Resin-based composite metamaterial based on chopped carbon fiber felt and integrating double functions of impact resistance and wave absorption and simplified preparation process of resin-based composite metamaterial

Abstract

The invention relates to the technical field of functional resin-based composite materials, in particular to a chopped carbon fiber felt-based impact-resistant and wave-absorbing dual-function-integrated resin-based composite metamaterial and a simplified preparation process thereof.The chopped carbon fiber felt-based impact-resistant and wave-absorbing dual-function-integrated resin-based composite metamaterial comprises an upper dielectric layer, an array structure layer, a lower dielectric layer and a bottom reflecting layer which are sequentially stacked from top to bottom; the array structure layer is of a central symmetry structure and is formed by periodically arranging m * n carbon fiber felt structure units; the carbon fiber felt structural unit is a square annular patch, the outer ring width L1 of the square annular patch is 23-26 mm, the inner ring width L2 of the square annular patch is 10-15 mm, and the periodic side length P of the carbon fiber felt structural unit is 30 mm. Due to the miniaturization design of the structural units, the oblique incidence responses of the metamaterial in a transverse electric polarization mode and a transverse magnetic polarization mode can reach 45 degrees and 60 degrees respectively; and when the incident angle of the transverse magnetic wave is up to 60 degrees, 80% of electromagnetic wave absorptivity can still be maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of functional resin-based composite materials, and in particular to a resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt and a simplified preparation process thereof. Background Art

[0002] In today's world of rapid development of informatization and intelligence, the intensive use of electromagnetic waves has led to a series of severe challenges such as electromagnetic interference, electromagnetic radiation and information security. Traditional electromagnetic wave absorbing materials mainly convert the incident electromagnetic wave energy into heat energy through a loss mechanism to achieve the purpose of electromagnetic shielding or electromagnetic wave absorption. Common absorbing materials include ferrite, carbon black, conductive polymers, etc. They have good absorbing properties, but they cannot meet the current complex environment's demand for electromagnetic wave absorption performance in terms of thickness, weight and absorbing bandwidth.

[0003] In order to further improve the electromagnetic wave absorption performance, metamaterial technology has been introduced into the field of wave absorption. Metamaterials are a type of artificial structural materials whose physical properties (such as dielectric constant and magnetic permeability) can be customized through precise design of structural units. In addition, wave-absorbing metamaterials can produce extraordinary electromagnetic responses within a specific frequency band, and have a wider absorption band, thinner thickness and higher absorption efficiency than traditional wave-absorbing materials. These characteristics make it have broad application prospects in the fields of radar stealth, radio interference suppression, wireless communications, etc.

[0004] Frequency Selective Surface (FSS) is an electromagnetic metamaterial with a periodic structure, generally composed of a patterned structure of metal or highly conductive materials, which can regulate the reflection, transmission and absorption characteristics of electromagnetic waves by changing the shape of the pattern and the arrangement of the periodic structure. At present, conventional FSS is generally designed and prepared based on patterned metal materials. Although the resonant frequency can be accurately adjusted by designing the pattern to control the characteristics of electromagnetic waves, there are problems of complex structure and high preparation cost. In particular, weak interfaces will be generated when embedded in composite materials, which will lead to delamination of the composite material at this interface or even overall failure. Summary of the invention

[0005] In order to obtain a metamaterial with a wider absorbing band, thinner thickness and higher absorbing efficiency and to solve the problem that the combination of the current materials used as superstructures with resin-based composite materials easily leads to delamination and failure of the entire system, the present invention provides a resin-based composite metamaterial with integrated impact resistance and absorbing dual functions based on chopped carbon fiber felt and a simplified preparation process thereof.

