Fiber in-plane permeability testing device and method

Abstract

The invention belongs to the technical field of composite material fiber permeability, and provides a fiber in-plane permeability testing device and method.The fiber in-plane permeability testing device is provided with a first mold and a second mold which are made of transparent materials, the first mold and the second mold are sealed through sealing edges, and a glue injection opening is formed in the center of the second mold; a plurality of extraction openings are formed in the edge position of the second mold; during testing, a fiber sample is placed between the first mold and the second mold, and the edges of the first mold and the second mold are sealed through the sealing edges; resin is injected into the glue injection opening at preset glue injection pressure, air extraction is conducted through the air extraction opening at preset air extraction pressure, and the flowing front edge of the resin in the x direction and the flowing front edge of the resin in the y direction within preset time are measured; the permeability is calculated according to the flowing front edge of the resin in the x direction and the flowing front edge of the resin in the y direction, the whole device is simple, easy to carry and high in environmental applicability, the glue injection opening is formed in the center of the second mold, and permeability testing errors caused by the fiber deflection angle are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material fiber permeability performance, and in particular relates to a fiber in-plane permeability testing device and method. Background Art

[0002] The fiber permeability of composite materials refers to the interaction and penetration ability between fibers and resins in composite materials, which directly affects the mechanical properties and overall quality of composite materials. Therefore, the fiber in-plane permeability test can help us understand the mechanical properties and overall quality of composite materials, which has important guiding and reference purposes for the production and use of composite materials.

[0003] Traditional permeability testing devices are installed through metal templates, bolts, guide rails and other connectors. After the experiment, there are problems such as difficult to clean the resin, heavy weight, difficulty in carrying, and low environmental applicability. At the same time, the test results are inaccurate. For example, in traditional testing devices, the injection ports are located on both sides of the mold. The test results will be biased due to the existence of the fiber deflection angle. In addition, the influence of the experimental equipment and experimental environment on the experimental parameters is not considered when calculating the permeability, resulting in low accuracy of the permeability calculation. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a fiber in-plane permeability testing device and method, wherein a fiber sample is placed between a first mold and a second mold, and the edges of the first mold and the second mold are sealed by edge sealing; resin is injected into the injection port at a preset injection pressure, and air is exhausted through the exhaust port at a preset exhaust pressure, and the flow front of the resin in the x direction and the flow front of the y direction within a preset time are measured; the permeability is calculated based on the flow front of the resin in the x direction and the flow front of the y direction. The overall device is simple, easy to carry, and has high environmental applicability, and the injection port is arranged at the center of the second mold, thereby reducing the permeability test error caused by the fiber deflection angle.

[0005] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a fiber in-plane permeability testing device, which adopts the following technical scheme:

[0006] A fiber in-plane permeability testing device comprises a first mold, a second mold, and an edge seal arranged between the first mold and the second mold; the first mold and the second mold are made of transparent materials, a glue injection port is arranged at the center position of the second mold, and a plurality of air extraction ports are arranged at the edge position of the second mold.

[0007] Furthermore, the first mold and the second mold are transparent acrylic plates.

[0008] Furthermore, the edge sealing is a sealing strip.

[0009] Further, two air extraction ports are symmetrically arranged on the second mold.

[0010] To achieve the above object, in a second aspect, the present invention further provides a method for testing the in-plane permeability of fibers, adopting the following technical solutions:

[0011] A method for testing the in-plane permeability of fibers, using the in-plane permeability testing device described in the first aspect, includes: placing a fiber specimen between the first mold and the second mold, and using the edge seal to seal the edges of the first mold and the second mold; injecting resin into the injection port at a preset injection pressure, and extracting air through the air extraction port at a preset air extraction pressure, measuring the flow fronts of the resin in the x-direction and the y-direction within a preset time; calculating the permeability based on the flow fronts of the resin in the x-direction and the y-direction.

[0012] Further, when calculating the permeability, the permeability K in the x-direction xx , and the permeability K in the y-direction yy are respectively:

[0013]

[0014] where μ is the resin viscosity; ε is the porosity; t is the time; ΔP is the injection pressure; r xe is the resin flow front in the x-direction; r0 is the radius of the injection port; r ye is the resin flow front in the y-direction.

[0015] Further, the porosity ε is:

[0016]

[0017] where b is the number of fiber layers; c is the areal density; d is the fiber density; h is the thickness of the cavity between the first mold and the second mold.

[0018] Further, the injection pressure ΔP is corrected as:

[0019]

[0020] where ΔP0 is the theoretical injection pressure; H is the average distance from the multiple air extraction ports to the injection port; H0 is the preset distance; P1 is the injection pressure provided by the injection equipment; P2 is the negative pressure value of the air extraction port; P3 is the preset pressure difference; μ(T) is the viscosity at the real-time temperature; μ ref is the reference viscosity at the reference temperature; γ, β, and δ are preset coefficients.

