Parametric modeling method of continuous fiber reinforced wave-absorbing composite material hybrid two-dimensional unit model

Abstract

The invention discloses a parametric modeling method for a continuous fiber reinforced wave-absorbing composite material hybrid two-dimensional unit model, and relates to a wave-absorbing composite material. Comprising the following steps: acquiring anisotropic fiber intrinsic dielectric parameters; obtaining geometric parameters required for establishing the hybrid two-dimensional unit model; setting the direction of the fiber bundle; setting a fiber section and obtaining a single-bundle fiber model; establishing a multilayer fiber hybrid two-dimensional unit model; establishing a fiber-reinforced wave-absorbing composite material hybrid two-dimensional unit model; and simulation condition setting and simulation calculation. A fiber weaving electromagnetic anisotropic structure is considered, based on fiber intrinsic dielectric constants in different directions, three-dimensional electromagnetic software is controlled through an MATLAB program to carry out automatic modeling, and a simple fiber mixed weaving two-dimensional unit model structure with the fiber broken line trend and the rhombic section is established. The model structure realizes high-precision and high-speed wave-absorbing performance calculation. Through verification, the calculation result of the model is highly consistent with the actually measured wave-absorbing performance, and the precision of predicting the wave-absorbing performance by a theoretical model is improved.

Description

Technical Field

[0001] The invention relates to a wave-absorbing composite material, in particular to a parameterized modeling method of a mixed two-dimensional unit model of a continuous fiber-reinforced wave-absorbing composite material. Background Art

[0002] With the rapid development of the information age, modern communication equipment and radar equipment are widely used in various fields of life, production, industry, science and military. While bringing convenience to people, the harm of electromagnetic waves to human body system and national defense security is becoming more and more serious. Therefore, higher requirements are put forward for the design and preparation of electromagnetic wave absorbing materials, that is, to ensure low thickness and low density of materials while achieving efficient electromagnetic wave absorption in a wider electromagnetic wave frequency band.

[0003] Therefore, it is crucial to design and prepare materials with good absorption performance in a wide frequency band. Studies have shown that by patterning metamaterial absorbers or regulating the parameters of the unit structure, they can achieve excellent electromagnetic wave absorption effects in multiple frequencies. In recent years, researchers have mixed different fibers to prepare absorbing materials with metamaterial characteristics. By adjusting the structural parameters, the absorption performance is excellent (Liu Y, Huang X, Yan X, et al. Pushing the limits of microwave absorption capability of carbon fiber in fabric design based on genetic algorithm[J]. Journal of Advanced Ceramics, 2023, 12(2):329-340.). However, the coupling relationship between the various parameters of mixed fiber reinforced composites with metamaterial characteristics is extremely strong, and it is often difficult to find a structure that meets the requirements by manually adjusting the parameters. Directly measuring the absorption performance of mixed fiber reinforced composites by experimental means alone is costly, time-consuming and labor-intensive, and is easily affected by many accidental factors during the test process. In addition, due to the complexity of the absorption mechanism, it is challenging to study the absorption mechanism based solely on experimental test results. Therefore, reliable simulation is needed to predict the microwave absorption performance of hybrid fiber reinforced composites.

[0004] The complex preform structure of hybrid fiber reinforced composites increases the difficulty of studying and predicting their microwave absorption performance. In order to better predict the microwave absorption performance of hybrid fiber reinforced composites and study the microwave absorption mechanism, it is necessary to establish an accurate geometric model, on which subsequent analysis is carried out to improve the accuracy of the prediction of microwave absorption performance. At present, researchers mostly set the fiber bundle direction as a curve and the cross section as an ellipse to establish an electromagnetic absorption prediction model (Jianjun Y, Wensuo M, Zuobin G, et al. A model for predicting electromagnetic waveabsorption of 3D bidirectional angle-interlock woven fabric-ScienceDirect[J].Polymer Testing, 2021, 100: 107272. Zhang Q, Pang L, Xiao P, et al. Designand numerical studies of microwave absorption structure based on hybrid weaveof fibers with different dielectric properties[J].Composite structures, 2023,323: 117460.). However, this method is difficult to produce meshes and increases the demand for computing resources. If the model can be simplified and unnecessary details can be removed, the difficulty and amount of calculation for mesh generation can be reduced. Volski et al. proposed a method of using the staircase approximation method to describe the yarn orientation of woven fabrics, which can not only maintain the true geometric shape of the yarn, but also ensure a reasonable calculation time (Volski V, Vandenbosch GA E. Full-wave electromagnetic modelling offabrics and composites[J]. Composites Science & Technology, 2009, 69(2):161-168.). Using a similar principle, the fiber hybrid unit model can be simplified to a model with a fiber orientation of a broken line and a rectangular cross section.Given that there are still some differences between the actual sample and the fiber hybrid unit model structure, and the model ignores the dielectric properties of highly conductive fibers, there are some differences between the test and calculation results (Li C, Cao QS, Zhou GM, et al. Anew stitched-plain weave fabric composite structure with reduced broadband radar cross-section[J]. Composite structures, 2023, 321(10):117261.). Therefore, based on the problems of the existing fiber hybrid unit model, it is necessary to continue to optimize and develop a technical method for efficient and high-quality modeling. Summary of the invention

