Integrally-formed stiffened wall plate with light weight and high overall strength as well as forming mold, forming method and application of integrally-formed stiffened wall plate

Abstract

The invention discloses an integrally-formed stiffened wall plate with light weight and high overall strength, and a forming mold, a forming method and application of the integrally-formed stiffened wall plate. The invention belongs to the technical field of stiffened wall plates and forming molds thereof. The technical problems that ribs and skin of an existing stiffened wall plate are prone to debonding and failure, so that the overall strength and reliability are poor, and an existing forming mold is not high in flexibility are solved. The lower edge strips integrated with the left vertical ribs and the right vertical ribs are arranged between the adjacent vertical ribs of the stiffened wall plate, and the lower edge strips and the skin are integrated through co-curing. The mold comprises an upper mold, a lower mold, a core mold and two L-shaped molds, the core mold and the two L-shaped molds are located between the upper mold and the lower mold, the core mold is in a right-angle U shape, the upper mold is clamped in a U-shaped opening, the vertical faces of the two L-shaped molds are horizontally and oppositely arranged inwards, and limiting blocks are arranged at the two ends of the vertical faces of the L-shaped molds and used for clamping the core mold. The forming method is convenient, co-curing forming is adopted, and the preparation process is simplified. The stiffened wall plate is applied to aircraft wings, fuselages and air inlets.

Description

Technical Field

[0001] The present invention belongs to the technical field of reinforced wall panels and their forming dies, and specifically relates to an integrated reinforced wall panel with both light weight and high overall strength, and its forming die, forming method and application. Background Art

[0002] Composite stiffened panels are widely used in aerospace, shipbuilding, automobile and shell structures due to their light weight, high strength and high load-bearing efficiency. These panels are connected to the skin and stiffeners through co-curing and secondary bonding technology. The mold plays a key role in the molding process to ensure the dimensional accuracy of the stiffened panels and control the thermal expansion during the curing process to avoid product deformation caused by the mismatch between the thermal expansion coefficients of the mold and the panel.

[0003] As the main load-bearing component in aircraft structure, the application of reinforced panels is becoming more and more widespread. This structure consists of skin and ribs, which are bonded together by co-bonding or secondary bonding technology. However, under load, debonding failure may occur between the ribs and the skin, affecting the overall strength and reliability of the structure. To improve the load-bearing capacity, the traditional method is to increase the thickness of the skin or the number of ribs, but this will increase the weight of the structure, which conflicts with the goal of lightweight design in the aerospace field. Traditional reinforced panel structures such as Figure 1 As shown. In order to ensure structural strength and achieve lightweight, the design and manufacture of composite reinforced panels need to comprehensively consider material selection, connection process and mold design. By optimizing these factors, the risk of debonding between ribs and skin can be effectively reduced, the structural performance can be improved, and the structural weight can be controlled to meet the strict requirements of the aerospace field for high-performance composite reinforced panels.

[0004] The researchers optimized the load-bearing capacity of the reinforced panels by co-curing the skin and the long spars, while reducing the space occupied, but faced the challenges of complex manufacturing processes and increased costs. There is also an integrated molding technology that uses primary and secondary ribs to effectively disperse the load and improve the anti-instability performance of the panels. However, its high-precision manufacturing process and specific size ratios limit the flexibility of the design. In addition, the use of adhesive curing and automatic tape laying processes has improved the anti-instability ability and manufacturing efficiency of the panels, but it requires high-precision equipment support and increases manufacturing costs. The above methods each demonstrate the efforts to improve performance through innovative structures and processes in aviation panel design, but also bring manufacturing complexity and cost issues.

