A rapid repair method for assembled composite materials

Abstract

This invention relates to a rapid repair method for assembled composite materials, comprising: S1, fabrication of a composite laminate; S2, cutting of the composite laminate; S3, drilling holes in hexagonal composite patch units; S4, obtaining a large number of hexagonal composite patch units; S5, bonding of alkali-free glass fiber cloth; S6, drilling holes in aluminum alloy sheets; S7, cutting of aluminum alloy sheets; S8, obtaining a large number of aluminum alloy connecting units; S9, assembling the repair patches; S10, adjusting the curved surface shape of the assembled structure; and S11, installing the assembled structure. By prefabricating and splicing a large number of hexagonal composite patch units and aluminum alloy connecting units, the manufacturing time for large-scale composite material repair is shortened, and the repair speed is improved. By changing the number of hexagonal composite patch units and aluminum alloy connecting units used, rapid repair of different damaged areas can be effectively achieved. By changing the bending shape of the aluminum alloy connecting units, rapid repair of composite material damage with different curvatures can be effectively achieved.

Description

Technical Field

[0001] This invention relates to the field of composite material repair, specifically a rapid repair method for assembled composite materials. Background Technology

[0002] Composite material repair is a crucial means of reducing composite material costs in aerospace, shipbuilding, and other fields. The fabrication of composite material patches consumes a significant amount of time in composite material repair, hindering rapid improvements in repair efficiency. Under field support conditions, the lack of corresponding composite material manufacturing equipment and tooling makes patch manufacturing difficult. Furthermore, because composite materials typically possess a certain curvature, the damaged area varies under different conditions, making pre-fabrication of repair patches challenging. Therefore, for field support or emergency missions, there is a need for methods to rapidly repair large-area composite material damage. Currently, numerous patents exist related to composite material repair methods. For example, Chinese patent CN202210535318.4, published on September 23, 2022, proposes a method for rapidly repairing aircraft structural damage using rapidly photocured composite materials. Chinese patent CN201410617517.5, published on January 25, 2019, proposes a rapid bonding repair method based on ultraviolet-cured composite materials. Chinese patent CN202310283702.4, published on July 14, 2023, proposes a rapid repair method for complex surface structure damage based on silicone rubber molds. However, these methods require special repair conditions or tooling in the field, have high environmental requirements, are complex to operate, and are difficult to guarantee repair quality or handle large-area, multi-curvature structural damage. Therefore, it is essential to propose a rapid, simple, and effective repair method for composite material damage of different areas and curvatures. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a rapid repair method for assembled composite materials.

[0004] A rapid repair method for assembled composite materials, the specific steps of which are as follows:

[0005] S1. Fabrication of composite laminate: Use prepreg cutting equipment to cut the preferred composite prepreg, complete the prepreg laying, and use vacuum bags to assemble and seal the prepreg composite board onto a flat metal mold;

[0006] S2. Cutting of composite laminate: Place the prepared composite laminate into a processing grinder and cut the composite laminate into hexagonal composite patch units, and grind out the overlap area around the patch.

[0007] S3. Hole making of hexagonal composite material patch unit: Use composite material drilling equipment to drill fastener holes in the overlap area to complete the preparation of hexagonal composite material patch unit;

[0008] S4. Obtain a large number of hexagonal composite material patch units;

[0009] S5. Alkali-free fiberglass cloth bonding: Using a preferred adhesive, the preferred alkali-free fiberglass cloth is bonded to one surface of the preferred aluminum alloy sheet, and the adhesive is then heated and cured.

[0010] S6. Drilling holes in aluminum alloy sheets: Using an automated mechanical drilling lathe, drill fastener holes in aluminum alloy sheets with alkali-free fiberglass cloth pasted on them.

[0011] S7. Aluminum alloy sheet cutting: Using a machining lathe, the pre-drilled aluminum alloy sheet is cut into rectangular aluminum alloy connecting units.

[0012] S8. Obtain a large number of aluminum alloy connection units;

[0013] S9. Repair patch assembly: Select the appropriate number of hexagonal composite material patch units and aluminum alloy connecting units according to the area of ​​the damaged area;

[0014] S10. Adjustment of the curved surface shape of the assembly structure: During the splicing of hexagonal composite material patches, the aluminum alloy connecting unit is corrected according to the shape of the damaged structural curved surface.

