Co-curing forming device and method for variable-curvature composite U-shaped stiffened wall plate

Abstract

The invention belongs to the technical field of composite material manufacturing, and discloses a co-curing forming device and method for a variable-curvature composite material U-shaped stiffened wallboard. The method comprises the following steps: paving a carbon fiber composite material skin on a wallboard forming die to obtain a wallboard skin preform; a first U-shaped rib combination body is obtained; a second U-shaped rib combination body is obtained; obtaining a third combination body; after all the devices are combined and positioned, a thermocouple for monitoring the temperature is placed, a vacuum nozzle is placed, finally, a vacuum bag is adopted for packaging, curing and demolding, and the variable-curvature composite U-shaped stiffened wall plate is obtained. A soft and hard combined pressurization mode is adopted, and the defects that product pressure transmission is difficult, the internal quality is poor after a product is cured and formed, and lossless layering and pores exist are overcome; and meanwhile, the defects that the axis degree of the U-shaped rib is out of tolerance, the forming quality of an R corner area is poor, and fibers are bent due to the fact that the core mold adopts a soft mold structure are overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material manufacturing, and in particular relates to a co-curing molding device and method for a U-shaped reinforced wallboard of a composite material with a variable curvature. Background Art

[0002] Advanced composite materials have gradually become the main structural materials for the new generation of aircraft at home and abroad due to their high specific strength, specific modulus, excellent corrosion resistance, fatigue resistance and designability. Composite stiffened panel structures are widely used in main load-bearing structures such as large wings and fuselages due to their good post-buckling bearing capacity and weight reduction effect.

[0003] In the prior art, the quality requirements for aircraft composite material I-shaped reinforced wall panels are very high, for example: the axial deviation of the U-shaped rib facade (such as ±0.75mm); the molding quality of the co-curing interface between the U-shaped rib and the wall panel skin (internal quality, no delamination, porosity); the surface accuracy of the upper surface of the U-shaped rib (such as ±0.5mm); and the prior art is generally aimed at T-shaped, I-shaped, cap-shaped and other parts with lying edge structures. For such U-shaped ribs and skins that are integrally connected and have no lying edge structures, the prior art is difficult to achieve, and the higher the facade height, the greater the manufacturing difficulty.

[0004] In large-size composite reinforced wall panels, U-shaped ribs and wall panels are mostly manufactured using co-bonding, co-curing, mechanical connection and other manufacturing processes. Since the co-bonding molding process has high requirements on the surface quality and matching accuracy of the bonding interface, it brings risks to the bonding quality. In addition, the co-bonding and secondary bonding processes will increase the number of product curing times, increase manufacturing costs, and reduce production efficiency. The mechanical connection process usually increases manufacturing costs due to the large amount of fasteners used, while increasing the overall weight. In the co-curing molding process, metal core molds are mostly used for the U-shaped ribs in the reinforced wall panels. Since the metal core molds are generally more rigid, the co-curing molding process requires high manufacturing accuracy of the metal core molds and the matching accuracy between the metal core molds and the wall panel molding molds, especially for the reinforced wall panels with variable bending structures. In addition, it is difficult to transmit pressure between the metal core molds and the wall panels during the curing molding process, which affects the internal quality of the product. When using flexible core molds or soft mold structures, the deformation of the core molds is difficult to control under high temperature and high pressure environments. At the same time, the flexible core molds or soft film structures require the transfer of the I-shaped ribs from the paving mold to the core mold. The deformation of the core mold and the transfer of the U-shaped ribs will affect the contour of the product surface. In addition, this type of core mold has a short service life and cannot be used for a long time. Therefore, it is increasingly important to seek a method that can ensure both the internal quality of the reinforced wall panels and the requirements for the contour of the reinforced wall panels. Summary of the invention

[0005] In order to overcome the problems existing in the related art, the disclosed embodiments of the present invention provide a co-curing molding device and method for a U-shaped reinforced wall panel of a composite material with a variable curvature.