[0005] Reinforced wall panel molds can be divided into metal molds, rubber molds, composite molds and combination molds according to the type of materials. Among them, metal molds are the most commonly used, and metal molds have the advantages of stable clamping and compact structure. However, metal molds have the problem of stress concentration, and the reinforced wall panels will be deformed and defective. Therefore, it is necessary to improve the metal mold. Some scholars have proposed a composite mold with an electrically anisotropic laminated structure, which matches the thermal expansion coefficient of the mold and the reinforced wall panel through zoned self-heating. There is also a silicone rubber-assisted reinforced wall panel mold to improve the density, quality and size accuracy of the longitudinal and transverse reinforced wall panels. However, the above molds all have the problem of low flexibility. Summary of the invention

[0006] In order to overcome the defects of the above-mentioned prior art, the present invention provides an integrated reinforced wall panel with both light weight and high overall strength, and a molding mold, a molding method and application thereof.

[0007] One of the purposes of the present invention is to provide an integrated reinforced wall panel that is both lightweight and has high overall strength, the reinforced wall panel comprising a bottom skin, a plurality of vertical ribs and an R zone;

[0008] Or it includes a bottom skin, multiple vertical ribs, multiple upper edge strips and an R zone, characterized in that a lower edge strip integrated with the left and right vertical ribs is provided between adjacent vertical ribs, and the lower edge strip is integrated with the skin through co-curing.

[0009] It is further defined that the reinforced wall panel has an I-type, T-type, J-type, Z-type, L-type or C-type configuration.

[0010] It is further defined that the reinforced wall panel is made of fiber resin prepreg.

[0011] Still further defined, the fibers include carbon fibers, glass fibers, and aramid fibers.

[0012] Still further defined, the resin includes epoxy resins, bismaleimide resins and cyanate ester resins.

[0013] It is further defined that the filler in the R region is a unidirectional fiber resin prepreg twist strip.

[0014] The second object of the present invention is to provide a mold for forming the above-mentioned reinforced wall panels, the mold comprising an upper mold, a lower mold, a core mold located therebetween, and two L-shaped molds, the core mold being a right-angle U-shape, the upper mold being clamped in the U-shaped mouth, the vertical surfaces of the two L-shaped molds being horizontally opposed inward, and limit blocks being provided at both ends of the vertical surfaces of the L-shaped molds for clamping the core molds.

[0015] It is further defined that the core mold in the mold is made of polymer and the rest is made of metal.

[0016] Further specifically, the polymer includes silicone rubber, polytetrafluoroethylene and polyimide, and the metal includes stainless steel, aluminum alloy and indium steel.

[0017] The third object of the present invention is to provide a method for forming the above-mentioned reinforced wall panel using the above-mentioned mold, and the method is carried out according to the following steps:

[0018] S1: Lay the prepreg on the lower mold according to the preset laying number and angle to obtain the bottom skin;

[0019] S2: Prepreg is laid on the outer surface of the core mold and between the two L-shaped molds and the core mold according to the configuration of the target reinforced wall panel and the preset number of prepreg laying layers and angles to obtain integrated vertical ribs and lower edge strips; wherein the number of core molds between the two L-shaped molds is determined according to the number of vertical ribs;

[0020] S3: The unidirectional prepreg is rolled into a twisted strip and filled in the gap between the L-shaped mold and the core mold as a filler in the R zone;

[0021] S4: when the prepreg is laid on the top surface where the vertical edge of the L-shaped mold is located, further prepreg is laid on the prepreg on the top surface where the vertical edge of the L-shaped mold is located according to the preset laying number and angle of the prepreg to obtain an upper edge strip;

[0022] S5: After sealing, the panel is cured in an autoclave, and a certain pressure is maintained during the curing process. After the curing is completed, the panel is demoulded to obtain an integrated reinforced wall panel that is lightweight and has high overall strength.

[0023] It is further defined that the curing procedure in S5 is: curing temperature is 100-200°C, heating rate is 1-10°C / min, pressure is 0.3-1.5MPa, and heat preservation and pressure holding time is 1-2h.

[0024] A fourth object of the present invention is to provide an application of the above-mentioned stiffened wall panel in aircraft wings, fuselages and air inlets.