[0015] S11. Installation of the assembly structure: Grind the edges of the assembled repair patch according to the geometry of the damaged area.

[0016] Step S1 requires placing the composite laminate into an autoclave and using the autoclave to evacuate the vacuum bag.

[0017] The vacuum degree of the composite material is not less than -0.95MPa, and the temperature-time curve and pressure-time curve adopt the manufacturing process requirements of the prepreg composite laminate.

[0018] In step S5, the thickness of the aluminum alloy sheet is preferably the same as the grinding depth of the hexagonal composite material patch unit.

[0019] The diameter of the fastener hole made in step S6 is consistent with the fastener hole of the hexagonal composite material patch unit.

[0020] Specifically, the spacing between the fastener holes in the same row is consistent with the spacing between the fasteners in the hexagonal composite material patch unit, and the spacing between the fastener holes in each column is consistent with the width of the overlap area of ​​the hexagonal composite material patch unit.

[0021] In step S7, the length of the aluminum alloy connecting unit is the same as the length of the short side of the overlapping area of ​​the hexagonal composite material patch unit, the width of the aluminum alloy connecting unit is twice the width of the overlapping area of ​​the hexagonal composite material patch unit, and the fastener holes of the aluminum alloy connecting unit are in the same position as the fastener holes of the overlapping area of ​​the hexagonal composite material patch unit.

[0022] The formula for estimating the number of hexagonal composite material patch units and aluminum alloy connecting units required in step S9 is: n≥Adam / Acom, where Adam represents the area of ​​the damaged area and Acom represents the area of ​​the hexagonal composite material patch unit.

[0023] Step S11 requires drilling holes in the area where the assembled structure overlaps with the damaged structure, and using preferred bolts to fix the assembled patch to the damaged area, thus completing the repair of the damaged area.

[0024] The beneficial effects of this invention are: by prefabricating and splicing a large number of hexagonal composite material patch units and aluminum alloy connecting units, the manufacturing time for large composite material repair is shortened and the repair speed is improved; by changing the number of hexagonal composite material patch units and aluminum alloy connecting units used, rapid repair of different damage areas can be effectively achieved; by changing the bending shape of the aluminum alloy connecting units, rapid repair of composite material damage with different curvatures can be effectively achieved. The entire repair process is simple and fast, and does not require special tools or fixtures. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Figure 1 This is a flowchart of the method of the present invention;

[0027] Figure 2 This is a schematic diagram of the cutting of the composite laminate of the present invention;

[0028] Figure 3 This is a front view of the hexagonal composite material patch of the present invention;

[0029] Figure 4 This is a schematic diagram of the aluminum alloy sheet cutting process of the present invention;

[0030] Figure 5 This is an isometric view of the aluminum alloy connecting unit of the present invention;

[0031] Figure 6 This is an isometric view of the composite material assembly structure of the present invention;

[0032] Figure 7 This is a schematic diagram of the repair of the composite material assembly structure of the present invention.

[0033] In the figure: 1. Composite laminate; 2. Hexagonal composite patch unit; 3. Composite bolt hole; 4. Overlap area; 5. Aluminum alloy plate; 6. Aluminum alloy connecting unit; 7. Bolt hole of aluminum alloy connecting plate; 8. Alkali-free glass fiber cloth; 9. Bolt; 10. Assembly structure; 11. Damaged area; 12. Damaged structure. Detailed Implementation

[0034] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below.

[0035] like Figures 1 to 7 As shown, a rapid repair method for assembled composite materials includes the following specific steps:

[0036] S1. Fabrication of composite laminate 1: The preferred composite prepreg is cut using a prepreg cutting device. Based on the manufacturing process of composite laminate 1, the prepreg is laid, and the prepreg composite board is assembled and sealed on a flat metal mold using a vacuum bag. The prepreg is CCF300 / QY8911.

[0037] S2. Cutting of composite laminate 1: Place the prepared composite laminate 1 into a processing grinder and cut the composite laminate 1 to make a hexagonal composite patch unit 2, and grind the overlapping area 4 around the patch.

