A fast-response, low-cost, and high-precision auxiliary maintenance method for composite components

Abstract

A fast-response, low-cost, high-precision auxiliary repair method for composite components includes the following steps: Step 1, based on the three-dimensional digital model of the damaged composite component in the installed state, prepare a composite process dummy with a tread consistent with the component working surface to form a solid or frame structure; Step 2, sequentially lay an aerogel film and a demoulding cloth on the surface of the process dummy, and after spreading, prepare a repair tool blank based on the process dummy surface in the damaged area on its surface, and package the blank after shaping; Step 3, after cooling and shaping the repair tool, polish its tread, and package the patch, repair tool and process auxiliary materials as a whole on the surface of the damaged composite component, and complete the repair of the composite component under high temperature and negative pressure. It is particularly suitable for the auxiliary repair process of aviation composite components with local damage and scattered characteristics in the damaged area, which can greatly improve the repair quality, reduce the repair cost, and shorten the repair cycle.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite material maintenance, and specifically relates to a fast-response, low-cost and high-precision composite material component auxiliary maintenance method, which is suitable for the auxiliary maintenance process of aviation composite material components with local damage and scattered characteristics of the damaged area. Background Art

[0002] After a composite component is damaged, it is necessary to restore the mechanical properties of the damaged area through maintenance operations. Traditional maintenance methods often use methods such as removing the damaged area, pasting patches and then bonding or mechanically connecting reinforcement plates to repair the damaged component to meet the structural maintenance requirements that are not high for component weight or surface contour. However, for aviation composite components, especially engine air inlet lips, fan covers, wings, fuselages and other structures with high requirements for weight and aerodynamic surface quality, it is necessary to rely on maintenance tools to ensure the internal and surface quality of the maintenance area. Considering the localization and dispersion of the damaged area of ​​aviation composite components, the current commonly used maintenance method is to use a local hand-layup fiberglass repair tool to assist the damaged area. This tool is increasingly used in the maintenance process of aviation composite components due to its advantages such as good conformability and light weight.

[0003] However, the hand-layup of FRP repair tooling in the damaged area of ​​the component in the free state has a poor match with the surface features of the damaged area, can only meet the needs of one repair process, cannot be reused, and is not environmentally friendly. It is difficult to meet the sustainable development needs of aviation composite material maintenance and cannot achieve fast response, low-cost, and high-precision maintenance of aviation composite materials.

[0004] Therefore, the present invention proposes a fast-response, low-cost, and high-precision auxiliary maintenance method for composite materials components, which avoids the bottleneck problem that additive manufacturing technology is difficult to apply to the field of aviation composite parts manufacturing, and applies it to the manufacture of composite material maintenance tooling to assist in completing the maintenance process of composite materials components. It is particularly suitable for the auxiliary maintenance process of aviation composite materials components with local damage and scattered characteristics of the damaged area. It can greatly improve the maintenance quality, reduce maintenance costs, shorten maintenance cycles, and improve the maintenance level of aviation composite materials while further promoting the green and sustainable development of the aviation composite material field. Summary of the invention

[0005] The purpose of the present invention is to provide a fast-response, low-cost, and high-precision auxiliary maintenance method for composite materials components, which avoids the bottleneck problem that additive manufacturing technology is difficult to apply to the field of aviation composite parts manufacturing, and applies it to the manufacture of composite material maintenance tooling to assist in completing the maintenance process of composite materials components. It is particularly suitable for the auxiliary maintenance process of aviation composite materials components with local damage and scattered characteristics of the damaged area, which can greatly improve the maintenance quality, reduce maintenance costs, and shorten the maintenance cycle.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A fast-response, low-cost, and high-precision composite material component auxiliary maintenance method comprises the following steps:

[0008] Step 1, based on the three-dimensional digital model of the damaged composite component in the installed state, prepare a composite process dummy with a tread consistent with the working surface of the component to form a solid or frame structure;

