Airborne cage type composite material structure and forming method thereof

Abstract

The invention provides a forming method of an airborne cage type composite material structure. The forming method comprises the steps that at least one laying layer set is designed according to the preset requirement of the airborne cage type composite material structure; the at least one laying layer group is laid to a preset position in the mold according to a preset sequence in a carbon fiber prepreg manner; pre-compacting and vacuumizing the at least one laying layer group to obtain a treated laying layer group; putting the mold and the treated laying layer group into an autoclave; and the treated laying layer set is cured, so that the airborne cage type composite material structure is obtained. According to the technical scheme, the airborne cage type composite material structure is generated in an integrated forming mode through the autoclave technology, the carbon fiber prepreg mode is adopted, and the characteristics that carbon fibers are light in mass and large in specific strength are utilized, so that the structural strength of the airborne cage type composite material structure is improved, and the airborne cage type composite material structure is lighter. The airborne cage type composite material structure is integrally formed, connecting pieces are not needed, stress distribution is uniform, and the structural strength is further improved.

Description

Technical Field

[0001] This application relates to the technical field of airborne structure forming, and more specifically, to an airborne cage composite structure and a forming method thereof. Background Art

[0002] The airborne cage structure is applied to various airborne devices and is the load-bearing structure of the airborne devices. The existing airborne cage structure is made of metal (such as titanium alloy, aluminum alloy, etc.).

[0003] The components of the airborne cage structure made of metal need to be connected by fasteners. The inventors of this application found that the prior art has at least the following problems. The holes (such as rivet holes, bolt holes) at the joints of the airborne cage structure will increase the local stress concentration coefficient of the airborne cage structure by 2 - 3 times, resulting in cracks being easily generated at the joints, thereby reducing the structural life of the airborne cage structure. The stress release at the joints of the airborne cage structure may also cause the deformation of the airborne cage structure. The airborne cage structure made of metal has a relatively large weight, which in turn increases the load weight of the airborne device.

[0004] The content of the background art section is only the technology known to the applicant and does not necessarily represent the prior art in this field. Summary of the Invention

[0005] The technical solution of this application aims to solve at least one of the above-mentioned technical problems.

[0006] According to one aspect of this application, a forming method of an airborne cage composite structure is provided, including: designing at least one ply group according to the preset requirements of the airborne cage composite structure; laying at least one ply group in a carbon fiber prepreg manner to a preset position inside the mold according to a preset order; pre-compacting and evacuating at least one ply group to obtain a processed ply group; placing the mold and the processed ply group into an autoclave; curing the processed ply group to obtain the airborne cage composite structure.

[0007] According to some embodiments of this application, before designing at least one ply group according to the preset requirements of the airborne cage composite structure, the forming method further includes: cleaning the mold; covering a film on the surface of the mold; drying the mold. The cleaning module includes cleaning the stains on the surface of the mold with acetone.

[0008] According to some embodiments of this application, before laying at least one ply group in a carbon fiber prepreg manner to a preset position inside the mold according to a preset order, the forming method further includes: cutting and blanking the carbon fiber prepreg raw material according to a preset ply pattern to obtain the carbon fiber prepreg.

[0009] According to some embodiments of the present application, pre-compacting and evacuating at least one ply group to obtain a processed ply group includes: sequentially laying a release cloth, a non-porous separator film, a breather felt, and a vacuum bag on the surface of at least one ply group; performing pre-compacting and evacuating treatment on at least one ply group to obtain a processed ply group, where the pre-compacting vacuum degree of each ply group is greater than or equal to 700 mbar, and the pre-compacting time is greater than or equal to 15 minutes.

[0010] According to some embodiments of the present application, curing the processed ply group to obtain an airborne cage composite structure includes: operating an autoclave according to a preset curing procedure to cure the processed ply group; demolding and trimming the processed ply group to obtain an airborne cage composite structure.

[0011] According to some embodiments of the present application, operating an autoclave according to a preset curing procedure to cure the processed ply group includes: for the ply group after the first temperature rise treatment, when the thermocouple temperature of the ply group reaches 80 ± 3 °C, maintaining the temperature for 30 to 35 minutes, with a heating rate of 1 to 2 °C per minute; for the ply group after the second temperature rise treatment, when the thermocouple temperature of the ply group reaches 130 ± 3 °C, maintaining the temperature for 240 minutes, with a heating rate of 1 to 2 °C per minute, to cure at least one ply group.

