Preparation method of latticed composite prepreg and composite honeycomb core

Abstract

The invention discloses a preparation method of a latticed composite material prepreg and a composite material honeycomb core, and relates to the field of preparation of composite material prepregs. Interconnection of the interiors of existing composite material cores is achieved through secondary machining and drilling after the cores are cured and formed, time and labor are wasted during machining, and internal damage is prone to being generated. The preparation method comprises the following steps: sticking release paper to an arrangement machine, laying a first layer of pre-impregnated resin fibers on the release paper, and heating and curing to enable the first layer of pre-impregnated resin fibers to be adhered to the release paper; taking down the release paper adhered with the pre-impregnated resin cellosilk from the arrangement machine, rotating the release paper and adhering the release paper to the arrangement machine again; laying a second layer of pre-impregnated resin fibers on release paper, and heating and curing the second layer of pre-impregnated resin fibers so as to enable the second layer of pre-impregnated resin fibers to be adhered to the release paper; and taking down the release paper adhered with the upper and lower layers of prepreg resin fibers from the arrangement machine to obtain the latticed composite prepreg. The method is mainly used for preparing the latticed composite prepreg.

Description

Technical Field

[0001] The invention relates to the technical field of composite material prepreg preparation, and 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 of them have excellent properties such as light weight and high strength / rigidity, and are widely used in the aerospace field. However, the cells inside the honeycomb core are not connected to each other. After the upper and lower panels are bonded, each honeycomb hole is closed independently. When the ambient temperature changes or the pressure difference after the ground assembly is launched into space, the air pressure inside the honeycomb core will change, causing the sandwich structure panel to be damaged or the surface core to debond. Therefore, holes are generally opened inside the honeycomb core to avoid the above problems. In addition, the holes inside the core can also be opened to arrange the lines inside the sandwich structure to save space.

[0003] At present, the main method to achieve internal interconnection of composite cores is to drill holes in the secondary processing after the core is solidified. However, for large composite cores, on the one hand, the secondary processing is time-consuming and labor-intensive, and the processing quality cannot be accurately controlled; on the other hand, the composite core is prone to internal damage during secondary processing, and the composite fiber breaks, affecting the performance of the core. 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 pasted to the layout 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 to the layout machine again;

[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 cross-arranged from the layout 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, and 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 a gap is left between two adjacent circles of the flexible arrangement plate in the radial direction.

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

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

[0016] S11, pasting and covering the release paper to the outside of the flexible layout plate, fixing one end of a plurality of pre-impregnated resin fiber filaments to one end of the release paper on the second rotating shaft, and extending the other ends of the plurality of pre-impregnated resin fiber filaments 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, while the flexible arrangement plate rotates with the second rotating shaft, the partition plates are inserted in sequence from the inside to the outside according to the spiral direction of the spiral slot, the flexible arrangement plate and the release paper are wound 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 comprises the following steps:

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

[0021] S22, rotating the release paper obtained in S21 according to the mesh shape requirements, and cutting out multiple release papers with the first layer of pre-impregnated resin fiber filaments adhered thereto according to the width of the flexible layout board, and pasting the cut release papers to the outside of the flexible layout board in sequence along the length direction of the flexible layout board.

[0022] Furthermore, the S3 comprises 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, and extending the other end of the plurality of pre-impregnated resin fiber filaments 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, while the flexible arrangement plate rotates with the second rotating shaft, the partition plates are inserted in sequence from the inside to the outside according to the spiral direction of the spiral slot, the flexible arrangement plate and the release paper are wound 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] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention adopts a cross-laying method to form a grid-like composite material prepreg, and uses the grid-like composite material prepreg to prepare a honeycomb core, so that the prepared honeycomb core has through openings and continuous fibers, and no secondary openings are required, thereby ensuring the performance of the honeycomb core. At the same time, the design of the mesh reduces the structural mass and increases the use function of the honeycomb core. Moreover, the prepared grid-like composite material prepreg has strong designability, and the performance of the composite material prepreg can be designed by changing the mesh aperture parameters and the fiber filament 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 partition plates and flexible layout plates to increase the length of the prepared composite material prepreg, forming a large-sized grid-shaped composite material prepreg, and ensuring that the fibers of the prepared honeycomb core are continuous. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are incorporated as 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-like 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-like prepreg.

