Alloy joint and composite i-beam connection structure

By designing an insulating adhesive layer and an elastic sealant connection structure between the composite material I-beam and the alloy joint, the problems of stress concentration and galvanic corrosion were solved, achieving an efficient and reliable connection and improving the durability and strength of the structure.

CN122447397APending Publication Date: 2026-07-24CHINA ACAD OF AEROSPACE AERODYNAMICS
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
CHINA ACAD OF AEROSPACE AERODYNAMICS
Filing Date
2026-04-30
Publication Date
2026-07-24

AI Technical Summary

Technical Problem

In the existing technology, the connection between titanium alloy joints and composite material I-beams suffers from stress concentration, insufficient reliability, and the risk of galvanic corrosion, resulting in poor structural durability.

Method used

The structure employs a composite material I-beam and alloy joint connection, with a design featuring first and second connection grooves. An insulating adhesive layer is placed inside the grooves, and the connection is achieved through fasteners and filled with elastic sealant. Carbon fiber composite materials and titanium alloy bolts are used to ensure a clear force transmission path.

Benefits of technology

It achieves efficient and reliable connection, with high connection strength, fatigue resistance and corrosion resistance, and reduces stress concentration and galvanic corrosion risk.

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Abstract

The application discloses an alloy joint and composite material I-beam connecting structure, comprising: a composite material I-beam and an alloy joint; the alloy joint has an I-shaped connecting part, the connecting part has a first connecting groove and a second connecting groove for accommodating two sides of the end part of the composite material I-beam, a hollow gap is arranged between the two connecting grooves and is used for inserting a vertical section of the composite material I-beam; connecting holes are formed in upper and lower edge strips of the first connecting groove and the second connecting groove, and the upper and lower flanges of the composite material I-beam are connected through a plurality of fasteners; an insulating adhesive layer is arranged between the inner surfaces of the connecting grooves and the composite material I-beam, and the end part of the inserted I-beam is bonded in the connecting grooves. The application has the advantages of clear force transmission path, offset part of bending moment by bending root couple, light weight, high connecting strength, high reliability, fatigue resistance, corrosion resistance and the like, and can be applied to telescopic wing unmanned aerial vehicle manufacturing.
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Description

Technical Field

[0001] This invention relates to the field of retractable wing unmanned aerial vehicle (UAV) structural design, and in particular to an alloy joint and composite material I-beam connection structure. Background Technology

[0002] In the aerospace industry, especially in the manufacturing of telescopic wing unmanned aerial vehicles (UAVs), achieving efficient and reliable connections between titanium alloy joints and composite material I-beams is a key technical challenge. Traditional bolted connections are prone to stress concentration at the edges of composite material holes, leading to premature failure; pure adhesive bonding lacks reliability and is extremely sensitive to processes and environments; furthermore, direct contact between composite materials and metals poses a risk of galvanic corrosion, affecting structural durability. Summary of the Invention The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a connection structure between an alloy joint and a composite material I-beam, so as to achieve an efficient and reliable connection between the alloy joint and the composite material I-beam.

[0003] The technical solution of the present invention is: an alloy joint and composite material I-beam connection structure, comprising: a composite material I-beam and an alloy joint; The alloy joint has a connecting part that matches the composite material I-beam. The connecting part has a first connecting groove and a second connecting groove that accommodate the end of the composite material I-beam. There is a hollow cavity between the two connecting grooves for inserting the vertical section of the composite material I-beam. The upper and lower edges of the first and second connecting grooves have connecting holes, which are connected to the upper and lower flanges of the composite material I-beam through multiple sets of fasteners; an insulating adhesive layer is provided between the inner surface of the connecting groove and the composite material I-beam, and the end of the I-beam located in the connecting groove is bonded to the connecting groove.

[0004] Furthermore, a gap is left between the composite material I-beam and the bottom of the connecting groove, and the inside is filled with elastic sealant.

[0005] Furthermore, the composite material I-beam is made of carbon fiber composite material.

[0006] Furthermore, the composite material I-beam is made of CCM40J carbon fiber prepreg laid continuously at the designed angle, and at least 5 layers of plain-weave glass fiber cloth are laid on the surface in contact with the alloy joint.

[0007] Furthermore, the alloy connector is made of titanium alloy.

[0008] Furthermore, the insulating adhesive layer is made of epoxy resin.

[0009] Furthermore, the epoxy resin adhesive layer has a thickness of 0.1~0.5mm.

[0010] Furthermore, the fastener is a titanium alloy bolt.