[0005] The purpose of the present invention is to provide a parametric modeling method for a mixed two-dimensional unit model of a continuous fiber reinforced absorbing composite material that combines electromagnetic mixing rules and parametric design, uses a simple model to accurately predict and optimize the absorbing performance of the composite material, and reduces manpower and material costs, in order to address the shortcomings of the existing fiber mixed unit model with curved fiber orientation and elliptical cross-section, which has high difficulty in generating grids and large amount of calculation, and the fiber mixed unit model with broken fiber orientation and rectangular cross-section still has certain differences from the actual measurement results. The method comprehensively considers the structural characteristics of the two-dimensional mixed composite material and the anisotropic properties of the fiber.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0007] The parametric modeling method of the mixed two-dimensional unit model of continuous fiber reinforced absorbing composite materials uses the electromagnetic mixing rules of composite materials or related composite laws to determine the intrinsic dielectric constant of the fiber in the direction parallel and perpendicular to the electric field, and adopts the parametric modeling method to set the fiber direction as a broken line and the cross section as a diamond. The automatic establishment of the model is controlled by the MATLAB program. The comparison of the calculation results with the experimental data shows that the model has a high accuracy in predicting the absorbing performance. The specific steps are as follows:

[0008] 1) Determine the dielectric constants of the fibers and matrix involved in the hybrid two-dimensional unit model: Since the fibers themselves are anisotropic, the waveguide method is used to test the dielectric constants of the continuous fiber reinforced absorbing composite materials parallel and perpendicular to the electric field direction. The intrinsic dielectric constants of the fibers parallel and perpendicular to the electric field direction are calculated by the mixing law or related composite law, and the dielectric constant of the matrix is ​​tested by the waveguide method or coaxial method;

[0009] In step 1), the fibers are divided into organic fibers and inorganic fibers, wherein the inorganic fibers include SiC ceramic fibers with adjustable resistivity (resistivity 0.1~10 7Ω·cm), glass fiber, quartz fiber, nitride fiber, alumina fiber and other fibers with different dielectric constants; organic fibers include aramid fiber, polyimide fiber, poly(p-phenylene benzobisoxazole) fiber and other fibers with different dielectric constants.

[0010] In step 1), the substrate is divided into low dielectric constant substrates such as inorganic substrates and organic substrates, wherein the inorganic substrate includes quartz ceramic substrate, nitride ceramic substrate, carbide ceramic substrate, oxide ceramic substrate, etc.; the organic substrate includes epoxy resin, bismaleimide resin, silicone resin, silicone rubber, etc.

[0011] 2) Determine the basic geometric parameters required for establishing the fiber hybrid two-dimensional unit model: Prepare the continuous fiber reinforced absorbing composite material by vacuum resin transfer molding, analyze the geometric characteristics of the fiber hybrid structure by scanning electron microscopy, and determine the basic geometric parameters for constructing the fiber hybrid two-dimensional unit model;

[0012] In step 2), the basic geometric parameters include fiber width, fiber spacing, thickness of a single-layer fiber mixed two-dimensional unit model, etc.

[0013] 3) Use MATLAB program to control the three-dimensional electromagnetic simulation software to automatically establish the mixed two-dimensional unit model of continuous fiber reinforced absorbing composite materials, specifically:

[0014] (1) A broken line is used to simulate the direction of the warp fiber bundles in the hybrid structure of continuous fiber reinforced absorbing composite materials. The broken line is represented by a piecewise function in the MATLAB program; the length and slope of the broken line are determined by the basic geometric parameters obtained in step 2).

