Method of repairing and repaired structure of co-cured metal composite honeycomb sandwich structure

Abstract

The application belongs to the technical field of co-cured metal composite honeycomb sandwich structure repair, and discloses a co-cured metal composite honeycomb sandwich structure repair method and a repair structure. The co-cured metal composite honeycomb sandwich structure repair method comprises the following steps: removing the damaged part on the outer surface to form a filling groove; opening a plurality of first connecting holes and a plurality of second connecting holes around the filling groove, so that the first connecting holes penetrate the metal sheet and the outer composite panel; filling the filling groove with a filler; covering the metal repair patch to cover the filling groove and the plurality of first connecting holes; fixing and connecting the second fastener with the first fastener; and gluing and fixing the composite repair patch to cover the plurality of second connecting holes. The combination of mechanical connection and gluing is simple to operate, has good fixing effect on the patch, can guarantee the original mechanical properties, and occupies less space after repair.

Description

Technical Field

[0001] This invention relates to the field of repair technology for co-cured metal composite honeycomb sandwich structures, and particularly to a repair method and repair structure for co-cured metal composite honeycomb sandwich structures. Background Technology

[0002] Co-cured metal composite honeycomb sandwich structures are formed by co-curing a thin sheet of aluminum alloy or other metal (e.g., 1 mm thick) with a honeycomb sandwich composite material structure. They are commonly used in aircraft skin structures, such as the leading edge skin of the tail fin. The honeycomb sandwich composite material structure includes an inner composite panel, an outer composite panel, and a honeycomb core material positioned between the two panels. The thin metal sheet is placed on the outer surface of the outer composite panel. During aircraft operation, this type of leading edge skin is susceptible to corrosion from wind and rain, as well as damage from bird strikes, hail, and impacts from stones, resulting in dents, cracks, and perforations in the thin metal sheet and the outer composite panel.

[0003] Existing repair methods mostly target honeycomb sandwich composite structures. Specifically, this involves removing the damaged composite panel to expose the honeycomb core, replacing the core, and then fabricating a repair layer to patch and restore the composite panel's layup. However, these methods are not suitable for honeycomb sandwich composite structures covered by thin metal sheets, i.e., co-cured metal composite honeycomb sandwich structures. Therefore, there is an urgent need to develop a repair method for co-cured metal composite honeycomb sandwich structures to repair damaged co-cured metal composite honeycomb sandwich structures. Summary of the Invention

[0004] The purpose of this invention is to provide a repair method and repair structure for a co-cured metal composite honeycomb sandwich structure. This method is simple to operate, provides good fixation of the patch, ensures the mechanical properties of the original structure, and the repaired co-cured metal composite honeycomb sandwich structure occupies less space.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] On the one hand, a repair method for a co-cured metal composite honeycomb sandwich structure is provided. The co-cured metal composite honeycomb sandwich structure includes a metal sheet, an outer composite panel, a honeycomb core material, and an inner composite panel arranged sequentially from the outside to the inside. The repair method for the co-cured metal composite honeycomb sandwich structure includes the following steps:

[0007] S1. Remove damaged areas on the outer surface of the co-cured metal composite honeycomb sandwich structure to form a filling groove;

[0008] S2. A plurality of first connection holes are opened on the outer surface of the co-cured metal composite honeycomb sandwich structure, surrounding the filling groove, and a plurality of second connection holes are opened on the inner surface of the co-cured metal composite honeycomb sandwich structure, so that the first connection holes penetrate the metal sheet and the outer composite panel, and the plurality of first connection holes and the plurality of second connection holes are respectively connected to each other.

[0009] S3. Fill the filling groove with filler material;

[0010] S4. Cover the outer surface of the co-cured metal composite honeycomb sandwich structure with a metal repair patch, and make the metal repair patch cover the filling groove and the plurality of first connection holes; pass the first fastener through the metal repair patch and the first connection holes in sequence, and fix the second fastener to the first fastener through the second connection holes;

[0011] S5. Adhere and fix the composite repair patch to the inner surface of the co-cured metal composite honeycomb sandwich structure, and make the composite repair patch cover the plurality of second connection holes.

[0012] Preferably, step S2 specifically includes: extending the first connecting hole through to the inner surface of the outer composite panel, and extending the second connecting hole through to the outer surface of the honeycomb core material.