[0006] The present invention is realized by the following technical scheme: a resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt, comprising an upper dielectric layer, an array structure layer, a lower dielectric layer and a bottom reflection layer stacked in sequence from top to bottom; The array structure layer is a centrosymmetric structure, which is composed of m×n carbon fiber felt structural units arranged periodically, wherein m≥4 and is an integer, and n≥4 and is an integer; the resistivity of the carbon fiber felt is 0.1-0.2 Ω·cm, the conductivity is 5-10 S / cm, and the square resistance is 3-35 Ω / sq; the carbon fiber felt structural unit is a square ring patch, and the outer ring width L of the square ring patch is 1 23~26 mm, inner ring width L 2 is 10-15 mm, and the periodic side length P of the carbon fiber felt structural unit is 30 mm; The upper dielectric layer, the lower dielectric layer and the bottom reflective layer are all made of a fiber cloth / resin-based composite material.

[0007] As a further improvement of the technical solution of the present invention, the fiber cloth in the fiber cloth / resin-based composite material of the upper dielectric layer and the lower dielectric layer is selected from any one or two or more of aramid fiber cloth, glass fiber cloth, ultra-high molecular weight polyethylene fiber cloth and quartz fiber cloth.

[0008] As a further improvement of the technical solution of the present invention, the thickness H of the upper dielectric layer is 1 and the thickness of the lower dielectric layer H 2 The length and width are 2.5 to 5 mm, and the length and width are consistent with the length and width of the array structure layer respectively.

[0009] As a further improvement of the technical solution of the present invention, the dielectric constant of the fiber cloth / resin-based composite material of the upper dielectric layer and the lower dielectric layer is 2.9-3.1, and the density is 0.6-1.25 g / cm 3 .

[0010] As a further improvement of the technical solution of the present invention, the fiber cloth in the fiber cloth / resin-based composite material of the bottom reflective layer is carbon fiber cloth, and the conductivity ζ of the bottom reflective layer is 1 For 10 4 ~10 5 S / m.

[0011] As a further improvement of the technical solution of the present invention, the thickness of the bottom reflection layer is 2-3 mm, and the length and width are respectively consistent with the length and width of the array structure layer.

[0012] As a further improvement of the technical solution of the present invention, the resin matrix of the fiber cloth / resin-based composite material is epoxy resin, and the curing agent is an acid anhydride curing agent.

[0013] The present invention also provides a simplified preparation process of a resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt, comprising the following steps: (S1) Design the structure of resin-based composite metamaterials with integrated dual functions of impact resistance and wave absorption; (S2) cutting the carbon fiber felt into square ring patches with the designed structural unit size according to the structure of the designed array structure layer, cutting a total of m×n square ring patches; (S3) cutting the fiber cloth of the upper dielectric layer and the lower dielectric layer respectively according to the length and width of the designed array structure layer; (S4) cutting the carbon fiber cloth of the bottom reflective layer according to the length and width of the designed array structure layer; (S5) Mix the epoxy resin and the curing agent evenly to obtain a resin glue liquid; after cleaning the mold and brushing the release agent, lay the cut carbon fiber cloth on the surface of the lower template of the mold, brushing a layer of resin glue liquid on each layer to the designed bottom reflection layer thickness; then lay the cut lower dielectric layer fiber cloth on it, brushing a layer of resin glue liquid on each layer to the designed lower dielectric layer thickness; then place the cut carbon fiber felt square ring patch on it according to the structure of the designed array structure layer; then lay the cut upper dielectric layer fiber cloth on it, brushing a layer of resin glue liquid on each layer to the designed upper dielectric layer thickness; after closing the mold, put the mold into a press for hot pressing to obtain a resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt.

[0014] As a further improvement of the simplified preparation process technical solution of the present invention, the process parameters of the hot pressing molding are: gel at 100°C for 50 minutes, then heat to 140°C and cure at 15MPa for two hours.

[0015] The resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt provided by the present invention and its simplified preparation process have the following advantages compared with the prior art: (1) The resin-based composite metamaterial with integrated impact resistance and wave absorption functions based on chopped carbon fiber felt of the present invention has excellent incident wave polarization and large incident angle stability. The miniaturized design of the structural unit enables the metamaterial of the present invention to respond to oblique incident waves of 45° and 60° in transverse electric (TE) polarization and transverse magnetic (TM) polarization modes, respectively; when the TM wave incident angle is as high as 60°, it can still maintain an electromagnetic wave absorption rate of 80%.

