S / Ku dual-band airborne radome structure and preparation method thereof

Abstract

The present invention discloses a S / Ku dual-band airborne radome cover structure and a preparation method thereof. The airborne radome cover structure is an A-type honeycomb sandwich structure, which includes an inner skin, a resin film, an adhesive film, a core layer, an adhesive film, a resin layer and an outer skin from the inside to the outside. The adhesive content on the inner side of the inner and outer skins is directionally increased by adding a low-weight resin film on the inner side of the inner and outer skins, and then a layer of low-weight carrier-free adhesive film is used to bond the inner and outer skins to the core layer. This method significantly improves the bonding strength of the interface between the inner and outer skins and the core layer while effectively controlling the adhesive content of the prepreg and the gram weight of the adhesive film. This method uses a hot autoclave heating and pressurizing co-curing molding method to cure the laid outer skin, resin film, adhesive film, core layer and inner skin. The prepared cover structure is lightweight and uniform, meeting the requirements of lightweight and high wave transmission of the radome.

Description

Technical Field

[0001] The present invention relates to the technical field of radar antenna covers, and in particular to an S / Ku dual-band airborne antenna cover body structure and a preparation method thereof. Background Art

[0002] The airborne radome is a functional composite structural part that not only needs to meet the requirements of aerodynamics, structural strength, environmental resistance and weight, but also needs to meet the requirements of electrical performance.

[0003] The skin wave-transmitting material of the traditional airborne radome is a glass fiber reinforced epoxy resin system. Regarding glass fiber reinforced materials, D-glass fiber has the best dielectric properties but poor mechanical properties, and S-glass fiber has excellent mechanical properties but poor dielectric properties. Although quartz fiber is expensive, it has the lowest dielectric loss tangent (tanδ=0.0002) and excellent mechanical properties. At present, most advanced foreign radomes have adopted quartz fiber as a reinforcement material. Regarding the matrix material, epoxy resin has excellent processability and mechanical properties, making it the most widely used resin matrix material. However, in recent years, the requirements for low dielectric loss, high temperature resistance, weather resistance and other performance requirements of advanced radar radomes have been continuously improved, and epoxy resin can no longer meet these requirements at the same time.

[0004] The typical structure of the airborne radome is a honeycomb sandwich structure, which has a high weight reduction efficiency. In order to reduce the manufacturing cost of composite materials, the co-curing molding process of the honeycomb sandwich structure has received more and more attention. The honeycomb sandwich structure and the co-curing molding method have more stringent requirements on the glue content of the prepreg, the glue content of the film, and the resin fluidity. Low glue content and high resin viscosity affect the panel molding quality and interface bonding performance of co-curing molding. High content and low resin viscosity can solve the above problems to a certain extent, but at the same time it will increase the weight of the cover and affect the wave transmission performance of the cover. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an S / Ku dual-band airborne radome cover structure and a preparation method thereof. This airborne radome overcomes the defects of traditional radomes such as heavy weight and poor wave transmission performance. The airborne radome prepared by this method is light, strong and uniform, meeting the requirements of light weight and high wave transmission of the airborne radome.

[0006] In order to solve the above technical problems, the S / Ku dual-band airborne antenna cover body structure of the present invention includes an outer skin, a resin film, an adhesive film, a core layer and an inner skin, the core layer is provided with adhesive films on both sides, the resin film is provided on the outside of the adhesive film, the outer skin and the inner skin are respectively arranged on the outside of the resin film, and the outer skin and the inner skin are respectively bonded to the two sides of the core layer through the resin film and the adhesive film.

[0007] Furthermore, the inner skin and the outer skin are made of hydroester quartz fiber prepreg, and the glue content is 40%.

[0008] Furthermore, the core layer is an aramid paper honeycomb board, and the honeycomb grade is aviation grade.

[0009] Furthermore, the resin film is a hydroester resin film, and the weight of the resin film is 25 g / ㎡.

[0010] Furthermore, the adhesive film is a toughened modified hydrogen ester carrier-free adhesive film, and the weight of the adhesive film is 100 g / ㎡.

