Light high-strength multi-layer composite wave-absorbing cellular board

Abstract

The utility model discloses a light high-strength multi-layer composite wave-absorbing cellular board which comprises a wave-transparent protective layer, a cellular core layer, an absorbing layer and a supporting layer, a grid layer is arranged between the wave-transparent protective layer and the cellular core layer, a plurality of cones which are arranged at equal intervals are arranged on the outer wall of the bottom of the cellular core layer, and the absorbing layer is arranged on the outer wall of the bottom of the cellular core layer. The absorbing layer is filled in gaps among the plurality of cones, and the absorbing layer is internally provided with carbon nanotubes which are distributed in a gradient manner. The wave-transparent protection layer is made of a quartz fiber and epoxy resin composite material, the thickness of the wave-transparent protection layer is 0.2 mm, and the grid layer is made of carbon fibers. The light high-strength multi-layer composite wave-absorbing cellular board disclosed by the utility model has the effects of improving the mechanical strength and the broadband wave-absorbing performance.

Description

Technical Field

[0001] This utility model relates to the field of electromagnetic wave absorbing materials and composite materials, and in particular to a lightweight, high-strength multilayer composite wave absorbing honeycomb panel. Background Technology

[0002] Radar-absorbing honeycomb panels are functional composite materials that combine the lightweight and high-strength characteristics of honeycomb structures with the ability to effectively absorb electromagnetic waves (radar waves, microwaves, etc.). They are primarily used in stealth technology, electromagnetic shielding, and microwave anechoic chambers, significantly reducing the radar cross-section (RCS) of target objects and preventing radar detection.

[0003] However, traditional absorbing honeycomb panels suffer from poor mechanical properties and narrow absorption frequency bands, making it difficult to balance structural strength and electromagnetic wave absorption performance. Furthermore, their insufficient lightweight design limits their application in fields such as stealth equipment.

[0004] For example, traditional aramid honeycomb requires the addition of excessive microwave absorbing agents due to its insulation properties, which reduces its strength. Furthermore, the single-layer structure cannot achieve broadband impedance matching, resulting in a sharp decline in performance in complex electromagnetic environments. Utility Model Content

[0005] This utility model discloses a lightweight, high-strength, multi-layer composite absorbing honeycomb panel, aiming to solve the technical problems of poor mechanical properties and narrow absorption frequency band of absorbing honeycomb panels, which make it difficult to balance structural strength and electromagnetic wave absorption performance, and the insufficient lightweighting limits its application in fields such as stealth equipment.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A lightweight, high-strength, multi-layer composite absorbing honeycomb panel includes a wave-transmitting protective layer, a honeycomb core layer, an absorption layer, and a support layer. A mesh layer is provided between the wave-transmitting protective layer and the honeycomb core layer. Several cones are arranged at equal intervals on the bottom outer wall of the honeycomb core layer. The absorption layer fills the gaps between the cones, and carbon nanotubes are arranged in a gradient distribution inside the absorption layer.

[0008] In this case, the composite absorbing honeycomb panel adopts a multi-layer structure. By setting a grid layer, a cone structure, and a gradient carbon nanotube absorption layer, the mechanical and absorption performance are synergistically optimized. The grid layer improves the bonding strength between the wave-transmitting protective layer and the honeycomb core, the cone structure increases the contact area of ​​the absorption layer and effectively improves the interface stress transmission efficiency, and the gradient distribution of carbon nanotubes (1-5wt%) inside the absorption layer forms an optimized impedance gradient structure, realizing the layer-by-layer attenuation of electromagnetic waves.

[0009] In a preferred embodiment, the top outer wall of the support layer has eight radially distributed main grooves, and several auxiliary grooves are provided between each two adjacent main grooves. The interior of the main grooves and the auxiliary grooves are filled with conductive adhesive.

[0010] Specifically, by using eight main grooves radially distributed at 45° equiangular angles, along with several auxiliary grooves to form a complete conductive network, the electromagnetic loss efficiency of the support layer 5 in the 8GHz band is improved by 40%, and the reflection loss is reduced to -12.4dB. The conductive adhesive filled in the grooves is an epoxy resin system containing 2wt% carbon nanotubes (viscosity 50mPa·s), which forms a stable three-dimensional conductive path after curing at 60℃, with the volume resistivity controlled at 10. 2 The Ω·cm ensures a good bond between the conductive adhesive and the carbon fiber matrix, guaranteeing excellent conductivity.

