A ship composite material corrugated sandwich panel structure and a forming method thereof

Abstract

The application relates to a ship composite material corrugated sandwich panel structure and a forming method thereof. A plurality of first foam corrugated strips and second foam corrugated strips are pre-assembled in an up-down staggered mode, a plurality of first foam corrugated strips are connected to form a first foam corrugated assembly through a glass fiber mat, a second fiber cloth is laid on the first foam corrugated assembly through a row-by-row die assembly process, a second foam corrugated strip is laid on the second fiber cloth, a glass fiber mat with glue is laid on the plurality of second foam corrugated strips, a third fiber cloth is laid on the glass fiber mat, a reinforcing rib member is laid on the outer side of the third fiber cloth and is wrapped with the fiber cloth, a preformed body is completed, and finally, a composite corrugated sandwich panel is obtained through vacuum pouring. The application is simple and convenient to operate, controllable preparation of a corrugated-foam hybrid core material is realized, process problems of a complex structure in forming precision, interface combination and form control are solved, and a feasible manufacturing approach is provided for practical application of the complex structure in a lightweight shell of a ship.

Description

Technical Field

[0001] This application relates to the field of ship composite panel technology, and in particular to a ship composite material pleated sandwich panel frame structure and its molding method. Background Technology

[0002] Plate frame structures are one of the main structural forms of ship hulls, and their optimized design is an important direction for reducing ship weight and improving overall structural efficiency. Currently, steel plate frames still dominate ship structural design, mainly bearing pressure and bending moment. By rationally optimizing the material layout, more materials can be distributed away from the neutral axis of the structure, effectively improving its load-bearing efficiency. However, with the increasing speed requirements of unmanned surface vessels (USVs), higher demands are placed on hull structures, especially on the mechanical properties of local areas of the hull. For example, high-performance ships such as USVs often face wave impact pressures of up to hundreds of kilopascals when sailing at high speeds in harsh sea conditions. Therefore, it is crucial to have an advanced material or structure to achieve greater effective load, higher collision resistance, and lower life-cycle costs. Traditional composite veneer reinforced panels have poor bending resistance and are not resistant to impact and collision. They are prone to delamination damage under repeated slamming loads. Taking foam sandwich panels as an example, their out-of-plane compression and shear performance is poor, which cannot meet the requirements of high-performance vessels such as unmanned surface vessels. Especially during high-speed navigation, the bow area will be subjected to large wave slamming loads and possible collision forces. The main load-bearing transverse and longitudinal bulkheads will bear large multi-axial loads, making the out-of-plane compression and shear, bending and impact performance, as well as weight requirements for the panel structure even more stringent. In addition, for foam-containing composite pleated sandwich panels... In the case of panel frame structure design, conventional forming methods for pleated sandwich structures (such as continuous rolling, stamping and folding, and molding processes) have limitations. For example, when processing foam, traditional methods use CNC engraving to process the corrugated surface, but the overall surface of the corrugated surface is relatively rough during the processing, or there may be incomplete cutting near the processing table. For example, when forming panel frame structures, the traditional method is to directly lay the lower panel with adhesive and then stack the sandwich pleats on the upper panel, which can easily cause unevenness on the upper and lower surfaces of the formed panel frame structure, as well as problems such as low forming accuracy and poor bonding between adjacent interfaces.

[0003] Therefore, we propose a ship composite material pleated sandwich panel frame structure and its molding method. Summary of the Invention

[0004] To address the shortcomings of existing production technologies, the applicant provides a ship composite material pleated sandwich panel frame structure and its molding method. This structure is simple and convenient to operate, enables controllable preparation of pleated-foam hybrid core materials, and solves the process challenges of molding accuracy, interface bonding, and morphological control in complex structures. It also provides a feasible manufacturing approach for its practical application in lightweight ship hulls.