[0016] (2) The resin-based composite metamaterial with integrated impact resistance and wave absorption functions based on chopped carbon fiber felt of the present invention can obtain excellent electromagnetic wave absorption performance through the loss of carbon fiber felt without using any wave absorption functional particles, and effectively solves the problems existing in the structural wave absorption composite materials prepared by the current conventional processes and methods, such as the easy agglomeration of wave absorption functional particles and the difficulty in preparation caused by the increase of the viscosity of the matrix resin due to the addition of wave absorption functional particles.

[0017] (3) The FSS resistor film patch of the present invention provides the metamaterial with excellent electromagnetic wave absorption performance through the ohmic loss generated by the induced current on the surface and the 1 / 4 wavelength resonance formed between the FSS resistor film patch and the dielectric layer. The metamaterial is constructed based on carbon fiber felt, which effectively solves the problems of the currently commonly used metal FSS, such as complex structure, high manufacturing cost, weak interface, and easy delamination of the composite material at this interface, which leads to overall failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a schematic structural diagram of the resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt of the present invention.

[0021] Figure 2 The schematic diagram of the structure unit (square ring patch) of the resin-based composite metamaterial array structure layer with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt of the present invention. Where: P is the periodic side length of the carbon fiber felt structure unit, L 1 is the outer ring width of the carbon fiber felt structural unit (square ring patch), L 2 is the inner ring width of the carbon fiber felt structural unit.

[0022] Figure 3 The present invention is a schematic structural diagram of an array structure layer having 6×6 structural units of a resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt.

[0023] Figure 4(a~g) are the simulation results of electromagnetic wave reflection loss (RL) of resin-based composite metamaterials based on chopped carbon fiber felt prepared in Example 1, Example 2, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4 and Comparative Example 5, respectively.

[0024] Figure 5 RL test results of the resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt prepared in Example 1.

[0025] Figure 6 (a~e) are the RL simulation results of the TE wave of the resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt prepared in Example 1 at incident angles of 0°, 15°, 30°, 45° and 60° respectively.

[0026] Figure 7 (a~e) are the RL simulation results of the TM wave of the resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt prepared in Example 1 at incident angles of 0°, 15°, 30°, 45° and 60° respectively.

[0027] Figure 8 (a~e) are the RL simulation results of the TE wave of the resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt prepared in Comparative Example 3 at incident angles of 0°, 15°, 30°, 45° and 60° respectively.

[0028] Fig. 9 (a~e) are the RL simulation results of the TE wave of the resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt prepared in Comparative Example 4 at incident angles of 0°, 15°, 30°, 45° and 60° respectively.

[0029] Fig.10 (a~e) are the RL simulation results of the TE wave of the resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt prepared in Comparative Example 5 at incident angles of 0°, 15°, 30°, 45° and 60° respectively.

[0030] Fig.11 (a and b) are the load-displacement curves of the resin-based composite materials prepared in Example 1 and Comparative Example 6 under the same impact energy, respectively. DETAILED DESCRIPTION

[0031] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0033] A resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt, comprising an upper dielectric layer, an array structure layer, a lower dielectric layer and a bottom reflection layer stacked in sequence from top to bottom; The array structure layer is a centrosymmetric structure, which is composed of m×n carbon fiber felt structural units arranged periodically, wherein m≥4 and is an integer, and n≥4 and is an integer; the resistivity of the carbon fiber felt is 0.1-0.2 Ω·cm, the conductivity is 5-10 S / cm, and the square resistance is 3-35 Ω / sq; the carbon fiber felt structural unit is a square ring patch, and the outer ring width L of the square ring patch is 1 23~26 mm, inner ring width L 2 is 10-15 mm, and the periodic side length P of the carbon fiber felt structural unit is 30 mm; The upper dielectric layer, the lower dielectric layer and the bottom reflective layer are all made of a fiber cloth / resin-based composite material.