[0013] Preferably, step S2 specifically includes: passing the first connecting hole through the inner surface of the outer composite panel and extending it to a first position inside the honeycomb core material, and passing the second connecting hole through the outer surface of the inner composite panel and extending it to the first position.

[0014] Preferably, step S3 includes filling the filling groove with potting compound and performing a curing operation.

[0015] Preferably, after filling the filling groove with the potting agent and performing a curing operation, the cured filler is further polished so that the outer surface of the cured filler is flush with the outer surface of the co-cured metal composite honeycomb sandwich structure.

[0016] Preferably, step S1 specifically includes: polishing the damaged portion of the co-cured metal composite honeycomb sandwich structure to form the filling groove.

[0017] Preferably, step S2 specifically includes: setting two sets of the first connecting holes, with the two sets respectively set on opposite sides of the filling groove. In each set of the first connecting holes, the distance between the center line of the first connecting hole near the edge of the metal repair patch and the outer edge line of the metal repair patch is equal to the distance between the center line of the first connecting hole near the side wall of the filling groove and the side wall of the filling groove.

[0018] Preferably, before step S4, the method further includes: manufacturing the metal repair patch; manufacturing the metal repair patch specifically includes: making the thickness of the metal repair patch equal to the sum of the thickness of the metal sheet and the thickness of the outer composite panel.

[0019] Preferably, the metal repair patch is sealed with sealant and the co-cured metal composite honeycomb sandwich structure.

[0020] On the other hand, a repair structure for a co-cured metal composite honeycomb sandwich structure is provided, comprising a co-cured metal composite honeycomb sandwich structure, wherein the co-cured metal composite honeycomb sandwich structure includes a metal sheet, an outer composite panel, a honeycomb core material, and an inner composite panel arranged sequentially from the outside to the inside; the co-cured metal composite honeycomb sandwich structure is provided with a filling groove, the filling groove being filled with a filler; the outer surface of the co-cured metal composite honeycomb sandwich structure is provided with a plurality of first connecting holes arranged around the filling groove, the first connecting holes penetrating the metal sheet and the outer composite panel; the inner surface of the co-cured metal composite honeycomb sandwich structure is provided with a plurality of second connecting holes, the plurality of first connecting holes and the plurality of second connecting holes respectively correspondingly communicating;

[0021] The repair structure for the co-cured metal composite honeycomb sandwich structure also includes:

[0022] A metal repair patch is applied to the outer surface of the co-cured metal composite honeycomb sandwich structure and covers the filling groove and the first connecting hole.

[0023] The first fastener is sequentially inserted through the metal repair patch and the first connecting hole;

[0024] The second fastener is fixedly connected to the first fastener through the second connecting hole;

[0025] The composite repair patch is glued to the inner surface of the co-cured metal composite honeycomb sandwich structure and can cover multiple second connection holes.

[0026] The beneficial effects of this invention are:

[0027] The present invention provides a repair method and structure for a co-cured metal composite honeycomb sandwich structure. Multiple first connecting holes are formed around the filling groove on the outer surface of the co-cured metal composite honeycomb sandwich structure, and multiple second connecting holes are formed on the inner surface of the co-cured metal composite honeycomb sandwich structure. After filling the filling groove with filler, a metal repair patch is placed on the outer surface of the co-cured metal composite honeycomb sandwich structure, covering the filling groove and the multiple first connecting holes. Then, the metal repair patch is fixedly connected to the co-cured metal composite honeycomb sandwich structure using first and second fasteners. Since the metal repair patch is a metal structure, and the outermost part of the co-cured metal composite honeycomb sandwich structure is a thin metal plate, mechanical connection provides good fixation of the metal repair patch, ensuring the mechanical properties of the overall structure. Finally, the composite repair patch is glued and fixed to the inner surface of the co-cured metal composite honeycomb sandwich structure, covering the multiple second connecting holes. The innermost part of the co-cured metal composite honeycomb sandwich structure is an inner composite panel, which is glued for good fixation of the composite repair patch, ensuring the mechanical properties of the overall structure. This method combines mechanical connection and adhesive repair, is simple to operate, has a good fixing effect on the patch, and can ensure the original mechanical properties. In addition, since the strength of the honeycomb core material is relatively low, the honeycomb core material can be partially or completely removed during drilling, which has little impact on the mechanical properties of the overall structure. Under this premise, the second fastener is set in the second connection hole, so that the repaired co-cured metal composite honeycomb sandwich structure occupies less space. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the repair structure of the co-cured metal composite honeycomb sandwich structure provided by the present invention.

