Grid wave absorber and preparation method thereof

Abstract

The invention discloses a grating wave absorber, and relates to the technical field of wave absorbing equipment, the grating wave absorber comprises a bottom plate layer, a core body layer and a panel layer which are connected in sequence, the core body layer comprises a first core body group and a second core body group, and the first core body group and the second core body group each comprise at least two core body bodies; each core body of the first core body group and all core bodies of the second core body group are arranged in a staggered manner, so that the core body layer is in a grid shape, and each core body comprises an electromagnetic loss wave-absorbing part and two metamaterial wave-absorbing layers arranged on the two sides of the first direction of the electromagnetic loss wave-absorbing part; the two sides, in the second direction, of each electromagnetic loss wave-absorbing part are connected with the bottom plate layer and the panel layer respectively, and the two sides of each metamaterial wave-absorbing layer are connected with the bottom plate layer and the panel layer respectively. The invention further provides a preparation method of the corresponding grating wave absorber. According to the grating wave absorber and the preparation method thereof, the wave absorbing performance and the bearing performance can be synergistically enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of wave absorbing equipment, and in particular to a grid wave absorber and a preparation method thereof. Background Art

[0002] The absorber is an important component of stealth technology. Traditional absorbers generally include a panel, a base plate and a composite material core structure. The composite material core structure is arranged between the panel and the base plate. The composite material core structure is mostly a simple electromagnetic loss absorbing structure or a simple metamaterial absorbing grid. Among them, the electromagnetic loss absorbing structure generally includes a honeycomb structure and an electromagnetic loss material added to the honeycomb structure to give it electromagnetic wave absorption ability, but the bearing capacity of the honeycomb structure needs to be improved, and the electromagnetic loss material often does not have bearing performance; the metamaterial absorbing grid includes a plurality of metamaterial absorbing plates arranged horizontally and vertically, and the single grid unit surrounded by the metamaterial absorbing plates is a hollow structure, and the bearing performance also needs to be improved. Therefore, the bearing efficiency of the composite material core of the current absorber is low, especially when the relative density of the composite material core structure of the absorber is less than 5%, the composite material core structure is very easy to buckle, which seriously reduces the bearing efficiency of the absorber. At the same time, a single-component absorbing structure is often difficult to achieve broadband and high-intensity absorption. Therefore, how to improve the absorbing capacity of the absorber and enhance its lightweight load-bearing efficiency has become a key issue that must be solved in the future integrated design of lightweight absorbers and load-bearing devices. Summary of the invention

[0003] The object of the present invention is to provide a grid absorber and a method for preparing the same, so as to solve the problems existing in the above-mentioned prior art and achieve the synergistic enhancement of the absorbing performance and the load-bearing performance.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a grid absorber, comprising a bottom plate layer, a core layer and a panel layer connected in sequence, the core layer comprising a first core group and a second core group, the first core group and the second core group each comprising at least two core bodies, each core body of the first core group and all the core bodies of the second core group are staggered so that the core layer is in a grid shape, the core body comprises an electromagnetic loss absorbing component and two metamaterial absorbing layers arranged on both sides of the electromagnetic loss absorbing component in a first direction, both sides of each electromagnetic loss absorbing component in a second direction are respectively connected to the bottom plate layer and the panel layer, and both sides of each metamaterial absorbing layer are respectively connected to the bottom plate layer and the panel layer.

[0006] Preferably, each of the electromagnetic loss absorbing components comprises a wave-transmitting honeycomb frame and an electromagnetic loss layer coated on the surface of the wave-transmitting honeycomb frame.

[0007] Preferably, each of the electromagnetic loss absorbing components is an absorbing foam core containing electromagnetic loss material.

[0008] Preferably, each core body of the first core body group is plugged into all the core bodies of the second core body group.

[0009] Preferably, the two sides of the second direction of each core body are respectively a first side and a second side, the electromagnetic loss absorbing component of the first core group is a first electromagnetic loss absorbing component, the electromagnetic loss absorbing component of the second core group is a second electromagnetic loss absorbing component, the first side of the first electromagnetic loss absorbing component is provided with at least two first grooves, the second side of the second electromagnetic loss absorbing component is provided with at least two second grooves, and the inner bottom wall of each of the first grooves of each of the first electromagnetic loss absorbing components is in contact with the inner bottom wall of one of the second grooves of one of the second electromagnetic loss absorbing components.

[0010] Preferably, the metamaterial absorbing layer includes a base layer and the metamaterial array layer arranged on one side of the base layer, and the other side of the base layer is fixedly connected to the electromagnetic loss absorbing component; each base layer is provided with at least two plug-in seam groups, each plug-in seam group includes two plug-in seams 5, the base layer of the first core group is the first base, and the base layer of the second core group is the second base, and the two plug-in seams of each plug-in seam group of each first base can be respectively inserted into the two plug-in seams of the corresponding second base.