[0015] (2) Using a rhombus to simulate the cross-sectional shape of the fiber bundle in the hybrid structure of the continuous fiber reinforced absorbing composite material, the rhombus is represented and fitted by a function in the MATLAB program; based on the broken line sweep of the fiber bundle cross section along the direction of the warp fiber bundle, a model of the warp fiber bundle is obtained; the major axis and minor axis lengths of the rhombus are respectively determined by the basic geometric parameters determined in step 2); the dielectric constant of the warp fiber bundle is determined by the preform configuration;

[0016] (3) Repeat steps (1) and (2) to represent the different warp and weft fiber orientations and fiber bundle cross-sectional shapes in the continuous fiber reinforced absorbing composite hybrid preform configuration using different piecewise functions in the MATLAB program, and then create the remaining warp and weft fiber orientations and fiber bundle cross-sectional shapes in the single-layer fiber hybrid two-dimensional unit model; based on the MATLAB platform, sweep the cross-section of each fiber bundle along the broken line of the corresponding fiber orientation to obtain a single-layer warp and weft fiber bundle model; the electromagnetic parameters of the warp and weft of the fiber bundle model are set according to the fiber properties corresponding to the preform configuration to obtain a complete single-layer fiber hybrid two-dimensional unit model.

[0017] In step (3), the preform may be in a plain woven fabric structure with two different fiber bundle orientations. The fiber bundles of the two different orientations may be represented by line segments with equal periods and slopes but opposite phases.

[0018] (4) According to the size and thickness of the preform configuration, the single-layer fiber hybrid two-dimensional unit model is replicated to form a complete multi-layer fiber hybrid two-dimensional unit model; the replication operation is performed by a MATLAB program.

[0019] (5) A multilayer fiber mixed two-dimensional unit model is wrapped with a cube model, and a Boolean subtraction operation is performed on the fibers of the multilayer fiber mixed two-dimensional unit model to remove the part of the cube model that interferes with the fiber bundle, thereby obtaining a complete continuous fiber reinforced absorbing composite material mixed two-dimensional unit model; the size and thickness of the cube model are determined by the preform configuration; the dielectric constant of the cube model is determined by the dielectric constant of the matrix; the setting of the cube and the Boolean subtraction operation are completed by relevant programs written in MATLAB.

[0020] In step (5), the geometric and material parameters of the cube model are determined by the geometric and material parameters obtained in steps (1) and (2). The simple fiber hybrid two-dimensional unit model significantly reduces the difficulty of meshing and the amount of calculation, thereby reducing the calculation cost.

[0021] (6) Set the boundary conditions, solver, port and meshing information of the hybrid two-dimensional unit model of continuous fiber reinforced absorbing composite materials in the MATLAB program, and perform simulation calculations on the absorbing performance;

[0022] In step (6), in the boundary condition setting, Xmin, Xmax, Ymin, and Ymax are set to Unit cell, Zmin is set to Electric (Et=0), and Zmax is set to Open (add space); the solver adopts a frequency domain solver; the ports are automatically arranged according to the setting of the boundary condition "Boundary Conditions" and no ports are manually added; the mesh division adopts adaptive mesh refinement.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) Taking into account the electromagnetic anisotropic structure of fiber woven materials, based on the fiber dielectric constants in different directions and combined with the MATLAB program to control the three-dimensional electromagnetic software automatic modeling method, the establishment of a two-dimensional unit model of anisotropic continuous fiber reinforced absorbing composite materials was completed in a targeted manner.

[0025] (2) The present invention adopts a simple fiber model structure with a fiber fold line orientation and a diamond cross section to achieve high-precision and high-speed calculation of the wave absorption performance. Compared with the traditional fiber model with a fiber curve orientation and an elliptical cross section, the difficulty of meshing and the amount of calculation are significantly reduced, thereby reducing the calculation cost. After verification, the calculation results of the model are highly consistent with the measured wave absorption performance, further improving the accuracy of the theoretical model in predicting the wave absorption performance.

[0026] (3) The modeling process of the present invention is fully parameterized. When the structural dimensions and electromagnetic parameters of the model change, the model can be quickly modified by simply modifying the function that controls the modeling. This is convenient and fast, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the process of the present invention.

[0028] Figure 2 Schematic diagram of scanning electron microscope for SiC fiber and glass fiber mixed plain fabric reinforced resin matrix composite material.