[0012] According to another aspect of the present application, an airborne cage composite structure is provided. The airborne cage composite structure is made by the forming method of the present application as claimed in the claims.

[0013] Beneficial effects

[0014] The technical solution of the present application generates an airborne cage composite structure by an integral forming method through an autoclave process. By using carbon fiber prepreg and taking advantage of the characteristics of light weight and high specific strength of carbon fiber, the structural strength of the cage composite structure is improved, and the airborne cage composite structure is made more lightweight. The airborne cage composite structure is integrally formed without connectors, resulting in uniform stress distribution and further improving the structural strength. Brief description of the drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 Shows a schematic flow chart of the forming method 1000 of the airborne cage composite structure in the embodiments of the present application;

[0017] Figure 2The flowchart of the forming method 2000 of the airborne cage composite structure according to the embodiment of the present application is shown;

[0018] Figure 3 The flowchart of the forming method 3000 of the airborne cage composite structure according to the embodiment of the present application is shown;

[0019] Figure 4 The flowchart of step S130 according to the embodiment of the present application is shown;

[0020] Figure 5 The flowchart of step S140 according to the embodiment of the present application is shown;

[0021] Figure 6 The flowchart of step S141 according to the embodiment of the present application is shown;

[0022] Figure 7 The structural schematic diagram of the airborne cage composite structure according to the embodiment of the present application is shown;

[0023] Figure 8 The structural schematic diagram of the mold according to the embodiment of the present application is shown;

[0024] Figure 9 The partial schematic diagram of the ply group according to the embodiment of the present application is shown.

[0025] Explanation of reference numerals:

[0026] Airborne cage composite structure 2; mold 1; rear eaves 11; front eaves 14; first stop block 12; second stop block 13; bottom mold 16; integrated board 15; first ply group 3; second ply group 4; third ply group 5; fourth ply group 6; fifth ply group 7. Detailed implementation manners

[0027] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Identical reference numerals in the figures denote identical or similar parts, and thus their repetitive description will be omitted.

[0028] The described features, structures or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of the present disclosure. However, those skilled in the art will realize that the technical solutions of the present disclosure can be practiced without one or more of these specific details, or can be implemented in other ways, components, materials, devices, etc. In these cases, well-known structures, methods, devices, implementations, materials or operations will not be shown or described in detail.

[0029] In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include steps or units not listed, or may optionally further include other steps or units inherent to these processes, methods, products, or apparatuses.

[0030] The terms "first", "second", etc. in the description and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order.

[0031] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative efforts fall within the scope of protection of this application.

[0032] Figure 1 The flowchart of the forming method 1000 of the airborne cage composite structure in the embodiment of this application is shown. As Figure 1 shown, the forming method 1000 of the airborne cage composite structure includes steps S110 - S140.

[0033] In step S110, at least one ply group is designed according to the preset requirements of the airborne cage composite structure. For example, the Fibersim software (composite material engineering software) can be used to perform ply design on the airborne cage composite structure to design at least one ply group. The preset requirements may include the shape and size of the airborne cage composite structure, and can be specifically customized according to user needs. For example, at least one ply group may include a first ply group, a second ply group, a third ply group, a fourth ply group, and a fifth ply group.

[0034] In step S120, at least one ply group is laid in the form of carbon fiber prepreg to a preset position inside the mold according to a preset order. For example, the carbon fiber prepreg can be obtained by cutting the raw material of the carbon fiber prepreg, and the raw material of the carbon fiber prepreg can be made by compounding carbon fiber yarn and epoxy resin according to a preset ratio by the user. For example, the preset position can be a position customized by the user, and is not limited herein. The overlap distance between each ply group can be 15 cm. As Figure 9 The partial schematic diagram of the ply group is shown. As Figure 9 shown, at least one ply includes a first ply group 3, a second ply group 4, a third ply group 5, a fourth ply group 6, and a fifth ply group 7.