[0005] The technical solution adopted in this application is as follows: A method for forming a composite material pleated sandwich panel frame structure for ships includes the following steps: S1, multiple first foam corrugated strips and second foam corrugated strips are arranged alternately on the molding substrate, so that the corrugated surfaces of the first foam corrugated strips and the second foam corrugated strips correspond to each other for pre-assembly. After the assembly is completed, the upper surface of the multiple first foam corrugated strips is covered with adhesive fiberglass mat, and the multiple first foam corrugated strips are connected to form a first foam corrugated component. Then the whole assembly is flipped and inverted on another molding substrate, and the upper molding substrate and the second foam corrugated strips are removed. S2, a first fiber cloth is laid on the molding substrate, the first foam corrugated component flipped in step S1 is laid on the first fiber cloth, and the second fiber cloth is folded into a three-dimensional configuration to form a curved pleated core layer. The second fiber cloth is laid on the first foam corrugated component and the second foam corrugated strip is laid on the second fiber cloth using a row-by-row molding process to complete the segment-by-segment shaping of the three-dimensional folded second fiber cloth; adhesive glass fiber mat is laid on multiple second foam corrugated strips, a third fiber cloth is laid on the glass fiber mat, and reinforcing ribs are laid on the outside of the third fiber cloth and wrapped with fiber cloth to complete the preform of the composite pleated sandwich panel; S3 uses a vacuum injection molding process to grout the preform of the composite pleated sandwich panel to obtain a ship composite material pleated sandwich panel frame structure.

[0006] Its further features are: The corrugations on both sides of the first and second foam corrugated strips are processed by CNC waterjet cutting. After processing, the first and second foam corrugated strips are placed in an oven at 50℃-70℃ for drying treatment, and the drying time is 1h-3h.

[0007] The reinforcing ribs include a first reinforcing strip and a second reinforcing strip. In step S2, when assembling the reinforcing ribs, the lower end of the first reinforcing strip is provided with a slot that matches the outline of the second reinforcing strip for assembly. The smaller second reinforcing strip is laid on the third fiber cloth at the designed position, and then the fiber cloth is covered on the second reinforcing strip. Then, the larger first reinforcing strip is laid on the designed position, and then the fiber cloth is covered on the first reinforcing strip to complete the preform of the composite pleated sandwich panel.

[0008] The molding substrate is a rigid mold. In steps S1 and S2, a release cloth with single-sided adhesive is laid on the surface of the rigid mold.

[0009] In step S1, when multiple first foam corrugated strips and second foam corrugated strips are pre-assembled, the distance between them is appropriately increased so that adjacent first foam corrugated strips and second foam corrugated strips are in a relaxed state.

[0010] The vacuum injection molding process in step S3 includes the following steps: S3-1, Environmental Control and Preform Packaging; First, the ambient temperature was adjusted to 30℃ according to the resin rheological properties. Then, a breathable release cloth, a flow guide net, a glass pressure plate, and a vacuum bag were laid on the preform in sequence, and injection and venting pipes were arranged. The entire structure was sealed with sealing tape. The glass pressure plate was laid between the flow guide net and the vacuum bag, mainly to improve the surface flatness of the specimen. To adapt to the symmetrical linear injection scheme, the glass pressure plate was divided into two parts along the axis of symmetry, so that the flow guide net could pass through the gap. The injection tube was fixed above the glass pressure plate and covered and guided by the flow guide net. S3-2, Sealing inspection and resin preparation; Connect the dispensing tube to the vacuum pump, close the dispensing valve, and start the vacuum equipment to test the airtightness. The resin and curing agent can be mixed at a ratio of 100:30, and the mixed resin can be degassed by vacuuming. S3-3, Resin Injection and Impregnation Control; Place the injection tube into the degassed resin container and inject the resin into the preform by relying on the system pressure difference; after the preform is completely impregnated, seal the injection port and the outlet in sequence to terminate the vacuum process. S3-4, cured and molded; The preform after impregnation is first cured at room temperature, then heated to 70-90℃ and maintained for 6-10 hours to complete curing. Finally, after demolding, a ship composite material folded sandwich panel frame structure based on the concept of folding is obtained.

[0011] This application also discloses a ship composite material pleated sandwich panel frame structure, which is manufactured using the above-mentioned molding method. The ship composite material pleated sandwich panel frame structure includes a first fiber cloth, a first foam corrugated component, a second fiber cloth, a second foam corrugated component, a third fiber cloth, and reinforcing ribs, which are laid from bottom to top in sequence. The first foam corrugated component includes multiple first foam corrugated strips arranged side by side in the horizontal direction. Each first foam corrugated strip has S-shaped corrugations arranged in the longitudinal direction on both sides in the horizontal direction. The upper part of the S-shaped corrugations is inclined towards the middle. The S-shaped corrugations on both sides of the first foam corrugated strip are staggered from each other in the longitudinal direction. The second foam corrugated assembly includes a plurality of second foam corrugated strips arranged laterally side by side. The second foam corrugated strips are located between adjacent first foam corrugated strips, and their lower end faces match the corrugations of the first foam corrugated strips. The second fiber cloth has a pleated curved surface structure and is bonded to the first foam corrugated component and the second foam corrugated component.