[0021] Further, when |H - H0| is less than the preset lower limit value, γ is 0, and when |H - H0| is greater than the preset upper limit value, the position of the air extraction port is reset.

[0022] Further, when |P1 - P2| is less than the preset lower limit value, reseal the edge.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. The present invention provides a first mold and a second mold made of transparent materials, and the first mold and the second mold are sealed by an edge seal. A glue injection port is provided at the center position of the second mold, and a plurality of air extraction ports are provided at the edge position of the second mold; during testing, the fiber specimen is placed between the first mold and the second mold, and the edge of the first mold and the second mold is sealed by the edge seal; resin is injected into the glue injection port at a preset injection pressure, and air is extracted through the air extraction ports at a preset air extraction pressure, and the flow fronts of the resin in the x-direction and the y-direction are measured within a preset time; the permeability is calculated based on the flow fronts of the resin in the x-direction and the y-direction. The overall device is simple, easy to carry, and has high environmental adaptability. Moreover, the glue injection port is provided at the center position of the second mold, reducing the permeability test error caused by the fiber deflection angle.

[0025] 2. Based on the improvement of the equipment, when calculating the permeability, the sealing condition of the edge seal, the distance between the glue inlet and the air extraction port, etc. will all affect the actual injection pressure entering the glue injection port, thereby affecting the final permeability calculation; based on this, the present invention corrects the injection pressure provided by the glue injection equipment through the distance between the air extraction port and the glue inlet, the difference between the negative pressure value of the air extraction port and the injection pressure provided by the glue injection equipment, and the temperature, etc., to improve the accuracy of the actual injection pressure entering the glue injection port when calculating the permeability, so as to achieve the purpose of improving the calculation accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The specification drawings constituting a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments and descriptions thereof of this embodiment are used to explain this embodiment and do not constitute an improper limitation on this embodiment.

[0027] Figure 1 It is a schematic structural diagram of the test device according to Embodiment 1 of the present invention;

[0028] Figure 2 It is a schematic layout diagram of the glue injection port and the air extraction port according to Embodiment 1 of the present invention;

[0029] Figure 3 It is the left glue injection position according to Embodiment 1 of the present invention;

[0030] Figure 4 It is the left glue injection resin flow profile according to Embodiment 1 of the present invention;

[0031] Figure 5 It is the middle side glue injection position according to Embodiment 1 of the present invention;

[0032] Figure 6 is the intermediate resin injection flow profile of Embodiment 1 of the present invention;

[0033] Figure 7 is the right - hand side resin injection position of Embodiment 1 of the present invention;

[0034] Figure 8 is the right - hand side resin injection flow profile of Embodiment 1 of the present invention;

[0035] Figure 9 is the test process record of Embodiment 1 of the present invention;

[0036] Figure 10 is the Matlab sub - program calculation process of the test process record of Embodiment 3 of the present invention;

[0037] Figure 11 is the simulation calculation result of the resin flow for 9000 s of Embodiment 3 of the present invention;

[0038] Figure 12 is the experimental result of the resin flow for 9000 s of Embodiment 3 of the present invention;

[0039] Among them, 1 is the first mold; 2 is the second mold; 3 is the edge seal; 4 is the injection port; 5 is the air extraction port. Detailed implementation manners

[0040] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0041] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0042] Embodiment 1:

[0043] As shown in Figure 1 and Figure 2 , this embodiment provides a fiber in - plane permeability test device, including a first mold 1 and a second mold 2, and an edge seal 3 provided between the first mold 1 and the second mold 2; the first mold 1 and the second mold 2 are made of transparent materials, a resin injection port 4 is provided at the center of the second mold 2, and a plurality of air extraction ports 5 are provided at the edge of the second mold 2.

[0044] Optionally, the first mold 1 and the second mold 2 are made of transparent acrylic plates, which is convenient for observing and measuring the resin diffusion situation. The edge seal 3 is a sealing strip. Two air extraction ports 5 are symmetrically provided on the second mold 2, or four air extraction ports 5 are evenly distributed.

[0045] In the traditional testing device, the injection ports are located on both sides of the mold, and the test results will be larger due to the existence of the fiber deflection angle. In this embodiment, the injection port 4 is arranged at the central position of the second mold 2, avoiding the permeability test error caused by the fiber deflection angle.

[0046] In this embodiment, the effect of setting the injection port 4 at the central position of the second mold 2 is verified by simulation means. Specifically, as Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 8 shown, it can be found that when injecting glue from a non-central position, the resin flow profile is easily affected by the fiber deflection angle during the laying process, deviating from the elliptical or circular profile (not meeting the requirements of Darcy's law: to reduce errors, the test profile should be as elliptical or circular as possible according to the fiber type), resulting in errors in the fiber permeability test. At the same time, to prevent the influence of edge effects, the injection of this test device is improved to central injection compared with the existing device.