[0034] Figure 2 This is a schematic diagram of the structure 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 This is a 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] Fig. 9 Schematic diagram of the structure of the curved wall honeycomb core mold.

[0042] Fig.10The stress test comparison diagrams of three kinds of composite honeycomb cores under the same compressive load, among which (a) is a hexagonal honeycomb core molded by compression molding using an open-pored composite prepreg tape and a hexagonal honeycomb core mold; (b) is a curved-wall honeycomb core molded by compression molding using an open-pored composite prepreg tape and a curved-wall honeycomb core mold; (c) is a hexagonal honeycomb core molded by compression molding 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] Embodiment 1:

[0046] The present application provides a method for preparing a grid-shaped composite material prepreg, and the specific preparation process is as follows:

[0047] S1, the release paper is pasted to the arrangement machine, and the fiber filaments impregnated with resin are laid and wound on the release paper in sequence to form a layer of pre-impregnated resin fiber filaments on the release paper, and the distance d1 between two adjacent fiber filaments can be adjusted according to actual needs; the pre-impregnated resin fiber filaments are heated and cured to make the first layer of pre-impregnated resin fiber filaments adhere to the release paper, wherein the resin is one of epoxy resin, polyimide resin or cyanate resin, and the resin has a high viscosity, which 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 arrangement machine, rotating the release paper by a certain angle according to the shape of the mesh, and pasting it to the arrangement machine again to change the arrangement direction of the first layer of pre-impregnated resin fiber filaments relative to the arrangement machine;

[0049] S3, laying the fiber filaments impregnated with resin 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, at this time, the first layer of pre-impregnated resin fiber filaments and the second layer of pre-impregnated resin fiber filaments are arranged crosswise, 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 adopts a cross-laying method to form a grid-shaped composite material prepreg, and uses the grid-shaped composite material prepreg to prepare a honeycomb core, so that the prepared honeycomb core has through openings and continuous fibers, and no secondary openings are required, thereby ensuring the performance of the honeycomb core. At the same time, the design of the mesh reduces the structural mass and increases the use function of the honeycomb core. Moreover, the prepared grid-shaped composite material prepreg has strong designability, and the performance of the composite material prepreg can be designed by changing the mesh aperture parameters and fiber filament width.

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

[0053] The first implementation method:

[0054] This embodiment provides a roller type cloth 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 sleeved 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, pasting and covering the release paper to the outer surface of the arrangement roller 2, laying a pre-impregnated resin fiber filament on the release paper, the motor drives the first rotating shaft 1 to rotate at a low speed 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, repeat S1 until a 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, the release paper with pre-impregnated resin fiber filaments is rotated 90°;

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

[0062] This embodiment uses the arrangement roller 2 to support the pre-impregnated resin fiber filaments, and the pre-impregnated resin fiber filaments are wound onto the release paper by rotation. After the first layer of pre-impregnated resin fiber filaments is wound and solidified, the release paper is peeled off and rotated from the arrangement roller 2, the direction of the first layer of pre-impregnated resin fiber filaments relative to the arrangement roller 2 is changed, and 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, realizing the preparation of a grid-shaped composite material prepreg. This arrangement machine has a simple structure and is easy to operate, and 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.

[0063] The second implementation method:

[0064] This embodiment provides a spiral plate type layout machine, such as Figures 2 to 7As shown, the spiral plate type layout 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 layout plate 7. The upper support plate 3 and the lower support plate 4 are arranged opposite to each other up and down, and the second rotating shaft 5 is rotatably installed 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 layout plate 7 is connected to the second rotating shaft 5, and the other end extends out of the upper support plate 3 and the lower support plate 4 and extends outward. 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 one 61, partition plate two 62, partition plate three 63, partition plate four 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. When all the partition plates are inserted and the flexible arrangement plate 7 is wrapped around the outside of all the partition plates, the motor is turned off. At this time, there is a gap between 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 the prepreg is used to prepare the honeycomb core, the sheet-like prepreg needs to be cut into strips and wound on the honeycomb mold. The strip-like prepreg cut from the small-area sheet-like prepreg is 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 the sheet structure cannot be formed. The design of the partition plate and the flexible layout plate 7 in this embodiment can increase the length of the prepared composite material prepreg, form a large-sized grid-like composite material prepreg, and ensure 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, and a gap is left between two adjacent circles 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 cross 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, pasting and covering the release paper to the outside of the flexible layout plate 7, fixing one end of the plurality of pre-impregnated resin fiber filaments to one end of the release paper on the second rotating shaft 5, and the other ends of the plurality of pre-impregnated resin fiber filaments extending out of the upper support plate 3 and the lower support plate 4 and extending outward and tensioning, and the plurality of pre-impregnated resin fiber filaments are arranged along the width direction of the flexible layout plate 7, and the width between two adjacent pre-impregnated resin fiber filaments is adjusted as needed;

[0067] S2, the motor drives the second rotating shaft 5 to rotate at a low speed through the reducer, and the flexible arrangement plate 7 rotates with the second rotating shaft 5, and 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 outer side of the partition plate 1 61 along with the flexible arrangement plate 7. When the outer side 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 outer side of the partition plate 2 62. When the outer side 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, and the flexible arrangement plate 7 begins to wind around the outer side of the partition plate 2 62. When the flexible arrangement plate 7 is completely covered, the partition plate three 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 three 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, at this time, the pre-impregnated resin fiber filaments are laid to the outside of 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 second rotating shaft 5;

[0068] S3, heating the flexible layout plate 7 by 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 layout plate 7, and remove the release paper with the first layer of pre-impregnated resin fiber filaments adhered to it from the flexible layout plate 7;

[0070] S5, when the mesh is square or rectangular, cut a plurality of release papers with the first layer of pre-impregnated resin fiber filaments adhered thereto according to the width of the flexible arrangement board 7, rotate the cut release papers by 90 degrees, and sequentially paste them on the flexible arrangement board 7 along the length direction of the flexible arrangement board 7, so that the length direction of the pre-impregnated resin fiber filaments on the release papers is consistent with the width direction of the flexible arrangement 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 turn, unfold the flexible layout plate 7, remove the release paper adhering the first layer of pre-impregnated resin fiber filaments and the second layer of pre-impregnated resin fiber filaments 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 formed mesh 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] Embodiment 2:

[0075] This embodiment provides a composite honeycomb core with internal openings, the honeycomb core is molded from a grid-shaped composite prepreg, and the honeycomb core 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-pored 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 required honeycomb core mold, winding the composite material prepreg tape around the honeycomb core mold and hot pressing and curing to form, and removing the honeycomb core mold after forming to obtain the composite material honeycomb core.

[0079] Since the honeycomb configuration and honeycomb preparation materials affect the mechanical properties of the honeycomb structure, this example studies the influence of the honeycomb configuration and preparation materials on the mechanical properties of the honeycomb structure. A hexagonal honeycomb core (hereinafter referred to as specimen 1) was molded using T300 braided prepreg tape and a hexagonal honeycomb core mold. Fig.10 A hexagonal honeycomb core (hereinafter referred to as specimen 2, as shown in Fig. Fig.10A curved-wall honeycomb core (hereinafter referred to as specimen 3, as shown in a) is formed by compression molding using an open-pored composite prepreg tape and a curved-wall honeycomb core mold. Fig.10 When preparing the curved wall honeycomb core, the selected curved wall honeycomb core mold structure parameters are as follows: Fig. 9 As shown, and are the curvature radii of the single-layer wall and the double-layer wall, l1 and l2 are the chord lengths of the curved wall corresponding to the single-layer wall and the double-layer wall, t1 and t2 correspond to the thickness of the single-layer wall and the double-layer wall, respectively. The size parameters of the specimens 1, 2, and 3 finally obtained are the same.