[0011] A method for preparing the above-mentioned airborne radome cover structure comprises the following steps: Step 1: Prepare mold and materials; Step 2: Lay adhesive films on both sides of the core layer, lay resin films on the outside of the adhesive films, lay inner skins and outer skins on the outside of the resin films, and place the outer skins on the surface of the metal female mold; Step 2: Use an autoclave to heat and pressurize the co-curing molding method to cure the laid outer skin, resin film, adhesive film, core layer and inner skin. The curing process parameters are 80°C constant temperature for 2 hours, 90°C constant temperature for 2 hours and then pressurized to 0.35MPa, 100°C constant temperature for 2 hours, 130°C constant temperature for 4 hours, and 180°C constant temperature for 4 hours. Step 3: After the temperature drops below 60°C, the product is opened and taken out of the can to obtain the airborne antenna cover structure. Since the S / Ku dual-band airborne radome structure and its preparation method of the present invention adopt the above-mentioned technical scheme, that is, the radome structure of this airborne radome is an A-type honeycomb sandwich structure, which is composed of inner skin, resin film, adhesive film, core layer, adhesive film, resin layer and outer skin from the inside to the outside; wherein, the adhesive content on the inner side of the inner and outer skin is directionally increased by adding a low-weight resin film on the inner side of the inner and outer skin, and then a layer of low-weight carrier-free adhesive film is used to bond the inner and outer skin to the core layer. This method significantly improves the bonding strength of the interface between the inner and outer skin and the core layer while effectively controlling the adhesive content of the prepreg and the gram weight of the adhesive film. This method uses a hot autoclave heating and pressurizing co-curing molding method to cure the laid outer skin, resin film, adhesive film, core layer and inner skin. The prepared cover structure is lightweight and uniform, meeting the requirements of lightweight and high wave transmission of the radome. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the structure of the S / Ku dual-band airborne antenna cover of the present invention; Figure 2 This is a schematic diagram of the relationship between the parallel polarization loss and the frequency at an incident angle of 0 to 45° for the cover structure; Figure 3 This is a schematic diagram of the relationship between the vertical polarization loss and frequency for an incident angle of 0 to 45° for this cover structure. DETAILED DESCRIPTION

[0013] Implementation example Figure 1 As shown, the S / Ku dual-band airborne antenna cover body structure of the present invention includes an outer skin 1, a resin film 2, an adhesive film 3, a core layer 4 and an inner skin 5, the adhesive film 3 is provided on both sides of the core layer 4, the resin film 2 is provided on the outside of the adhesive film 3, the outer skin 1 and the inner skin 5 are respectively provided on the outside of the resin film 2, and the outer skin 1 and the inner skin 5 are respectively bonded to the two sides of the core layer 4 through the resin film 2 and the adhesive film 3.

[0014] Preferably, the inner skin 5 and the outer skin 1 are hydroester quartz fiber prepreg, and the glue content is 40%. The material model is QW100 / HWP-CE03, which has a low dielectric constant and loss tangent, excellent mechanical properties and process properties, and can withstand 180°C for a long time.

[0015] Preferably, the core layer 4 is an aramid paper honeycomb board, and the honeycomb grade is aviation grade.

[0016] Preferably, the resin film 2 is a hydroester resin film, and the weight of the resin film 2 is 25 g / ㎡. The resin film is the same as the prepreg resin used for the inner and outer skins. The resin film can directionally increase the resin content on the inner side of the inner and outer skins, which is beneficial to enhance the bonding between the honeycomb and the skin.

[0017] Preferably, the adhesive film 3 is a toughened modified hydrogen ester carrier-free adhesive film, and the weight of the adhesive film 3 is 100 g / ㎡. The adhesive film model is FY-QJ10, and the adhesive film is used for bonding between the inner and outer skins and the core honeycomb.

[0018] Hydrogenated ester resin has a low shrinkage rate, excellent dielectric properties, high temperature resistance, low moisture absorption rate and excellent mechanical properties. Hydrogenated ester resin has a stable and extremely low dielectric constant (ε=2.8~3.2) and dielectric loss tangent (tanδ=0.002~0.008), better dielectric properties and better environmental resistance. The inner and outer skins, resin films and adhesive films of the onboard antenna cover structure of this machine are made of hydrogenated ester resin materials, which makes the cover structure light and highly transparent.