[0034] As a further improvement of the technical solution of the present invention, the fiber cloth in the fiber cloth / resin-based composite material of the upper dielectric layer and the lower dielectric layer is selected from any one or two or more of aramid fiber cloth, glass fiber cloth, ultra-high molecular weight polyethylene fiber cloth and quartz fiber cloth.

[0035] As a further improvement of the technical solution of the present invention, the thickness H of the upper dielectric layer is 1 and the thickness of the lower dielectric layer H 2 The length and width are 2.5 to 5 mm, and the length and width are consistent with the length and width of the array structure layer respectively.

[0036] As a further improvement of the technical solution of the present invention, the dielectric constant of the fiber cloth / resin-based composite material of the upper dielectric layer and the lower dielectric layer is 2.9-3.1, and the density is 0.6-1.25 g / cm 3 .

[0037] As a further improvement of the technical solution of the present invention, the fiber cloth in the fiber cloth / resin-based composite material of the bottom reflective layer is carbon fiber cloth, and the conductivity ζ of the bottom reflective layer is 1 For 10 4 ~10 5 S / m.

[0038] As a further improvement of the technical solution of the present invention, the thickness of the bottom reflection layer is 2-3 mm, and the length and width are respectively consistent with the length and width of the array structure layer.

[0039] As a further improvement of the technical solution of the present invention, the resin matrix of the fiber cloth / resin-based composite material is epoxy resin, and the curing agent is an acid anhydride curing agent.

[0040] The present invention also provides a simplified preparation process of a resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt, comprising the following steps: (S1) Design the structure of resin-based composite metamaterials with integrated dual functions of impact resistance and wave absorption; (S2) cutting the carbon fiber felt into square ring patches with the designed unit size according to the structure of the designed array structure layer, cutting a total of m×n square ring patches; (S3) cutting the fiber cloth of the upper dielectric layer and the lower dielectric layer respectively according to the length and width of the designed array structure layer; (S4) cutting the carbon fiber cloth of the bottom reflective layer according to the length and width of the designed array structure layer; (S5) Mix the epoxy resin and the curing agent evenly to obtain a resin glue liquid; after cleaning the mold and brushing the release agent, lay the cut carbon fiber cloth on the surface of the lower template of the mold, brushing a layer of resin glue liquid on each layer to the designed bottom reflection layer thickness; then lay the cut lower dielectric layer fiber cloth on it, brushing a layer of resin glue liquid on each layer to the designed lower dielectric layer thickness; then place the cut carbon fiber felt square ring patch on it according to the structure of the designed array structure layer; then lay the cut upper dielectric layer fiber cloth on it, brushing a layer of resin glue liquid on each layer to the designed upper dielectric layer thickness; after closing the mold, put the mold into a press for hot pressing to obtain a resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt.

[0041] As a further improvement of the simplified preparation process technical solution of the present invention, the process parameters of the hot pressing molding are: gel at 100°C for 50 minutes, then heat to 140°C and cure at 15MPa for two hours.

[0042] The technical solution of the present invention is described in detail below through specific embodiments.

[0043] The software used for electromagnetic simulation in the present invention is microwave radio frequency simulation software CST microwave studio2021.

[0044] According to GJB 2038A-2011 "Test Method for Reflectivity of Radar Absorbing Materials", RL is tested by the bow method. Impact performance test is carried out according to ASTM D 7136 "Standard Test Method for Measuring the Damage Resistance of a Fiber-Reinforced Polymer Matrix Composite to a Drop-Weight Impact Event". Example 1

[0045] A resin-based composite metamaterial with integrated impact resistance and wave absorption functions based on chopped carbon fiber felt, the specific structure is as follows Figure 1 As shown, it includes an upper dielectric layer, an array structure layer, a lower dielectric layer and a bottom reflection layer which are stacked in sequence from top (incident direction of electromagnetic waves) to bottom.

