Large thickness honeycomb sandwich radome structure with rounded corners

Abstract

The utility model discloses a big thickness honeycomb sandwich radar radome structure with arc corner, the arc section both ends of this structure are connected linear section respectively, and the mounting section is arranged in the linear section of end part, and the linear section is equipped with honeycomb sandwich, and the arc section is equipped with foam sandwich, and the mounting section is equipped with glass fiber reinforced plastic laminated board, and the two side surfaces and end surface of honeycomb sandwich, foam sandwich and glass fiber reinforced plastic laminated board are equipped with inner skin and outer skin through adhesive film, and the curved surface obtained by numerical control processing matches the curved surface of arc section, the structure overcomes the defect of traditional honeycomb sandwich curved surface shaping processing, avoids the layered skin of radome outside, makes the fillet place core material better adhere to the mould, and improves the structural performance and electric performance of the arc corner of radome.

Description

Technical Field

[0001] This utility model relates to the field of radar radome technology, and in particular to a thick honeycomb sandwich radar radome structure with rounded corners. Background Technology

[0002] The honeycomb sandwich structure of the radome has the core advantages of "lightweight, high specific strength and bending stiffness, and large size adaptability", making it the mainstream choice for large airborne and ground-based radar radomes.

[0003] For thick honeycomb sandwich layers, bending them along the mold's curvature to fit the mold surface presents challenges due to the rigidity of the honeycomb thickness, making natural bonding difficult. This also hinders the effective transmission of curing pressure to the inner side of the rounded corners, easily leading to defects such as delamination of the outer skin of the honeycomb sandwich layer. The traditional method involves deforming the honeycomb using a semi-cured honeycomb with some flexibility. On a specific rounded corner forming mold, the honeycomb sandwich layer is shaped by secondary heating and curing. The bonded surface of the shaped honeycomb sandwich layer is then sanded before the skin is applied. However, for thick honeycomb sandwich layers with small rounded corners, this method causes extrusion deformation of the honeycomb inside the rounded corners, damaging the regular hexagonal honeycomb structure and affecting the structural and electrical performance of the radome. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a thick honeycomb sandwich radar radome structure with rounded corners. This structure overcomes the defects of traditional honeycomb sandwich curved surface shaping treatment, avoids the delamination of the outer skin of the radome, makes the core material at the rounded corners fit the mold better, and improves the structural and electrical performance of the rounded corners of the radome.

[0005] To solve the above-mentioned technical problems, the present invention provides a thick honeycomb sandwich radar radome structure with rounded corners, comprising a straight section, a rounded section, and a mounting section. The two ends of the rounded section are respectively connected to the straight section. The mounting section is located at the end of the straight section. The straight section is provided with a honeycomb sandwich, the rounded section is provided with a foam sandwich, and the mounting section is provided with a fiberglass laminate. The two sides and the end faces of the honeycomb sandwich, the foam sandwich, and the fiberglass laminate are provided with an inner skin and an outer skin through an adhesive film. The curved surface of the foam sandwich is CNC machined to match the curved surface of the rounded section.

[0006] Furthermore, the honeycomb interlayer is an aramid paper honeycomb interlayer with a honeycomb density of 64 g / m³ and a thickness of 24 mm; the foam interlayer is a PMI foam interlayer with a foam density of 75 g / m³ and a thickness of 24 mm.

[0007] Furthermore, the inner and outer skins are fiber-reinforced epoxy resin or cyanate ester prepregs with a resin content of 40%.

[0008] Furthermore, the adhesive film is an epoxy adhesive film or a cyanate ester adhesive film with a thickness of 0.2 mm.

[0009] Furthermore, the fiberglass laminate is a fiber-reinforced epoxy resin laminate.

[0010] Furthermore, the outer radius of the arc segment is R40mm, and the inner radius is R16mm. Because this utility model's thick honeycomb sandwich radar radome structure with rounded corners adopts the above-mentioned technical solution, namely, the two ends of the rounded segment of this structure are respectively connected to straight segments, the mounting segment is located at the end of the straight segment, the straight segment has a honeycomb sandwich, the rounded segment has a foam sandwich, and the mounting segment has a fiberglass laminate. The two sides and end faces of the honeycomb sandwich, foam sandwich, and fiberglass laminate are provided with inner and outer skins through an adhesive film. The curved surface of the foam sandwich is CNC machined to match the curved surface of the rounded segment. This structure overcomes the defects of traditional honeycomb sandwich curved surface shaping treatment, avoids the delamination of the outer skin of the radome, allows the core material at the rounded corners to better fit the mold, and improves the structural and electrical performance of the rounded corners of the radome. Attached Figure Description

[0011] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the thick honeycomb sandwich radar radome structure with rounded corners of this utility model. Detailed Implementation

[0012] Implementation, for example Figure 1 As shown, the thick honeycomb sandwich radar radome structure with rounded corners of this utility model includes a straight section 1, a rounded section 2, and a mounting section 3. The two ends of the rounded section are respectively connected to the straight section. The mounting section is located at the end of the straight section. The straight section is provided with a honeycomb sandwich layer. The rounded section is provided with a foam sandwich layer. The mounting section is provided with a fiberglass laminate. The two sides and the end faces of the honeycomb sandwich layer, the foam sandwich layer, and the fiberglass laminate are provided with an inner skin and an outer skin through an adhesive film. The curved surface of the foam sandwich layer is CNC machined to match the curved surface of the rounded section.