[0035] In step S130, at least one ply group is pre-compacted and evacuated to obtain a processed ply group.

[0036] In step S140, the mold and the processed ply group are placed into an autoclave; the processed ply group is cured to obtain an airborne cage composite structure. For example, the autoclave can be a carbon fiber autoclave, which can provide pressure and temperature for the carbon fiber prepreg during the curing cycle of the carbon fiber prepreg.

[0037] In the above embodiments, the airborne cage composite structure is generated by an integral molding method through the autoclave process. By using the carbon fiber prepreg and taking advantage of the characteristics of light weight and high specific strength of carbon fiber, the structural strength of the cage composite structure is improved, and the airborne cage composite structure is made lighter. The airborne cage composite structure is integrally molded without connectors, so that the stress distribution is uniform, further improving the structural strength.

[0038] Figure 2 The flowchart of the forming method 2000 of the airborne cage composite structure according to the embodiment of the present application is shown. As Figure 2 shown, the forming method 2000 of the airborne cage composite structure includes steps S210-S270. Steps S240-S270 are the same as steps S110-S140 mentioned above and will not be described in detail here.

[0039] In step S210, the mold is cleaned. For example, acetone can be used to clean the stains on the surface of the mold.

[0040] In step S220, a film is covered on the surface of the mold. For example, release wax can be applied inside the mold to cover the mold with a film, which is beneficial to demolding the carbon fiber prepreg.

[0041] In step S230, the mold is dried.

[0042] Through the above embodiments, the mold preparation work before the formation of the airborne cage composite structure is completed. The airborne cage composite structure is generated by an integral molding method through the autoclave process. By using the carbon fiber prepreg and taking advantage of the characteristics of light weight and high specific strength of carbon fiber, the structural strength of the cage composite structure is improved, and the airborne cage composite structure is made lighter. The airborne cage composite structure is integrally molded without connectors, so that the stress distribution is uniform, further improving the structural strength.

[0043] Figure 3 The flowchart of the forming method 3000 of the airborne cage composite structure according to the embodiment of the present application is shown. As Figure 3As shown, the forming method 3000 of the airborne cage composite structure includes steps S310 - S350. Step S310 is the same as step S110 mentioned above, and steps S330 - S350 are the same as steps S120 - S140 mentioned above, which will not be elaborated here.

[0044] In step S320, the carbon fiber prepreg raw material is cut according to a preset laying pattern to obtain the carbon fiber prepreg. For example, the preset laying pattern can be the laying pattern of at least one layer group designed by the user through Fibersim software.

[0045] Through the above embodiments, the preparation work of the carbon fiber prepreg in the process of the forming method of the airborne cage composite structure is completed.

[0046] Figure 4 The flow schematic diagram of step S130 in the embodiment of the present application is shown. As Figure 4 shown, step S130 includes step S131 and step S132.

[0047] In step S131, a release cloth, a non - porous isolation film, a breather felt, and a vacuum bag are sequentially laid on the surface of at least one layer group.

[0048] In step S132, the at least one layer group is subjected to pre - compaction and vacuum treatment to obtain the treated layer group.

[0049] Through the above embodiments, through laying the release cloth, the non - porous isolation film, the breather felt, and the vacuum bag, the vacuum treatment of the at least one layer group is completed after vacuum pumping.

[0050] Figure 5 The flow schematic diagram of step S140 in the embodiment of the present application is shown. As Figure 5 shown, step S140 includes step S141 and step S142.

[0051] In step S141, the autoclave is operated according to a preset curing program to cure the treated layer group.

[0052] In step S142, the treated layer group is demolded and trimmed to obtain the airborne cage composite structure.

[0053] Through the above embodiments, the airborne cage composite structure is generated by the autoclave process.

[0054] Figure 6 The flow schematic diagram of step S141 in the embodiment of the present application is shown. As Figure 6 shown, step S141 includes step S1411 and step S1412.

[0055] In step S1411, for the laminate stack after the first heat-up treatment, when the thermocouple temperature of the laminate stack reaches 80 ± 3 °C, keep it at this temperature for 30 to 35 minutes, with a heating rate of 1 to 2 °C per minute.