[0009] Step 2, laying an aerogel film and a demoulding cloth on the surface of the process dummy in sequence, wherein the aerogel film is used as a heat insulation layer to prevent the overheating of the repair tool blank from affecting the quality of the process dummy surface. After spreading, a repair tool blank is prepared in the damaged area on the surface with the process dummy surface as a reference, and the blank is shaped and then packaged; the purpose of shaping is to compact the blank and fit it to the process dummy surface, and the compaction of the blank is performed by rolling or patting the blank mechanically or manually; the purpose of packaging is to further ensure that the repair tool is fitted to the process dummy surface during the shaping process, and to ensure the surface contour of the repair tool;

[0010] Step 3, after cooling and finalizing the repair tool blank, polish its tread surface. The purpose of polishing is to ensure the effective flow of resin in the patch in the repair area and to ensure the surface accuracy of the repair tool. The patch, repair tool and process auxiliary materials are packaged as a whole on the surface of the damaged composite component, and the repair of the composite component is completed under high temperature and negative pressure.

[0011] In the step 1, the preparation method of the process dummy is additive manufacturing; the material is a resin-based composite material, the reinforcement of the resin-based composite material is preferably glass fiber or basalt fiber chopped or pulp products, and the matrix of the resin-based composite material is preferably PE, PP, PVC, PS, ABS general plastic.

[0012] In the step 1, the process dummy can be used as a forming mold for a repair tool for local damage of a component or as a master mold for replicating a full-size repair tool.

[0013] In the step 2, the preparation method of the maintenance tool blank is additive manufacturing; the material is a resin-based composite material, the reinforcement of the resin-based composite material is preferably a carbon fiber chopped product, and the matrix of the resin-based composite material is preferably PPS, PI, PEI, PASF, PSF, PEAK, PEEK high-temperature resistant thermoplastic resin.

[0014] The thickness of the aerogel film in step 2 is ≤0.1 mm, and the thickness of the release cloth is ≤0.05 mm.

[0015] Compared with the prior art, the present invention has the following technical effects:

[0016] 1. Maintenance cycle: The additive manufacturing process of composite component maintenance tooling only includes the melting and deposition of the blank and the cooling and shaping of the tooling, which can significantly shorten the component maintenance cycle while reducing the manufacturing cycle of the maintenance tooling.

[0017] 2. Maintenance cost: Considering the number of times the maintenance tooling materials are used and their recyclability, the material usage cost and manufacturing cost of the maintenance tooling can be reduced, thus significantly reducing the maintenance cost of components.

[0018] 3. Process applicability: Through the regulation of repair tooling materials and structures, it is suitable for manufacturing repair tools with different surface features and sizes, and can meet the repair process of aviation composite components with local damage and dispersed characteristics of the damaged area.

[0019] 4. Repair quality: With the help of composite material process fake parts, it can be ensured that the repair tooling is consistent with the surface characteristics of the component in the installed state, avoiding problems such as large deviation in surface contour caused by hand-laid fiberglass tooling in the free state of the component.

[0020] 5. Sustainability: Using general plastics or thermoplastic resins as the matrix to manufacture composite material repair tools is conducive to the environmentally friendly recycling of tools, reduces the space occupied by tools, and achieves green and sustainable development in the field of composite material component maintenance. DETAILED DESCRIPTION

[0021] The contents disclosed in the present invention, including the preparation method and process of process dummies and maintenance tooling, the material selection of process dummies and maintenance tooling and other key technical points should be regarded as the protection scope of the present invention.

[0022] The resin-based composite material is selected based on the three-dimensional digital model of the component additive manufacturing process dummy and the local damage area repair tooling to assist in the repair process of the composite material component. The invention uses additive manufacturing technology and material recyclability to give it fast response, high precision and low cost characteristics, and is suitable for the operation and maintenance stage of aviation composite components with local damage and irregular distribution of damage areas.

[0023] The auxiliary repair process of the composite right fan cover of a V2500 aircraft engine is used as an example to further illustrate the present invention. The typical damage area occurs on the outer skin of the right fan cover, and the distances between the center position and the upper edge (UPR direction) and the rear edge (AFT direction) are 1044mm±2mm and 259mm±2mm respectively, and the maximum radius R is 107mm±1mm.

