Ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure

Abstract

The invention belongs to the technical field of microwave absorption, and particularly relates to an extremely-wideband bionic tree-shaped microwave absorption-mechanical bearing structure which comprises a plurality of unit cells which are fixedly connected to a bottom plate and distributed in an array mode, each unit cell comprises a trunk, the trunk is fixedly connected to the bottom plate, the axis of the trunk is perpendicular to the bottom plate, the trunk is coaxially and fixedly connected with a plurality of slices, and the slices are arranged on the bottom plate. The multiple sheets are parallel to the bottom plate, the distance between every two adjacent sheets is equal, and the sizes of the multiple sheets are gradually reduced from bottom to top. According to the ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure, the minimum reflection loss is lower than-9 dB within the frequency range of 2-18 GHz, incident electromagnetic waves can be efficiently absorbed, reflection is reduced, and therefore the stealth effect of flight equipment is improved; the 3D printing technology is adopted for manufacturing, the preparation process is more flexible and efficient, high mechanical strength is achieved, and the structure is more stable and reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of microwave absorption, and in particular relates to an extremely broadband bionic tree-shaped microwave absorption-mechanical bearing structure. Background Art

[0002] The rapid popularization and widespread application of electronic communication technology have greatly improved the convenience of daily life and industrial production. However, these advances have also brought challenges such as electromagnetic interference (EMI) and electromagnetic pollution. These problems not only pose a threat to human health, but also challenge the electromagnetic compatibility and anti-interference ability of electronic equipment.

[0003] However, the microwave absorption effect of the structure used for microwave absorption in the prior art is not ideal. Therefore, an extremely broadband bionic tree-shaped microwave absorption-mechanical bearing structure is proposed. Summary of the invention

[0004] The purpose of the present invention is to provide an extremely broadband bionic tree-shaped microwave absorption-mechanical bearing structure to solve the above problems.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] An extremely broadband bionic tree-shaped microwave absorption-mechanical bearing structure comprises: a plurality of unit cells, all fixedly connected to a bottom plate, the plurality of unit cells being arranged in an array, the unit cells comprising a trunk, the trunk being fixedly connected to the bottom plate, the axis of the trunk being perpendicular to the bottom plate, a plurality of thin sheets being coaxially fixedly connected to the trunk, the plurality of thin sheets being parallel to the bottom plate, the distance between two adjacent thin sheets being equal, and the sizes of the plurality of thin sheets being gradually reduced from bottom to top.

[0007] In the ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure of the present invention, the materials of the bottom plate, the trunk and the thin slice include: by mass fraction, 94% ABS powder, 5% polypyrrole nanotubes and 1% multi-walled carbon nanotubes.

[0008] In the ultra-broadband bionic tree-shaped microwave absorption-mechanical bearing structure of the present invention, the cross-sectional shape of the thin slice is a regular polygon or a circle.

[0009] In the ultra-broadband bionic tree-shaped microwave absorption-mechanical bearing structure of the present invention, the thickness t1 of the thin sheet is 0.2-1.0 mm.

[0010] In the ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure of the present invention, the trunk is truncated cone-shaped, the bottom diameter D1 of the trunk is 20-40 mm, the top diameter of the trunk is 11-25 mm, and the trunk height H2 is 6-8 mm.

[0011] In an extremely broadband bionic tree-shaped microwave absorption-mechanical bearing structure of the present invention, the number of the thin sheets is three, the cross-sectional shape of the thin sheets is a regular quadrilateral, the length / width L2 of the thin sheet located at the bottom is 20 to 40 mm, the length / width L3 of the thin sheet located in the middle is 20 to 38 mm, the length / width L4 of the thin sheet located at the top is 20 to 38 mm, and the distance H3 between two adjacent thin sheets is 1.5 to 3.5 mm.

[0012] A method for manufacturing the ultra-broadband bionic tree-shaped microwave absorption-mechanical bearing structure comprises the following steps:

[0013] The manufacturing materials are mixed and made into wires, the model of the ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure optimized by the ant colony algorithm is imported into the 3D printing slicing software for slicing, the printing parameters are set, the printing code is generated, the printing code is input into the printer, the wires are installed on the printer, the printer is adjusted, and then printing is started. After printing is completed, the ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure is post-processed and the production is completed.

[0014] Compared with the prior art, the present invention has the following advantages and technical effects:

[0015] The ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure of the present invention has a minimum reflection loss of less than -9dB in the frequency range of 2 to 18GHz, can efficiently absorb incident electromagnetic waves, reduce reflection, and thus improve the stealth effect of flight equipment; it is manufactured using 3D printing technology, the preparation process is more flexible and efficient, and it has higher mechanical strength and a more stable and reliable structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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 are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor:

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 is a reflectivity curve diagram of the present invention at different incident angles;

[0019] Figure 3 A schematic diagram of a three-point bending test of the present invention;

[0020] Figure 4 is a bending strength curve diagram of the present invention;

[0021] Figure 5is a reflectivity curve diagram of different numbers of thin sheets of the present invention;

[0022] Figure 6 is a reflectivity curve diagram of different flake shapes of the present invention;

[0023] Figure 7 It is a reflectivity curve diagram of different numbers of side edges of the trunk in the present invention;

[0024] Figure 8 This is the optimization flow chart of the ant colony algorithm in the present invention;

[0025] Among them, 1. bottom plate; 2. main trunk; 3. thin slices. DETAILED DESCRIPTION

[0026] 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.