[0046] The upper dielectric layer is made of aramid fiber cloth / resin-based composite material with a dielectric constant of 3 and a density of 1.25g / cm 3 , thickness H 1 =3mm, length is 180mm, width is 180mm.

[0047] The lower dielectric layer is made of aramid fiber cloth / resin-based composite material with a dielectric constant of 3 and a density of 1.25g / cm 3 , thickness H 2 =3mm, length is 180mm, width is 180mm.

[0048] The array structure layer consists of 6×6 carbon fiber felt structural units (such as Figure 2 As shown) periodic arrangement composition (such as Figure 3 As shown); the resistivity of the carbon fiber felt is 0.18Ω·cm, the conductivity is 5.55S / cm, and the square resistance is 35 Ω / sq; the P of the carbon fiber felt structural unit is 30 mm, L 1 = 25 mm, L 2 =12.5 mm.

[0049] The bottom reflective layer is made of carbon fiber cloth / resin matrix composite material with conductivity ζ 1 5.9×10 4 S / m; thickness is 2mm, length is 180mm, width is 180mm.

[0050] The simplified preparation process includes the following steps: (S1) cutting the upper dielectric layer aramid fiber cloth and the lower dielectric layer aramid fiber cloth into respective lengths and widths of 180 mm; (S2) cutting the carbon fiber cloth into a length and a width of 180 mm; (S3) cutting the carbon fiber felt into square ring patches with designed dimensions according to the structure of the designed array structure layer, with a total of 6×6 patches cut; (S4) Epoxy resin E51 and curing agent cis-hexahydrophthalic anhydride HHPA are weighed in a mass ratio of 1:0.8, mixed evenly, and vacuum-defoamed at 80°C for 30 minutes to obtain resin glue; after cleaning the mold and brushing the release agent, the cut carbon fiber cloth is laid on the surface of the lower template, and a layer of resin glue is brushed on each layer, and a total of 4 layers of carbon fiber cloth are laid; then the cut lower dielectric layer aramid fiber cloth is laid thereon, and a layer of resin glue is brushed on each layer, and a total of 15 layers of lower dielectric layer aramid fiber cloth are laid; then the cut carbon fiber felt square ring patches are placed according to the structure of the designed array structure layer; then the cut upper dielectric layer aramid fiber cloth is laid, and a layer of resin glue is brushed on each layer, and a total of 15 layers of upper dielectric layer aramid fiber cloth are laid; after closing the mold, the mold is placed in a press for hot pressing, and then cooled and demolded to obtain an 8mm thick resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt. The hot pressing process parameters were as follows: gelation at 100°C for 50 min, then heating to 140°C and curing at 15 MPa for two hours.

[0051] like Figure 5 As shown in the figure, the effective absorption bandwidth of RL≤-10dB of the resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt prepared in this embodiment reaches 10.6GHz (5.5-8.3GHz, 9.8-17.6GHz), and the minimum reflection loss RL min It is -45dB. Example 2

[0052] Except for the following parameters, the rest are exactly the same as in Example 1.

[0053] The square resistance of carbon fiber felt is 20 Ω / sq.

[0054] Depend on Figure 4 (b) It can be seen that the RL of the resin-based composite metamaterial obtained in this embodiment min It appears at 7.28 GHz, producing an absorption of -38.90 dB; the effective absorption bandwidth (RL≤-10 dB) in the range of 2-18 GHz is 9.76 GHz. Comparative Example 1

[0055] Except for the following parameters, the rest are exactly the same as in Example 1.

[0056] Thickness H 1 =2.5 mm; thickness H 2 =2.5 mm; the square resistance of carbon fiber felt is 15 Ω / sq, L1 = 20 mm, L 2 =10mm.