[0025] The advantages of the present invention compared to the prior art are:

[0026] (1) The mold of the present invention is highly flexible and has a wide range of applications. It can prepare various types of reinforced wall panels, including I-type, T-type and Z-type, etc. Different types of reinforced wall panels can be prepared by selecting different stacking positions of reinforced wall panel prepreg; the size of the combined mold is determined according to the size of the reinforced wall panel. The combined mold can be selected from different types of polymers and metals. The material of the combined mold matching the thermal expansion coefficient of the reinforced wall panel can reduce thermal stress and prevent deformation and defects of the reinforced wall panel.

[0027] (2) The reinforced wall panels obtained by the method of the present invention have small deformation and few defects. By making the skin and the reinforcement into a whole with continuous fiber material, the stability and bearing capacity of the structure are improved. It has a large bonding area, effectively disperses the interface stress, reduces local stress concentration, and improves the anti-peeling ability. The polymer part of the mold (such as silicone rubber) can adapt to the shape and contour of the product surface, ensuring a good fit between the mold and the product, thereby reducing deformation and residual stress caused by shape mismatch during the curing process. At the same time, the polymer part of the mold (such as silicone rubber) has a low modulus and good conformability, and the pressure transmission during the molding process is more uniform, thereby reducing the defects of the test piece.

[0028] (3) The molding method of the present invention is convenient, and the co-curing molding is adopted to simplify the preparation process. In addition, the reinforced wall panel of the present invention is 11.10% lighter than the traditional reinforced wall panel, and the material cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the existing I-shaped reinforced wall panel;

[0030] Figure 2 It is a structural schematic diagram of the I-shaped reinforced wall panel of the present invention;

[0031] Figure 3 It is a schematic diagram of the structure of the molding die of the present invention;

[0032] Figure 4 Schematic diagram of the structure and dimensions of the I-shaped reinforced wall panel of Example 1; wherein (a) is the front view dimension, (b) is the top view dimension, and (c) is the three-dimensional structure schematic diagram;

[0033] Figure 5 Schematic diagram of prepreg laying during the forming process of the I-shaped reinforced wall panel of Example 1; wherein (a) and (b) represent different angles;

[0034] Figure 6 This is a schematic diagram of the local ply direction of the I-shaped reinforced wall panel prepreg of Example 1;

[0035] Figure 7 The temperature and curing degree of the I-shaped reinforced wall panel of Example 1 vary with time;

[0036] Figure 8 This is a physical picture of the I-shaped reinforced wall panel obtained in Example 1; wherein (a) and (b) represent different angles;

[0037] Fig. 9 Defect detection diagrams of I-shaped reinforced wall panels obtained in Example 1 and the comparative example; wherein (a) is the comparative example, and (b) is Example 1;

[0038] Fig.10The warping deformation analysis of the I-shaped stiffened wall panels obtained in Example 1 and the comparative example; wherein (a) is the comparative example, and (b) is Example 1;

[0039] Fig.11 The compression failure pictures of the I-shaped reinforced wall panels obtained in Example 1 and the comparative example; wherein (a) is the comparative example, and (b) is Example 1;

[0040] Fig.12 The axial compression test load-displacement curves of the I-shaped reinforced wall panels obtained in Example 1 and the comparative example;

[0041] Fig.13 Schematic diagram of the mold structure and prepreg placement for forming the T-shaped reinforced wall panel in Example 3;

[0042] Fig.14 It is a structural schematic diagram of a T-shaped reinforced wall panel of Example 3;

[0043] In the figure, 1-lower edge strip, 2-upper edge strip, 3-vertical rib, 4-skin, 5-R zone, 6-upper mold, 7-core mold, 8-L-type mold, 9-lower mold, 10-preg. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0045] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

[0046] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0048] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0050] The following embodiments all carry out conventional steps including but not limited to the following steps for forming reinforced wall panels when making the reinforced wall panels:

[0051] Use a blanking machine to cut the prepreg into preset sizes and mark the placement position and angle on the back of each piece of prepreg.