[0024] A fast-response, low-cost, and high-precision composite material component auxiliary maintenance method comprises the following steps:

[0025] Step 1, according to the three-dimensional digital model of the right fan cover obtained in the installed state, select short-cut GF / ABS composite materials to prepare a tread consistent with the aerodynamic surface characteristics of the right fan cover based on the fused deposition method to form a process dummy of GF / ABS composite materials with a solid structure, wherein GF is glass fiber and ABS is acrylonitrile-butadiene-styrene copolymer; polish the surface to a surface accuracy of ≤±0.15mm;

[0026] Step 2: Lay an aerogel film with a thickness of 80 μm and a polyimide release cloth with a thickness of 65 μm on the surface of the process dummy in sequence, spread and fix them on the surface of the process dummy to ensure that the surface is flat and wrinkle-free; the aerogel film is used as a heat insulation layer to prevent the overheating of the repair tool blank from affecting the surface quality of the process dummy;

[0027] Step 3, according to the local surface characteristics of the component damage area corresponding to the surface of the process dummy, select short-cut CF / PASF composite materials to prepare a repair tool blank based on the melt extrusion deposition method, wherein CF is carbon fiber, PASF is polyarylsulfone resin, and the rolled blank is bonded to the process dummy surface. The blank thickness is not less than 6 mm, the size is centered at the center of the damage area, and the radius is not less than (R+38n+k) mm, wherein n is the number of patch layers, k is the margin, and k≥12.7 mm; the purpose of packaging is to further ensure that the repair tool is bonded to the process dummy surface during the shaping process to ensure the surface contour of the repair tool;

[0028] Step 4: Lay polyimide release cloth and polyimide vacuum bag and then package them under negative pressure throughout the process until the repair tool body is cooled and shaped. Grind the surface of the repair tool and polish its tread surface until the surface roughness is no more than Ra3.2. The purpose of polishing is to ensure the effective flow of resin in the patch in the repair area and to ensure the surface accuracy of the repair tool. Package the patch, repair tool and process auxiliary materials as a whole on the surface of the damaged composite component, and complete the repair of the composite component under high temperature and negative pressure.

[0029] The process dummy manufactured in step 1 can be used as a forming mold for the right fan cover repair tooling. For large-area repairs or over-standard repairs of the right fan cover, it can also be used to reproduce the right fan cover repair tooling with full-size surface features.

[0030] If the damaged composite material component contains multiple damages with discrete features, repair tool blanks for the multiple damages can be manufactured simultaneously in step 3, and the synchronous repair process for the multiple damages can be completed through step 4.

Claims

1. A fast-response, low-cost, high-precision composite material component auxiliary maintenance method, characterized in that: The following steps are involved: Step 1, based on the three-dimensional digital model of the damaged composite component in the installed state, prepare a tread consistent with the working surface of the component to form a composite process dummy with a solid or frame structure; Step 2, laying an aerogel film and a demoulding cloth on the surface of the process dummy in sequence, and after spreading, preparing a repair tool blank in the damaged area of ​​the surface based on the profile of the process dummy, and then packaging the blank after shaping; Step 3, after cooling and finalizing the repair tool blank, polishing its tread surface, encapsulating the patch, the repair tool and process auxiliary materials as a whole on the surface of the damaged composite component, and completing the repair of the composite component under high temperature and negative pressure; In the step 1, the preparation method of the process dummy is additive manufacturing; the material is a resin-based composite material, the reinforcement of the resin-based composite material is glass fiber or basalt fiber chopped or pulp products, and the matrix of the resin-based composite material is general plastic; In the step 2, the preparation method of the maintenance tool blank is additive manufacturing; the material is a resin-based composite material, the reinforcement of the resin-based composite material is a carbon fiber chopped product, and the matrix of the resin-based composite material is a high-temperature resistant thermoplastic resin.

2. The fast-response, low-cost, high-precision composite material component auxiliary maintenance method according to claim 1, characterized in that: In the step 1, the process dummy can be used as a forming mold for a repair tool for local damage of a component or as a master mold for replicating a full-size repair tool.

3. The fast-response, low-cost, high-precision composite material component auxiliary maintenance method according to claim 1, characterized in that: The thickness of the aerogel film in step 2 is ≤0.1 mm, and the thickness of the release cloth is ≤0.05 mm.