[0029] In the picture:

[0030] 1. Co-cured metal composite honeycomb sandwich structure; 11. Filling groove; 12. First connecting hole; 13. Metal sheet; 14. Outer composite panel; 15. Second connecting hole; 16. Honeycomb core material; 17. Inner composite panel; 2. Metal repair patch; 3. First fastener; 4. Second fastener; 5. Composite repair patch. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0032] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the communication between the inner ends of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0034] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0035] This invention provides a repair method for co-cured metal composite honeycomb sandwich structures, which can restore the original structural mechanical properties and can be used for the repair of aircraft, wind turbine blades, or other structures with this type of structure. The repair is highly feasible, as the method does not involve new processes and can be completed using conventional processes and tools. Furthermore, the repair materials are easy to store and obtain; the materials used in this method are commonly used in mechanical connection and adhesive bonding repairs, demonstrating good applicability. In addition, the selected repair materials are low-cost, and the repair steps are simple, reducing the downtime repair costs for aircraft operating on air routes.

[0036] like Figure 1 As shown, the co-cured metal composite honeycomb sandwich structure 1 includes a metal sheet 13, an outer composite panel 14, a honeycomb core material 16, and an inner composite panel 17 arranged sequentially from the outside to the inside. The repair method for the co-cured metal composite honeycomb sandwich structure provided by the present invention includes the following steps:

[0037] S1. Remove the damaged parts on the outer surface of the co-cured metal composite honeycomb sandwich structure 1 to form a filling groove 11;

[0038] S2. A plurality of first connecting holes 12 are opened on the outer surface of the co-cured metal composite honeycomb sandwich structure 1, surrounding the filling groove 11, and a plurality of second connecting holes 15 are opened on the inner surface of the co-cured metal composite honeycomb sandwich structure 1, so that the first connecting holes 12 penetrate the metal sheet 13 and the outer composite panel 14, and the plurality of first connecting holes 12 and the plurality of second connecting holes 15 are respectively connected.

[0039] S3. Fill the filling groove 11 with filler material;

[0040] S4. A metal repair patch 2 is applied to the outer surface of the co-cured metal composite honeycomb sandwich structure 1, and the metal repair patch 2 covers the filling groove 11 and multiple first connection holes 12; the first fastener 3 is passed through the metal repair patch 2 and the first connection hole 12 in sequence, and the second fastener 4 is fixedly connected to the first fastener 3 through the second connection hole 15.

[0041] S5. The composite repair patch 5 is glued and fixed to the inner surface of the co-cured metal composite honeycomb sandwich structure 1, and the composite repair patch 5 covers multiple second connection holes 15. Specifically, sealant is applied to the outer wall of the inner composite panel 17, and then the composite repair patch 5 is attached to the sealant and cured.

[0042] This invention provides a plurality of first connecting holes 12 formed around a filling groove 11 on the outer surface of a co-cured metal composite honeycomb sandwich structure 1, and a plurality of second connecting holes 15 formed on the inner surface of the co-cured metal composite honeycomb sandwich structure 1. After filling the filling groove 11 with filler, a metal repair patch 2 is placed on the outer surface of the co-cured metal composite honeycomb sandwich structure 1, covering the filling groove 11 and the first connecting holes 12. Then, the metal repair patch 2 is fixedly connected to the co-cured metal composite honeycomb sandwich structure 1 by a first fastener 3 and a second fastener 4. The repair patch 2 is a metal structure. The outermost part of the co-cured metal composite honeycomb sandwich structure 1 is a thin metal plate 13, which is mechanically connected, providing a good fixation effect for the metal repair patch 2 and ensuring the mechanical properties of the overall structure. Finally, the composite repair patch 5 is glued and fixed to the inner surface of the co-cured metal composite honeycomb sandwich structure 1, and the composite repair patch 5 covers multiple second connection holes 15. The innermost part of the co-cured metal composite honeycomb sandwich structure 1 is an inner composite panel 17, which is glued, providing a good fixation effect for the composite repair patch 5 and ensuring the mechanical properties of the overall structure. This method combines mechanical connection and glued repair, is simple to operate, provides a good fixation effect for the patch, and can ensure the original mechanical properties. In addition, since the strength of the honeycomb core material 16 is relatively low, removing part or all of the honeycomb core material 16 during drilling has little impact on the mechanical properties of the overall structure. Under this premise, the second fastener 4 is placed in the second connection hole 15, so that the repaired co-cured metal composite honeycomb sandwich structure 1 occupies less space.