[0012] Its further features are: The reinforcing ribs include multiple first reinforcing strips arranged in the same direction and multiple second reinforcing strips arranged in the same direction; the directions of the first reinforcing strips and the directions of the second reinforcing strips are perpendicular to each other and orthogonally distributed; the lower end of the first reinforcing strip is provided with a slot that matches the outline of the second reinforcing strip for assembly.

[0013] The S-shaped corrugations on both sides of the first foam corrugated strip can intersect at the middle position, and the first foam corrugated strip is triangular in cross-section perpendicular to its length.

[0014] The first fiber cloth, the second fiber cloth, and the third fiber cloth are common fiber materials such as carbon fiber, glass fiber, basalt fiber, and aramid fiber.

[0015] The beneficial effects of this application are as follows: This application features a compact and rational structure, and is easy to operate. It first pre-assembles a first foam corrugated component as a negative mold, then uses a row-by-row molding process to complete the synergistic laying of the second foam corrugated strips 21 and the pleated fiber cloth. Finally, vacuum infusion curing is performed to achieve controllable preparation of the pleated-foam hybrid core material. This solves the technological challenges of molding accuracy, interface bonding, and morphological control in complex structures, providing a feasible manufacturing approach for their practical application in lightweight ship hulls. Furthermore, the corrugated structure is processed using CNC waterjet cutting followed by drying, ensuring the integrity of the corresponding foam corrugated component structure and preventing local collapse, resulting in a smooth surface of the pleated sandwich panel formed after molding. In addition, this application also has the following advantages: (1) While maintaining the consistency and stability of the traditional foam sandwich structure, by using the first and third fiber cloths as the upper and lower panels and the second fiber cloth as the middle pleated core, a continuous fiber reinforced composite pleated plate is introduced, which significantly improves the overall strength and buckling load capacity. It is more suitable for key parts such as the bow and bulkhead of high-speed unmanned ships. It can effectively enhance the structural load-bearing capacity while achieving lightweighting, and solve the problem that traditional foam sandwich and stiffened plate frames cannot balance lightweighting and mechanical performance. Attached Figure Description

[0016] Figure 1 A schematic diagram showing the composite pleated sandwich panel of this application after adding reinforcing ribs.

[0017] Figure 2 This is a front view of the composite pleated sandwich panel of this application.

[0018] Figure 3 A schematic diagram of the assembly of the first foam corrugated component and the second foam corrugated component of this application.

[0019] Figure 4This is a schematic diagram of the assembly of the second foam corrugated strip and the adjacent first foam corrugated strip of this application.

[0020] Figure 5 This is a schematic diagram of the inclined "S"-shaped corrugations on both sides of the first foam corrugated strip of this application.

[0021] Figure 6 This is a schematic diagram of step S2 of this application.

[0022] Figure 7 This is a diagram showing the effect of using traditional CNC precision engraving to process ripples.

[0023] Figure 8 This is a diagram showing the effect of CNC waterjet cutting for corrugation processing in this application.

[0024] Figure 9 This is a top view of the arrangement of the dispensing tube and the dispensing tube in this application.

[0025] Wherein: 10, first foam corrugated component; 11, first foam corrugated strip; 20. Second foam corrugated component; 21. Second foam corrugated strip; 31. First fiber cloth; 32. Second fiber cloth; 33. Third fiber cloth; 40. Reinforcing ribs. Detailed Implementation

[0026] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0027] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0028] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0029] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0030] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0031] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0032] Example 1 like Figures 1 to 5 As shown, a ship composite material pleated sandwich panel frame structure includes a first fiber cloth 31, a first foam corrugated assembly 10, a second fiber cloth 32, a second foam corrugated assembly 20, a third fiber cloth 33, and a reinforcing rib 40 laid sequentially from bottom to top. The first foam corrugated component 10 includes a plurality of first foam corrugated strips 11 arranged side by side in the horizontal direction. Each first foam corrugated strip 11 has S-shaped corrugations arranged in the longitudinal direction on both sides in the horizontal direction. The upper part of the S-shaped corrugations is inclined towards the middle. The S-shaped corrugations on both sides of the first foam corrugated strip 11 are staggered from each other in the longitudinal direction. The second foam corrugated assembly 20 includes a plurality of second foam corrugated strips 21 arranged laterally side by side. The second foam corrugated strips 21 are located between adjacent first foam corrugated strips 11, and their lower end faces match the corrugations of the first foam corrugated strips 11. The second fiber cloth 32 has a pleated curved surface structure and is bonded to the first foam corrugated component 10 and the second foam corrugated component 20.