[0052] Prepare breathable felt, perforated isolation film, release cloth, vacuum bag, etc., and cut them into preset sizes in preparation for vacuum curing and molding.

[0053] Use a non-woven fabric dipped in acetone solution to wipe the mold until there is no contaminant on the non-woven fabric, and then dry the mold. Make sure there are no foreign particles or dust on the surface of the mold to avoid contaminating the product, and avoid particles scratching the vacuum bag during the vacuuming process. Paste a circle of sealing tape on the outside of the line area of ​​the lower mold product, and evenly apply three layers of release agent on the lower mold inside the tape. After each layer of release agent is applied, the mold needs to be placed in a 60℃ oven to dry for 30 minutes before continuing to apply the next layer of release agent. For the two L-shaped molds, the above method is also used to apply three layers of release agent. Other metal molds use the method of sticking adhesive release cloth to ensure that the mold can be demolded smoothly. Polymer molds are easy to demold, so no additional treatment is required.

[0054] When sealing, evacuate to -0.1MPa. If the pressure drops within -0.005MPa after 15 minutes, it means that the seal is good.

[0055] In each step of the production process, after laying the prepreg and the breathable felt, the sealing strip is pasted and the vacuum bag is filled with vacuum to remove the bubbles in the prepreg and compact the prepreg. The vacuum is drawn once every 4 layers of prepreg are laid.

[0056] The number of core molds between the L-shaped molds depends on the number of vertical ribs. The upper mold is used to compact the core molds. Therefore, the number of upper molds depends on the number of core molds.

[0057] The mold parameters involved in the following embodiments are shown in Table 1-2.

[0058] Table 1 Polymer mold

[0059] Silicone rubber mold Tieling Fengrun Rubber Seal Products Co., Ltd. PTFE mold Zhenjiang Lieri Sealing Technology Co., Ltd. Polyimide mold Changzhou Yaan New Materials Co., Ltd.

[0060] Table 2 Metal mold

[0061]

[0062] Example 1 (combination Figure 2-6 ): The forming method of the integrated I-shaped reinforced wall panel of this embodiment is carried out according to the following steps:

[0063] (1) Material preparation: Use CCF300 / 7901 as prepreg and follow Figure 4 The size specifications shown are cut into the required size of the reinforced wall panel, and the mold release agent is evenly applied three times on the mold. The mold is a silicone rubber / stainless steel combination, in which the core mold 7 is made of silicone rubber and the rest is stainless steel.

[0064] (2) Figure 5 As shown, the prepreg is laid on the lower mold 9 in the layering order of [45 / -45 / 0 / 90 / 0] to obtain the bottom skin 4;

[0065] According to the I-type structure, the prepreg is laid on the outer surface of the core mold 7 and between the two L-shaped molds 8 and the core mold 7 in the order of [45 / -45 / 0 / 90 / 0 / 0 / 90 / 0], and the prepreg is laid along the outer surface of the core mold 7, the contact surface between the L-shaped mold 8 and the core mold 7, the contact surface between the L-shaped mold 8 and the lower mold 9, and the top surface where the vertical edge of the L-shaped mold 8 is located, to obtain an integrated vertical rib 3 and a lower edge strip 1;

[0066] Four 60mm×450mm unidirectional prepregs are rolled up to make twist strips, the left and right L-shaped molds 8 are molded together, and then the unidirectional prepreg twist strips are used as fillers to fill the gap between the L-shaped mold 8 and the bottom of the core mold 7 as fillers for the R region 5, and then the core mold 7 is molded together, and the unidirectional prepreg twist strips are used as fillers to fill the gap between the L-shaped mold 8 and the top of the core mold 7 as fillers for the R region 5;