[0013] Preferably, the honeycomb interlayer is an aramid paper honeycomb interlayer with a honeycomb density of 64 g / m³ and a thickness of 24 mm; the foam interlayer is a PMI foam interlayer with a foam density of 75 g / m³ and a thickness of 24 mm.

[0014] PMI foam is a high-end closed-cell foam material with excellent specific strength, heat resistance (can withstand temperatures above 180°C for extended periods), good dielectric properties, and chemical stability. It is typically sandwiched between carbon fiber or glass fiber panels to form a lightweight yet robust "sandwich structure," widely used for weight reduction and structural performance improvement. Its superior dielectric properties also make it suitable for electromagnetically transparent structures such as radar radomes.

[0015] Preferably, the inner and outer skins are fiber-reinforced epoxy resin or cyanate ester prepregs with a resin content of 40%. Fiber-reinforced epoxy resin or cyanate ester prepregs are high-performance composite material intermediates, made by pre-impregnating reinforcing fibers (such as carbon fiber, glass fiber, aramid, etc.) in an epoxy resin or cyanate ester matrix, and have the characteristics of high strength, lightweight, and easy molding.

[0016] Preferably, the adhesive film is an epoxy adhesive film or a cyanate ester adhesive film with a thickness of 0.2 mm.

[0017] Preferably, the fiberglass laminate is a fiber-reinforced epoxy resin laminate.

[0018] Preferably, the outer radius of the arc segment is R40mm and the inner radius is R16mm.

[0019] The fabrication of this radar radome structure begins with mold preparation and material preparation. Then, on the surface of the metal mold, the outer skin, adhesive film, honeycomb interlayer for straight sections and foam interlayer for curved sections, fiberglass laminate, and inner skin are laid sequentially. On the inner skin surface, auxiliary materials such as an isolation membrane, breathable felt, vacuum nozzle, and vacuum bag film are further laid. Curing is performed using an autoclave with heating and pressurization. After cooling to below 60°C, the product is removed from the autoclave, yielding the radar radome body. The autoclave heating and pressurization method is a composite material molding process that utilizes the uniform temperature and pressure provided by the autoclave equipment to allow the prepreg to complete the curing reaction in the mold, forming a component of the required shape and meeting quality requirements.

[0020] This radar radome structure uses PMI foam as the core layer for the arc segment. CNC machining enhances precision, ensuring the PMI foam surface perfectly matches the arc segment's surface. This guarantees a high degree of fit between the layers during molding, improving molding quality and preventing defects such as skin delamination. Furthermore, it eliminates the need for traditional honeycomb sandwich surface shaping and bonding surface polishing processes, increasing manufacturing efficiency. The PMI foam core layer also simultaneously provides structural and electrical performance, solving the challenge of rounded corner molding in thick honeycomb sandwich structures.

Claims

1. A thick honeycomb sandwich radar radome structure with rounded corners, comprising a straight section, a rounded section, and a mounting section, wherein the two ends of the rounded section are respectively connected to the straight section, and the mounting section is located at the end of the straight section, characterized in that: The straight section is provided with a honeycomb interlayer, the arc section is provided with a foam interlayer, and the installation section is provided with a fiberglass laminate. The two sides and ends of the honeycomb interlayer, the foam interlayer, and the fiberglass laminate are provided with inner and outer skins through an adhesive film. The curved surface of the foam interlayer is CNC machined to match the curved surface of the arc section.

2. The thick honeycomb sandwich radar radome structure with rounded corners according to claim 1, characterized in that: The honeycomb interlayer is an aramid paper honeycomb interlayer with a honeycomb density of 64 g / m³ and a thickness of 24 mm; the foam interlayer is a PMI foam interlayer with a foam density of 75 g / m³ and a thickness of 24 mm.

3. The thick honeycomb sandwich radar radome structure with rounded corners according to claim 1 or 2, characterized in that: The inner and outer skins are made of fiber-reinforced epoxy resin or cyanate ester prepreg with a resin content of 40%.

4. The thick honeycomb sandwich radar radome structure with rounded corners according to claim 3, characterized in that: The adhesive film is an epoxy adhesive film or a cyanate ester adhesive film with a thickness of 0.2 mm.

5. The thick honeycomb sandwich radar radome structure with rounded corners according to claim 3, characterized in that: The fiberglass laminate is a fiber-reinforced epoxy resin laminate.

6. The thick honeycomb sandwich radar radome structure with rounded corners according to claim 1, characterized in that: The outer radius of the arc segment is R40mm, and the inner radius is R16mm.

Images