[0006] The technical scheme is as follows: A co-curing molding method for a U-shaped reinforced wall panel of a variable curvature composite material comprises: S1, laying a carbon fiber composite material skin on a wall panel forming mold to obtain a preform of the wall panel skin; S2, obtaining the first assembly of U-shaped ribs, laying the ribs on the U-shaped rib core mold, laying the web insert layer preform on the web insert layer laying mold; then, combining the core mold and the web insert layer laying mold, and positioning them with a cone pin; after positioning, placing the preformed R-angle carbon twist strips on both sides of the core mold, respectively, to obtain the first assembly of U-shaped ribs; S3, after cold compaction by pressurizing in an autoclave, obtain a second assembly of U-shaped ribs; after compaction, remove the web inserting paving molds on both sides of the first assembly of U-shaped ribs in sequence; then, place the first assembly of U-shaped ribs in sequence on the flip connection plate, use taper pins for positioning, and bolts for fastening and connection to obtain a second assembly of U-shaped ribs; S4, obtaining a third combination; S5, after all the devices are assembled and positioned, a thermocouple for monitoring the temperature is placed, and a vacuum nozzle is placed, and a vacuum bag is used for packaging, curing, and demoulding to obtain a variable curvature composite material U-shaped reinforced wall panel.

[0007] In step S4, a third assembly is obtained, including: flipping the second assembly onto the wall panel forming mold, and positioning it using a positioning seat and a taper pin; after the positioning is completed, removing the flip connection plate, and the first positioning core mold, the third positioning core mold, and the fifth positioning core mold in the core mold in turn, leaving the second positioning core mold and the fourth positioning core mold in the core mold, and placing a pressurized core mold on both sides of the U-shaped rib to obtain the third assembly.

[0008] Furthermore, the variable curvature composite U-shaped stiffened wall panels obtained by this method are used in the main load-bearing structures of large wings and fuselages.

[0009] Another object of the present invention is to provide a co-curing molding device for a U-shaped reinforced wall panel of a composite material with a variable curvature, wherein the device implements the co-curing molding method for the U-shaped reinforced wall panel of a composite material with a variable curvature, and the device comprises: Siding panel forming mold, used for laying and curing and forming of siding panel skin; Web plate insert paving mold, used for laying and transferring insert prefabricated bodies at the U-shaped rib edge strips; Core mold, used for U-shaped rib paving; Flip the connecting plate to be used for positive assembly after U-shaped ribs are laid, and then flip the whole plate to position it with the wall panel skin; The pressurized core mold is used to ensure uniform pressure transmission during the curing process of the U-shaped ribs; The wall panel forming die is provided with a connection plate positioning seat, and the upper surface of the connection plate positioning seat is provided with a positioning cone pin connected to the flip connection plate; The flip connection plate is provided with a first positioning pin hole for positioning with the wall panel forming mold and a core mold for laying the U-shaped ribs; a pressurized core mold is placed on both sides of the U-shaped ribs; The core molds respectively include 5 rib paving molds, namely the first positioning core mold, the second positioning core mold, the third positioning core mold, the fourth positioning core mold, and the fifth positioning core mold. The 5 rib paving molds are all provided with second positioning pin holes for positioning with the flip connection plate; the core molds are positioned and connected with the flip connection plate through the second positioning pin holes; The web plate inserting layer paving mold is provided with a third positioning pin hole for the core mold.

[0010] Furthermore, the wall panel forming mold is a metal frame structure.

[0011] Furthermore, the pressurized core mold is vulcanized rubber.

[0012] In combination with all the above-mentioned technical solutions, the beneficial effects of the present invention are as follows: the present invention can reduce the deformation of the U-shaped ribs during the transfer process, and at the same time directly lay them on the core mold, thereby improving the fit between the core mold and the U-shaped ribs, which is beneficial to improving the positioning accuracy when the U-shaped ribs are combined with the wall panel skin.