[0067] Lay the prepreg on the top surface of the vertical edge of the L-shaped mold 8 in the order of [0 / 90 / 0 / 45 / -45] to obtain the upper edge strip 2, lay the upper edge strip pressing plate, and close the upper mold 6 for compaction;

[0068] (3) After sealing, solidify in an autoclave. Under the condition of vacuum pressure ≥ 0.08MPa, heat to 80℃ at a rate of 2℃ / min, keep warm for 30min, then continue to heat to 120℃, keep warm for 1.5h. After keeping warm at 120℃ for 30min, pressurize the tank to 0.4MPa and keep the pressure until the end of the insulation. Cool down at a rate of 1.5℃ / min, open the autoclave after the temperature of each point of the reinforced wall panel drops to 60℃, remove the vacuum bag and demould after the temperature of each point of the reinforced wall panel drops to room temperature, use engraving machine and cutting machine to cut off the excess, detect the external dimensions and internal defects, and obtain an integrated reinforced wall panel with both light weight and high overall strength (see Figure 8 ). In terms of weight, the new integrated reinforced wall panel is 11.10% lighter than the traditional reinforced wall panel.

[0069] Comparative example: Traditional reinforced wall panels (see Figure 1 ) is prepared by dry stud-wet skin co-bonding, wherein the prepreg material and curing process are the same as those in Example 1, and a stainless steel mold is used. The specific preparation steps are as follows:

[0070] ① Preparation of ribs: After applying release agent to the mold, lay the prepreg in the order of [45 / -45 / 0 / 90 / 0 / 0 / 90 / 0]. Vacuum the mold after laying four layers of prepreg.

[0071] ② Place 60mm×450mm unidirectional prepreg in the R area and roll it up to make twist strips as fillers in the R area, a total of 2.

[0072] ③ Lay the upper edge strip in the laying order of [0 / 90 / 0 / 45 / -45].

[0073] ④ According to the curing process of Example 1, seal and cure, demould and trim, and perform overall inspection to obtain the cured dry ribs.

[0074] ⑤The skin is laid out in the order of [45 / -45 / 0 / 90 / 0].

[0075] ⑥ Dry stud-wet skin combination (place 60mm×450mm unidirectional prepreg in the R area and roll it up to make twisted strips as fillers in the R area, a total of 2).

[0076] ⑦ According to the curing process of Example 1, seal and cure, demould and trim, and conduct overall inspection.

[0077] 1. Defect detection:

[0078] After detection by the C-scan system, black indicates that there are no defects in the composite material test piece, and white indicates that there are defects in the composite material test piece. The reinforced wall panel prepared by the stainless steel mold in the comparative example has scattered white areas in the middle, and there are many defects ( Fig. 9 a). However, the silicone rubber / stainless steel combined mold of Example 1 of the present invention has no obvious white area ( Fig. 9 b) The combined mold has good conformability, uniform pressure transmission and reduced defects.

[0079] (II) Warping deformation analysis:

[0080] The deformation of the entire surface of the reinforced wall panel is tested using a 3D handheld scanner. Fig.10 As shown in the figure. It can be seen from the figure that the reinforced wall panels prepared by these two molds show no deformation in the middle of the skin, but the deformation on both sides of the skin along the length direction of the reinforced wall panels is large. The maximum deformation of the reinforced wall panels prepared by the stainless steel mold in the comparative example is 1.076mm, and the maximum deformation of the reinforced wall panels prepared by the silicone rubber / stainless steel combination mold is 0.863mm. The deformation of the reinforced wall panels prepared by the stainless steel mold is significantly greater than that of the reinforced wall panels prepared by the silicone rubber / stainless steel mold.

[0081] (III) Compression performance test of reinforced wall panels:

[0082] The results are as follows Fig.11 As shown in the figure, the failure of the reinforced wall panel prepared by the traditional method of the comparative example mainly occurs in the debonding of the ribs and the skin, while the integrated reinforced wall panel prepared by the silicone rubber / stainless steel combination mold of Example 1 of the present invention does not experience debonding failure.