[0011] Preferably, the material of the panel layer is a glass fiber composite material, and the material of the bottom plate layer is a carbon fiber composite material.

[0012] Preferably, each core body of the first core body group and each core body of the second core body group are perpendicular to each other, and a metamaterial array layer is provided on the base layer between two adjacent electromagnetic loss absorbing components.

[0013] The present invention provides a method for preparing the grid absorber, comprising the following steps:

[0014] The bottom plate layer, the panel layer and a plurality of the core bodies are obtained, and the method for obtaining each of the core bodies includes: obtaining a plurality of the electromagnetic loss absorbing components and a plurality of the metamaterial absorbing layers, and connecting two of the metamaterial absorbing layers to two sides of one of the electromagnetic loss absorbing components in a first direction, respectively, to form one of the core bodies;

[0015] The core bodies of the first core group are arranged alternately with all the core bodies of the second core group to form a grid-shaped core layer, the core layer is arranged between the bottom plate layer and the panel layer, the two sides of the second direction of each electromagnetic loss absorbing component are respectively connected to the bottom plate layer and the panel layer, and the two sides of each metamaterial absorbing layer are respectively connected to the bottom plate layer and the panel layer.

[0016] Preferably, the method further includes: plugging each core body of the first core body group with all the core bodies of the second core body group to form a grid-shaped core layer, and the method of plugging the core bodies to form the grid-shaped core layer includes:

[0017] The two sides of the second direction of each core body are respectively the first side and the second side, the electromagnetic loss absorbing component of the first core group is the first electromagnetic loss absorbing component, the electromagnetic loss absorbing component of the second core group is the second electromagnetic loss absorbing component, and the first side of the first electromagnetic loss absorbing component is provided with at least two first grooves; the metamaterial absorbing layer includes a substrate layer and the metamaterial array layer provided on one side of the substrate layer, and the other side of the substrate layer is fixedly connected to the electromagnetic loss absorbing component; each substrate layer is provided with at least two plug-in seam groups, each of which includes two plug-in seams 5, the substrate layer of the first core group is the first substrate, the substrate layer of the second core group is the second substrate, and the two plug-in seams of each plug-in seam group of each first substrate can be respectively inserted into the two plug-in seams of the corresponding second substrate;

[0018] Each of the first grooves of the first core body is arranged opposite to a second groove of the second core body, and the first core body and the corresponding second core body are moved toward each other until the inner bottom wall of each of the first grooves of each of the first core bodies contacts the inner bottom wall of the corresponding groove, and the two insertion seams of each of the insertion seam groups of each of the first bases are respectively inserted into the two insertion seams of the corresponding second base.

[0019] Compared with the prior art, the present invention has achieved the following technical effects:

[0020] The present invention provides a grid absorber and a preparation method thereof, comprising a bottom plate layer, a core layer and a panel layer connected in sequence, the core layer comprising a first core group and a second core group, the first core group and the second core group each comprising at least two core bodies, each core body of the first core group and all core bodies of the second core group are staggered so that the core layer is in a grid shape, the core body comprises an electromagnetic loss absorbing component and two metamaterial absorbing layers arranged on both sides of the electromagnetic loss absorbing component in a first direction, both sides of each electromagnetic loss absorbing component in a second direction are respectively connected to the bottom plate layer and the panel layer, and both sides of each metamaterial absorbing layer are respectively connected to the bottom plate layer and the panel layer. Among them, the bottom plate layer, core layer and panel layer can form a primary composite material grid sandwich structure, the electromagnetic loss absorbing components and the metamaterial absorbing layer can form a secondary hybrid core, forming a multi-level absorbing structure, which can effectively improve the buckling strength of the core, thereby greatly improving the load-bearing efficiency of the structure; the electromagnetic loss absorbing components and the metamaterial absorbing layer have high-intensity absorption capabilities for electromagnetic waves in L, S, C, X, Ku and other bands and incident at multiple angles, thereby achieving a synergistic enhancement of absorbing performance and load-bearing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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 will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the structure of the grid absorber provided in Example 1;

[0023] Figure 2 A schematic diagram of the structure of the core layer provided in Example 1;

[0024] Figure 3 A schematic diagram of the structure of the metamaterial array layer provided in Example 1;

[0025] Figure 4 A schematic diagram of the structure of the electromagnetic loss absorbing component provided in Example 1;

[0026] Figure 5 is a comparison diagram of the reflection coefficients of the absorber in Example 2 and the background technology at typical incident angles of TM waves;

[0027] Figure 6 1 is a comparison diagram of the reflection coefficients of the absorber in Example 2 and the background technology at typical incident angles of TE waves;

[0028] Figure 7 is a comparison diagram of the reflection coefficients of the absorber in Example 2 and the background technology when the electromagnetic wave is vertically incident;

[0029] Figure 8 It is a comparison chart of the compressive strength and specific energy absorption of the absorber in Example 2 and the background technology.