[0019] The cover structure of the onboard radome increases the glue content on the inner and outer skins by adding a low-weight resin film on the inside of the inner and outer skins, and then uses a layer of low-weight carrier-free adhesive film to bond the inner and outer skins to the core layer. This method significantly improves the bonding strength of the honeycomb interface between the inner and outer skins and the core layer while effectively controlling the glue content of the prepreg and the grammage of the adhesive film. The prepared product is lightweight and has good uniformity, meeting the requirements of lightweight and high wave transmittance of the radome.

[0020] A method for preparing the above-mentioned airborne radome cover structure comprises the following steps: Step 1: Prepare mold and materials; Step 2: Lay adhesive films on both sides of the core layer, lay resin films on the outside of the adhesive films, lay inner skins and outer skins on the outside of the resin films, and place the outer skins on the surface of the metal female mold; Step 2: Use an autoclave to heat and pressurize the co-curing molding method to cure the laid outer skin, resin film, adhesive film, core layer and inner skin. The curing process parameters are 80°C constant temperature for 2 hours, 90°C constant temperature for 2 hours and then pressurized to 0.35MPa, 100°C constant temperature for 2 hours, 130°C constant temperature for 4 hours, and 180°C constant temperature for 4 hours. Step 3: After the temperature drops below 60°C, the product is opened and taken out of the can to obtain the airborne antenna cover structure.

[0021] The airborne radome structure prepared by this method has passed environmental tests such as humidity, heat, salt spray, and mildew, and meets the environmental requirements for the product. It has passed mechanical tests such as static, vibration, and impact, and has shown excellent structural performance, meeting the structural performance requirements of the airborne radome. Without affecting the structural strength, the weight of the prepreg and the film is strictly controlled, and the molding process is fully resisted. The prepared radome is light and uniform, meeting the electrical performance requirements of the airborne radome. The weight per unit area of ​​the wave-transmitting area (including anti-rain erosion and antistatic coatings) can be controlled within 0.8kg / ㎡, such as Figure 2 and Figure 3 As shown, in the wave-transmitting area (including anti-rain erosion and antistatic coatings) at an incident angle of 45° in the S and Ku bands, the wave transmission loss is better than 0.6dB, and it has the characteristics of light weight and high wave transmission.

Claims

1. An S / Ku dual-band airborne antenna cover structure, characterized in that: The invention comprises an outer skin, a resin film, an adhesive film, a core layer and an inner skin. Adhesive films are arranged on both sides of the core layer, the resin film is arranged on the outer side of the adhesive film, the outer skin and the inner skin are arranged on the outer side of the resin film respectively, and the outer skin and the inner skin are respectively bonded to both sides of the core layer by the resin film and the adhesive film.

2. The S / Ku dual-band airborne antenna cover structure according to claim 1, characterized in that: The inner skin and the outer skin are made of hydroester quartz fiber prepreg and have a glue content of 40%.

3. The S / Ku dual-band airborne antenna cover structure according to claim 1, characterized in that: The core layer is an aramid paper honeycomb board, and the honeycomb grade is aviation grade.

4. The S / Ku dual-band airborne antenna cover structure according to claim 1, characterized in that: The resin film is a hydroester resin film, and the weight of the resin film is 25 g / ㎡.

5. The S / Ku dual-band airborne antenna cover structure according to claim 1, characterized in that: The adhesive film is a toughened modified hydrogen ester carrier-free adhesive film, and the gram weight of the adhesive film is 100 g / ㎡.

6. A method for preparing the airborne radome structure according to any one of claims 1 to 5, characterized in that The steps include: Step 1: Prepare mold and materials; Step 2: Lay adhesive films on both sides of the core layer, lay resin films on the outside of the adhesive films, lay inner skins and outer skins on the outside of the resin films, and place the outer skins on the surface of the metal female mold; Step 2: Use an autoclave to heat and pressurize the co-curing molding method to cure the laid outer skin, resin film, adhesive film, core layer and inner skin. The curing process parameters are 80°C constant temperature for 2 hours, 90°C constant temperature for 2 hours and then pressurized to 0.35MPa, 100°C constant temperature for 2 hours, 130°C constant temperature for 4 hours, and 180°C constant temperature for 4 hours. Step 3: After the temperature drops below 60°C, the product is opened and taken out of the can to obtain the airborne antenna cover structure.

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