filaments so that the second layer of pre-impregnated resin fiber filaments adheres to the release paper;

[0010] S4, removing the release paper with the upper and lower layers of pre-impregnated resin fiber filaments adhered and arranged crosswise from the arrangement machine to obtain a grid-shaped composite material prepreg.

[0011] Furthermore, the meshes of the grid-like composite material prepreg are square, rectangular or parallelogram.

[0012] Furthermore, the arrangement machine includes a first rotating shaft and an arrangement roller, the arrangement roller is mounted on the first rotating shaft and rotates with the first rotating shaft; the release paper is pasted and covered on the outer surface of the arrangement roller, one end of the pre-impregnated resin fiber filament is bonded to the release paper, and the first rotating shaft is rotated, and the arrangement roller and the release paper rotate with the first rotating shaft so that the pre-impregnated resin fiber filament is wrapped around the release paper.

[0013] Furthermore, the arrangement machine includes a spiral slot, a second rotating shaft, a spiral partition plate and a flexible arrangement plate, the second rotating shaft is installed at the center of the spiral slot and can rotate; the spiral partition plate includes multiple partition plates, and the multiple partition plates are inserted in sequence along the spiral direction of the spiral slot; one end of the flexible arrangement plate is connected to the second rotating shaft, and the other end extends outward, and the release paper is pasted and covered to the outside of the flexible arrangement plate; the second rotating shaft is rotated, and the flexible arrangement plate rotates with the second rotating shaft, while the partition plates are inserted in sequence from the inside to the outside according to the spiral direction of the spiral slot, and the flexible arrangement plate is wrapped around the partition plate so that there is a gap between two adjacent circles of the flexible arrangement plate in the radial direction.

[0014] Furthermore, the arrangement machine also includes a heating device to solidify the pre-impregnated resin fiber filaments.

[0015] Furthermore, the S1 includes the following steps:

[0016] S11, pasting and covering the outer side of the flexible layout plate with release paper, fixing one end of a plurality of pre-impregnated resin fiber filaments to one end of the release paper on the second rotating shaft, with the other ends of the plurality of pre-impregnated resin fiber filaments extending outward, and arranging the plurality of pre-impregnated resin fiber filaments along the width direction of the flexible layout plate;

[0017] S12, rotating the second rotating shaft. As the flexible layout plate rotates with the second rotating shaft, the partition plates are sequentially inserted from the inside to the outside in the spiral direction of the spiral slot. The flexible layout plate and the release paper are wrapped around the partition plate, and the first layer of pre-impregnated resin fiber filaments covers the outer surface of the release paper.

[0018] S13, heating the flexible layout board to solidify the pre-impregnated resin fiber filaments so that the first layer of pre-impregnated resin fiber filaments adheres to the release paper.

[0019] Furthermore, the S2 includes the following steps:

[0020] S21, removing the partition plate, unfolding the flexible layout plate, and removing the release paper with the first layer of pre-impregnated resin fiber filaments adhered thereto from the flexible layout plate;

[0021] S22, rotate the release paper obtained in S21 according to the requirements of the mesh shape, and cut out multiple release papers with the first layer of pre-impregnated resin fiber filaments adhered to them according to the width of the flexible arrangement board. The cut release papers are sequentially pasted to the outside of the flexible arrangement board along the length direction of the flexible arrangement board.

[0022] Furthermore, the S3 includes the following steps:

[0023] S31, fixing one end of a plurality of pre-impregnated resin fiber filaments to one end of the release paper on the second rotating shaft, with the other ends of the plurality of pre-impregnated resin fiber filaments extending outward, and arranging the plurality of pre-impregnated resin fiber filaments along the width direction of the flexible arrangement plate;

[0024] S32, rotating the second rotating shaft. As the flexible layout plate rotates along with the second rotating shaft, the partition plates are sequentially inserted from the inside to the outside in the spiral direction of the spiral slot. The flexible layout plate and the release paper are wrapped around the partition plate, and the second layer of pre-impregnated resin fiber filaments covers the first layer of pre-impregnated resin fiber filaments on the outer surface of the release paper.

[0025] S33, heating the flexible layout board to solidify the second layer of pre-impregnated resin fiber filaments, so that the second layer of pre-impregnated resin fiber filaments adheres to the release paper and the first layer of pre-impregnated resin fiber filaments.