[0030] In the figure: 100, grid absorber; 1, bottom plate layer; 2, panel layer; 3, core body; 301, first side; 302, second side; 4, electromagnetic loss absorbing component; 401, wave-transmitting honeycomb skeleton; 402, electromagnetic loss layer; 403, first electromagnetic loss absorbing component; 404, second electromagnetic loss absorbing component; 5, metamaterial absorbing layer; 501, substrate layer; 502, metamaterial array layer; 503, conductive layer; 504, conductive connection layer; 505, plug-in seam; 506, first substrate; 507, second substrate; 508, plug-in base. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The object of the present invention is to provide a grid absorber and a method for preparing the same, so as to solve the problems existing in the above-mentioned prior art and achieve the synergistic enhancement of the absorbing performance and the load-bearing performance.

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] like Figures 1 to 4As shown, the present embodiment provides a grid absorber 100, comprising a bottom plate layer 1, a core layer and a panel layer 2 connected in sequence, the core layer comprising a first core group and a second core group, the first core group and the second core group each comprising at least two core bodies 3, each core body 3 of the first core group and all core bodies 3 of the second core group are staggered so that the core layer is in a grid shape, the core body 3 comprises an electromagnetic loss absorbing component 4 and two layers of metamaterial absorbing layers 5 arranged on both sides of the electromagnetic loss absorbing component 4 in a first direction, both sides of each electromagnetic loss absorbing component 4 in a second direction are respectively connected to the bottom plate layer 1 and the panel layer 2, and both sides of each metamaterial absorbing layer 5 are respectively connected to the bottom plate layer 1 and the panel layer 2. Among them, the bottom plate layer 1, the core layer and the panel layer 2 can form a primary composite material grid sandwich structure, the electromagnetic loss absorbing component 4 and the metamaterial absorbing layer 5 can form a secondary hybrid core to form a multi-level absorbing structure, and the metamaterial absorbing layer 5 can connect the bottom plate layer 1 and the panel layer 2 to play a major bearing role; on the one hand, the electromagnetic loss absorbing component 4 plays an auxiliary bearing role by connecting with the bottom plate layer 1 and the panel layer 2, and on the other hand, the electromagnetic loss absorbing component 4 can laterally support the metamaterial absorbing layer 5 to improve the bearing capacity of the electromagnetic loss absorbing component 4, thereby effectively improving the buckling strength of the core, thereby greatly improving the bearing efficiency of the structure; the electromagnetic loss absorbing component 4 and the metamaterial absorbing layer 5 have high-intensity absorption capabilities for electromagnetic waves in L, S, C, X, Ku and other bands and incident at multiple angles, thereby achieving synergistic enhancement of absorbing performance and bearing performance.

[0036] In this embodiment, each electromagnetic loss absorbing component 4 includes a wave-transmitting honeycomb frame 401 and an electromagnetic loss layer 402 coated on the surface of the wave-transmitting honeycomb frame 401 .

[0037] In this embodiment, all electromagnetic loss absorbing components 4 of the first core group are plugged into all electromagnetic loss absorbing components 4 of the second core group, which is convenient for size expansion and application.

[0038] In this embodiment, the two sides of the second direction of each core body 3 are respectively the first side 301 and the second side 302, the electromagnetic loss absorbing component 4 of the first core group is the first electromagnetic loss absorbing component 403, the electromagnetic loss absorbing component 4 of the second core group is the second electromagnetic loss absorbing component 404, the first side 301 of the first electromagnetic loss absorbing component 403 is provided with at least two first grooves, the second side 302 of the second electromagnetic loss absorbing component 404 is provided with at least two second grooves, and the inner bottom wall of each first groove of each first electromagnetic loss absorbing component 403 is in contact with the inner bottom wall of a second groove of a second electromagnetic loss absorbing component 404. By making each first groove of the first electromagnetic loss absorbing component 403 face a second groove of a second electromagnetic loss absorbing component 404, and making the first electromagnetic loss absorbing component 403 and the corresponding second electromagnetic loss absorbing component 404 move toward each other, until the inner bottom wall of each first groove of each first electromagnetic loss absorbing component 403 contacts the inner bottom wall of the corresponding second electromagnetic loss absorbing component 404, the electromagnetic loss absorbing component 4 of the first core group and the electromagnetic loss absorbing component 4 of the second core group are plugged and locked, and the continuity of each electromagnetic loss absorbing component 4 of the core layer is maintained, thereby reducing the adverse effect of the large thickness of the electromagnetic loss absorbing component 4 on the mechanical properties, which is beneficial to improving the bearing performance of the structure.