[0080] Compression tests were performed on specimens 1, 2, and 3 respectively. Fig.10 As shown in the figure, under the same compression load, the out-of-plane compression strength of specimen 1 is 2.93MPa, and the out-of-plane compression strength of specimen 2 is 1.63MPa, and the compression strength decreases by 44.37%, indicating that the mechanical properties of the open-cell honeycomb core are weaker than those of the honeycomb core formed by normal fiber reinforced composite prepreg. The honeycomb structure made of plain woven prepreg is prone to buckling failure under the out-of-plane compression load due to the uniform and continuous wall surface. At this time, the structure can continue to bear until the wall buckling is transformed into a large deformation to produce material damage, and the structural compression strength reaches the maximum value; while the wall surface of the open-cell honeycomb is discontinuous, and the wall surface is directly broken after the out-of-plane compression load exceeds the material limit, so the structural compression strength is relatively low. The out-of-plane compression strength of specimen 3 is 2.21MPa, which is 35.58% higher than that of specimen 2, and only 24.57% lower than that of specimen 1. It shows that the curved-wall open-cell honeycomb formed by combining the curved-wall honeycomb with the open-cell prepreg can improve the anti-buckling ability of the structure. Moreover, due to the porous characteristics of the wall surface, the total mass of the curved wall open-cell honeycomb is smaller. The same size curved wall open-cell honeycomb compression test piece under the same standard weighs only 3.76g, which is 59.39% lower than the composite honeycomb made of T300 woven prepreg (9.26g), showing the great advantages of open-cell prepreg and its curved wall honeycomb structure.

[0081] The embodiments described above are merely descriptions of preferred implementation modes 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 pasted to the layout 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 to the layout machine again; 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 cross-arranged from the layout machine to obtain a grid-shaped composite material prepreg.

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

3. The method for preparing a grid-shaped composite material prepreg according to claim 1, characterized in that: 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 wound around the release paper.

4. The method for preparing a grid-shaped composite material prepreg according to claim 1, characterized in that: 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, and 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 a gap is left between two adjacent circles of the flexible arrangement plate in the radial direction.

5. The method for preparing a grid-shaped composite material prepreg according to claim 3 or 4, characterized in that: The arrangement machine also includes a heating device to cure the pre-impregnated resin fiber filaments.

6. The method for preparing a grid-shaped composite material prepreg according to claim 4, characterized in that: The S1 comprises the following steps: S11, pasting and covering the release paper to the outside of the flexible layout plate, fixing one end of a plurality of pre-impregnated resin fiber filaments to one end of the release paper on the second rotating shaft, and extending the other ends of the plurality of pre-impregnated resin fiber filaments 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, while the flexible arrangement plate rotates with the second rotating shaft, the partition plates are inserted in sequence from the inside to the outside according to the spiral direction of the spiral slot, the flexible arrangement plate and the release paper are wound 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.

7. The method for preparing a grid-shaped composite material prepreg according to claim 6, characterized in that: The S2 comprises the following steps: S21, removing the partition plate, unfolding the flexible layout plate, and removing the release paper to which the first layer of pre-impregnated resin fiber filaments are adhered from the flexible layout plate; S22, rotating the release paper obtained in S21 according to the mesh shape requirements, and cutting out multiple release papers with the first layer of pre-impregnated resin fiber filaments adhered thereto according to the width of the flexible layout board, and pasting the cut release papers to the outside of the flexible layout board in sequence along the length direction of the flexible layout board.

8. The method for preparing a grid-shaped composite material prepreg according to claim 7, characterized in that: The S3 comprises 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, and extending the other end of the plurality of pre-impregnated resin fiber filaments 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, while the flexible arrangement plate rotates with the second rotating shaft, the partition plates are inserted in sequence from the inside to the outside according to the spiral direction of the spiral slot, the flexible arrangement plate and the release paper are wound 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.

9. 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 described in claim 1, and the composite honeycomb core includes a plurality of honeycomb units arranged in an array.

10. The composite honeycomb core with internal openings according to claim 9, characterized in that: The honeycomb unit is a curved-wall honeycomb.

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