[0083] like Fig.12 As shown, the compression failure load of the reinforced wall panel prepared by the traditional method in the comparative example is 167.59 kN, the compression failure load of the integrated reinforced wall panel prepared by the silicone rubber / stainless steel combination mold is 183.11 kN, and the load-bearing capacity of the integrated reinforced wall panel is 8.48% higher.

[0084] In summary, when silicone rubber and stainless steel combined molds are used, the mold will conduct heat during the product curing process. Silicone rubber has a low thermal conductivity, which can slow down the heat conduction speed and prevent the surface temperature of the product from dropping rapidly due to excessive cooling, which is beneficial to the uniform distribution of the internal temperature of the product and the control of the cooling rate, reducing the deformation and residual stress caused by thermal stress. At the same time, rubber has good elasticity and low modulus. When the product is affected by internal stress during the curing process, the rubber mold can relieve these stresses through its elastic properties and reduce the deformation and residual stress caused by stress on the product.

[0085] Example 2 (combined Figure 2-5 ): The forming method of the integrated I-shaped reinforced wall panel of this embodiment is carried out according to the following steps:

[0086] (1) Material preparation: Use T800 / QY9511 as prepreg and follow Figure 4 The size specifications shown are cut into the required size of the reinforced wall panel, and the mold release agent is evenly applied to the mold three times. The mold is an indium steel / polyimide combination, in which the core mold 7 is made of polyimide and the rest is indium steel.

[0087] (2) Figure 5 As shown, the prepreg is laid on the lower mold 9 in a layering order of [45 / 45 / 0 / 90 / 90] to obtain the bottom skin 4;

[0088] According to the I-shaped structure, the prepreg is laid on the outer surface of the core mold 7 and between the two L-shaped molds 8 and the core mold 7 in the order of [45 / 45 / 0 / 90 / 90 / 0 / -45 / -45], and the prepreg is laid along the outer surface of the core mold 7, the contact surface between the L-shaped mold 8 and the core mold 7, the contact surface between the L-shaped mold 8 and the lower mold 9, and the top surface where the vertical edge of the L-shaped mold 8 is located, to obtain an integrated vertical rib 3 and a lower edge strip 1;

[0089] Four 60mm×450mm unidirectional prepregs are rolled up to make twist strips, the left and right L-shaped molds 8 are molded together, and then the unidirectional prepreg twist strips are used as fillers to fill the gap between the L-shaped mold 8 and the bottom of the core mold 7 as fillers for the R region 5, and then the core mold 7 is molded together, and the unidirectional prepreg twist strips are used as fillers to fill the gap between the L-shaped mold 8 and the top of the core mold 7 as fillers for the R region 5;

[0090] Lay the prepreg on the top surface of the vertical edge of the L-shaped mold 8 in the order of [0 / 90 / 0 / 45 / 0] to obtain the upper edge strip 2, lay the upper edge strip pressing plate, and close the upper mold 6 for compaction;

[0091] (3) After sealing, solidify in an autoclave. Under the condition of vacuum pressure ≥ 0.08MPa, heat to 40℃ at a rate of 2℃ / min, keep warm for 25min, then continue to heat to 185℃ and pressurize the tank to 0.4MPa for 2h. After the pressure and heat preservation, continue to heat to 195℃ at a rate of 2℃ / min and keep warm for 4h. Cool down at a rate of 1.5℃ / min, open the autoclave after the temperature of each point of the reinforced wall panel drops to 60℃, remove the vacuum bag and demould after the temperature of each point of the reinforced wall panel drops to room temperature, use engraving machine and cutting machine to cut off the excess, detect the external dimensions and internal defects, and obtain an integrated reinforced wall panel with both light weight and high overall strength.