[0011] As described above, the lightweight, high-strength multilayer composite absorbing honeycomb panel includes a wave-transmitting protective layer, a honeycomb core layer, an absorption layer, and a support layer. It also includes a mesh layer between the wave-transmitting protective layer and the honeycomb core layer, a plurality of equally spaced cones on the bottom outer wall of the honeycomb core layer, the absorption layer filling the gaps between the cones, and gradient-distributed carbon nanotubes within the absorption layer. The lightweight, high-strength multilayer composite absorbing honeycomb panel provided by this invention has the technical effect of improving mechanical strength and broadband wave absorption performance. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the lightweight, high-strength, multi-layer composite absorbing honeycomb panel proposed in this utility model.

[0013] Figure 2 This is a cross-sectional structural diagram of the lightweight, high-strength, multi-layer composite absorbing honeycomb panel proposed in this utility model.

[0014] Figure 3 This is a schematic diagram of the unfolded structure of the lightweight, high-strength multilayer composite absorbing honeycomb panel proposed in this utility model.

[0015] Figure 4 This is a partial structural schematic diagram of the lightweight, high-strength, multi-layer composite absorbing honeycomb panel proposed in this utility model.

[0016] In the attached diagram: 1. Wave-transmitting protective layer; 2. Mesh layer; 3. Honeycomb core layer; 4. Absorbing layer; 5. Supporting layer; 6. Cone; 7. Auxiliary groove; 8. Main groove. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and marked in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0018] The lightweight, high-strength, multi-layer composite absorbing honeycomb panel disclosed in this utility model is mainly used to address the problems of poor mechanical properties and narrow absorption frequency bands in absorbing honeycomb panels, which make it difficult to balance structural strength and electromagnetic wave absorption performance. In addition, its insufficient lightweight design limits its application in fields such as stealth equipment.

[0019] Reference Figure 1 , Figure 2 and Figure 3 The lightweight, high-strength multilayer composite absorbing honeycomb panel includes a wave-transmitting protective layer 1, a honeycomb core layer 3, an absorption layer 4, and a support layer 5. A mesh layer 2 is provided between the wave-transmitting protective layer 1 and the honeycomb core layer 3. Several cones 6 are arranged at equal intervals on the bottom outer wall of the honeycomb core layer 3. The absorption layer 4 fills the gaps between the cones 6, and carbon nanotubes are arranged in a gradient distribution inside the absorption layer 4.

[0020] The absorbent layer 4 is disposed between the honeycomb core layer 3 and the support layer 5, and the thickness of the absorbent layer 4 is 0.2 mm.

[0021] The absorbing layer 4 is made of glass fiber or quartz fiber and contains a gradient-distributed carbon nanotube mixture. It is impregnated with modified epoxy resin (containing 1-5 wt% carbon nanotubes). After curing, the resin content is about 50%, which can prevent the deformation of the honeycomb structure and increase the strength of the material. Utilizing the principle of Jaumann absorbers, the impedance gradient principle is adopted, that is, from top to bottom, the impedance of each layer of material gradually decreases. By changing the impedance of the absorbing layer 4, the thickness can be adjusted, which is applicable to the absorption design of almost all frequency bands.

[0022] In the specific implementation process, the composite absorbing honeycomb panel adopts a multi-layer structure. By setting a grid layer 2, a cone structure 6, and a gradient carbon nanotube absorption layer 4, the mechanical and absorption performance are synergistically optimized. The grid layer 2 improves the bonding strength between the wave-transmitting protective layer 1 and the honeycomb core. The cone structure 6 increases the contact area of ​​the absorption layer 4, effectively improving the interface stress transmission efficiency. The gradient distribution of carbon nanotubes (1-5wt%) inside the absorption layer 4 forms an optimized impedance gradient structure, realizing the layer-by-layer attenuation of electromagnetic waves.

[0023] Reference Figure 2 and Figure 3 In a preferred embodiment, the wave-transparent protective layer 1 is a composite material of quartz fiber and epoxy resin, the thickness of the wave-transparent protective layer 1 is 0.2 mm, and the mesh layer 2 is made of carbon fiber.

[0024] Specifically, the wave-transparent protective layer 1 is made of quartz fiber and resin composite material and contains 5 wt% silicon carbide particles, which can enhance wear resistance, disperse stress, and prevent deformation of the honeycomb structure. This high wave-transparent material can also reduce high-frequency reflection. The carbon fiber mesh layer 2 between the wave-transparent protective layer 1 and the honeycomb core layer 3 can enhance the bonding force.

[0025] Reference Figure 3 In a preferred embodiment, the honeycomb core layer 3 is made of aramid paper honeycomb material.

[0026] It should be noted that the thickness of the honeycomb core layer 3 is adjustable. It adopts a hexagonal lattice structure with a lattice side length of 4.8 mm and a density of 0.048 kg / cm3. It is impregnated with modified epoxy resin (containing 2-8 wt% conductive carbon black) through vacuum assistance. After curing, the resin content is about 30%, which provides a lightweight support framework. The porous structure enhances the diffuse reflection of electromagnetic waves.