[0013] Compared with the prior art, the U-shaped ribs in the present invention are reinforced wall panels with no lying edge structure, which is a product structure form that has not been promoted in the current industry. This type of product structure form greatly reduces the stress concentration of parts with lying edge structure (such as: T-shaped, I-shaped, and hat-shaped reinforced wall panels) during use, greatly improving the service life of the product. The present invention abandons the traditional method of positioning the ribs in a forward and sequential manner, and adopts a positioning method in which the ribs are first positioned in combination on the connecting plate for hot compaction, and then the whole is flipped over. Since the ribs are positioned on the connecting plate, during the hot compaction operation, as the uncured layers of the parts become more and more compact, the ribs are closer to the theoretical position. In the traditional forward positioning method, during the sequential positioning process, since the part skin and ribs are not solidified, the ribs adhere to the skin after positioning and can no longer be moved by other means. As a result, in addition to the accumulation of positioning errors in the traditional positioning method itself, there is also a positioning deviation caused by the uncured layers not reaching the theoretical thickness. Therefore, the overall flipping positioning of the present invention solves the problem of being unable to guarantee the position accuracy of the rib axis, and at the same time improves the positioning accuracy from the general ±1mm to ±0.75mm; The present invention adopts a soft and hard combination pressurization method, which avoids the difficulty of product pressure transmission caused by the traditional pure metal core mold structure, poor internal quality of the product after curing and molding, lossless delamination, porosity and other defects; at the same time, it avoids the defects of U-shaped rib axis accuracy out of tolerance, poor R corner area molding quality, fiber buckling and other defects caused by the core mold using a soft film structure (such as airpad, silicone rubber, etc.); The present invention widely promotes the use of the forming of variable curvature stiffened wall panels, and greatly improves the forming quality of such parts; the success of the forming method described in the present invention indicates that such parts can be more used in fuselage, vertical tail, horizontal tail, door and other sections, and the structural form of such parts can improve the stress concentration problem caused by the structural form of stiffened wall panels in the current aviation field to a certain extent, while reducing the weight of the fuselage structure; the reform of the forming method of the present invention indicates the successful progress of domestic stiffened wall panels from stiffened wall panels with lying edge structures (T-shaped, I-shaped, hat-shaped) to integrated variable curvature U-shaped stiffened wall panels with no lying edge structures; for the integrated U-shaped stiffened wall panels without lying edges, the axis control accuracy of the parts with large size, multiple curvatures and variable cross-section structures is ±0.75mm, and the internal quality defects such as delamination are improved to Class B. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the description, serve to explain the principles of the present disclosure; Figure 1 Schematic diagram of a co-curing molding device for a U-shaped reinforced wall panel of a composite material with variable curvature provided in an embodiment of the present invention; Figure 2 Schematic diagram of a U-shaped reinforced wall panel of a composite material with variable curvature provided in an embodiment of the present invention; Figure 3 It is a partial enlarged schematic diagram of the positioning cone pin of the connection plate positioning seat provided in an embodiment of the present invention; Figure 4 Schematic diagram of a rib paving core mold provided by an embodiment of the present invention; Figure 5 It is a schematic diagram of a paving mold including five ribs provided by an embodiment of the present invention; Figure 6 It is a schematic diagram of the positioning connection between the second positioning pin hole and the flip connection plate provided by an embodiment of the present invention; Figure 7 This is a physical picture of the pressurized core mold provided by an embodiment of the present invention; Figure 8 It is a schematic diagram of a third positioning pin hole provided on the web plate intercalation paving die provided in an embodiment of the present invention; Fig. 9 It is a schematic diagram of the combination of a core mold and a web plate intercalation paving mold provided by an embodiment of the present invention; Fig.10 is a schematic diagram of a first positioning pin hole provided on the flip connection plate provided in an embodiment of the present invention; Fig.11 Schematic diagram of a U-shaped reinforced wall panel with an integrated structure without lying edges provided by an embodiment of the present invention; Fig.12 This is a schematic diagram of the overall flipping, positioning and co-curing molding of the U-shaped rib reinforced wall panel provided by an embodiment of the present invention; Fig.13 is a rib placement diagram provided by an embodiment of the present invention; Fig.14 This is a rib overall flip positioning diagram provided by an embodiment of the present invention; Fig.15 This is a state diagram of a U-shaped reinforced wallboard of a composite material with a variable curvature obtained after encapsulation and curing of the present invention; Fig.16 It is a flow chart of the overall flipping, positioning and co-curing molding method of the U-shaped rib reinforced wall panel provided by the embodiment of the present invention; In the figure: 1. wall panel forming mold; 2. web plate insert paving mold; 3. connection plate positioning seat; 4. core mold; 401. first positioning core mold; 402. second positioning core mold; 403. third positioning core mold; 404. fourth positioning core mold; 405. fifth positioning core mold; 5. flip connection plate; 6. second positioning pin hole; 7. pressurizing core mold; 8. positioning cone pin; 9. first positioning pin hole; 10. third positioning pin hole; 11. wall panel skin; 12. U-shaped ribs; 13. carbon twist strips. DETAILED DESCRIPTION