[0092] Example 3 (combined Figure 13-14 ): The forming method of the integrated T-shaped reinforced wall panel of this embodiment is carried out according to the following steps:

[0093] (1) Material preparation: CCF300 / 7901 is used as prepreg, cut into the required size of the reinforced wall panel, and evenly apply the release agent three times on the mold. The mold is a combination of silicone rubber / stainless steel, where the core mold 7 is made of silicone rubber and the rest is made of stainless steel.

[0094] (2) Fig.13 As shown, the prepreg is laid on the lower mold 9 in the layering order of [90 / 90 / 0 / 45 / 45] to obtain the bottom skin 4;

[0095] According to the T-shaped structure, the prepreg is laid on the outer surface of the core mold 7, between the two L-shaped molds 8 and the core mold 7, and between the two core molds 7 in the order of [45 / 45 / 0 / 90 / 90 / 0 / 90 / 0], and the prepreg is laid along the outer surface of the core mold 7 (the U-shaped top surface is not laid), the contact surface between the L-shaped mold 8 and the core mold 7, the contact surface between the two core molds 7, and the contact surface between the L-shaped mold 8 and the lower mold 9 to obtain an integrated vertical rib 3 and a lower edge strip 1;

[0096] Three 60mm×450mm unidirectional prepregs are rolled up to make twist strips, the left and right L-shaped molds 8 are closed, and then the unidirectional prepreg twist strips are used as fillers to fill the gap between the L-shaped mold 8 and the bottom of the core mold 7 as fillers for the R area 5;

[0097] (3) After sealing, solidify in an autoclave. Under the condition of vacuum pressure ≥ 0.08MPa, heat to 80℃ at a rate of 2℃ / min, keep warm for 30min, then continue to heat to 120℃, keep warm for 1.5h. After keeping warm at 120℃ for 30min, pressurize the tank to 0.4MPa and keep the pressure until the end of the insulation. Cool down at a rate of 1.5℃ / min, open the autoclave after the temperature of each point of the reinforced wall panel drops to 60℃, remove the vacuum bag and demould after the temperature of each point of the reinforced wall panel drops to room temperature, use engraving machine and cutting machine to cut off the excess, detect the external dimensions and internal defects, and obtain an integrated reinforced wall panel with both light weight and high overall strength.

[0098] Example 4 (combined Figure 13-14 ): The forming method of the integrated T-shaped reinforced wall panel of this embodiment is carried out according to the following steps:

[0099] (1) Material preparation: EH105 is used as prepreg, cut into the required size of the reinforced wall panel, and the mold release agent is evenly applied three times on the mold. The mold is a combination of aluminum alloy / polytetrafluoroethylene, in which the core mold 7 is made of polytetrafluoroethylene and the rest is made of aluminum alloy.

[0100] (2) Fig.13 As shown, the prepreg is laid on the lower mold 9 in a layering order of [45 / 45 / 0 / 90 / 90] to obtain the bottom skin 4;

[0101] According to the T-shaped structure, the prepreg is laid on the outer surface of the core mold 7, between the two L-shaped molds 8 and the core mold 7, and between the two core molds 7 in the order of [45 / 45 / 0 / 90 / 0 / 90 / 90 / 0], and the prepreg is laid along the outer surface of the core mold 7 (the U-shaped top surface is not laid), the contact surface between the L-shaped mold 8 and the core mold 7, the contact surface between the two core molds 7, and the contact surface between the L-shaped mold 8 and the lower mold 9 to obtain an integrated vertical rib 3 and a lower edge strip 1;

[0102] Three 60mm×450mm unidirectional prepregs are rolled up to make twist strips, the left and right L-shaped molds 8 are closed, and then the unidirectional prepreg twist strips are used as fillers to fill the gap between the L-shaped mold 8 and the bottom of the core mold 7 as fillers for the R area 5;

[0103] (3) After sealing, solidify in an autoclave. Under vacuum conditions, pressurize to 0.6 MPa, heat to 180°C at a rate of 2°C / min, and keep warm and pressurized for 2 hours. Cool at a rate of 2°C / min. After the temperature of each point of the reinforced wall panel drops to 60°C, open the autoclave. After the temperature of each point of the reinforced wall panel drops to room temperature, remove the vacuum bag and demould. Use engraving machines and cutting machines to cut off the excess, detect the external dimensions and internal defects, and obtain an integrated reinforced wall panel with both light weight and high overall strength.