[0056] In step S1412, for the laminate stack after the second heat-up treatment, when the thermocouple temperature of the laminate stack reaches 130 ± 3 °C, keep it at this temperature for 240 minutes, with a heating rate of 1 to 2 °C per minute, to cure at least one laminate stack.

[0057] For example, keep the pressure in the autoclave at 0.4 ± 0.02 MPa throughout the process; after the heat preservation ends, cool the laminate stack from 130 °C to 45 °C, with a cooling rate of 1 to 2 °C per minute. After the cooling ends, release the pressure in the autoclave; when the temperature of the autoclave body drops to 45 °C, open the autoclave door.

[0058] In the above embodiments, the curing process of at least one laminate stack is completed by following the preset vacuum degree, temperature, heat preservation, heating, heat preservation, cooling, and pressure release processes.

[0059] Figure 8 The structural schematic diagram of the mold according to the embodiment of the present application is shown. As Figure 8 shown, the mold 1 includes a rear eaves 11, a front eaves 14, a first stop block 12, a second stop block 13, a bottom mold 16, and an integrated board 15.

[0060] Figure 7 The structural schematic diagram of the airborne cage composite structure according to the embodiment of the present application is shown. As Figure 7 shown, the airborne cage composite structure 2 is integrally formed. The airborne cage composite structure 2 is made by the forming method of the airborne cage composite structure of the present application.

[0061] Finally, it should be noted that the above are only the preferred embodiments of the present application and are not used to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions of the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A forming method for an airborne cage-type composite structure, characterized in that, include: designing at least one ply group according to preset requirements of the airborne cage composite structure; Laying the at least one ply group to a preset position inside the mold according to a preset sequence by using carbon fiber prepreg; Pre-compacting and vacuuming the at least one ply group to obtain a processed ply group; placing the mold and the processed ply assembly into an autoclave; The processed ply group is cured to obtain the airborne cage-type composite structure.

2. The forming method of the airborne cage composite structure according to claim 1, wherein Before designing at least one ply group according to preset requirements of the airborne cage composite structure, the molding method further includes: Cleaning the mold, including: Using acetone to clean the stains on the surface of the mold; Laminating the surface of the mold; The mold was allowed to dry.

3. The forming method of the airborne cage composite structure according to claim 1, characterized in that, Before laying the at least one ply group in a carbon fiber prepreg manner to a preset position inside the mold according to a preset sequence, the molding method further includes: The carbon fiber prepreg raw material is cut and cut according to a preset layer pattern to obtain the carbon fiber prepreg.

4. The forming method of the airborne cage composite structure according to claim 1, characterized in that The pre-compacting and vacuuming the at least one ply group to obtain a processed ply group comprises: Laying a release cloth, a non-porous isolation film, a breathable felt and a vacuum bag in sequence on the surface of the at least one ply laying group; The at least one ply group is subjected to pre-compaction and vacuum treatment to obtain the treated ply group, wherein the pre-compaction vacuum degree of each ply group is greater than or equal to 700 mbar, and the pre-compaction time is greater than or equal to 15 minutes.

5. The forming method of the airborne cage composite structure according to claim 1, characterized in that, The curing of the processed ply group to obtain the airborne cage-type composite structure includes: Running the autoclave according to a preset curing program to cure the treated ply group; The processed ply group is demoulded and trimmed to obtain the airborne cage-type composite structure.

6. The forming method of the airborne cage composite structure according to claim 5, characterized in that, The step of operating the autoclave according to a preset curing program to cure the treated ply assembly comprises: After the first heating treatment, the ply group is kept warm for 30 to 35 minutes at a heating rate of 1 to 2 degrees Celsius per minute when the galvanic temperature of the ply group reaches 80±3 degrees Celsius; After the secondary temperature rise treatment, the ply group is kept warm for 240 minutes at a heating rate of 1 to 2 degrees Celsius per minute when the thermocouple temperature of the ply group reaches 130±3 degrees Celsius, so as to solidify the at least one ply group.

7. An airborne cage composite structure, characterized in that, The airborne cage-type composite structure is made by the molding method described in any one of claims 1-6.

Images