[0038] S3. Hole making of hexagonal composite material patch unit 2: Use composite material drilling equipment to drill fastener holes in the overlap area 4 to complete the preparation of hexagonal composite material patch unit 2;

[0039] S4. Obtain a large number of hexagonal composite material patch units 2;

[0040] S5. Adhesion of alkali-free fiberglass cloth 8: Adhere the preferred alkali-free fiberglass cloth 8 to one surface of the preferred aluminum alloy plate 5 using the preferred adhesive, and complete the heat curing of the adhesive.

[0041] S6. Drilling holes in aluminum alloy sheet 5: Using an automated mechanical drilling lathe, drill fastener holes in the aluminum alloy sheet 5 with alkali-free fiberglass cloth 8 pasted on it.

[0042] S7. Cutting aluminum alloy sheet 5: Using a machining lathe, cut the drilled aluminum alloy sheet 5 into rectangular aluminum alloy connecting units 6.

[0043] S8. Obtain a large number of aluminum alloy connection units 6;

[0044] S9. Repair patch assembly: Based on the area of ​​the damaged area 11, select the corresponding number of hexagonal composite material patch units 2 and aluminum alloy connecting units 6;

[0045] S10. Adjustment of the curved surface shape of the assembly structure 10: During the splicing process of the hexagonal composite material patch, the aluminum alloy connecting unit 6 is corrected according to the curved surface shape of the damaged structure 12 so that the shape of the assembled structure 10 after splicing meets the requirements of the curved surface shape of the damaged area 11.

[0046] S11. Installation of assembly structure 10: According to the geometry of the damaged area 11, the edges of the spliced ​​repair patch are polished.

[0047] Step S1 requires placing the composite laminate 1 into an autoclave, using the autoclave to evacuate the vacuum bag, and heating and pressurizing according to the composite material manufacturing process requirements to complete the manufacturing of the composite laminate 1. The composite laminate 1 is provided with several sets of composite bolt holes 3, which are located on the center line of the overlap area 4 and are evenly distributed.

[0048] The vacuum degree of the composite material is not lower than -0.95MPa, and the temperature-time curve and pressure-time curve adopt the manufacturing process requirements of the prepreg composite laminate 1.

[0049] In step S5, the thickness of the preferred aluminum alloy sheet 5 is consistent with the grinding depth of the hexagonal composite material patch unit 2.

[0050] The overlapping area 4 is located on the inner side of the edge of the hexagonal composite material patch 2, with a width of 20mm and a grinding depth of 2mm.

[0051] The diameter of the fastener hole made in step S6 is consistent with that of the composite material bolt hole 3.

[0052] Specifically, the spacing between the fastener holes in the same row is consistent with the spacing between the fasteners in the hexagonal composite material patch unit 2, and the spacing between the fastener holes in each column is consistent with the width of the overlap area 4 of the hexagonal composite material patch unit 2.

[0053] In step S7, the length of the aluminum alloy connecting unit 6 is the same as the length of the short side of the overlapping area 4 of the hexagonal composite material patch unit 2, the width of the aluminum alloy connecting unit 6 is twice the width of the overlapping area 4 of the hexagonal composite material patch unit 2, and the bolt holes 7 of the aluminum alloy connecting plate are in the same position as the fastener holes of the overlapping area 4 of the hexagonal composite material patch unit 2.

[0054] The aluminum alloy connecting unit 6 is provided with several sets of aluminum alloy connecting plate bolt holes 7.

[0055] The formula for estimating the number of hexagonal composite material patch units 2 and aluminum alloy connecting units 6 required in step S9 is: n≥Adam / Acom, where Adam represents the area of ​​the damaged area 11 and Acom represents the area of ​​the hexagonal composite material patch unit 2. According to the geometry of the damaged area 11, the aluminum alloy connecting unit 6 and the hexagonal composite material patch unit 2 are assembled using preferred bolts 9.

[0056] Step S11 requires drilling holes in the area where the assembly structure 10 and the damaged structure 12 overlap, and using preferred bolts 9 to fix the assembly patch to the damaged area 11, thus completing the repair of the damaged area 11.

[0057] Example:

[0058] Step 1: Cut the CCF300 / QY8911 composite prepreg using a prepreg cutting device. Based on the manufacturing process of composite laminate 1, complete the prepreg laying and use a vacuum bag to assemble and seal the prepreg composite board onto a flat metal mold. Place the composite laminate 1 into an autoclave and use the autoclave to evacuate the vacuum bag. Heat and pressurize according to the composite manufacturing process requirements to produce a 4mm thick composite laminate 1. The vacuum degree is usually not lower than -0.95MPa. The temperature-time curve and pressure-time curve adopt the manufacturing process requirements of CCF300 / QY8911 prepreg composite laminate 1.