[0026] A composite honeycomb core with internal openings is formed by winding grid-shaped composite prepregs. The composite honeycomb core comprises a plurality of honeycomb units arranged in an array.

[0027] Furthermore, the honeycomb unit is a curved-wall honeycomb.

[0028] The beneficial effects of the present invention compared with the prior art are:

[0029] 1. The present invention employs a cross-laying method to form a grid-like composite prepreg. This grid-like composite prepreg is then used to prepare a honeycomb core. This results in a core with continuous, continuous openings, eliminating the need for secondary openings. This ensures the core's performance, while also reducing structural mass and increasing its functionality. Furthermore, the resulting grid-like composite prepreg is highly designable, allowing for performance adjustments by modifying parameters such as the mesh aperture and fiber width.

[0030] 2. The roller arrangement machine of the present invention has a simple structure and is easy to operate. The entire preparation process is simple and convenient. The shape and parameters of the mesh can be adjusted as needed, and it is suitable for preparing small-sized grid-shaped composite material prepregs.

[0031] 3. The spiral plate layout machine of the present invention adopts the design of the partition plate and the flexible layout plate to increase the length of the prepared composite material prepreg, forming a large-sized grid-shaped composite material prepreg, ensuring that the fibers of the prepared honeycomb core are continuous. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are incorporated in and constitute a part of this application and are used to provide a further understanding of the present invention.

[0033] Figure 1 Schematic diagram of the roller arrangement machine in Example 1 of the present application for preparing a grid-shaped composite material prepreg; wherein (a) is a schematic diagram of the first layer of preimpregnated resin fiber filaments wound on the arrangement roller; (b) is a schematic diagram of the first layer of preimpregnated resin fiber filaments laid on the release paper; (c) is a schematic diagram of the second layer of preimpregnated resin fiber filaments wound on the arrangement roller; and (d) is a schematic diagram of the grid-shaped prepreg.

[0034] Figure 2 This is a structural schematic diagram of the spiral plate arrangement machine in Example 2 of the present application.

[0035] Figure 3 Schematic diagram of the structure of the partition plate.

[0036] Figure 4 Schematic diagram of the first layer of pre-impregnated resin fiber filaments wound on the flexible layout board.

[0037] Figure 5 Schematic diagram of a release paper with a first layer of pre-impregnated resin fiber filaments rotated 90° and laid on a flexible layout board.

[0038] Figure 6 Schematic diagram of the second layer of pre-impregnated resin fiber filaments laid on the release paper.

[0039] Figure 7 This is a schematic diagram of a release paper with a first layer of pre-impregnated resin fiber filaments laid on a flexible layout board rotated at an angle less than 90°.

[0040] Figure 8 Schematic diagram of the winding process of the curved-wall honeycomb core mold and the open-cell composite prepreg tape.

[0041] Figure 9 Schematic diagram of the structure of the curved wall honeycomb core mold.

[0042] Figure 10The stress test comparison diagram of three types of composite honeycomb cores under the same compressive load, among which (a) is a hexagonal honeycomb core molded by using an open-pored composite prepreg tape and a hexagonal honeycomb core mold; (b) is a curved-wall honeycomb core molded by using an open-pored composite prepreg tape and a curved-wall honeycomb core mold; (c) is a hexagonal honeycomb core molded by using a T300 woven prepreg tape and a hexagonal honeycomb core mold.

[0043] Explanation of the reference numerals: 1-first rotating shaft; 2-arranging roller; 3-upper support plate; 31-spiral slot; 4-lower support plate; 5-second rotating shaft; 6-spiral partition plate; 61-partition plate one; 62-partition plate two; 63-partition plate three; 64-partition plate four; 7-flexible arrangement plate. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0045] Example 1:

[0046] The present invention provides a method for preparing a grid-shaped composite material prepreg. The specific preparation process is as follows:

[0047] S1, affixing release paper to a layout machine, laying and winding resin-impregnated fiber filaments on the release paper in sequence to form a layer of pre-impregnated resin fiber filaments on the release paper, wherein the spacing d1 between two adjacent fiber filaments can be adjusted according to actual needs; heating and curing the pre-impregnated resin fiber filaments so that the first layer of pre-impregnated resin fiber filaments adheres to the release paper, wherein the resin is one of epoxy resin, polyimide resin, or cyanate resin, and the resin has a high viscosity that can bond the fiber filaments to the release paper, and the fiber filaments are one of carbon fiber, glass fiber, or quartz fiber;