[0043] Optionally, in this embodiment, step S2 specifically includes: penetrating the first connecting hole 12 to the inner surface of the outer composite panel 14, and penetrating the second connecting hole 15 to the outer surface of the honeycomb core material 16. With this operation, when the metal repair patch 2 is installed using the first fastener 3 and the second fastener 4, the second fastener 4 directly adheres to and abuts against the inner surface of the outer composite panel 14. Since the outer composite panel 14 is stronger than the honeycomb core material 16, the fixing effect is good. Optionally, in other embodiments, step S2 specifically includes: penetrating the first connecting hole 12 to the inner surface of the outer composite panel 14 and extending it to a first position within the honeycomb core material 16, and penetrating the second connecting hole 15 to the outer surface of the inner composite panel 17 and extending it to the first position. With this operation, when the metal repair patch 2 is installed using the first fastener 3 and the second fastener 4, the second fastener 4 adheres to and abuts against the surface of the honeycomb core material 16 at the first position, and the fixing effect is also relatively good.

[0044] Optionally, in this embodiment, step S3 includes: filling the filling groove 11 with potting compound and performing a curing operation, which is convenient and ensures complete adhesion between the filler and the filling groove 11. Further, after filling the filling groove 11 with potting compound and performing the curing operation, the cured filler is further polished to make its outer surface flush with the outer surface of the co-cured metal composite honeycomb sandwich structure 1, resulting in better overall structural mechanical properties after repair. Optionally, in other embodiments, filling the filling groove 11 with filler includes: pre-fabricating a filler block and installing the filler block in the filling groove 11.

[0045] Optionally, in this embodiment, step S1 specifically includes: grinding the damaged portion of the co-cured metal composite honeycomb sandwich structure 1 to form a filling groove 11, which has a good removal effect on the damaged area. Using a pneumatic grinding tool for grinding results in high work efficiency.

[0046] Optionally, step S2 specifically includes: setting two sets of first connecting holes 12, with the two sets respectively set on opposite sides of the filling groove 11. In each set of first connecting holes 12, the distance between the center line of the first connecting hole 12 near the edge of the metal repair patch 2 and the outer edge of the metal repair patch 2 is equal to the distance between the center line of the first connecting hole 12 near the sidewall of the filling groove 11 and the sidewall of the filling groove 11. This saves material while ensuring mechanical properties. Optionally, in this embodiment, in each set of first connecting holes 12, two rows of first connecting holes 12 are provided along the extension direction of the co-cured metal composite honeycomb sandwich structure 1; the first fastener 3 is a bolt, and the second fastener 4 is a nut. The thread diameter of the bolt is D. The distance between the center line of the first connecting hole 12 near the edge of the metal repair patch 2 and the outer edge of the metal repair patch 2 is 2.5D. The distance between the center line of the first connecting hole 12 near the sidewall of the filling groove 11 and the sidewall of the filling groove 11 is 2.5D. The distance between the center lines of the two first connecting holes 12 is 4D-6D. Furthermore, the first fastener 3 is a 4 / 32-inch or 5 / 32-inch shear-resistant high-lock bolt, and the second fastener 4 is a high-lock nut or a self-locking nut. In addition, before fixing the first fastener 3 and the second fastener 4 together, a flat washer is placed first, and then the nut is tightened to prevent the fasteners from loosening and to reduce wear on the outer composite panel 14.

[0047] Optionally, in this embodiment, before step S4, the method further includes: fabricating a metal repair patch 2; fabricating the metal repair patch 2 specifically includes: making the thickness of the metal repair patch 2 equal to the sum of the thickness of the metal sheet 13 and the thickness of the outer composite panel 14. This saves material while ensuring the mechanical properties of the overall structure. Optionally, the material of the metal repair patch 2 is aluminum alloy or titanium alloy.