[0059] Step 2: Place the prepared composite material laminate 1 into a processing grinder, cut the composite material laminate 1 to make a hexagonal composite material patch unit 2, and grind an overlap area 4 of a certain depth and width around the patch; the overlap area 4 is located on the inner side of the edge of the hexagonal composite material patch unit 2, with a width of 20mm and a grinding depth of 2mm.

[0060] Step 3: Use composite material drilling equipment to drill composite material bolt holes 3 in the overlap area 4 to complete the preparation of the hexagonal composite material patch unit 2; the composite material bolt holes 3 are located on the center line of the overlap area 4 and are evenly distributed;

[0061] Step 4: By going through steps one to three above, the hexagonal composite material patch unit 2 can be obtained;

[0062] Step 5: Use the preferred adhesive to bond the preferred alkali-free glass fiber cloth 8 to one of the preferred aluminum alloy sheet 5, and complete the heat curing of the adhesive; the thickness of the preferred aluminum alloy sheet 5 is consistent with the grinding depth of the hexagonal composite material patch unit 2, which is 2mm;

[0063] Step 6: Using an automated mechanical drilling lathe, drill bolt holes 7 for the aluminum alloy connecting plates 5 on which the alkali-free glass fiber cloth 8 has been pasted; the diameter of the bolt holes 7 for the aluminum alloy connecting plates is the same as that of the composite material bolt holes 3 of the hexagonal composite material patch unit 2; the spacing between the bolt holes 7 of the same row of aluminum alloy connecting plates is the same as the spacing between the composite material bolt holes 3 of the hexagonal composite material patch unit 2; the spacing between the bolt holes 7 of each row of aluminum alloy connecting plates is the same as the width of the overlap area 4 of the hexagonal composite material patch unit 2;

[0064] Step 7: Using a machining lathe, cut the pre-drilled aluminum alloy sheet 5 into rectangular aluminum alloy connecting units 6; the length of the aluminum alloy connecting unit 6 is the same as the length of the short side of the overlapping area 4 of the hexagonal composite material patch unit 2; the width of the aluminum alloy connecting unit 6 is twice the width of the overlapping area 4 of the hexagonal composite material patch unit 2; the bolt holes 7 of the aluminum alloy connecting sheet of the aluminum alloy connecting unit 6 are aligned with the positions of the composite material bolt holes 3 on the overlapping area 4 of the hexagonal composite material patch unit 2.

[0065] Step 8: Through steps five to seven above, a large number of aluminum alloy connecting units 6 can be obtained;

[0066] Step 9: Based on the area of ​​the damaged area 11 on the damaged structure 12, select a certain number of the hexagonal composite material patch units 2 and the aluminum alloy connecting units 6; the estimation formula for the required number of hexagonal composite material patch units 2 and aluminum alloy connecting units 6 is: n≥Adam / Acom, where Adam represents the area of ​​the damaged area 11 and Acom represents the area of ​​the hexagonal composite material patch unit 2; based on the geometry of the damaged area 11, use preferred bolts 9 to assemble the aluminum alloy connecting units 6 and the hexagonal composite material patch units 2;

[0067] Step 10: During the splicing process of the hexagonal composite material patch unit 2 and the aluminum alloy connecting unit 6, the aluminum alloy connecting unit 6 is corrected according to the curved shape of the damaged structure 12 so that the shape of the assembled structure 10 after splicing meets the curved shape requirements of the damaged structure 12.

[0068] Step 11: Grind the edges of the assembled structure 10 according to the geometry of the damaged area 11; use a drilling device to drill holes in the overlapping area 4 of the assembled structure 10 and the damaged area 11, and use the preferred bolts 9 to fix the assembled structure 10 to the damaged structure 12 to complete the repair of the damaged area 11.

[0069] The preparation of the hexagonal composite material patch unit 2 and the aluminum alloy connecting unit 6 in steps one to eight are completed in advance; after damage occurs to the large-size composite material structure, only steps nine to eleven are needed to complete the damage repair.