[0048] S2, removing the release paper with the pre-impregnated resin fiber filaments from the layout machine, rotating the release paper by a certain angle according to the shape of the mesh, and sticking it to the layout machine again to change the layout direction of the first layer of pre-impregnated resin fiber filaments relative to the layout machine;

[0049] S3, laying the resin-impregnated fiber filaments in sequence according to the first laying method and winding them on the release paper to form a second layer of pre-impregnated resin fiber filaments on the release paper, wherein the first layer of pre-impregnated resin fiber filaments and the second layer of pre-impregnated resin fiber filaments are arranged in an interlaced manner, and the distance d2 between two adjacent fiber filaments can be adjusted according to actual needs; heating and curing the pre-impregnated resin fiber filaments so that the second layer of pre-impregnated resin fiber filaments adheres to the release paper;

[0050] S4, removing the release paper with the upper and lower layers of pre-impregnated resin fiber filaments adhered thereto from the layout machine to obtain a grid-shaped composite material prepreg with square, rectangular or parallelogram meshes.

[0051] This embodiment employs a cross-laying method to form a grid-like composite prepreg. This grid-like composite prepreg is then used to prepare a honeycomb core. This results in a core with continuous, continuous openings, eliminating the need for secondary openings. This ensures the core's performance, while also reducing structural mass and increasing its functionality. Furthermore, the resulting grid-like composite prepreg offers high design flexibility, allowing for performance adjustments by modifying parameters such as the mesh aperture and fiber width.

[0052] like Figures 1 to 7 As shown, this embodiment realizes the preparation of grid-shaped composite material prepreg based on two types of arrangement machines, which are a roller arrangement machine and a spiral plate arrangement machine. The structural forms of the two arrangement machines and the corresponding preparation methods are described below.

[0053] The first implementation method:

[0054] This embodiment provides a roller type arrangement machine, such as Figure 1 As shown, the roller type cloth arrangement machine includes a motor, a first rotating shaft 1, a cloth arrangement roller 2 and a heating device. The first rotating shaft 1 is connected to the motor shaft of the motor and rotates with the motor shaft. The cloth arrangement roller 2 is mounted on the first rotating shaft 1 and rotates with the first rotating shaft 1.

[0055] The specific process of preparing grid-shaped composite material prepreg using a roller arrangement machine is as follows:

[0056] S1: Paste and cover the release paper on the outer surface of the arrangement roller 2, lay a pre-impregnated resin fiber filament on the release paper, and drive the first rotating shaft 1 to rotate at a low speed through the motor through the reducer. The arrangement roller 2 rotates with the first rotating shaft 1, and the pre-impregnated resin fiber filament is wound on the release paper as the first rotating shaft 1 rotates;

[0057] S2, repeating S1 until the plurality of pre-impregnated resin fiber filaments are laid on the release paper and a layer of pre-impregnated resin fiber filaments is formed on the release paper, wherein the arrangement direction of the plurality of pre-impregnated resin fiber filaments is the same as the axial direction of the first rotating shaft 1, and the width between two adjacent pre-impregnated resin fiber filaments is adjusted as needed;

[0058] S3, using the heating device on the layout machine to slightly solidify the resin, and the resin and fiber filaments adhere to the release paper together;

[0059] S4, removing the release paper with the pre-impregnated resin fiber filaments from the arrangement roller 2;

[0060] S5, when the mesh is square or rectangular, rotate 90 degrees to adhere the release paper with pre-impregnated resin fiber filaments;

[0061] S6, repeating S1 to S4 to obtain a grid-shaped composite material prepreg.