[0029] Figure 3 Schematic diagram for establishing the first warp fiber bundle unit model.

[0030] Figure 4 Schematic diagram for establishing the second warp fiber bundle unit model.

[0031] Figure 5 Schematic diagram of establishing a multi-layer fiber mixed two-dimensional unit model.

[0032] Figure 6 Schematic diagram of the mixed two-dimensional unit model of SiC fiber and glass fiber mixed plain fabric reinforced resin matrix composite material.

[0033] Figure 7 This is a comparison chart between the model calculation and the measured results. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the following embodiments will further illustrate the present invention in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] like Figure 1 A parameterized modeling method for a continuous fiber reinforced wave absorbing composite mixed two-dimensional unit model, characterized in that it comprises the following steps:

[0036] 1) Using the electromagnetic mixing law or related composite law, the dielectric constant of the anisotropic fiber reinforced resin matrix composite material and the dielectric constant of the matrix are tested to obtain the intrinsic dielectric constant of the anisotropic fiber;

[0037] 2) Based on the scanning electron microscope images of more than one structural unit of the continuous fiber reinforced absorbing composite material, the geometric parameters required for establishing the fiber mixed two-dimensional unit model are obtained;

[0038] 3) Use piecewise function to simulate the fiber orientation in the continuous fiber reinforced absorbing composite material structure and set the fiber bundle orientation;

[0039] 4) Using a piecewise function to simulate the cross section of a fiber bundle in a continuous fiber reinforced absorbing composite material structure, setting the cross section shape of the fiber bundle, and sweeping the cross section of the fiber bundle along the broken line of the fiber direction to obtain a fiber bundle model (single fiber bundle model);

[0040] 5) According to the preform configuration, the remaining warp and weft fiber bundle models in the single-layer fiber hybrid 2D unit model are established, and the electromagnetic parameters of each fiber bundle are set to obtain a complete single-layer fiber hybrid 2D unit model. Then, according to the thickness of the preform, the single-layer fiber hybrid 2D unit model is replicated to obtain a complete multi-layer fiber hybrid 2D unit model;

[0041] 6) According to the matrix size and electromagnetic parameters in the preform configuration, a cube is established as the matrix to completely cover the multi-layer fiber mixed two-dimensional unit model, and a Boolean subtraction operation is performed on the matrix and the multi-layer fiber mixed two-dimensional unit model to remove the part of the matrix interfering with the fiber bundle, thereby obtaining the continuous fiber reinforced absorbing composite material mixed two-dimensional unit model.

[0042] 7) Set the boundary conditions, solver, port and meshing information of the hybrid two-dimensional unit model of continuous fiber reinforced absorbing composite materials, and perform simulation calculations on the absorbing performance.

[0043] In steps 3) and 4), a broken line is used to simulate the direction of the fiber bundle, and a rhombus is used to simulate the cross-sectional shape of the fiber bundle. The broken line and the rhombus are both represented by different piecewise functions.

[0044] In step 5), in establishing the single-layer fiber mixed two-dimensional unit model, the preform of the present invention is configured as a plain fabric structure with two different fiber bundle orientations. The two fiber bundles with different orientations can be represented by line segments with equal periods and slopes but opposite phases.

[0045] In step 6), the matrix is ​​filled between the fiber bundles of the fiber mixed two-dimensional unit model, which is more consistent with the actual situation.

[0046] In step 7), the simple fiber hybrid two-dimensional unit model significantly reduces the difficulty of meshing and the amount of calculation, thereby reducing the computational cost.

[0047] The following example takes the parametric modeling of a SiC fiber and glass fiber mixed plain fabric reinforced resin-based composite material preform as an example, and the MATLAB program is used to control the three-dimensional electromagnetic simulation software to automatically establish the model. The process is as follows:

[0048] (1) Since SiC fiber and glass fiber have electromagnetic anisotropy, the dielectric constants of SiC fiber and glass fiber in the direction perpendicular to and parallel to the electric field were tested before the model was established. SiC fiber and glass fiber were cut into various sizes: 47.55mm, 22.15mm, 34.85mm, 15.80mm, 22.86mm, 10.16mm, 15.78mm and 7.90mm, and neatly placed in the corresponding rectangular molds in one direction. After epoxy resin and curing agent (4:1 mass ratio) were mixed evenly, the two fibers were impregnated by vacuum resin transfer molding and kept at room temperature for 24 hours for curing. The dielectric constant of the cured sample in the range of 4~18GHz was tested by vector network analyzer and waveguide method. The dielectric constant of epoxy resin was also prepared and tested by the same method. According to the test results, the intrinsic dielectric constant of the fiber was calculated by the mixing rule shown in formula (1). The volume ratio of fiber matrix was controlled at 1:3.