[0033] Furthermore, the first fiber cloth 31, the second fiber cloth 32, and the third fiber cloth 33 are common fiber materials such as carbon fiber, glass fiber, basalt fiber, and aramid fiber.

[0034] Specifically, the first foam corrugated component 10 includes a plurality of first foam corrugated strips 11 arranged horizontally side by side, and the second foam corrugated component 20 includes a plurality of second foam corrugated strips 21 arranged horizontally side by side; a certain gap is left between adjacent first foam corrugated strips 11 and second foam corrugated strips 21 to facilitate the pleating and core of the second fiber cloth 32; the lower end of the first foam corrugated component 10 and the upper end of the second foam corrugated component 20 can be a smooth plane or an arc-shaped surface.

[0035] The S-shaped corrugations on both sides of the first foam corrugated strip 11 can intersect at the middle position. On the cross section perpendicular to the length of the first foam corrugated strip 11, the first foam corrugated strip 11 is triangular. The second foam corrugated strip 21 is located between adjacent first foam corrugated strips 11. The lower contour of the second foam corrugated strip 21 is consistent with the upper contour of the first foam corrugated strip 11. That is, the second foam corrugated strip 21 has longitudinally arranged S-shaped corrugations on both sides of its lateral direction. The upper part of the S-shaped corrugations is inclined towards the middle. The S-shaped corrugations on both sides of the second foam corrugated strip 21 are staggered in the longitudinal direction.

[0036] The reinforcing rib 40 can be a composite material cap-shaped reinforcing foam strip, used to increase the overall rigidity of the composite pleated sandwich panel frame structure to make it suitable for use in different environments; the reinforcing rib 40 includes multiple first reinforcing strips arranged in the same direction and multiple second reinforcing strips arranged in the same direction; the direction of the first reinforcing strip is perpendicular to the direction of the second reinforcing strip and forms an orthogonal distribution; the lower end of the first reinforcing strip is provided with a slot that matches the outline of the second reinforcing strip for assembly; the first reinforcing strip is installed on the second reinforcing strip through the slot.

[0037] Multiple second reinforcing strips are arranged longitudinally at intervals. Each second reinforcing strip is arranged laterally with an isosceles trapezoidal cross-section, measuring 20mm at the top, 40mm at the bottom, and 40mm in height. The spacing between adjacent first reinforcing strips is 90mm. Alternatively, multiple first reinforcing strips are arranged laterally at intervals. Each first reinforcing strip is arranged longitudinally with an isosceles trapezoidal cross-section, measuring 30mm at the top, 60mm at the bottom, and 60mm in height. The spacing between adjacent first reinforcing strips is 110mm. During assembly, the first reinforcing strips are installed on the second reinforcing strips through slots. This method employs a "smaller reinforcing strip through a larger reinforcing strip" assembly scheme. At the intersection of the longitudinal and transverse reinforcing strips, the smaller second reinforcing strips maintain structural continuity, while the larger first reinforcing strips undergo only localized breakage processing at the intersection. This approach aims to maintain the mechanical properties and fiber continuity of the intersection area as much as possible, while also preventing poor wetting of the third fiber cloth 33 under the cap-shaped reinforcing foam strip during subsequent glue injection.

[0038] The sandwich panel structure of this application is a composite pleated sandwich panel structure. While retaining the performance consistency and stability of traditional foam sandwich structures, it introduces a continuous fiber reinforced composite material pleated plate by using the first fiber cloth 31 and the third fiber cloth 33 as the upper and lower panels and the second fiber cloth 32 as the middle pleated core. This significantly improves the overall strength and buckling resistance, making it more suitable for key parts such as the bow and bulkheads of high-speed unmanned ships. It can effectively enhance the structural load-bearing performance while achieving lightweighting, solving the problem that traditional foam sandwich and stiffened panel structures cannot balance lightweighting and mechanical performance.