[0062] This embodiment utilizes the arrangement roller 2 to support the pre-impregnated resin fiber filaments, and rotates the pre-impregnated resin fiber filaments to wind them onto the release paper. After the first layer of pre-impregnated resin fiber filaments is wound and solidified, the release paper is peeled off from the arrangement roller 2 and rotated to change the direction of the first layer of pre-impregnated resin fiber filaments relative to the arrangement roller 2. Then, the second layer of pre-impregnated resin fiber filaments is laid and wound on the release paper. The first layer of pre-impregnated resin fiber filaments and the second layer of pre-impregnated resin fiber filaments form a cross shape, thereby realizing the preparation of a grid-shaped composite material prepreg. This type of arrangement machine has a simple structure and is easy to operate. The entire preparation process is simple and convenient. The shape and parameters of the mesh can be adjusted as needed. It is suitable for preparing small-sized grid-shaped composite material prepregs.

[0063] Second implementation method:

[0064] This embodiment provides a spiral plate type arrangement machine, such as Figures 2 to 7As shown, the spiral plate arrangement machine includes a motor, an upper support plate 3, a lower support plate 4, a second rotating shaft 5, a spiral partition plate 6, and a flexible arrangement plate 7. The upper support plate 3 and the lower support plate 4 are arranged vertically opposite each other. The second rotating shaft 5 is rotatably mounted between the upper support plate 3 and the lower support plate 4. The lower end of the second rotating shaft 5 extends out of the lower support plate 4 and is connected to the motor shaft of the motor to rotate with the motor shaft. One end of the flexible arrangement plate 7 is connected to the second rotating shaft 5, and the other end extends outward from the upper support plate 3 and the lower support plate 4. A spiral slot 31 is opened on the upper support plate 3 and / or the lower support plate 4 with the second rotating shaft 5 as the center. The spiral partition plate 6 is composed of multiple partition plates. The multiple partition plates are inserted into the spiral slot 31 in sequence from the upper support plate 3 along the spiral direction of the spiral slot 31. The spiral partition plate 6 is located between the upper support plate 3 and the lower support plate 4; according to the insertion order of the partition plates, the multiple partition plates are divided into partition plate 1 61, partition plate 2 62, partition plate 3 63, partition plate 4 64... The motor drives the second rotating shaft 5 to rotate at a low speed through the reducer. While the flexible arrangement plate 7 rotates with the second rotating shaft 5, the partition plate 1 61 is inserted into the spiral slot 31, and the flexible arrangement plate 7 is wrapped around the outside of the partition plate 1 61. When the outside of the partition plate 1 61 is about to be completely covered by the flexible arrangement plate 7, the partition plate 2 62 is inserted into the spiral slot 31, and the flexible arrangement plate 7 begins to wrap around the outside of the partition plate 2 62. When the outside of the partition plate 2 62 is about to be completely covered by the flexible arrangement plate 7, the partition plate 3 63 is inserted into the spiral slot 31, and the flexible arrangement plate 7 begins to wrap around the outside of the partition plate 3 63, and so on. The motor is turned off when all the partition plates are inserted and the flexible arrangement plate 7 is wrapped around the outside of all the partition plates. At this time, there is a gap between the two adjacent circles of the flexible arrangement plate 7 in the radial direction. Since the roller layout machine can only prepare small-area sheet-like grid-like composite material prepregs, the preparation efficiency is low, and when using the prepreg to prepare the honeycomb core, the sheet-like prepreg needs to be cut into strips and wound on the honeycomb mold. The strip prepregs cut from the small-area sheet-like prepreg are limited in length, resulting in the fibers of the prepared large-area honeycomb core being discontinuous, affecting the performance of the honeycomb core. Moreover, the prepreg resin fiber filaments are sticky. If the flexible layout plate 7 is laminated together during spiral winding, after the prepreg resin fiber filaments are heated and cured, all the prepreg resin fiber filaments will be bonded together and will not be able to form a sheet structure. The design of the partition plate and the flexible layout plate 7 used in this embodiment can increase the length of the prepared composite material prepreg, forming a large-sized grid-like composite material prepreg, and ensuring that the fibers of the prepared honeycomb core are continuous. The longer flexible arrangement plate 7 is driven by the second rotating shaft 5 so that the flexible arrangement plate 7 is wound around the partition plate and forms a spiral shape, with a gap left between two adjacent turns of the flexible arrangement plate 7 to prevent the heated and cured pre-impregnated resin fibers from sticking together.The partition plate can be an arc-shaped plate or a straight plate, as long as the combination of multiple partition plates can form a continuous spiral shape. In addition, the cross-section of the partition plate is "L"-shaped, and the partition plate is supported on the upper support plate 3 by its own weight and the horizontal plate on the top. The height of the partition plate can be slightly larger than the distance between the upper support plate 3 and the lower support plate 4. After the partition plate is inserted into the upper support plate 3, the partition plate passes through the lower support plate 4 and is limited by the upper support plate 3 and the lower support plate 4. The flexible layout plate 7 can be completely attached to the outside of the partition plate under the drive of the second rotating shaft 5, and the partition plate will not move due to the extrusion force.