[0039] It should be noted that the first groove and the second groove have the same depth, so that the inner bottom wall of each first groove of each first electromagnetic loss absorbing component 403 contacts the inner bottom wall of the corresponding second electromagnetic loss absorbing component 404 .

[0040] In this embodiment, the metamaterial absorbing layer 5 includes a base layer 501 and a metamaterial array layer 502 arranged on one side of the base layer 501. The other side of the base layer 501 is fixedly connected to the electromagnetic loss absorbing component 4. The metamaterial array layer 502 includes a plurality of conductive layers 503 arranged in sequence along the height direction of the core body 3. A gap is left between two adjacent conductive layers 503. The dimension of the conductive layer 503 along the direction perpendicular to the height of the core body 3 is the length of the conductive layer 503. The length of the conductive layer 503 of the metamaterial array layer 502 increases linearly from top to bottom along the height direction of the core body 3, thereby achieving a better impedance matching effect and a wider bandwidth and high-intensity electromagnetic wave absorption performance.

[0041] In this embodiment, each base layer 501 is provided with at least two plug-in seam groups, each plug-in seam group includes two plug-in seams 505, the base layer 501 of the first core group is the first base 506, and the base layer 501 of the second core group is the second base 507, and the two plug-in seams 505 of each plug-in seam group of each first base 506 can be respectively inserted into the two plug-in seams 505 of the corresponding second base 507.

[0042] As a preferred embodiment, the distance between the two plug-in seams 505 of each plug-in seam group is equal to the thickness of the electromagnetic loss absorbing component 4 connected thereto, and the length of each plug-in seam 505 is equal to the depth of the first groove or the second groove on the electromagnetic loss absorbing component 4 connected thereto. After the electromagnetic loss absorbing component 4 of the first core group and the electromagnetic loss absorbing component 4 of the second core group are plugged and locked, the base portion between the two plug-in seams 505 of each plug-in seam group of each base layer 501 is defined as a plug-in base portion 508, and each plug-in base portion 508 can contact the inner side wall of the corresponding first groove or the second groove, and one end of each plug-in base portion 508 of each first core group away from the corresponding first groove can contact the inner bottom wall of the corresponding second groove of the second core group, and one end of each plug-in base portion of each second core group away from the second groove can contact the inner bottom wall of the corresponding first groove of the first core group, so as to ensure the bearing capacity of the base layer 501.

[0043] In this embodiment, each core body 3 of the first core group is perpendicular to each core body 3 of the second core group, and a metamaterial array layer 502 is provided on the base layer 501 between two adjacent electromagnetic loss absorbing components 4 .

[0044] As a preferred embodiment, the panel layer 2 is a wave-transmitting panel, preferably a glass fiber composite material, or a composite material such as aramid fiber, quartz fiber, etc., and the relative dielectric constant is preferably 2 to 6. The bottom plate layer 1 is a reflective bottom plate, preferably a carbon fiber composite material, or a high conductivity material such as graphene and metal. The thickness of the panel layer 2 and the bottom plate layer 1 is preferably 0.2 to 2 mm; the core layer height is preferably 6 to 40 mm, more preferably 10 to 30 mm; the core layer is composed of a total of M*M units (core body 3) distributed in a transverse and longitudinal periodic manner, and the periodic length of the core body 3 in each direction is preferably 20 to 50 mm, more preferably 25 to 40 mm, and the range of M is preferably 5 to 30, more preferably 8 to 15.

[0045] As a preferred embodiment, the base layer 501 is a glass fiber composite material; the thickness of the electromagnetic loss absorbing component 4 (i.e., the size of the electromagnetic loss absorbing component 4 along the first direction) is preferably 5 to 15 mm, more preferably 8 to 12 mm; the thickness of the base layer 501 is preferably 0.2 to 1 mm, more preferably 0.2 to 0.5 mm.

[0046] As a preferred embodiment, a conductive connection layer 504 is provided in the middle between two adjacent conductive layers 503, and the two ends of the conductive connection layer 504 are respectively fixedly connected to the two adjacent conductive layers 503 (preferably integrally formed) to form a fishbone array. The conductive layer 503 in the fishbone array of the metamaterial array layer 502 grows linearly along the negative z-axis, and has a better electromagnetic wave convergence capability. The conductive layer 503 and the conductive connection layer 504 include at least one of carbon fiber / carbon powder / graphite / metal strip / graphene, more preferably carbon fiber or graphene. The thickness of the metamaterial array layer 502 is 0 to 0.5 mm, more preferably 0 to 0.125 mm. The metamaterial array layer 502 is composed of M*M units distributed periodically in the transverse and longitudinal directions, and the period length in each direction is preferably 20 to 50 mm, more preferably 30 to 40 mm; the range of M is preferably 5 to 30, more preferably 8 to 15.