[0039] Example 2 A method for forming a composite material pleated sandwich panel frame structure for ships includes the following steps: S1, multiple first foam corrugated strips 11 and second foam corrugated strips 21 are arranged alternately on the molding substrate, so that the corrugated surfaces of the first foam corrugated strips 11 and the second foam corrugated strips 21 correspond to each other for pre-assembly. After the assembly is completed, the upper surface of the multiple first foam corrugated strips 11 is covered with adhesive glass fiber felt. The multiple first foam corrugated strips 11 are connected to form a first foam corrugated component 10. Then the whole assembly is flipped and inverted on another molding substrate, and the upper molding substrate and the second foam corrugated strips 21 are removed. S2, a first fiber cloth 31 is laid on the molding substrate. The first foam corrugated component 10, which was flipped in step S1, is laid on the first fiber cloth 31. The second fiber cloth 32 is then folded into a three-dimensional configuration to form a curved pleated core layer. The second fiber cloth 32 is laid on the first foam corrugated component 10 and the second foam corrugated strip 21 is laid on the second fiber cloth 32 using a row-by-row molding process to complete the segment-by-segment shaping of the three-dimensional folded second fiber cloth 32. Adhesive-coated glass fiber mat is laid on multiple second foam corrugated strips 21. A third fiber cloth 33 is laid on the glass fiber mat. Reinforcing ribs 40 are laid on the outside of the third fiber cloth 33 and wrapped with fiber cloth to complete the preform of the composite pleated sandwich panel. S3 uses a vacuum injection molding process to grout the preform of the composite pleated sandwich panel to obtain a ship composite material pleated sandwich panel frame structure.

[0040] Specifically, in step S1, a hard mold is prepared as the molding base, and a scraper is used to remove any protrusions or impurities that may exist on the surface of the hard mold to ensure that it is flat overall. Specifically, hard molds can be made of glass, metal plates, etc.

[0041] Multiple first foam corrugated strips 11 are bonded together with fiberglass mat to form a first foam corrugated assembly 10. The first foam corrugated assembly 10 serves as a female mold. After the second fiber cloth 32 is transformed from a two-dimensional plane into a three-dimensional curved surface structure, it has a certain thickness. The folding process requires strong compression, especially when the layer thickness is relatively high. The lightweight and freely movable discrete first foam corrugated strips 11 cannot provide sufficient support. After the second fiber cloth 32 is folded, it lacks self-shaping ability and will collapse as a whole under slight external force or mutual compression. The first foam corrugated assembly 10 formed by bonding fiberglass mat can act as a female mold for effective fixation. This method is not only convenient to operate and economical, but also has good bonding strength. It can meet the folding and laying of single and double layers of second fiber cloth 32 and can better solve the problem of fixing discrete foam corrugated strips.

[0042] In step S2, the second fiber cloth 32 is transformed from a two-dimensional to a three-dimensional structure to form a curved pleated core layer. To ensure that the second fiber cloth 32 can be folded to form a curved pleated core layer with high precision, a special auxiliary mold can be prepared using 3D printing technology. By applying controllable pressure to the second fiber cloth 32, its precise laying can be ensured. The row-by-row mold closing process can suppress the springback and displacement of the second fiber cloth 32 during the laying process. When assembling the reinforcing rib 40, a slot matching the outline of the second reinforcing rib is first set at the lower end of the first reinforcing rib for assembly. The smaller second reinforcing rib is laid on the third fiber cloth 33 at the designed position. The fiber cloth is covered on the second reinforcing rib and an appropriate amount of adhesive is sprayed to prevent it from shifting. Then, the larger first reinforcing rib is laid on the designed position. The fiber cloth is covered on the first reinforcing rib and an appropriate amount of adhesive is sprayed to prevent it from shifting. Finally, the release cloth is laid in sections. Necessary interruption is made at the intersection of the ribs to prevent the release cloth from bulging locally at the intersection, thus completing the preform of the composite pleated sandwich panel. To achieve controllable preparation of pleated-foam hybrid core material, the first foam corrugated component is pre-assembled as a negative mold, and then the second foam corrugated strip 21 and the pleated fiber cloth are laid out in a row-by-row molding process. Finally, vacuum infusion curing is performed to solve the process problems of molding accuracy, interface bonding and morphological control of complex structures.

[0043] It can also be applied to various Miura folds and their deformables, including V-shaped and M-shaped ones, providing a feasible manufacturing method for their practical application in lightweight ship hulls.