[0065] The specific process of preparing grid-shaped composite material prepreg using a spiral plate arrangement machine is as follows:

[0066] S1, affix and cover the release paper to the outside of the flexible arrangement plate 7, fix one end of a plurality of pre-impregnated resin fiber filaments to one end of the release paper on the second rotating shaft 5, and extend the other ends of the plurality of pre-impregnated resin fiber filaments out of the upper support plate 3 and the lower support plate 4 and extend outward and be tensioned. The plurality of pre-impregnated resin fiber filaments are arranged along the width direction of the flexible arrangement plate 7, and the width between two adjacent pre-impregnated resin fiber filaments is adjusted as needed;

[0067] S2, the motor drives the second shaft 5 to rotate at a low speed through the reducer, and the flexible arrangement plate 7 rotates with the second shaft 5, while the partition plate 1 61 is inserted into the spiral slot 31, and the plurality of pre-impregnated resin fiber filaments are wound around the outside of the partition plate 1 61 along with the flexible arrangement plate 7. When the outside of the partition plate 1 61 is about to be completely covered by the flexible arrangement plate 7, the partition plate 2 62 is inserted into the spiral slot 31, and the flexible arrangement plate 7 begins to wind around the outside of the partition plate 2 62. When the outside of the partition plate 2 62 is about to be completely covered by the flexible arrangement plate 7, the partition plate 2 62 is inserted into the spiral slot 31. When the flexible arrangement plate 7 is completely covered, the partition plate 3 63 is inserted into the spiral slot 31, and the flexible arrangement plate 7 begins to be wound around the outside of the partition plate 3 63, and so on, until all the partition plates are inserted and the pre-impregnated resin fiber filaments and the flexible arrangement plate 7 are wound around the outside of all the partition plates, the motor is turned off, and at this time, the pre-impregnated resin fiber filaments are laid to the outside of the release paper and form a layer of pre-impregnated resin fiber filaments on the release paper, wherein the arrangement direction of the plurality of pre-impregnated resin fiber filaments is the same as the axial direction of the second rotating shaft 5;

[0068] S3, heating the flexible layout plate 7 using a heating device on the layout machine to solidify the pre-impregnated resin fiber filaments so that the pre-impregnated resin fiber filaments adhere to the release paper;

[0069] S4, remove the partition plates in sequence, unfold the flexible arrangement plate 7, and remove the release paper with the first layer of pre-impregnated resin fiber filaments adhered to it from the flexible arrangement plate 7;

[0070] S5. When the mesh is square or rectangular, cut multiple sheets of release paper with the first layer of pre-impregnated resin fiber filaments adhered thereto according to the width of the flexible layout board 7. Rotate the cut release paper 90 degrees and adhere them to the flexible layout board 7 in sequence along the length direction of the flexible layout board 7 so that the length direction of the pre-impregnated resin fiber filaments on the release paper is consistent with the width direction of the flexible layout board 7.

[0071] S6, repeating S1 to S3 until the second layer of pre-impregnated resin fiber filaments adheres to the release paper;

[0072] S7, remove the partition plates in sequence, unfold the flexible layout plate 7, remove the release paper with the first layer of pre-impregnated resin fiber filaments and the second layer of pre-impregnated resin fiber filaments adhered thereto from the flexible layout plate 7, and obtain a grid-shaped composite material prepreg.

[0073] In this embodiment, the shape of the mesh can be adjusted by changing the rotation angle of the release paper to which the first layer of pre-impregnated resin fiber filaments is adhered. When the rotation angle is 90°, the mesh formed is a square or a rectangle. When the rotation angle is less than 90° or greater than 90°, the mesh shape is a parallelogram.