[0048] Optionally, in this embodiment, a plaster mold is made using the inner surface of the same and undamaged co-cured metal composite honeycomb sandwich structure 1. After molding, the composite repair patch 5 is fabricated. This ensures that the outer surface of the composite repair patch 5 conforms to the inner surface of the co-cured metal composite honeycomb sandwich structure 1. Optionally, in this embodiment, the thickness of the composite repair patch 5 is the same as the thickness of the inner composite panel 17, saving material while ensuring the overall structural mechanical properties. Optionally, in this embodiment, the distance between the edge line of the outer edge of the composite repair patch 5 and the center line of the first connecting hole 12 near the outer edge of the composite repair patch 5 is greater than or equal to 50 mm. Optionally, the composite repair patch 5 uses the same material as the inner composite panel 17.

[0049] Optionally, in this embodiment, the metal repair patch 2 is sealed at the bonding surface with a sealant and a co-cured metal composite honeycomb sandwich structure 1. This provides better fixation for the metal repair patch 2 and further ensures the mechanical properties of the overall structure. Furthermore, a wet installation method is used to install bolts, nuts, and flat washers, and sealant is applied to the outer edge of the metal repair patch 2 for corner sealing, improving connection strength and enhancing the fixation effect. In addition, the sealant used is a two-component synthetic rubber-based aerospace sealant.

[0050] like Figure 1 As shown, the present invention also provides a repair structure for a co-cured metal composite honeycomb sandwich structure, including a co-cured metal composite honeycomb sandwich structure 1. The co-cured metal composite honeycomb sandwich structure 1 includes a metal sheet 13, an outer composite panel 14, a honeycomb core material 16, and an inner composite panel 17 arranged sequentially from the outside to the inside. The co-cured metal composite honeycomb sandwich structure 1 is provided with a filling groove 11, which is filled with a filler. The outer surface of the co-cured metal composite honeycomb sandwich structure 1 is provided with a plurality of first connecting holes 12 arranged around the filling groove 11, and the first connecting holes 12 penetrate the metal sheet 13 and the outer composite panel 14. The inner surface of the co-cured metal composite honeycomb sandwich structure 1 is provided with a plurality of second connecting holes 15. The first connecting hole 12 is connected to multiple second connecting holes 15 respectively; the repair structure of the co-cured metal composite honeycomb sandwich structure also includes a metal repair patch 2, a first fastener 3, a second fastener 4 and a composite repair patch 5. The metal repair patch 2 is covered on the outer surface of the co-cured metal composite honeycomb sandwich structure 1 and can cover the filling groove 11 and the first connecting hole 12; the first fastener 3 is sequentially inserted through the metal repair patch 2 and the first connecting hole 12; the second fastener 4 is fixedly connected to the first fastener 3 through the second connecting hole 15; the composite repair patch 5 is glued and fixed on the inner surface of the co-cured metal composite honeycomb sandwich structure 1 and can cover multiple second connecting holes 15. The structure has good mechanical properties and saves space.

[0051] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A repair method for a co-cured metal composite honeycomb sandwich structure, wherein the co-cured metal composite honeycomb sandwich structure (1) comprises a metal sheet (13), an outer composite panel (14), a honeycomb core material (16), and an inner composite panel (17) arranged sequentially from the outside to the inside, characterized in that, The repair method for the co-cured metal composite honeycomb sandwich structure includes the following steps: S1. Remove the damaged parts on the outer surface of the co-cured metal composite honeycomb sandwich structure (1) to form a filling groove (11). S2. A plurality of first connecting holes (12) are opened on the outer surface of the co-cured metal composite honeycomb sandwich structure (1) surrounding the filling groove (11), and a plurality of second connecting holes (15) are opened on the inner surface of the co-cured metal composite honeycomb sandwich structure (1), so that the first connecting holes (12) penetrate the metal sheet (13) and the outer composite panel (14), and the plurality of first connecting holes (12) and the plurality of second connecting holes (15) are respectively connected to each other; S3. Fill the filling groove (11) with filler material; S4. A metal repair patch (2) is applied to the outer surface of the co-cured metal composite honeycomb sandwich structure (1), and the metal repair patch (2) covers the filling groove (11) and the plurality of first connecting holes (12); the first fastener (3) is passed through the metal repair patch (2) and the first connecting hole (12) in sequence, and the second fastener (4) is fixedly connected to the first fastener (3) through the second connecting hole (15); S5. The composite repair patch (5) is glued and fixed to the inner surface of the co-cured metal composite honeycomb sandwich structure (1), and the composite repair patch (5) covers a plurality of the second connection holes (15). Step S3 further includes: filling the filling groove (11) with potting compound and performing a curing operation; after filling the filling groove (11) with potting compound and performing a curing operation, it further includes polishing the cured filler so that the outer surface of the cured filler is flush with the outer surface of the co-cured metal composite honeycomb sandwich structure (1).