[0070] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely prisms of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A rapid repair method for assembled composite materials, characterized in that: The specific steps are as follows: S1. Fabrication of composite laminate (1): Use prepreg cutting equipment to cut the preferred composite prepreg, complete the prepreg laying, and use a vacuum bag to seal the prepreg composite board assembly on a flat metal mold. S2, Cutting of composite laminate (1): Place the prepared composite laminate (1) into a processing grinder and cut the composite laminate (1) to make a hexagonal composite patch unit (2), and grind out the overlap area (4) around the patch. S3. Hole making of hexagonal composite material patch unit (2): Use composite material drilling equipment to drill fastener holes in the overlap area (4) to complete the preparation of hexagonal composite material patch unit (2); S4. Obtain a large number of hexagonal composite material patch units (2); S5. Alkali-free fiberglass cloth (8) bonding: Using a preferred adhesive, the preferred alkali-free fiberglass cloth (8) is bonded to one surface of the preferred aluminum alloy plate (5), and the adhesive is heated and cured. S6. Hole making of aluminum alloy plate (5): Using an automated mechanical drilling lathe, fastener holes are drilled in the aluminum alloy plate (5) with alkali-free glass fiber cloth (8) pasted on it. S7. Cutting of aluminum alloy sheet (5): Using a machining lathe, the aluminum alloy sheet (5) with holes is cut into rectangular aluminum alloy connecting units (6). S8. Obtain a large number of aluminum alloy connecting units (6); S9. Repair patch assembly: Based on the area of ​​the damaged area (11), select the corresponding number of hexagonal composite material patch units (2) and aluminum alloy connecting units (6); S10, Assembly structure (10) curved surface shape adjustment: During the splicing of hexagonal composite material patch, the aluminum alloy connecting unit (6) is corrected according to the curved surface shape of the damaged structure (12); S11. Installation of the assembly structure (10): According to the geometry of the damaged area (11), the edges of the spliced ​​repair patch are polished.

2. The rapid repair method for assembled composite materials according to claim 1, characterized in that: Step S1 requires placing the composite laminate (1) into an autoclave and using the autoclave to evacuate the vacuum bag.

3. The rapid repair method for assembled composite materials according to claim 2, characterized in that: The vacuum degree of the composite material is not less than -0.95MPa, and the temperature-time curve and pressure-time curve adopt the manufacturing process requirements of the prepreg composite laminate (1).

4. The rapid repair method for assembled composite materials according to claim 1, characterized in that: In step S5, the thickness of the preferred aluminum alloy sheet (5) is consistent with the grinding depth of the hexagonal composite material patch unit (2).

5. The rapid repair method for assembled composite materials according to claim 1, characterized in that: The diameter of the fastener hole made in step S6 is consistent with that of the composite material bolt hole (3).

6. The rapid repair method for assembled composite materials according to claim 5, characterized in that: Specifically, the spacing between the fastener holes in the same row is consistent with the fastener spacing of the hexagonal composite material patch unit (2), and the spacing between the fastener holes in each row is consistent with the width of the overlap area (4) of the hexagonal composite material patch unit (2).

7. The rapid repair method for assembled composite materials according to claim 1, characterized in that: The length of the aluminum alloy connecting unit (6) in step S7 is consistent with the length of the short side of the overlapping area (4) of the hexagonal composite material patch unit (2), the width of the aluminum alloy connecting unit (6) is twice the width of the overlapping area (4) of the hexagonal composite material patch unit (2), and the bolt hole (7) of the aluminum alloy connecting plate is consistent with the fastener hole position of the overlapping area (4) of the hexagonal composite material patch unit (2).

8. The rapid repair method for assembled composite materials according to claim 1, characterized in that: The formula for estimating the number of hexagonal composite material patch units (2) and aluminum alloy connecting units (6) required in step S9 is: n≥Adam / Acom, where Adam represents the area of ​​the damaged area (11) and Acom represents the area of ​​the hexagonal composite material patch unit (2).

9. A rapid repair method for assembled composite materials according to claim 1, characterized in that: Step S11 requires drilling holes in the area where the assembled structure (10) and the damaged structure (12) overlap, and using bolts (9) to fix the assembled patch to the damaged area (11) to complete the repair of the damaged area (11).

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