[0074] Example 2:

[0075] This embodiment provides a composite honeycomb core with internal openings. The honeycomb core is molded from a grid-like composite prepreg and can be an open-cell honeycomb of various honeycomb configurations, preferably a honeycomb core formed by an array of curved-wall honeycomb units.

[0076] The preparation process of composite honeycomb core is as follows:

[0077] S1, cutting the grid-shaped composite material prepreg into strips to form an open-pore composite material prepreg tape, wherein the width of the composite material prepreg tape is determined according to needs, and the mesh shape of the composite material prepreg tape is also determined according to needs;

[0078] S2, selecting the desired honeycomb core mold, winding the composite material prepreg tape around the honeycomb core mold and hot pressing and curing it into shape, and removing the honeycomb core mold after forming to obtain a composite material honeycomb core.

[0079] Since honeycomb configuration and honeycomb preparation materials affect the mechanical properties of honeycomb structures, this example studies the influence of honeycomb configuration and preparation materials on the mechanical properties of honeycomb structures. A hexagonal honeycomb core (hereinafter referred to as specimen 1) was molded using T300 braided prepreg tape and a hexagonal honeycomb core mold. Figure 10 As shown in c), a hexagonal honeycomb core was molded using an open-pored composite prepreg tape and a hexagonal honeycomb core mold (hereinafter referred to as specimen 2, as shown in Figure 10As shown in a), a curved wall honeycomb core was formed by compression molding using an open-pored composite prepreg tape and a curved wall honeycomb core mold (hereinafter referred to as specimen 3, as shown in Figure 10 As shown in b), when preparing the curved wall honeycomb core, the selected curved wall honeycomb core mold structural parameters are as follows Figure 9 As shown, and The curvature radii of the single-layer wall and double-layer wall, l1 and l2 are the chord lengths of the curved wall for the single-layer wall and double-layer wall, respectively. t1 and t2 correspond to the thicknesses of the single-layer wall and double-layer wall, respectively. The resulting dimensional parameters of Specimens 1, 2, and 3 are identical.

[0080] Compression tests were performed on specimens 1, 2, and 3, respectively. Figure 10 As shown, under the same compressive load, the out-of-plane compressive strength of specimen 1 was 2.93 MPa, while that of specimen 2 was 1.63 MPa, a 44.37% decrease in compressive strength. This indicates that the mechanical properties of open-cell honeycomb cores are weaker than those made from standard fiber-reinforced composite prepregs. Honeycomb structures made from plain woven prepregs, due to their uniform and continuous walls, are prone to buckling failure under out-of-plane compressive loads. At this point, the structure can continue to load-bearing until the wall buckling transforms into large deformation, resulting in material damage and reaching its maximum compressive strength. Open-cell honeycombs, on the other hand, have discontinuous walls. When the out-of-plane compressive load exceeds the material limit, the walls shatter, resulting in relatively low compressive strength. Specimen 3 achieved an out-of-plane compressive strength of 2.21 MPa, a 35.58% increase compared to specimen 2 and a only 24.57% decrease compared to specimen 1. This demonstrates that combining curved-wall honeycombs with open-cell prepregs can improve the structure's buckling resistance. Furthermore, the porous nature of the curved-wall open-cell honeycomb allows for a lower total structural mass. A compression test specimen of the same size and size, under the same standard, weighed only 3.76g, a 59.39% reduction compared to a composite honeycomb made from T300 woven prepreg (9.26g), demonstrating the significant advantages of the open-cell prepreg and its curved-wall honeycomb structure.