[0027] 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.

[0028] Reference Figure 1 The present invention discloses an extremely broadband bionic tree-shaped microwave absorption-mechanical bearing structure, comprising: a plurality of unit cells, all fixedly connected to a bottom plate 1, the plurality of unit cells are arranged in an array, the unit cells comprise a trunk 2, the trunk 2 is fixedly connected to the bottom plate 1, the axis of the trunk 2 is perpendicular to the bottom plate 1, a plurality of thin sheets 3 are coaxially fixedly connected to the trunk 2, the plurality of thin sheets 3 are parallel to the bottom plate 1, the distance between two adjacent thin sheets 3 is equal, and the sizes of the plurality of thin sheets 3 are gradually reduced from bottom to top.

[0029] In a feasible embodiment, the materials of the bottom plate 1 , the main body 2 and the thin sheet 3 include: by mass fraction, 94% ABS powder, 5% polypyrrole nanotubes and 1% multi-walled carbon nanotubes.

[0030] In a feasible embodiment, the cross-sectional shape of the sheet 3 is a regular polygon or a circle.

[0031] In a feasible embodiment, the thickness t1 of the sheet 3 is 0.2-1.0 mm.

[0032] In a feasible embodiment, the trunk 2 is in the shape of a truncated cone, the bottom diameter D1 of the trunk 2 is 20-40 mm, the top diameter of the trunk 2 is 11-25 mm, and the height H2 of the trunk 2 is 6-8 mm.

[0033] The trunk 2 can also be configured as a prism.

[0034] In a feasible embodiment, the number of thin sheets 3 is three, the cross-sectional shape of the thin sheets 3 is a regular quadrilateral, the length / width L2 of the thin sheet 3 at the bottom is 20 to 40 mm, the length / width L3 of the thin sheet 3 in the middle is 20 to 38 mm, the length / width L4 of the thin sheet 3 at the top is 20 to 38 mm, and the distance H3 between two adjacent thin sheets 3 is 1.5 to 3.5 mm.

[0035] A method for manufacturing an extremely broadband bionic tree-shaped microwave absorption-mechanical bearing structure, the steps are as follows:

[0036] The manufacturing materials are mixed and made into wires, the model of the ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure optimized by the ant colony algorithm is imported into the 3D printing slicing software for slicing, the printing parameters are set, the printing code is generated, the printing code is input into the printer, the wires are installed on the printer, the printer is adjusted, and then printing is started. After printing is completed, the ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure is post-processed and the production is completed.

[0037] One specific example:

[0038] Reference Figure 1 The ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure of the present invention includes a base plate 1, a plurality of trunks 2 are fixedly connected to the top surface of the base plate 1, the plurality of trunks 2 are arranged in an array, three thin sheets 3 are fixedly connected to the trunk 2 in sequence from bottom to top, the three thin sheets 3 are arranged at equal intervals, the thin sheets 3 are coaxially arranged with the trunk 2, the thickness of the thin sheets 3 is t1=0.8mm, the length / width of the thin sheet 3 at the bottom is L2=40mm, the length / width of the thin sheet 3 at the middle is L3=38mm, the length / width of the thin sheet 3 at the top is L4=25mm, the distance between two adjacent thin sheets 3 is H3=3.5mm, the thickness of the base plate 1 is H1=2mm, the height of the trunk 2 is H2=8mm, the bottom diameter of the trunk 2 is D1=36mm, and the top diameter of the trunk 2 is D2=12.5mm.

[0039] Preparation method:

[0040] 94% by mass of ABS powder, 5% of polypyrrole nanotubes and 1% of multi-walled carbon nanotubes are added to a mixer for mixing at the same time, the mixed raw materials are added to a twin-screw extruder for multiple times, the powder is made into wires with a diameter of 1.70 to 1.80 mm, the extremely broadband bionic tree-shaped microwave absorption-mechanical bearing structure is optimized by an ant colony algorithm, the optimized extremely broadband bionic tree-shaped microwave absorption-mechanical bearing structure model is imported into a 3D printing slicing software for slicing, the printer printing speed is set to 100 mm / s, the nozzle diameter is 0.6 mm, a G code is generated after slicing, the generated G code is substituted into a desktop FDM 3D printer, and the prepared wire is pressed on the 3D printer in advance, the 3D printer is leveled, the hot bed temperature of the 3D printer is set to 50°C, the cooling fan is turned on, and printing is started after preheating is completed. After printing is completed, the semi-finished product obtained by printing is placed in an environment of 50 to 60°C for heat treatment to eliminate stress, so as to obtain an extremely broadband bionic tree-shaped microwave absorption-mechanical bearing structure.