[0027] Reference Figure 3 and Figure 4 In a preferred embodiment, the top outer wall of the support layer 5 has eight radially and evenly distributed main grooves 8, and several auxiliary grooves 7 are provided between two adjacent main grooves 8. The interior of the main grooves 8 and the auxiliary grooves 7 are filled with conductive adhesive.

[0028] Specifically, by using eight main grooves 8 arranged radially at 45° equiangular angles, along with several auxiliary grooves 7 to form a complete conductive network, the electromagnetic loss efficiency of the support layer 5 in the 8GHz band is improved by 40%, and the reflection loss is reduced to -12.4dB. The conductive adhesive (not shown in the figure) filling the grooves is an epoxy resin system containing 2wt% carbon nanotubes (viscosity 50mPa·s), which forms a stable three-dimensional conductive path after curing at 60℃, with the volume resistivity controlled at 10. 2 The Ω·cm ensures good bonding between the conductive adhesive (not shown in the figure) and the carbon fiber matrix, guaranteeing good conductivity.

[0029] Reference Figure 4 In a preferred embodiment, the main groove 8 and the auxiliary groove 7 are interconnected to form a biomimetic spider web structure, and the support layer 5 is a carbon fiber and epoxy resin composite material with a thickness of 1 mm.

[0030] Specifically, the support layer 5, made of carbon fiber and epoxy resin, provides core mechanical support (compressive strength ≥15MPa). Boron nitride doping (3wt%) reduces thermal conductivity to ≤0.03W / (m·K), adapting to high-temperature environments. The biomimetic spider web structure optimizes stress transmission, resulting in a flexural modulus of support layer 5 ≥800MPa (ASTM D790) and reduced interfacial contact resistance (≤10Ω·cm). Adhesive is applied at the intersection of the main and auxiliary grooves 7, and the surface is plasma-treated for node reinforcement.

[0031] Working principle: During use, electromagnetic waves penetrate each functional layer sequentially from top to bottom. When passing through the wave-transparent protective layer 1, the quartz fiber composite material containing 5wt% silicon carbide disperses the incident stress while ensuring a wave transmittance of over 92%. Subsequently, the electromagnetic waves enter the honeycomb core layer 3, where its hexagonal lattice structure induces multi-level scattering. The conductive carbon black modified resin generates dielectric loss. The gradient carbon nanotubes in the absorption layer 4 achieve impedance gradient according to the Jaumann principle, converting electromagnetic wave energy into heat energy. The biomimetic spider web grooves in the support layer 5 contain 2wt% carbon nanotube conductive adhesive, which further dissipates energy through eddy current loss.

[0032] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. The substitutions may be replacements of some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made based on the technical solution and inventive concept of this utility model should all be covered within the protection scope of this utility model.

Claims

1. A lightweight, high-strength, multi-layer composite absorbing honeycomb panel, comprising a wave-transmitting protective layer (1), a honeycomb core layer (3), an absorbing layer (4), and a supporting layer (5), characterized in that, A mesh layer (2) is provided between the wave-transparent protective layer (1) and the honeycomb core layer (3). Several cones (6) are arranged at equal intervals on the bottom outer wall of the honeycomb core layer (3). The absorption layer (4) fills the gaps between the cones (6) and carbon nanotubes are arranged in a gradient distribution inside the absorption layer (4).

2. The lightweight, high-strength multilayer composite absorbing honeycomb panel according to claim 1, characterized in that, The wave-transparent protective layer (1) is a composite material of quartz fiber and epoxy resin, the thickness of the wave-transparent protective layer (1) is 0.2 mm, and the mesh layer (2) is made of carbon fiber.

3. The lightweight, high-strength multilayer composite absorbing honeycomb panel according to claim 2, characterized in that, The honeycomb core layer (3) is made of aramid paper honeycomb material.

4. The lightweight, high-strength multilayer composite absorbing honeycomb panel according to claim 1, characterized in that, The top outer wall of the support layer (5) has eight radially distributed main grooves (8), and several auxiliary grooves (7) are provided between two adjacent main grooves (8). The interior of the main grooves (8) and the auxiliary grooves (7) are filled with conductive adhesive.

5. The lightweight, high-strength multilayer composite absorbing honeycomb panel according to claim 4, characterized in that, The main groove (8) and the auxiliary groove (7) are interconnected to form a biomimetic spider web structure.

6. The lightweight, high-strength multilayer composite absorbing honeycomb panel according to claim 5, characterized in that, The support layer (5) is a composite material of carbon fiber and epoxy resin with a thickness of 1 mm.

7. The lightweight, high-strength multilayer composite absorbing honeycomb panel according to claim 1, characterized in that, The absorbent layer (4) is disposed between the honeycomb core layer (3) and the support layer (5), and the absorbent layer (4) has a thickness of 0.2 mm.

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