[0015] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0016] The innovation of the present invention is that the present invention provides a new structural form of wall panel skin parts. The matching accuracy control of multi-curvature wall panels is difficult. Through the method of the present invention, the cold compaction and soft-hard combination pressurization of the autoclave are used to greatly reduce the internal quality defects such as pores and delamination caused by the poor matching degree between the rib R angle and the wall panel skin at the multi-curvature change parts due to the tooling matching tolerance. The delamination defect in the lossless grade of the parts is improved from the common C level in the industry to B level. In addition, the connection plate used in the present invention is positioned and turned over as a whole, which improves the positioning accuracy of the ribs from ±1mm in the industry to ±0.75mm; at the same time, compared with the process compaction method of steel tooling used in the initial single-curvature U-shaped reinforced wall panel test pieces in the industry, the present invention adopts the autoclave cold compaction pressurization method for the forming of the variable curvature reinforced wall panel in the process, and the variable curvature interface is pressurized.

[0017] Embodiment 1, as Figure 1-Figure 15 As shown, the variable curvature composite material U-shaped reinforced wall panel co-curing molding device provided by the embodiment of the present invention includes: a wall panel molding mold 1, a web insert layer laying mold 2, a connection plate positioning seat 3, a core mold 4, a flip connection plate 5, a pressurized core mold 7, a positioning cone pin 8, a first positioning pin hole 9, a second positioning pin hole 6, a wall panel skin 11, and a U-shaped rib 12; Among them, the wall panel forming mold 1 is used for laying and curing and forming the wall panel skin 11; The web intercalation paving mold 2 is used for paving and transferring the intercalation preform at the edge of the U-shaped rib 12; The core mold 4 is used for laying the U-shaped ribs 12; Flip the connecting plate 5 to be used for positive assembly after the U-shaped ribs 12 are laid, and then flip the whole plate 5 to be positioned with the skin 11; The pressurized core mold 7 is used to ensure that the pressure of the U-shaped rib 12 is evenly transmitted during the curing process; Exemplarily, the wall panel forming mold 1 is a metal frame structure; The wall panel forming mold 1 is provided with a connecting plate positioning seat 3, and the upper surface of the connecting plate positioning seat 3 is provided with a positioning cone pin 8 connected to the flip connecting plate 5. Figure 3 As shown; The flip connecting plate 5 is provided with a first positioning pin hole 9 for positioning with the wall panel forming mold 1 and a core mold 4 for laying the U-shaped ribs 12, and the flip connecting plate 5 is provided with a first positioning pin hole 9; The core mold 4 includes five rib paving molds, namely a first positioning core mold 401, a second positioning core mold 402, a third positioning core mold 403, a fourth positioning core mold 404, and a fifth positioning core mold 405. Figure 5As shown; a second positioning pin hole 6 is provided on each of them for positioning with the flip connecting plate 5; the core mold 4 is positioned and connected with the flip connecting plate 5 through the second positioning pin hole 6. Figure 6 As shown; For example, Figure 7 As shown, a pressurized core mold 7 is placed on both sides of the U-shaped rib 12. The pressurized core mold 7 is made of vulcanized rubber. The web intercalation paving mold 2 is provided with a third positioning pin hole 10 connected to the core mold 4. The combination of the core mold 4 and the web intercalation paving mold 2 is as shown in FIG. Figure 8 , Fig. 9 shown.