[0081] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A method for preparing a grid-like composite material prepreg, characterized in that: The specific preparation process is as follows: S1, the release paper is attached to the arrangement machine, and the first layer of pre-impregnated resin fiber filaments is laid on the release paper and heated and cured so that the first layer of pre-impregnated resin fiber filaments adheres to the release paper; S2, removing the release paper with the pre-impregnated resin fiber filaments from the layout machine, rotating the release paper and sticking it back to the layout machine; S3, laying a second layer of pre-impregnated resin fiber filaments on the release paper and heating and curing the second layer of pre-impregnated resin fiber filaments so that the second layer of pre-impregnated resin fiber filaments adheres to the release paper; S4, removing the release paper with the upper and lower layers of pre-impregnated resin fiber filaments adhered and arranged crosswise from the arrangement machine to obtain a grid-shaped composite material prepreg; The arrangement machine includes a spiral slot, a second rotating shaft, a spiral partition plate and a flexible arrangement plate. The second rotating shaft is installed at the center of the spiral slot and can rotate; the spiral partition plate includes multiple partition plates, and the multiple partition plates are inserted in sequence along the spiral direction of the spiral slot; one end of the flexible arrangement plate is connected to the second rotating shaft, and the other end extends outward, and the release paper is pasted and covered to the outside of the flexible arrangement plate; the second rotating shaft is rotated, and the flexible arrangement plate rotates with the second rotating shaft. At the same time, the partition plates are inserted in sequence from the inside to the outside according to the spiral direction of the spiral slot, and the flexible arrangement plate is wrapped around the partition plate so that there is a gap between the two adjacent circles of the flexible arrangement plate in the radial direction.

2. The method for preparing a grid-shaped composite material prepreg according to claim 1, wherein: The mesh holes of the grid-shaped composite material prepreg are square, rectangular or parallelogram.

3. The method for preparing a grid-shaped composite material prepreg according to claim 1, wherein: The arrangement machine further comprises a heating device to solidify the pre-impregnated resin fiber filaments.

4. The method for preparing a grid-shaped composite material prepreg according to claim 1, wherein: The S1 includes the following steps: S11, pasting and covering the outer side of the flexible layout plate with release paper, fixing one end of a plurality of pre-impregnated resin fiber filaments to one end of the release paper on the second rotating shaft, with the other ends of the plurality of pre-impregnated resin fiber filaments extending outward, and arranging the plurality of pre-impregnated resin fiber filaments along the width direction of the flexible layout plate; S12, rotating the second rotating shaft. As the flexible layout plate rotates with the second rotating shaft, the partition plates are sequentially inserted from the inside to the outside in the spiral direction of the spiral slot. The flexible layout plate and the release paper are wrapped around the partition plate, and the first layer of pre-impregnated resin fiber filaments covers the outer surface of the release paper. S13, heating the flexible layout board to solidify the pre-impregnated resin fiber filaments so that the first layer of pre-impregnated resin fiber filaments adheres to the release paper.

5. The method for preparing a grid-shaped composite material prepreg according to claim 4, wherein: The S2 comprises the following steps: S21, removing the partition plate, unfolding the flexible layout plate, and removing the release paper with the first layer of pre-impregnated resin fiber filaments adhered thereto from the flexible layout plate; S22, rotate the release paper obtained in S21 according to the requirements of the mesh shape, and cut out multiple release papers with the first layer of pre-impregnated resin fiber filaments adhered to them according to the width of the flexible arrangement board. The cut release papers are sequentially pasted to the outside of the flexible arrangement board along the length direction of the flexible arrangement board.

6. The method for preparing a grid-shaped composite material prepreg according to claim 5, wherein: The S3 includes the following steps: S31, fixing one end of a plurality of pre-impregnated resin fiber filaments to one end of the release paper on the second rotating shaft, with the other ends of the plurality of pre-impregnated resin fiber filaments extending outward, and arranging the plurality of pre-impregnated resin fiber filaments along the width direction of the flexible arrangement plate; S32, rotating the second rotating shaft. As the flexible layout plate rotates along with the second rotating shaft, the partition plates are sequentially inserted from the inside to the outside in the spiral direction of the spiral slot. The flexible layout plate and the release paper are wrapped around the partition plate, and the second layer of pre-impregnated resin fiber filaments covers the first layer of pre-impregnated resin fiber filaments on the outer surface of the release paper. S33, heating the flexible layout board to solidify the second layer of pre-impregnated resin fiber filaments, so that the second layer of pre-impregnated resin fiber filaments adheres to the release paper and the first layer of pre-impregnated resin fiber filaments.

7. A composite honeycomb core with internal openings, characterized in that The composite honeycomb core is formed by winding a grid-shaped composite material prepreg obtained by the preparation method according to claim 1, and the composite material honeycomb core includes a plurality of honeycomb units arranged in an array.

8. The composite honeycomb core with internal openings according to claim 7, characterized in that: The honeycomb unit is a curved-wall honeycomb.

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