[0104] The above are only preferred specific embodiments of the present invention, which are all different implementations based on the overall concept of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An integrated reinforced wall panel with both light weight and high overall strength, the reinforced wall panel comprising a bottom skin (4), a plurality of vertical ribs (3) and an R zone (5); Or it includes a bottom skin (4), a plurality of vertical ribs (3), a plurality of upper edge strips (2) and an R zone (5), characterized in that: A lower edge strip (1) which is integrated with both the left and right vertical ribs (3) is provided between adjacent vertical ribs (3), and the lower edge strip (1) and the skin (4) are integrated through co-curing.

2. The reinforced wall panel according to claim 1, characterized in that: The reinforced wall panel configuration is I-type, T-type, J-type, Z-type, L-type or C-type.

3. The reinforced wall panel according to claim 1, characterized in that: The reinforced wall panel is made of fiber resin prepreg.

4. The reinforced wall panel according to claim 1, characterized in that: The filler in the R zone (5) is a unidirectional fiber resin prepreg twist strip.

5. A mold for forming the reinforced wall panel according to any one of claims 1 to 4, characterized in that: The mold comprises an upper mold (6), a lower mold (9), a core mold (7) and two L-shaped molds (8) located therebetween, the core mold (7) being a right-angled U-shape, the upper mold (6) being clamped in the U-shaped opening, the vertical surfaces of the two L-shaped molds (8) being horizontally opposed inwardly, and limit blocks being provided at both ends of the vertical surfaces of the L-shaped molds (8) for clamping the core mold (7).

6. The mold according to claim 5, characterized in that: The core mold (7) in the mold is made of polymer, and the rest is made of metal.

7. The mold according to claim 6, characterized in that: Polymers include silicone rubber, polytetrafluoroethylene and polyimide, and metals include stainless steel, aluminum alloy and indium steel.

8. A method for forming the reinforced wall panel according to claim 1 using the mold according to claim 5, characterized in that: The method: S1: Laying the prepreg on the lower mold (9) according to the preset laying number and angle to obtain the bottom skin (4); S2: Prepreg is laid on the outer surface of the core mold (7) and between the two L-shaped molds (8) and the core mold (7) according to the configuration of the target reinforced wall panel and the preset number of prepreg laying layers and angles, so as to obtain an integrated vertical rib (3) and a lower edge strip (1); wherein the number of the core molds (7) between the two L-shaped molds (8) is determined according to the number of the vertical ribs (3); S3: rolling the unidirectional prepreg into twisted strips and filling the gap between the L-shaped mold (8) and the core mold (7) as a filler for the R zone (5); S4: when the prepreg is laid on the top surface where the vertical edge of the L-shaped mold (8) is located, further prepreg is laid on the prepreg on the top surface where the vertical edge of the L-shaped mold (8) is located according to the preset number of prepreg laying layers and angles, to obtain an upper edge strip (2); S5: After sealing, the panel is cured in an autoclave, and a certain pressure is maintained during the curing process. After the curing is completed, the panel is demoulded to obtain an integrated reinforced wall panel that is lightweight and has high overall strength.

9. The method according to claim 8, characterized in that The curing procedure in S5 is: curing temperature is 100-200°C, heating rate is 1-10°C / min, pressure is 0.3-1.5MPa, and heat preservation and pressure holding time is 1-2h.

10. Use of the stiffened wall panel according to any one of claims 1 to 4 in aircraft wings, fuselages and air inlets.

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