[0049] (1)

[0050] : Dielectric constant of composite material; : Fiber volume ratio; : Dielectric constant of substrate

[0051] (2) Use an automatic weaving machine to weave a certain proportion of SiC fiber and glass fiber in a plain weave pattern, cut the woven fabric into a size of 50mm×50mm, and stack several layers of woven fabric. Use the same method as in step 1) to cure the multiple layers of woven fabric, and use a scanning electron microscope to analyze the cross-section of the woven fabric after curing and the fiber woven fabric before curing. The schematic diagram of the scanning electron microscope of the SiC fiber and glass fiber mixed plain weave fabric reinforced resin matrix composite material is shown in the figure. Figure 2 As shown, according to the analysis results, the parameters of the unit weaving model are determined, such as the fiber spacing D=2mm, the major axis L=1.5mm, the minor axis S=0.15mm, and the thickness H=0.31mm of the single-layer fiber mixed two-dimensional unit model.

[0052] (3) Use piecewise functions to simulate the direction of the first warp fiber bundle and the cross-sectional shape of the fiber bundle. The direction is composed of four line segments, namely:

[0053] (2)

[0054] (3)

[0055] (4)

[0056] (5)

[0057] Among them, H is the thickness of the single-layer fiber mixed two-dimensional unit model, S is the short axis of the fiber section, D is the fiber spacing, L is the fiber width (the long axis of the fiber section), x and y are the values ​​on the x-axis and y-axis of the function coordinate system, respectively. By substituting the k value from 1 to 8 into the corresponding function, the direction of the first warp fiber bundle can be obtained ( Figure 3 ). In addition, the cross-sectional shape of the fiber bundle is simulated by the function (Equations 6 and 7), and its shape is approximately a rhombus with a major axis of L and a minor axis of S.

[0058] Based on the cross-section of the fiber bundle, a fold line sweep along the direction of the warp fiber bundle is used to obtain a model of a warp fiber bundle, such as Figure 3 shown.

[0059] (6)

[0060] (7)

[0061] (4) The piecewise function is also used to simulate the direction of the second warp fiber bundle and the cross-sectional shape of the fiber bundle; since the fiber blended fabric adopts plain weave, the fiber bundle direction of the second warp fiber bundle and the first warp fiber bundle are parallel in the warp direction, with the same period and slope, but opposite phase. Therefore, the direction of the second warp fiber bundle is simulated by piecewise function formulas (8) to (11). The cross-sectional shape of the second warp fiber bundle is the same as that of the first warp fiber bundle, and is still simulated by formulas (6) and (7). Then, based on the cross-sectional sweep of the second warp fiber bundle along the broken line of the direction of the second warp fiber bundle, the model of the second warp fiber bundle is obtained, as shown in Figure 4 shown.

[0062] (8)

[0063] (9)

[0064] (10)

[0065] (11)

[0066] (5) According to the fiber arrangement, fiber weaving pattern and other parameters of the SiC fiber and glass fiber mixed plain woven fabric reinforced resin-based composite material preform configuration, repeat the operations in steps (3) and (4) to supplement the remaining warp and weft fiber bundles in the single-layer SiC fiber and glass fiber mixed plain woven fabric reinforced resin-based composite material mixed two-dimensional unit model. And set the electromagnetic parameters of the weft and warp fiber bundles to obtain a complete single-layer fiber mixed two-dimensional unit model ( Figure 5 ). Then, the single-layer fiber mixed two-dimensional unit model is replicated according to the thickness of the preform configuration to obtain a multi-layer fiber mixed two-dimensional unit model.

[0067] (6) Add a matrix unit to the multi-layer fiber mixed two-dimensional unit model in step (5). The geometric and material parameters of the matrix unit are determined by the geometric and material parameters obtained in steps (1) and (2). Perform a Boolean subtraction operation on the matrix unit and the multi-layer fiber mixed two-dimensional unit model to remove the part of the matrix interfering with the fiber bundle, and obtain the final SiC fiber and glass fiber mixed plain fabric reinforced resin matrix composite material mixed two-dimensional unit model ( Figure 6 ).