[0011] The present invention also relates to a telescopic wing unmanned aerial vehicle, comprising the aforementioned alloy joint and composite material I-beam connection structure.

[0012] The advantages of this invention compared to the prior art are: The present invention has a clear force transmission path, and the root couple after bending can offset part of the bending moment. It has the advantages of light weight, high connection strength, high reliability, fatigue resistance and corrosion resistance. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the alloy joint structure of the present invention; Figure 2 This is a schematic diagram of the composite material I-beam structure of the present invention; Figure 3 This is an assembly diagram of the connection structure of the present invention. Detailed Implementation

[0014] To better understand the technical solution of the present invention, the specific embodiments of the present invention are described below.

[0015] The alloy joint and composite material I-beam connection structure proposed in this invention, such as Figure 1 and Figure 2 As shown, it includes a carbon fiber composite I-beam 2 and a titanium alloy joint 1; as Figure 3 As shown, the titanium alloy joint has an I-shaped connecting groove. The end of the I-beam is inserted into and bonded to the connecting groove. The upper and lower flanges of the titanium alloy joint are fastened to the upper and lower flanges of the I-beam by multiple sets of bolts 4. An insulating adhesive layer 3 is provided between the inner surface of the connecting groove of the titanium alloy joint and the I-beam. A gap is left between the end of the I-beam and the bottom of the connecting groove, and the gap is filled with elastic sealant.

[0016] The processing and assembly methods for the connection structure are as follows: 1. The titanium alloy joint is machined and manufactured, and its connecting groove size is clearance-fitted with the end of the I-beam; 2. The composite material I-beam adopts a molding process, and CCM40J carbon fiber prepreg is laid continuously at the design angle. Five layers of plain weave glass fiber cloth are laid on the contact surface with the titanium alloy joint. 3. Apply 0.2mm of epoxy resin adhesive to the inner surface of the titanium alloy connector groove; 4. Slowly press the end of the I-beam into the connecting groove to the predetermined position, ensuring that the adhesive layer is uniform; 5. Install titanium alloy bolts through the pre-drilled holes and tighten them to the specified torque.

[0017] This invention has the advantages of clear force transmission path, partial bending moment cancellation by the root couple after bending, light weight, high connection strength, high reliability, fatigue resistance and corrosion resistance.

[0018] It is understood that this invention has been described through embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific circumstances without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by this invention.

[0019] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A connection structure between an alloy joint and a composite material I-beam, characterized in that, include: Composite material I-beam (2) and alloy joint (1); The alloy joint (1) has a connecting part that matches the composite material I-beam (2). The connecting part has a first connecting groove and a second connecting groove that accommodate the end of the composite material I-beam (2). The two connecting grooves are hollow cavities for inserting the vertical section of the composite material I-beam (2). The upper and lower edges of the first and second connecting grooves have connecting holes, which are connected to the upper and lower flanges of the composite material I-beam (2) by multiple sets of fasteners (4); an insulating adhesive layer (3) is provided between the inner surface of the connecting groove and the composite material I-beam (2), and the end of the I-beam located in the connecting groove is bonded to the connecting groove.

2. The alloy joint and composite material I-beam connection structure according to claim 1, characterized in that: There is a gap between the composite material I-beam (2) and the bottom of the connecting groove, and the inside is filled with elastic sealant.

3. The alloy joint and composite material I-beam connection structure according to claim 1, characterized in that: The composite material I-beam (2) is made of carbon fiber composite material.

4. The alloy joint and composite material I-beam connection structure according to claim 3, characterized in that: The composite material I-beam (2) is made of CCM40J carbon fiber prepreg laid at the design angle, and at least 5 layers of plain weave glass fiber cloth are laid on the contact surface with the alloy joint (1).

5. The alloy joint and composite material I-beam connection structure according to claim 1, characterized in that: The alloy connector (1) is made of titanium alloy.

6. The alloy joint and composite material I-beam connection structure according to claim 1, characterized in that: The insulating adhesive layer (3) is made of epoxy resin.

7. The alloy joint and composite material I-beam connection structure according to claim 1, characterized in that: The epoxy resin adhesive layer has a thickness of 0.1~0.5mm.

8. The alloy joint and composite material I-beam connection structure according to claim 1, characterized in that: The fasteners are titanium alloy bolts.

9. A retractable wing unmanned aerial vehicle, characterized in that: It includes the alloy joint and composite material I-beam connection structure as described in any one of claims 1 to 8.