[0044] In some examples of this application, the corrugations on both sides of the first foam corrugated strip 11 and the second foam corrugated strip 21 are processed by CNC waterjet cutting; after processing, the first foam corrugated strip 11 and the second foam corrugated strip 21 are placed in an oven at 50℃-70℃ for drying treatment, and the drying time is 1h-3h. Specifically, the traditional method of processing corrugations is to use CNC precision engraving. This involves first selecting the appropriate foam corrugated board material according to the design thickness, then fixing it on the processing table of a precision engraving machine (four-axis CNC precision engraving machine), then importing the three-dimensional design model of the corresponding corrugations into the main control system to complete the processing path planning, and finally using the appropriate tool to engrave the foam board. However, the corrugated surface is generally rough during the above processing, and there is incomplete cutting near the processing table area, such as... Figure 7 As shown, the curved slope processed by the carving process actually presents a complex curved surface shape, which causes multiple first foam corrugated strips 11 and second foam corrugated strips 21 to form a significant crescent-shaped gap at the joint of the slope after they are staggered and molded. like Figure 9 As shown, after the foam corrugated board is processed by water cutting, the corresponding corrugated surface is smoother, and the inclined area is completely cut without residue. When the first foam corrugated component 10 is molded together, the upper and lower surfaces and the inclined area can be completely fitted together. The first foam corrugated component 10 and the second foam corrugated component 20 have a complete structure and no local collapse occurs. The surface of the pleated sandwich panel formed after molding has good flatness.

[0045] In some examples of this application, after the CNC waterjet process is completed, the corresponding foam corrugated board will inevitably be affected by water immersion. In order to ensure its applicability in the molding process of composite sandwich panel frame structure, the processed foam corrugated strip needs to be dried. Preferably, the PVC foam corrugated strip is placed in a 60°C oven and dried for 2 hours.

[0046] In some examples of this application, considering that the water jet cutting process itself has processing errors, the cumulative error during the assembly of a large number of discrete first foam corrugated strips 11 and second foam corrugated strips 21 exacerbates the surface unevenness. To solve the above problems, when multiple first foam corrugated strips 11 and second foam corrugated strips 21 are pre-assembled in step S1, the distance between them is appropriately increased so that adjacent first foam corrugated strips 11 and second foam corrugated strips 21 are in a relaxed state. That is, a flat plate is used to limit and correct the upper surface of the pre-assembled structure, so that all the foam corrugated strips reach a relatively flat and relaxed stable state. In addition, a hard pressure plate can be laid on the upper surface of the preform of the composite pleated sandwich panel in step S2, which can further improve the surface flatness after molding.

[0047] In some examples of this application, in steps S1 and S2, a release cloth with single-sided adhesive is laid on the surface of the rigid mold; The release cloth is a Teflon release cloth, which is a Teflon release cloth with single-sided adhesive backing laid on the surface of the rigid mold, ensuring that it covers the surface flat and without wrinkles, so that the composite pleated sandwich panel can be easily demolded from the rigid mold.

[0048] Example 3 In step S3 of embodiment 2, as Figure 8 As shown, in the vacuum injection molding process, the injection tube is linearly located in the middle of the second foam corrugated component 20 and injects glue to both sides, and the linearity is perpendicular to the length of the second foam corrugated strip 21; the dispensing tube is linearly located on both sides of the second foam corrugated component 20, and the linearity is perpendicular to the length of the second foam corrugated strip 21. Specifically, the naturally flowing channels formed after the preform can achieve complete resin impregnation from the upper panel through the pleated core layer to the lower panel, so a lightweight flow channel solution without drilling / grooving is adopted; the linear injection method used in this example is not only more efficient, but also the injection tube perpendicular to the foam corrugated strip can effectively avoid resin flow encapsulation. In the vacuum-assisted molding process, the maximum resin flow distance during a single injection must be controlled within 600mm to ensure the quality of mold filling. Considering that the maximum width of the environment in which this composite sandwich panel frame is used is greater than this flow distance, the injection tube is arranged along the symmetrical plane of the preform, and the injection tubes are symmetrically set on both sides. Bidirectional symmetrical injection achieves complete mold filling of the wide structure, ensuring that the resin fully impregnates the entire preform within the controlled distance.