[0047] As a preferred embodiment, in a metamaterial array layer 502, the number of conductive layers 503 is preferably 6 to 30; the width of a single conductive layer 503 is preferably 0.5 to 1.5 mm, more preferably 0.7 to 1.2 mm; the spacing between adjacent conductive layers 503 is preferably 0 to 1 mm, more preferably 0.2 to 0.7 mm; the length of the conductive layer 503 with the smallest length is preferably 1 to 10 mm, more preferably 4 to 8 mm; the length variation gradient of adjacent conductive layers 503 is preferably 0.5 to 2.5 mm, more preferably 1 to 2 mm; the width of the conductive connection layer 504 is preferably 0 to 5 mm; the maximum conductivity of the conductive layer 503 and the conductive connection layer 504 is preferably 700 to 8×108 S / m, more preferably 1×104 to 1×108 S / m.

[0048] As a preferred embodiment, the wave-transmitting honeycomb skeleton 401 is composed of a wave-transmitting bearing material, and the wave-transmitting bearing material is preferably glass fiber / aramid paper honeycomb / foam, etc., and is more preferably aramid paper honeycomb; the relative dielectric constant is preferably 1-5, and the relative dielectric constant is more preferably 1.02-1.3; the electromagnetic loss layer 402 is composed of an electromagnetic loss material, and the electromagnetic loss material is preferably graphite / carbon black / graphene / acetylene / carbon nanotubes, etc., and is more preferably carbon black, acetylene, etc.; the relative dielectric constant is preferably 10-400, and the relative dielectric constant is more preferably 20-200; the loss tangent is preferably 0.5-3, and the loss tangent is more preferably 1-2.5. The secondary hybrid core constructed in this embodiment utilizes the bearing performance of the metamaterial absorbing layer 5 and the electromagnetic loss absorbing component 4 to effectively improve the buckling critical load value of the core body 3, thereby greatly improving the mechanical properties of the structure such as compressive strength and specific energy absorption; at the same time, the high dielectric loss characteristics of the electromagnetic loss material and the ability of the metamaterial absorbing layer 5 to converge electromagnetic waves are utilized to significantly improve the electromagnetic wave absorption intensity of the structure. The multi-level design of the grid absorber 100 provided in this embodiment can achieve a synergistic enhancement of the absorbing performance and the load-bearing performance.

[0049] As a preferred embodiment, the honeycomb holes of the wave-transmitting honeycomb skeleton 401 are regular hexagons, and the side length of the honeycomb holes is preferably 0.9-5.4 mm, more preferably 0.9-2.7 mm; the wall thickness of the honeycomb skeleton is preferably 0.02-0.1 mm, more preferably 0.025-0.075 mm; the thickness of the electromagnetic loss material coated on the surface of the skeleton is preferably 0.01-0.1 mm, more preferably 0.02-0.08 mm.

[0050] As a preferred embodiment, the metamaterial absorbing layer 5 is bonded to the base layer 501 and cured. The electromagnetic loss absorbing component 4 and the base layer 501 are fixedly bonded to the bottom plate layer 1 and the panel layer 2 with an adhesive and cured to obtain a multi-level grid hybrid absorber. The above-mentioned adhesive is preferably epoxy resin, and the curing treatment is preferably thermal curing. The curing temperature is preferably 40 to 150°C, more preferably 100 to 120°C; the curing time is preferably 1 to 5h, more preferably 1 to 2h; the curing pressure is preferably 0.8 to 1 bar, more preferably 1 bar. The curing treatment is preferably carried out in a molding die. The electromagnetic loss absorbing component 4 and the metamaterial absorbing layer 5 can be closely attached to the bottom plate layer 1 and the panel layer 2 through high-temperature molding curing, thereby improving the load-bearing performance. The adhesive is preferably epoxy resin glue. As a preferred embodiment, the method of curing the electromagnetic loss absorbing component 4 and the base layer 501 with the bottom plate layer 1 and the panel layer 2 using an adhesive includes: fixing the bottom plate layer 1, the panel layer 2 and the core body 3 by a clamping or pressing method, keeping the temperature at 40-60°C for 4 hours or curing at a high temperature of 120°C for 1.5 hours. After curing, the clamping device is removed, and the surface adhesive and dirt are cleaned.

[0051] The grid absorber 100 provided in this embodiment can be applied in the field of structural bearing or stealth technology. The electromagnetic functional design potential brought by its multi-level structural design can introduce different electromagnetic loss materials into each level of the structure (core body 3) to construct a hybrid absorber with better electromagnetic performance. The metamaterial array can achieve efficient and precise control of electromagnetic waves through the design of microstructures, thereby achieving the purposes of on-demand design and structural reverse design, which can effectively meet the needs.