[0018] Embodiment 2, as a further preferred embodiment of the present invention, the wall panel forming die 1 adopts a reinforced wall panel structure, which is gradually developed from the T-shaped rib reinforced wall panel and the I-shaped rib reinforced wall panel of the prior art to the U-shaped reinforced wall panel with no horizontal edge integrated structure of the present invention (such as Fig.11 , where the U-shaped reinforced siding has no lying edge, and the U-shaped reinforcement 12 and the siding skin 11 are integrated into a structure), gradually replacing the weakened lying edge structure of the reinforcement, greatly reducing the stress concentration caused by the lying edge structure during the use of the parts, but greatly increasing the difficulty in manufacturing and production. This difficulty is mainly reflected in the increase of the rib axis accuracy from the previous ±1mm to ±0.75mm, and the change of this type of siding forming method, as follows: A. The accuracy of the rib axis is improved to ±0.75mm: Since the T-shaped or I-shaped ribs and the skin are two independent parts, and there is a gap between the lying edges of each rib and they are independent sub-components, when the ribs and the skin are combined, multiple sets of positioners can be used to position them separately without interfering with each other. However, for U-shaped reinforced wall panels, the ribs have no lying edge structure, that is, multiple sets of ribs and the wall panels are an integrated structure, and the positions of the ribs affect each other. When positioning the ribs, they can only be positioned one by one, and the positioning errors accumulate, which makes the accuracy of the rib axis very easy to exceed the tolerance; B. Changes in forming methods: Since the T-shaped or I-shaped ribs and the skin are two independent parts, there are many options for forming such panels, such as bolt connection, secondary bonding, co-bonding, co-curing, etc. However, since the ribs and the panel skin of the U-shaped reinforced panel are integrated into an integrated structure, its forming method can only be co-curing, as follows: Examples of T-shaped or I-shaped reinforced wall panel forming methods: (1) In the prior art, T-shaped rib reinforced wall panels and I-shaped rib reinforced wall panels are formed by secondary bonding; that is, the wall panel skin and the T-shaped ribs or I-shaped ribs are first cured, and then the cured T-shaped ribs or I-shaped ribs are positioned with the cured wall panel skin by a positioner, and then bonded and formed for secondary bonding; (2) In the prior art, T-shaped rib reinforced wall panels and I-shaped rib reinforced wall panels are formed by co-bonding; that is, the wall panel skin is first solidified, and then the laid T-shaped ribs or I-shaped ribs are positioned with the solidified wall panel skin using a positioner and co-bonded to form the wall panel skin; (3) The T-shaped rib reinforced wall panels and I-shaped rib reinforced wall panels of the prior art adopt a co-curing molding method; that is, the wall panel skin is laid first, and then the laid T-shaped ribs or I-shaped ribs are positioned with the laid wall panel skin using a positioner, and co-cured and molded; Exemplarily, the U-shaped reinforced wall panel forming method of the present invention is as follows: The U-shaped reinforced siding is formed by co-curing, such as Fig.12 The overall flip positioning and co-curing molding principle of the U-shaped rib reinforced wall panel. Including: The ribs are laid, the carbon twist strips 13 are placed, the ribs are combined, hot compacted, the skin is laid and the ribs are flipped and positioned as a whole, the flip connection plate 5 is removed, the first positioning core mold 401, the third positioning core mold 403, and the fifth positioning core mold 405 are laid and molded, the pressurized core mold 7 is placed, and the package is cured; Among them, Fig.13 As shown, the carbon twist strip 13 is placed including: S101, positioning the third positioning core mold 403 on the flip connection plate 5, then placing all the web inserting and laying molds 2 on both sides, and then placing the carbon twist strips 13 on both sides; S102, placing the second positioning core mold 402 and the fourth positioning core mold 404 close to the third positioning core mold 403 on the flip connection plate 5, and then placing the web intercalation layer paving mold 2 and the ribs on the left side of the second positioning core mold 402, and then placing the web intercalation layer paving mold 2 and the carbon twist strip 13 on the right side of the fourth positioning core mold 404; S103 , placing the first positioning core mold 401 and the fifth positioning core mold 405 close to the second positioning core mold 402 and the fourth positioning core mold 404 on the flip connection plate 5 , and then placing the carbon twisted strip 13 .