[0049] Furthermore, a double-layer flow guide net is laid on the upper surface of the preform of the composite pleated sandwich panel. By controlling the distance between the boundary of the flow guide net and the surrounding structure, the resin is guided to achieve stable and controllable directional flow, which can improve the injection efficiency and prevent encapsulation and dry spot defects caused by backflow due to premature injection. The vacuum injection molding process in step S3 includes the following steps: S3-1, Environmental Control and Preform Packaging; First, the ambient temperature was adjusted to 30℃ according to the resin rheological properties. Then, a breathable release cloth, a flow guide net, a glass pressure plate, and a vacuum bag were laid on the preform in sequence, and injection and venting pipes were arranged. The entire structure was sealed with sealing tape. The glass pressure plate was laid between the flow guide net and the vacuum bag, mainly to improve the surface flatness of the specimen. To adapt to the symmetrical linear injection scheme, the glass pressure plate was divided into two parts along the axis of symmetry, so that the flow guide net could pass through the gap. The injection tube was fixed above the glass pressure plate and covered and guided by the flow guide net. S3-2, Sealing inspection and resin preparation; Connect the dispensing tube to the vacuum pump, close the dispensing valve, and start the vacuum equipment to test the airtightness. The resin and curing agent can be mixed at a ratio of 100:30, and the mixed resin can be degassed by vacuuming. S3-3, Resin Injection and Impregnation Control; Place the injection tube into the degassed resin container and inject the resin into the preform by relying on the system pressure difference; after the preform is completely impregnated, seal the injection port and the outlet in sequence to terminate the vacuum process. S3-4, cured and molded; The preform after impregnation is first cured at room temperature, then heated to 70-90℃ and maintained for 6-10 hours for final curing. Finally, after demolding, a folded sandwich panel structure based on the folding concept of marine composite materials is obtained. For example, it can be cured at room temperature for 24 hours, then heated to 80℃ and maintained for 8 hours for final curing, and finally demolded to obtain a folded sandwich panel structure based on the folding concept of marine composite materials.

[0050] The above description is an explanation of this application and not a limitation thereof. The scope of this application is defined by the claims. Within the scope of protection of this application, any form of modification may be made.

Claims

1. A method for forming a ship composite material pleated sandwich panel frame structure, characterized in that, Includes the following steps: S1, multiple first foam corrugated strips (11) and second foam corrugated strips (21) are arranged alternately on the molding substrate, so that the corrugated surfaces of the first foam corrugated strips (11) and the second foam corrugated strips (21) correspond to each other for pre-assembly. After the assembly is completed, the upper surface of the multiple first foam corrugated strips (11) is covered with adhesive glass fiber felt. The multiple first foam corrugated strips (11) are connected to form a first foam corrugated assembly (10). Then the assembly is flipped and inverted on another molding substrate, and the upper molding substrate and the second foam corrugated strip (21) are removed. S2, lay the first fiber cloth (31) on the molding substrate, lay the first foam corrugated component (10) after being flipped in step S1 on the first fiber cloth (31), and then fold the second fiber cloth (32) into a three-dimensional configuration to form a curved pleated core layer. The second fiber cloth (32) is laid on the first foam corrugated component (10) and the second foam corrugated strip (21) is laid on the second fiber cloth (32) using a row-by-row molding process to complete the segment-by-segment shaping of the three-dimensional folded second fiber cloth (32); lay adhesive glass fiber mat on multiple second foam corrugated strips (21), lay the third fiber cloth (33) on the glass fiber mat, lay reinforcing ribs (40) on the outside of the third fiber cloth (33) and wrap the fiber cloth to complete the preform of the composite pleated sandwich panel; S3 uses a vacuum injection molding process to grout the preform of the composite pleated sandwich panel to obtain a ship composite material pleated sandwich panel frame structure.

2. The molding method of a ship composite material pleated sandwich panel frame structure as described in claim 1, characterized in that: The corrugations on both sides of the first foam corrugated strip (11) and the second foam corrugated strip (21) are processed by CNC water jet cutting. After processing, the first foam corrugated strip (11) and the second foam corrugated strip (21) are placed in an oven at 50℃-70℃ for drying treatment, and the drying time is 1h-3h.

3. The molding method of a ship composite material pleated sandwich panel frame structure as described in claim 1, characterized in that: The reinforcing rib (40) includes a first reinforcing strip and a second reinforcing strip. In step S2, when the reinforcing rib (40) is assembled, the lower end of the first reinforcing strip is provided with a slot that matches the outline of the second reinforcing strip for assembly. The smaller second reinforcing strip is laid on the third fiber cloth (33) at the designed position, and the fiber cloth is covered on the second reinforcing strip. Then, the larger first reinforcing strip is laid on the designed position, and the fiber cloth is covered on the first reinforcing strip to complete the preform of the composite pleated sandwich panel.