[0052] As a preferred embodiment, the grid absorber 100 provided in this embodiment is composed of a glass fiber wave-transmitting panel, a carbon fiber reflective bottom plate, and a primary structure core (core layer); the primary structure core comprises 9×9 units (core body 3) periodically distributed in the transverse and longitudinal directions, and the unit is composed of a metamaterial array layer 502, a secondary structure wave-absorbing honeycomb core, and a secondary structure base layer 501; the glass fiber wave-transmitting panel and the carbon fiber reflective bottom plate are square; the metamaterial array layer 502 is arranged on each side of the secondary structure glass fiber base layer 501; the metamaterial wave-absorbing layer 5 is a fishbone carbon fiber array, and the fishbone carbon fiber array is composed of gradient distributed carbon fiber strips; the wave-absorbing honeycomb core is composed of an electromagnetic loss layer 402 and a wave-transmitting honeycomb skeleton 401;

[0053] The thickness of the glass fiber wave-transmitting panel and the carbon fiber reflective bottom plate is t1 = 0.5 mm, and the shape is a square with a side length equal to the unit period length p x =p y =31.6 mm, the dielectric constant of the glass fiber is 4.3, and the conductivity of the carbon fiber material along the fiber direction and perpendicular to the fiber direction is set to 3.5×10 4 S / m and 89S / m. The thickness of the fishbone carbon fiber array is h1 = 0.125 mm, and the array period is p x =p y =31.6mm, one unit contains 13 carbon fiber strips (conductive layer 503), the width of a single conductive layer 503 is w=1mm; the spacing between adjacent conductive layers 503 is s=0.5mm, the length of the top conductive layer 503 is l1=5.86mm, the length gradient of adjacent carbon fiber strips is dl=1.17mm, and the width of the conductive connection layer 504 is c=4mm. The unit period length p of the core body 3 x =p y =31.6mm, core height h=20mm. The height of the wave-absorbing honeycomb core is preferably h0=10mm; the wave-transmitting honeycomb skeleton 401 is a wave-transmitting aramid paper honeycomb with a relative dielectric constant of 1.06, a side length of the wave-transmitting honeycomb skeleton 401 of 1.83mm, a wall thickness of the wave-transmitting honeycomb skeleton 401 of 0.05mm, and an electromagnetic loss material composed of carbon black and acetylene, etc., coated on the surface of the wave-transmitting honeycomb skeleton 401 with a thickness of 0.02mm. The relative dielectric constant of the mixed material is 200, and the loss tangent is 2; the base layer 501 is a glass fiber composite material with a thickness of 0.375mm and a period length p x =p y =31.6mm.

[0054] The electromagnetic performance of the grid absorber 100 in Example 1 and the absorber in Comparative Example 1 was simulated and tested. The structure of the absorber in Comparative Example 1 includes a panel, a bottom plate and a composite material core structure. The composite material core structure is arranged between the panel and the bottom plate. The composite material core structure is mostly a simple electromagnetic loss absorbing structure. The electromagnetic loss absorbing structure includes a honeycomb structure and an electromagnetic loss material added to the honeycomb structure. Comparison of the absorbing performance of the grid absorber 100 in Example 1 and the absorber in Comparative Example 1 Figures 5 to 7 As shown by Figure 5 It can be seen that for TM waves, as the incident angle θ increases, the average reflection coefficient of the grid absorber 100 of Example 1 decreases from -16.6 dB to -22.8 dB. In contrast, the average reflection coefficient of the absorber in Comparative Example 1 fluctuates between -12 dB and -15 dB, which is significantly higher than that in Example 1, indicating that the absorbing performance of the grid absorber 100 of Example 1 is much higher than that of the absorber in Comparative Example 1. Figure 6 It can be seen that for TE waves, the average reflection loss of the grid absorber 100 of Example 1 gradually decreases with the increase of θ. When θ exceeds 45°, although the average reflection coefficient of the grid absorber 100 of Example 1 is slightly higher than the average reflection coefficient of the absorber in Comparative Example 1, the reflection coefficient of the grid absorber 100 of Example 1 in the low frequency band is still relatively low. Based on the above analysis, the grid absorber 100 of Example 1 has a significantly better absorbing performance than the absorber in Comparative Example 1. Figure 7 It can be seen that the average reflection coefficient of the grid absorber 100 in Example 1 is generally lower than the reflection coefficient of the absorber in Comparative Example 1 within the frequency band range of 2-18 GHz and the incident angle range of 0-60°. The grid absorber 100 in Example 1 has a significantly lower reflection coefficient than the traditional absorbing structure in Comparative Example 1, thus exhibiting higher absorbing performance.