[0068] (7) In the MATLAB program, the boundary conditions, solver, port and meshing information of the two-dimensional unit model of SiC fiber and glass fiber hybrid plain fabric reinforced resin matrix composite material are set, and then the model is simulated to simulate the reflection loss RL curve of the model. The boundary conditions are set as Unit cell, Xmin, Xmax, Ymin, and Ymax are the boundary ranges, Zmin is set as Electric (Et=0), and Zmax is set as Open (add space); the frequency domain solver is used to solve the wave absorption performance of the model; the port is automatically arranged according to the setting of the boundary condition "Boundary Conditions"; the meshing adopts adaptive mesh refinement to improve the simulation accuracy.

[0069] (8) Using an automatic weaving machine, weave a plain woven fabric of SiC fiber and glass fiber according to the preform configuration, repeat the same curing process as in step (1) to prepare a plain woven fabric reinforced resin-based composite material of SiC fiber and glass fiber.

[0070] The free space measurement method was used to test the wave absorption performance of the composite material with a size of 180 mm × 180 mm. Compared with the models with the same parameters and fiber fold line orientation, and the cross sections are elliptical, rectangular, hexagonal, and octagonal, the simulation results of the diamond cross-section model of the present invention have a higher degree of match with the measured results ( Figure 7 ), verify the accuracy and effectiveness of the model of the present invention.

[0071] The present invention deeply studies the wave absorption performance of SiC fiber and glass fiber mixed plain woven fabric reinforced resin-based composite materials, and establishes an accurate prediction model. A parametric modeling method is adopted to control the three-dimensional electromagnetic simulation software through the MATLAB program to realize the automatic establishment and simulation analysis of the model. The present invention successfully establishes a parametric model of a SiC fiber and glass fiber mixed plain woven fabric reinforced resin-based composite material preform, and proves the accuracy and effectiveness of the model through simulation analysis and experimental verification. The model can not only be used to predict the wave absorption performance of composite materials, but also provide strong support for material design and optimization.

[0072] The above embodiments are only preferred embodiments of the present invention and cannot be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. Parametric modeling method of continuous fiber reinforced absorbing composite mixed two-dimensional unit model, characterized by The following steps are involved: 1) Determine the dielectric constants of the fibers and matrix involved in the hybrid two-dimensional unit model: Since the fibers themselves are anisotropic, the waveguide method is used to test the dielectric constants of the continuous fiber reinforced absorbing composite materials parallel and perpendicular to the electric field direction. The intrinsic dielectric constants of the fibers parallel and perpendicular to the electric field direction are calculated by the mixing law or related composite law, and the dielectric constant of the matrix is ​​tested by the waveguide method or coaxial method; 2) Determine the basic geometric parameters required for establishing the fiber hybrid two-dimensional unit model: Prepare the continuous fiber reinforced absorbing composite material by vacuum resin transfer molding, analyze the geometric characteristics of the fiber hybrid structure by scanning electron microscopy, and determine the basic geometric parameters for constructing the fiber hybrid two-dimensional unit model; 3) Use MATLAB program to control three-dimensional electromagnetic simulation software to automatically establish a mixed two-dimensional unit model of continuous fiber reinforced absorbing composite materials. The steps include: setting the fiber bundle direction; setting the fiber cross-section and obtaining a single fiber bundle model; establishing a multi-layer fiber mixed two-dimensional unit model; establishing a mixed two-dimensional unit model of fiber reinforced absorbing composite materials; setting simulation conditions and simulation calculations.

2. The parameterized modeling method of the continuous fiber reinforced absorbing composite material mixed two-dimensional unit model according to claim 1, characterized in that In step 1), the fibers are divided into organic fibers and inorganic fibers, wherein the inorganic fibers include SiC ceramic fibers with adjustable resistivity, glass fibers, quartz fibers, nitride fibers, and alumina fibers with different dielectric constants; the organic fibers include aramid fibers, polyimide fibers, and poly(p-phenylene benzobisoxazole) fibers with different dielectric constants; the resistivity of SiC ceramic fibers with adjustable resistivity is 0.1-10 7 Ω·cm.