[0019] Before the ribs are turned over and positioned as a whole, a carbon fiber composite material skin is laid on the wall panel forming mold 1 to obtain a wall panel skin 11 preform, that is, a skin layup; like Fig.14 As shown, during the overall flipping and positioning of the ribs, the flip connection plate 5 is used to perform the overall flipping and positioning.

[0020] like Fig.15 As shown, after encapsulation and curing, a variable curvature composite material U-shaped reinforced wall panel is obtained.

[0021] Experiments show that the advantages and disadvantages of the present invention are compared with those of the prior art, see Table 1.

[0022] Table 1 Comparison of advantages and disadvantages between the present invention and the prior art

[0023] Embodiment 3, as Fig.16 As shown, the co-curing molding method of the variable curvature composite material U-shaped stiffened wall panel provided by the embodiment of the present invention includes the following steps: S1, laying a carbon fiber composite material skin on a wall panel forming die 1 to obtain a preform of a wall panel skin 11; S2, laying the ribs on the core mold 4 of the U-shaped ribs, laying the web intercalation preform on the web intercalation mold 2, then combining the core mold 4 and the web intercalation mold 2, and positioning them using the cone pins on the web intercalation mold 2; after positioning, placing the preformed R-angle carbon twist strips 13 on both sides of the core mold 4, respectively, to obtain the first assembly of U-shaped ribs; S3, after cold compaction in the autoclave (70°C, 700 KPa, 25 min), the web intercalation paving molds 2 on both sides of the first U-shaped rib assembly are removed in sequence, and then the first U-shaped rib assembly is placed on the flip connection plate 5 in sequence, and the web intercalation paving mold 2 is used for positioning with a taper pin, and bolts are used for fastening and connection to obtain a second U-shaped rib assembly; S4, flip the second assembly onto the wall panel forming mold 1, and use the connection plate positioning seat 3 and the positioning cone pin 8 on the wall panel forming mold 1 to position it; after the positioning is completed, remove the flip connection plate 5, the first positioning core mold 401, the third positioning core mold 403, and the fifth positioning core mold 405 in the core mold 4 in turn, leaving the second positioning core mold 402 and the fourth positioning core mold 404 in the core mold 4, and place the pressurized core mold 7 on both sides of the U-shaped rib to obtain the third assembly; S5, after all the devices are assembled and positioned, a thermocouple for monitoring the temperature is placed, and a vacuum nozzle is placed, and finally a vacuum bag is used for packaging, curing, and demoulding to obtain a variable curvature composite U-shaped reinforced wall panel.

[0024] It can be known from the above embodiments that the technical solution used in the present invention is a large-size U-shaped reinforced wall panel made of a composite material with variable curvature. This reinforced wall panel structure is widely used in main load-bearing structures such as civil aircraft and military aircraft. At present, the domestic co-bonding molding process is mostly used for this structural product, and the co-curing molding process is mainly used for product research and development. There are not many real applications in model products. In the co-curing molding process, U-shaped ribs are mostly positive combination process methods, but the ribs are not accurately positioned, and defects such as layered pores are prone to appear inside. The product quality is unstable and cannot be applied to batch production. The overall flipping solution used in the present invention solves the problem of rib positioning in traditional process methods. At the same time, the pressurization mode of soft cover plate pressurization + metal core mold positioning solves the problem of difficult pressure transmission of traditional metal core molds, and the solution is reliable and stable. At present, the solution has been verified on a certain model of main load-bearing products and can be applied to batch production. The flip molding process solution is also applicable to I-shaped ribs, J-shaped ribs, hat-shaped ribs, etc.

[0025] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered within the protection scope of the present invention.