[0055] The mechanical properties of the grid absorber 100 in Example 1 and the absorber in Comparative Example 1 were simulated and tested. The compressive strength of the grid absorber 100 in Example 1 was 9.85 MPa, and the compressive strength of the absorber in Comparative Example 1 was 2.31 MPa. At the same time, the density of the grid absorber 100 in Example 1 was 120 kg / m 3 The density of the absorber in Comparative Example 1 is 48 kg / m 3 The grid absorber 100 in Example 1 achieves broadband (2-18 GHz), large angle (0-60°), high intensity (average reflection loss -16.9 dB) electromagnetic wave absorption and lightweight (density 120 kg / m 3 ), integrated design of wave-absorbing and load-bearing with high structural load-bearing efficiency (compression strength 9.85MPa).

[0056] The electromagnetic performance of the grid absorber 100 in Example 1 and the absorber in Comparative Example 2 was simulated and tested. The structure of the absorber in Comparative Example 2 includes a panel, a bottom plate and a composite material core structure. The composite material core structure is arranged between the panel and the bottom plate. The composite material core structure is mostly a simple metamaterial absorbing grid. The metamaterial absorbing grid includes a plurality of metamaterial absorbing plates arranged horizontally and vertically. For TM waves and TE waves, the absorbing performance of the grid absorber 100 in Example 1 and the absorber in Comparative Example 2 is compared as shown in FIG. Figure 7 As shown by Figure 7 It can be seen that within the frequency band range of 2-18 GHz, the reflection coefficient of the grid absorber 100 in Example 1 is smaller than the reflection coefficient of the absorber in Comparative Example 2. Compared with the traditional absorbing structure in Comparative Example 2, the grid absorber 100 in Example 1 has a significantly lower reflection coefficient, thus exhibiting higher absorbing performance.

[0057] like Figure 8 As shown, the mechanical properties of the grid absorber 100 in Example 1 and the absorber in Comparative Example 2 are simulated and tested. For different strain values, the stress value of Example 1 is greater than or equal to the stress value of Comparative Example 2, and for different strain values, the energy absorption capacity of Example 1 is greater than or equal to the energy absorption capacity of Comparative Example 2. Therefore, the grid absorber 100 in Example 1 has higher structural load-bearing efficiency.

[0058] Example 2

[0059] This embodiment provides a grid absorber 100 , in which each electromagnetic loss absorbing component 4 is an absorbing foam core containing electromagnetic loss material.

[0060] In this embodiment, the absorbing foam core is obtained by mixing a foam material having a certain load-bearing property such as polymethacrylimide with an electromagnetic loss material and then foaming it. The foaming density is preferably 30 to 180 kg / m3, and more preferably 40 to 80 kg / m3.

[0061] The other structures of this embodiment are the same as those of the embodiment.

[0062] Example 3

[0063] This embodiment provides a method for preparing the grid absorber 100 in Embodiment 1, comprising the following steps:

[0064] A bottom plate layer 1, a panel layer 2 and a plurality of core bodies 3 are obtained, and a method for obtaining each core body 3 includes: obtaining a plurality of electromagnetic loss absorbing components 4 and a plurality of metamaterial absorbing layers 5, and connecting two metamaterial absorbing layers 5 to two sides of an electromagnetic loss absorbing component 4 in a first direction, respectively, to form a core body 3;

[0065] The core bodies 3 of the first core group are arranged alternately with all the core bodies 3 of the second core group to form a grid-like core layer, the core layer is arranged between the bottom plate layer 1 and the panel layer 2, the two sides of each electromagnetic loss absorbing component 4 in the second direction are connected to the bottom plate layer 1 and the panel layer 2 respectively, and the two sides of each metamaterial absorbing layer 5 are connected to the bottom plate layer 1 and the panel layer 2 respectively.

[0066] In this embodiment, the method further includes: plugging each core body 3 of the first core body group with all the core bodies 3 of the second core body group to form a grid-shaped core layer. The method of plugging the core bodies 3 to form a grid-shaped core layer includes:

[0067] The two sides of the second direction of each core body 3 are respectively the first side 301 and the second side 302, the core body 3 of the first core body group is the first core body 3, and the core body 3 of the second core body group is the second core body 3, at least two first grooves are opened on the first side 301 of the first core body 3, and at least two second grooves are opened on the second side 302 of the second core body 3; each first groove of the first core body 3 is arranged opposite to a second groove of a second core body 3, and the first core body 3 and the corresponding second core body 3 are moved toward each other until the inner side wall of each first groove of each first core body 3 contacts the outer side wall of the corresponding second core body 3, and the inner bottom wall of each first groove of each first core body 3 contacts the inner bottom wall of the corresponding groove.