[0057] Depend on Figure 4 (c) It can be seen that the RL of the resin-based composite metamaterial obtained in this comparative example min It appears at 8.78 GHz, producing an absorption of -16.70 dB; the effective absorption bandwidth (RL≤-10 dB) in the range of 2-18 GHz is 3.39 GHz. Comparative Example 2

[0058] Except for the following parameters, the rest are exactly the same as in Example 1.

[0059] Thickness H 1 =3.5 mm; thickness H 2 =3.5 mm; the square resistance of carbon fiber felt is 25 Ω / sq, L 1 = 20 mm, L 2 =10mm.

[0060] Depend on Figure 4 (d) It can be seen that the RL of the resin-based composite metamaterial obtained in this comparative example min It appears at 8.22 GHz, producing an absorption of -47.66 dB; the effective absorption bandwidth (RL ≤ -10 dB) in the range of 2-18 GHz is 4.18 GHz. Comparative Example 3

[0061] Except for the following parameters, the rest are exactly the same as in Example 1.

[0062] Thickness H 1 =2 mm; thickness H 2 =2 mm. Figure 4 (e) It can be seen that the RL of the resin-based composite metamaterial obtained in this comparative example min It appears at 14.42 GHz, producing -26.84 dB absorption; the effective absorption bandwidth (RL ≤ -10 dB) in the range of 2-18 GHz is 5.8 GHz. Comparative Example 4

[0063] Except for the following parameters, the rest are exactly the same as in Example 1.

[0064] Carbon fiber felt structural unit L 1 =21mm, L 2 =8mm.

[0065] Depend on Figure 4 (f) It can be seen that the RL of the resin-based composite metamaterial obtained in this comparative example minIt appears at 18 GHz, producing an absorption of -22.83 dB; the effective absorption bandwidth (RL≤-10 dB) in the range of 2-18 GHz is 6.84 GHz. Comparative Example 5

[0066] Except for the following parameters, the rest are exactly the same as in Example 1.

[0067] Carbon fiber felt structural unit L 1 =28mm, L 2 =20mm.

[0068] Depend on Figure 4 (g) It can be seen that the RLmin of the resin-based composite metamaterial obtained in this comparative example appears at 18 GHz, resulting in an absorption of -16.12 dB; the effective absorption bandwidth (RL≤-10 dB) in the range of 2-18 GHz is 5.94 GHz.

[0069] contrast Figure 4 (a)~ Figure 4 (g) It can be seen that the absorption bandwidth of the metamaterials prepared in Examples 1 and 2 of the present invention is significantly improved by 42.7% to 212.7% compared with the metamaterials prepared in Comparative Examples 1 to 5.

[0070] Depend on Figure 6 (a~e), Figure 8 (a~e), Fig. 9 (a~e) and Fig.10 (a-e) It can be seen that compared with the metamaterials prepared in Comparative Examples 3, 4 and 5, the metamaterial prepared in Example 1 of the present invention has a stable wave absorption performance when the incident angle increases from 0° to 45° in the TE polarization mode. Figure 7 As shown in (a-e), in the TM polarization mode, when the incident angle increases from 0° to 60°, the wave absorption performance of the metamaterial obtained in Example 1 remains stable, and the angle stability is good. This shows that the metamaterial of the present invention has excellent polarization stability and angle insensitivity. Because the designed structural unit has symmetry and miniaturization characteristics, the oblique incidence response of the metamaterial of the present invention in the TE mode and TM mode can reach 45° and 60° respectively. Comparative Example 6

[0071] Completely the same as Example 1, except that there is no array structure layer.

[0072] from Fig.11It can be seen from the load-displacement curves of (a) and 10 (b) that when the impact energy is 20J, the ability of the resin-based composite metamaterial with integrated impact resistance and wave absorption functions based on chopped carbon fiber felt of the present invention to resist the maximum impact load during the impact process is higher than that of the composite material of comparative example 6, indicating that the introduction of the array structural layer based on carbon fiber felt will not affect the impact resistance of the composite material.