2. The repair method for the co-cured metal composite honeycomb sandwich structure according to claim 1, characterized in that, Step S2 specifically includes: extending the first connecting hole (12) through to the inner surface of the outer composite panel (14) and extending the second connecting hole (15) through to the outer surface of the honeycomb core material (16).

3. The repair method for the co-cured metal composite honeycomb sandwich structure according to claim 1, characterized in that, Step S2 specifically includes: passing the first connecting hole (12) through the inner surface of the outer composite panel (14) and extending it to a first position inside the honeycomb core material (16); and passing the second connecting hole (15) through the outer surface of the inner composite panel (17) and extending it to the first position.

4. The repair method for the co-cured metal composite honeycomb sandwich structure according to claim 1, characterized in that, Step S1 specifically includes: grinding the damaged part of the co-cured metal composite honeycomb sandwich structure (1) to form the filling groove (11).

5. The repair method for the co-cured metal composite honeycomb sandwich structure according to claim 1, characterized in that, Step S2 specifically includes: setting two sets of the first connecting holes (12), and the two sets are respectively set on opposite sides of the filling groove (11). In each set of the first connecting holes (12), the distance between the center line of the first connecting hole (12) near the edge of the metal repair patch (2) and the outer edge line of the metal repair patch (2) is equal to the distance between the center line of the first connecting hole (12) near the side wall of the filling groove (11) and the side wall of the filling groove (11).

6. The repair method for the co-cured metal composite honeycomb sandwich structure according to claim 1, characterized in that, Before step S4, the process further includes: making the metal repair patch (2); making the metal repair patch (2) specifically includes: making the thickness of the metal repair patch (2) equal to the sum of the thickness of the metal sheet (13) and the thickness of the outer composite panel (14).

7. The repair method for the co-cured metal composite honeycomb sandwich structure according to claim 1, characterized in that, The metal repair patch (2) is sealed with sealant and the co-cured metal composite honeycomb sandwich structure (1) at the bonding surface.

8. A repair structure for a co-cured metal composite honeycomb sandwich structure, comprising a co-cured metal composite honeycomb sandwich structure (1), wherein the co-cured metal composite honeycomb sandwich structure (1) comprises a metal sheet (13), an outer composite panel (14), a honeycomb core material (16), and an inner composite panel (17) arranged sequentially from the outside to the inside, characterized in that, The co-cured metal composite honeycomb sandwich structure (1) is provided with a filling groove (11), and the filling groove (11) is filled with a filler. The outer surface of the co-cured metal composite honeycomb sandwich structure (1) is provided with a plurality of first connecting holes (12) arranged around the filling groove (11), and the first connecting holes (12) penetrate the metal sheet (13) and the outer composite panel (14). The inner surface of the co-cured metal composite honeycomb sandwich structure (1) is provided with a plurality of second connecting holes (15), and the plurality of first connecting holes (12) and the plurality of second connecting holes (15) are respectively connected. The repair structure for the co-cured metal composite honeycomb sandwich structure also includes: Metal repair patch (2) is applied to the outer surface of the co-cured metal composite honeycomb sandwich structure (1) and can cover the filling groove (11) and the first connecting hole (12). The first fastener (3) is sequentially inserted through the metal repair patch (2) and the first connecting hole (12). The second fastener (4) is fixedly connected to the first fastener (3) through the second connecting hole (15); The composite repair patch (5) is glued to the inner surface of the co-cured metal composite honeycomb sandwich structure (1) and can cover multiple second connection holes (15).

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