[0068] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A grid absorber, characterized in that: The invention comprises a bottom plate layer, a core layer and a panel layer connected in sequence, wherein the core layer comprises a first core group and a second core group, wherein the first core group and the second core group each comprise at least two core bodies, wherein each core body of the first core group and all the core bodies of the second core group are staggered so that the core layer is in a grid shape, wherein the core body comprises an electromagnetic loss absorbing component and two metamaterial absorbing layers arranged on both sides of the electromagnetic loss absorbing component in a first direction, wherein both sides of each electromagnetic loss absorbing component in a second direction are respectively connected to the bottom plate layer and the panel layer, and both sides of each metamaterial absorbing layer are respectively connected to the bottom plate layer and the panel layer.

2. The grid absorber according to claim 1, characterized in that: Each of the electromagnetic loss absorbing components comprises a wave-transmitting honeycomb frame and an electromagnetic loss layer coated on the surface of the wave-transmitting honeycomb frame.

3. The grid absorber according to claim 1, characterized in that: Each of the electromagnetic loss absorbing components is an absorbing foam core containing electromagnetic loss material.

4. The grid absorber according to claim 2, characterized in that: Each core body of the first core body group is plugged into all the core bodies of the second core body group.

5. The grid absorber according to claim 4, characterized in that: The two sides of the second direction of each of the core bodies are respectively a first side and a second side, the electromagnetic loss absorbing component of the first core group is a first electromagnetic loss absorbing component, the electromagnetic loss absorbing component of the second core group is a second electromagnetic loss absorbing component, the first side of the first electromagnetic loss absorbing component is provided with at least two first grooves, the second side of the second electromagnetic loss absorbing component is provided with at least two second grooves, and the inner bottom wall of each of the first grooves of each of the first electromagnetic loss absorbing components is in contact with the inner bottom wall of one of the second grooves of one of the second electromagnetic loss absorbing components.

6. The grid absorber according to claim 1, characterized in that: The metamaterial absorbing layer includes a base layer and the metamaterial array layer arranged on one side of the base layer, and the other side of the base layer is fixedly connected to the electromagnetic loss absorbing component; each base layer is provided with at least two plug-in seam groups, each of the plug-in seam groups includes two plug-in seams 5, the base layer of the first core group is the first base, and the base layer of the second core group is the second base, and the two plug-in seams of each plug-in seam group of each first base can be respectively inserted into the two plug-in seams of the corresponding second base.

7. The grid absorber according to claim 2, characterized in that: The material of the panel layer is a glass fiber composite material, and the material of the bottom plate layer is a carbon fiber composite material.

8. The grid absorber according to claim 6, characterized in that: Each core body of the first core body group and each core body of the second core body group are perpendicular to each other, and a metamaterial array layer is arranged on the base layer between two adjacent electromagnetic loss absorbing components.

9. A method for preparing a grid absorber according to any one of claims 1 to 8, characterized in that: The steps include: The bottom plate layer, the panel layer and a plurality of the core bodies are obtained, and the method for obtaining each of the core bodies includes: obtaining a plurality of the electromagnetic loss absorbing components and a plurality of the metamaterial absorbing layers, and connecting two of the metamaterial absorbing layers to two sides of one of the electromagnetic loss absorbing components in a first direction, respectively, to form one of the core bodies; The core bodies of the first core group are arranged alternately with all the core bodies of the second core group to form a grid-shaped core layer, the core layer is arranged between the bottom plate layer and the panel layer, the two sides of the second direction of each electromagnetic loss absorbing component are respectively connected to the bottom plate layer and the panel layer, and the two sides of each metamaterial absorbing layer are respectively connected to the bottom plate layer and the panel layer.

10. The method for preparing a grid absorber according to claim 9, characterized in that: Also includes: Each core body of the first core body group is plugged into all the core bodies of the second core body group to form a grid-shaped core layer. The method of plugging the core bodies into the grid-shaped core layer includes: The two sides of the second direction of each core body are respectively the first side and the second side, the electromagnetic loss absorbing component of the first core group is the first electromagnetic loss absorbing component, the electromagnetic loss absorbing component of the second core group is the second electromagnetic loss absorbing component, and the first side of the first electromagnetic loss absorbing component is provided with at least two first grooves; the metamaterial absorbing layer includes a substrate layer and the metamaterial array layer provided on one side of the substrate layer, and the other side of the substrate layer is fixedly connected to the electromagnetic loss absorbing component; each substrate layer is provided with at least two plug-in seam groups, each of which includes two plug-in seams 5, the substrate layer of the first core group is the first substrate, the substrate layer of the second core group is the second substrate, and the two plug-in seams of each plug-in seam group of each first substrate can be respectively inserted into the two plug-in seams of the corresponding second substrate; Each of the first grooves of the first core body is arranged opposite to a second groove of the second core body, and the first core body and the corresponding second core body are moved toward each other until the inner bottom wall of each of the first grooves of each of the first core bodies contacts the inner bottom wall of the corresponding groove, and the two insertion seams of each of the insertion seam groups of each of the first bases are respectively inserted into the two insertion seams of the corresponding second base.

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