[0073] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. A resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt, characterized in that: It includes an upper dielectric layer, an array structure layer, a lower dielectric layer and a bottom reflective layer stacked in sequence from top to bottom; The array structure layer is a centrosymmetric structure, which is composed of m×n carbon fiber felt structural units arranged periodically, wherein m≥4 and is an integer, and n≥4 and is an integer; the resistivity of the carbon fiber felt is 0.1-0.2 Ω·cm, the conductivity is 5-10 S / cm, and the square resistance is 3-35 Ω / sq; the carbon fiber felt structural unit is a square ring patch, the outer ring width L1 of the square ring patch is 23-26 mm, the inner ring width L2 is 10-15 mm, and the periodic side length P of the carbon fiber felt structural unit is 30 mm; The upper dielectric layer, the lower dielectric layer and the bottom reflective layer are all made of a fiber cloth / resin-based composite material.

2. The resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt according to claim 1, characterized in that: The fiber cloth in the fiber cloth / resin-based composite material of the upper dielectric layer and the lower dielectric layer is selected from any one or two or more of aramid fiber cloth, glass fiber cloth, ultra-high molecular weight polyethylene fiber cloth and quartz fiber cloth.

3. The resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt according to claim 1, characterized in that: The thickness H1 of the upper dielectric layer and the thickness H2 of the lower dielectric layer are 2.5-5 mm, and the length and width are respectively consistent with the length and width of the array structure layer.

4. The resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt according to claim 1, characterized in that: The dielectric constant of the fiber cloth / resin-based composite material of the upper dielectric layer and the lower dielectric layer is 2.9-3.1, and the density is 0.6-1.25 g / cm 3 .

5. The resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber mat according to claim 1, characterized in that: The fiber cloth in the fiber cloth / resin-based composite material of the bottom reflective layer is carbon fiber cloth, and the conductivity ζ1 of the bottom reflective layer is 10 4 ~10 5 S / m.

6. The resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt according to claim 1, characterized in that: The thickness of the bottom reflection layer is 2-3 mm, and the length and width are respectively consistent with the length and width of the array structure layer.

7. The resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt according to claim 1, characterized in that: The resin matrix of the fiber cloth / resin-based composite material is epoxy resin, and the curing agent is an acid anhydride curing agent.

8. A streamlined preparation process for a resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt, characterized in that: The steps include: (S1) Design the structure of resin-based composite metamaterials with integrated dual functions of impact resistance and wave absorption; (S2) cutting the carbon fiber felt into square ring patches with the designed structural unit size according to the structure of the designed array structure layer, cutting a total of m×n square ring patches; (S3) cutting the fiber cloth of the upper dielectric layer and the lower dielectric layer respectively according to the length and width of the designed array structure layer; (S4) cutting the carbon fiber cloth of the bottom reflective layer according to the length and width of the designed array structure layer; (S5) Mix the epoxy resin and the curing agent evenly to obtain a resin glue liquid; after cleaning the mold and brushing the release agent, lay the cut carbon fiber cloth on the surface of the lower template of the mold, brushing a layer of resin glue liquid on each layer to the designed bottom reflection layer thickness; then lay the cut lower dielectric layer fiber cloth on it, brushing a layer of resin glue liquid on each layer to the designed lower dielectric layer thickness; then place the cut carbon fiber felt square ring patch on it according to the structure of the designed array structure layer; then lay the cut upper dielectric layer fiber cloth on it, brushing a layer of resin glue liquid on each layer to the designed upper dielectric layer thickness; after closing the mold, put the mold into a press for hot pressing to obtain a resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt.

9. The simplified preparation process of a resin-based composite metamaterial with integrated impact resistance and wave absorption dual functions based on chopped carbon fiber felt according to claim 8, characterized in that: The process parameters of the hot pressing molding are as follows: gel at 100°C for 50 minutes, then heat to 140°C and cure at 15MPa for two hours.

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