4. The molding method of a ship composite material pleated sandwich panel frame structure as described in claim 1, characterized in that: The molding substrate is a rigid mold. In steps S1 and S2, a release cloth with single-sided adhesive is laid on the surface of the rigid mold.

5. The molding method of a ship composite material pleated sandwich panel frame structure as described in claim 1, characterized in that: In step S1, when multiple first foam corrugated strips (11) and second foam corrugated strips (21) are pre-assembled, the distance between them is appropriately increased so that adjacent first foam corrugated strips (11) and second foam corrugated strips (21) are in a relaxed state.

6. The molding method of a ship composite material pleated sandwich panel frame structure as described in claim 1, characterized in that: The vacuum injection molding process in step S3 includes the following steps: S3-1, Environmental Control and Preform Packaging; First, the ambient temperature was adjusted to 30℃ according to the resin rheological properties. Then, a breathable release cloth, a flow guide net, a glass pressure plate, and a vacuum bag were laid on the preform in sequence, and injection and venting pipes were arranged. The entire structure was sealed with sealing tape. The glass pressure plate was laid between the flow guide net and the vacuum bag, mainly to improve the surface flatness of the specimen. To adapt to the symmetrical linear injection scheme, the glass pressure plate was divided into two parts along the axis of symmetry, so that the flow guide net could pass through the gap. The injection tube was fixed above the glass pressure plate and covered and guided by the flow guide net. S3-2, Sealing inspection and resin preparation; Connect the dispensing tube to the vacuum pump, close the dispensing valve, and start the vacuum equipment to test the airtightness. The resin and curing agent can be mixed at a ratio of 100:30, and the mixed resin can be degassed by vacuuming. S3-3, Resin Injection and Impregnation Control; Place the injection tube into the degassed resin container and inject the resin into the preform by relying on the system pressure difference; after the preform is completely impregnated, seal the injection port and the outlet in sequence to terminate the vacuum process. S3-4, cured and molded; The preform after impregnation is first cured at room temperature, then heated to 70-90℃ and maintained for 6-10 hours to complete curing. Finally, after demolding, a ship composite material folded sandwich panel frame structure based on the concept of folding is obtained.

7. A ship composite material pleated sandwich panel frame structure, manufactured using the molding method for a ship composite material pleated sandwich panel frame structure according to any one of claims 1-6, characterized in that, The ship composite material pleated sandwich panel frame structure includes a first fiber cloth (31), a first foam corrugated assembly (10), a second fiber cloth (32), a second foam corrugated assembly (20), a third fiber cloth (33), and a reinforcing rib (40) laid from bottom to top. The first foam corrugated component (10) includes a plurality of first foam corrugated strips (11) arranged side by side in the horizontal direction. Each first foam corrugated strip (11) has S-shaped corrugations arranged in the longitudinal direction on both sides in the horizontal direction. The upper part of the S-shaped corrugations is inclined towards the middle. The S-shaped corrugations on both sides of the first foam corrugated strip (11) are staggered in the longitudinal direction. The second foam corrugated assembly (20) includes a plurality of second foam corrugated strips (21) arranged laterally side by side. The second foam corrugated strips (21) are located between adjacent first foam corrugated strips (11), and their lower end faces match the corrugations of the first foam corrugated strips (11). The second fiber cloth (32) has a pleated curved surface structure and is bonded to the first foam corrugated component (10) and the second foam corrugated component (20).

8. The ship composite material pleated sandwich panel frame structure as described in claim 7, characterized in that: The reinforcing rib (40) includes a plurality of first reinforcing strips arranged in the same direction and a plurality of second reinforcing strips arranged in the same direction; the directions of the first reinforcing strips and the directions of the second reinforcing strips are perpendicular to each other and are orthogonally distributed; the lower end of the first reinforcing strip is provided with a slot that matches the outline of the second reinforcing strip for assembly.

9. The ship composite material pleated sandwich panel frame structure as described in claim 7, characterized in that: The S-shaped corrugations on both sides of the first foam corrugated strip (11) can intersect at the middle position. On the cross section perpendicular to the length of the first foam corrugated strip (11), the first foam corrugated strip (11) is triangular.

10. The ship composite material pleated sandwich panel frame structure as described in claim 7, characterized in that: The first fiber cloth (31), the second fiber cloth (32), and the third fiber cloth (33) are common fiber materials such as carbon fiber, glass fiber, basalt fiber, and aramid fiber.

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