3. The parameterized modeling method of the continuous fiber reinforced absorbing composite mixed two-dimensional unit model according to claim 1, characterized in that In step 1), the substrate is divided into an inorganic substrate and an organic substrate with a low dielectric constant, wherein the inorganic substrate includes a quartz ceramic substrate, a nitride ceramic substrate, a carbide ceramic substrate, and an oxide ceramic substrate; the organic substrate includes epoxy resin, bismaleimide resin, silicone resin, and silicone rubber.

4. The parameterized modeling method of the continuous fiber reinforced absorbing composite mixed two-dimensional unit model according to claim 1, characterized in that In step 2), the basic geometric parameters include fiber width, fiber spacing, and thickness of a single-layer fiber mixed two-dimensional unit model.

5. The parameterized modeling method of the continuous fiber reinforced absorbing composite material mixed two-dimensional unit model according to claim 1, characterized in that In step 3), the MATLAB program is used to control the three-dimensional electromagnetic simulation software to automatically establish the mixed two-dimensional unit model of the continuous fiber reinforced absorbing composite material, and the specific steps are: (1) Use a broken line to simulate the direction of the warp fiber bundle in the hybrid structure of the continuous fiber reinforced absorbing composite material. Use a piecewise function to represent the broken line in the MATLAB program. The length and slope of the broken line are determined by the basic geometric parameters obtained in step 2). (2) Using a rhombus to simulate the cross-sectional shape of the fiber bundle in the hybrid structure of the continuous fiber reinforced absorbing composite material, the rhombus is represented and fitted by a function in the MATLAB program; based on the broken line sweep of the fiber bundle cross section along the direction of the warp fiber bundle, a model of the warp fiber bundle is obtained; the major axis and minor axis lengths of the rhombus are respectively determined by the basic geometric parameters determined in step 2); the dielectric constant of the warp fiber bundle is determined by the preform configuration; (3) Repeat steps (1) and (2) to represent the different warp and weft fiber orientations and fiber bundle cross-sectional shapes in the continuous fiber reinforced absorbing composite hybrid preform configuration using different piecewise functions in the MATLAB program, and then create the remaining warp and weft fiber orientations and fiber bundle cross-sectional shapes in the single-layer fiber hybrid two-dimensional unit model; Based on the MATLAB platform, the cross section of each fiber bundle is swept along the fold line corresponding to the fiber direction to obtain a single-layer warp and weft fiber bundle model; the electromagnetic parameters of the warp and weft of the fiber bundle model are set according to the fiber properties corresponding to the preform configuration to obtain a complete single-layer fiber mixed two-dimensional unit model; (4) According to the size and thickness of the preform configuration, the single-layer fiber hybrid two-dimensional unit model is copied to form a complete multi-layer fiber hybrid two-dimensional unit model; the copying operation is performed by the MATLAB program; (5) A cube model is used to cover a multi-layer fiber mixed two-dimensional unit model, and a Boolean subtraction operation is performed on the fibers of the multi-layer fiber mixed two-dimensional unit model to remove the part of the cube model that interferes with the fiber bundle, thereby obtaining a complete continuous fiber reinforced absorbing composite material mixed two-dimensional unit model; the size and thickness of the cube model are determined by the preform configuration; the dielectric constant of the cube model is determined by the dielectric constant of the matrix; the setting of the cube and the Boolean subtraction operation are completed by relevant programs written in MATLAB; the simple fiber mixed two-dimensional unit model significantly reduces the difficulty of meshing and the amount of calculation, thereby reducing the calculation cost; (6) The boundary conditions, solver, port and meshing information of the hybrid two-dimensional unit model of continuous fiber reinforced absorbing composite materials are set in the MATLAB program, and the absorbing performance is simulated and calculated.

6. The parameterized modeling method of the continuous fiber reinforced absorbing composite mixed two-dimensional unit model as claimed in claim 5, characterized in that In step (3), the preform is configured as a plain woven fabric structure, and has two different fiber bundle orientations. The fiber bundles of the two different orientations can be represented by line segments with the same period and slope but opposite phases.

7. The parameterized modeling method of the mixed two-dimensional unit model of the continuous fiber reinforced absorbing composite material according to claim 5, characterized in that In step (6), in the boundary condition setting, Xmin, Xmax, Ymin, and Ymax are set to Unitcell, Zmin is set to Electric, and Et=0; Zmax is set to Open, add space; the solver adopts a frequency domain solver; the ports are automatically arranged according to the boundary condition settings, and no ports are manually added; the mesh division adopts adaptive mesh refinement.

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