Claims

1. A co-curing molding method for a U-shaped reinforced wall panel of a variable curvature composite material, characterized in that: The method includes: S1, laying a carbon fiber composite material skin on a wall panel forming mold (1) to obtain a preform of a wall panel skin (11); S2, obtaining a first assembly of U-shaped ribs, laying the ribs on the core mold (4) of the U-shaped ribs, and laying the web insert layer preform on the web insert layer laying mold (2); then, combining the core mold (4) and the web insert layer laying mold (2), and positioning them using a cone pin; after positioning is completed, placing preformed R-angle area carbon twist strips (13) on both sides of the core mold (4), respectively, to obtain a first assembly of U-shaped ribs; S3, after cold compaction by pressurizing in an autoclave, obtaining a second assembly of U-shaped ribs; after compaction, removing the web inserting layer paving molds (2) on both sides of the first assembly of U-shaped ribs in sequence; then, placing the first assembly of U-shaped ribs in sequence on the flip connection plate (5), positioning with taper pins, and fastening with bolts to obtain a second assembly of U-shaped ribs; S4, obtaining a third combination; S5, after all the devices are assembled and positioned, a thermocouple for monitoring the temperature is placed, and a vacuum nozzle is placed, and a vacuum bag is used for packaging, curing, and demoulding to obtain a variable curvature composite material U-shaped reinforced wall panel.

2. The co-curing molding method of the variable curvature composite material U-shaped reinforced wall panel according to claim 1, characterized in that: In step S4, a third assembly is obtained, including: turning over the second assembly onto the wall panel forming mold (1) and positioning it using the positioning seat (3) and the cone pin; after the positioning is completed, removing the turning connecting plate (5) and the first positioning core mold (401), the third positioning core mold (403), and the fifth positioning core mold (405) in the core mold (4) in sequence, leaving the second positioning core mold (402) and the fourth positioning core mold (404) in the core mold (4), and placing a pressurizing core mold (7) on both sides of the U-shaped rib to obtain the third assembly.

3. The co-curing molding method of the variable curvature composite material U-shaped reinforced wall panel according to claim 1, characterized in that: The variable curvature composite U-shaped stiffened wall panels obtained by this method are used in the main load-bearing structures of large wings and fuselages.

4. A co-curing molding device for a U-shaped reinforced wall panel made of a variable curvature composite material, characterized in that: The device implements the co-curing molding method of the variable curvature composite material U-shaped stiffened wall panel according to any one of claims 1 to 3, and the device comprises: A wall panel forming mold (1) is used for laying and curing the wall panel skin (11); A web intercalation paving mold (2) is used for paving and transferring intercalation preforms at the edge of the U-shaped ribs (12); A core mold (4) is used for laying the U-shaped ribs (12); The connecting plate (5) is turned over to be assembled in a forward direction after the U-shaped ribs (12) are laid, and then the whole plate is turned over to be positioned with the wall panel skin (11); A pressurized core mold (7) is used to ensure that pressure is evenly transmitted during the curing process of the U-shaped ribs (12); A connecting plate positioning seat (3) is provided on the wall panel forming die (1), and a positioning cone pin (8) connected to the flip connecting plate (5) is provided on the upper surface of the connecting plate positioning seat (3); The flip connection plate (5) is provided with a first positioning pin hole (9) for positioning with the wall panel forming die (1) and a core die (4) for laying the U-shaped ribs (12); a pressurizing core die (7) is placed on both sides of the U-shaped ribs (12); The core mold (4) comprises five rib paving molds, namely a first positioning core mold (401), a second positioning core mold (402), a third positioning core mold (403), a fourth positioning core mold (404), and a fifth positioning core mold (405). The five rib paving molds are each provided with a second positioning pin hole (6) for positioning with the flip connection plate (5); the core mold (4) is connected to the flip connection plate (5) through the second positioning pin hole (6); The web plate inserting layer paving mould (2) is provided with a third positioning pin hole (10) for the core mould (4).

5. The co-curing molding device of the variable curvature composite material U-shaped reinforced wall panel according to claim 4 is characterized in that: The wall panel forming mold (1) is a metal frame structure.

6. The co-curing molding device for U-shaped reinforced wall panels made of composite materials with variable curvature according to claim 4, characterized in that: The pressurizing core mold (7) is made of vulcanized rubber.

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