[0041] In the present application, the mixture of ABS powder, polypyrrole nanotubes and multi-walled carbon nanotubes forms a composite material with high dielectric loss, which can effectively convert electromagnetic wave energy into heat energy, thereby achieving electromagnetic wave absorption. The addition of polypyrrole nanotubes and multi-walled carbon nanotubes enhances the conductivity of the material, forms a spatially continuous conductive network, and further promotes the dissipation of electromagnetic waves;

[0042] The precise control of the diameter of the composite wire prepared by the twin-screw extruder ensures the consistency and uniformity of the wire. The consistency and uniformity of the wire are crucial to the accuracy and performance of the structure in the subsequent 3D printing process, because the uniformity of the wire directly affects the mechanical properties and electromagnetic properties of the printed bionic tree structure.

[0043] 3D printing technology allows precise control of printing parameters, such as printing speed and nozzle diameter, to optimize the density and porosity of the structure. The density and porosity of the structure directly affect the propagation and absorption of electromagnetic waves inside the material, and are crucial for adjusting the material's absorbing properties.

[0044] Reference Figure 7 ,This application uses the mechanical bearing-microwave absorption structure model optimized by ant colony algorithm to ensure that the structure has the best absorbing effect while meeting the mechanical properties. The spatial multi-layer structure of the bionic tree structure is conducive to the deep penetration and multiple reflection of electromagnetic waves, which improves the absorption efficiency;

[0045] Heat treatment after printing helps release the stress generated during the printing process and helps further optimize the internal structure of the material, thereby improving its microwave absorption performance and ensuring the long-term stability and performance of the material;

[0046] The reflectivity and three-point bending of the ultra-broadband bionic tree-shaped microwave absorption-mechanical bearing structure were tested, and the microwave absorption performance and mechanical bearing capacity of the ultra-broadband bionic tree-shaped microwave absorption-mechanical bearing structure were evaluated. Figure 2-7 It can be seen that the solution of this embodiment is one of the better solutions.

[0047] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0048] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. An extremely broadband bionic tree-shaped microwave absorption-mechanical bearing structure, characterized in that: include: A plurality of unit cells are fixedly connected to a base plate (1), and the plurality of unit cells are distributed in an array. The unit cells include a trunk (2), the trunk (2) is fixedly connected to the base plate (1), the axis of the trunk (2) is perpendicular to the base plate (1), a plurality of thin sheets (3) are coaxially fixedly connected to the trunk (2), the plurality of thin sheets (3) are parallel to the base plate (1), the distance between two adjacent thin sheets (3) is equal, and the sizes of the plurality of thin sheets (3) are gradually reduced from bottom to top.

2. The ultra-broadband bionic tree-shaped microwave absorption-mechanical bearing structure according to claim 1, characterized in that: The materials of the bottom plate (1), the trunk (2) and the thin sheet (3) include: by mass fraction, 94% ABS powder, 5% polypyrrole nanotubes and 1% multi-walled carbon nanotubes.

3. The ultra-broadband bionic tree-shaped microwave absorption-mechanical bearing structure according to claim 1, characterized in that: The cross-sectional shape of the sheet (3) is a regular polygon or a circle.

4. The ultra-broadband bionic tree-shaped microwave absorption-mechanical bearing structure according to claim 1, characterized in that: The thickness t1 of the sheet (3) is 0.2-1.0 mm.

5. The ultra-broadband bionic tree-shaped microwave absorption-mechanical bearing structure according to claim 1, characterized in that: The trunk (2) is in the shape of a truncated cone, the bottom diameter D1 of the trunk (2) is 20 to 40 mm, the top diameter of the trunk (2) is 11 to 25 mm, and the height H2 of the trunk (2) is 6 to 8 mm.

6. The ultra-broadband bionic tree-shaped microwave absorption-mechanical bearing structure according to claim 1, characterized in that: The number of the thin sheets (3) is three, the cross-sectional shape of the thin sheets (3) is a regular quadrilateral, the length / width L2 of the thin sheet (3) at the bottom is 20 to 40 mm, the length / width L3 of the thin sheet (3) at the middle is 20 to 38 mm, the length / width L4 of the thin sheet (3) at the top is 20 to 38 mm, and the distance H3 between two adjacent thin sheets (3) is 1.5 to 3.5 mm.

7. A method for manufacturing the ultra-broadband bionic tree-shaped microwave absorption-mechanical bearing structure according to any one of claims 1 to 6, characterized in that: Here are the steps: The manufacturing materials are mixed and made into wires, the model of the ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure optimized by the ant colony algorithm is imported into the 3D printing slicing software for slicing, the printing parameters are set, the printing code is generated, the printing code is input into the printer, the wires are installed on the printer, the printer is adjusted, and then printing is started. After printing is completed, the ultra-wideband bionic tree-shaped microwave absorption-mechanical bearing structure is post-processed and the production is completed.

Images