[0047] In this embodiment, the influence of the injection port quantity and flow rate is verified by designing different injection ports. See Table 1 for the resin filling time under different numbers of air extraction ports:

[0048] Table 1 Resin filling time under different numbers of air extraction ports

[0049] Number of air extraction ports 1 2 3 4 5 6 Filling time 837s 810s 812s 820s 803s 834s

[0050] The results show that in a closed vacuum environment, the resin flow rate does not change with the number of air extractions. To ensure the overall structural balance of the device, two symmetric air extraction ports can be selected.

[0051] In some embodiments, to ensure the in-plane permeability test accuracy of the fiber preform under the process conditions of vacuum-assisted resin transfer molding (VARTM), the test device design needs to meet the following requirements: use a highly transparent polymethyl methacrylate (PMMA) observation cavity, cooperate with a high-speed CCD imaging system to realize real-time monitoring of the resin flow front; set arrayed air extraction ports 5 (Φ8mm) at the mold edge, adopt a ring-shaped vacuum pipeline topology structure, and maintain the vacuum degree fluctuation ≤ ±50 Pa through a multi-channel pressure feedback device; arrange a conical tapered injection port (cone angle 15° ± 1°) at the geometric center of the mold, and be equipped with a high-precision metering pump (flow error < 0.5%) and a gradient pressure control system.

[0052] Optionally, the first mold 1 and the second mold 2 are made of transparent plates with surface treatment; vacuum quick-change interfaces (inner diameter Φ12mm) are arranged equidistantly on the edge of the mold cavity according to the ASTMD5687 standard, and a closed-loop flow channel network is constructed through a polytetrafluoroethylene vacuum pipeline. Two groups of circumferential interfaces are connected in parallel through a multi-way manifold and connected to a vacuum pump group. The central interface is used as a resin injection channel, and a high-precision electric needle valve (accuracy ±0.1% FS) is used to achieve dynamic control of vacuum degree (0-100kPa adjustable, response time <50ms).

[0053] In some embodiments, the test device is connected to a heating platform for experiments, and a pressure sensor is embedded between the fiber layers. By adjusting the pressure of a high-precision electric needle valve-the temperature of the heating platform-the resin flow, a fiber permeability test system and implementation method with integrated temperature-pressure-flow rate-electric field multi-field synchronous regulation is realized.

[0054] like Figure 9 The figure shows the penetration of resin into the fiber surface during the test, where r xe 、r ye They are the positions of the resin filling front at time t in the directions of the major axis Ra and the minor axis Rb, respectively, which can be obtained by recording the distance between the major and minor axes of the resin elliptical filling front at each moment.

[0055] Table 2 Resin filling front position at time t in the direction of long axis Ra and short axis Rb

[0056]

[0057]

[0058] Embodiment 2:

[0059] The present embodiment provides a fiber in-plane permeability testing method, using the fiber in-plane permeability testing device as described in Example 1, including: placing the fiber sample between the first mold 1 and the second mold 2, and sealing the edges of the first mold 1 and the second mold 2 using the edge sealing 3; injecting resin into the injection port 4 at a preset injection pressure, and exhausting air through the exhaust port 5 at a preset exhaust pressure, measuring the flow front of the resin in the x direction and the flow front of the y direction within a preset time; calculating the permeability based on the flow front of the resin in the x direction and the flow front of the y direction.

[0060] Optionally, when calculating permeability, the permeability K in the x direction xx , and the permeability K in the y direction yy They are:

[0061]

[0062] Wherein, μ is the resin viscosity; ε is the porosity; t is the time; ΔP is the injection pressure, which can be understood as the injection pressure provided by the injection device, the total pressure of the injection pressure provided by the injection device or the negative pressure value of the air extraction port, or the pressure at the injection port detected by the corresponding sensor; r xe is the resin flow front in the x direction; r0 is the radius of the injection port; r ye is the resin flow front in the y direction.

[0063] Optionally, the porosity ε is:

[0064]

[0065] Wherein, b is the number of fiber layers; c is the areal density; d is the fiber density; h is the thickness of the cavity between the first mold and the second mold.

[0066] Based on the improvement of the equipment, when calculating the permeability, the sealing condition of the edge seal, the distance between the glue inlet and the air extraction port, etc. will all affect the actual injection pressure entering the injection port, thereby affecting the final permeability calculation; and the change in the temperature of the rubber compound will cause a significant change in the viscosity (μ), further affecting the flow resistance, making the actual injection pressure deviate from the theoretical value and reducing the accuracy of the permeability calculation. Based on this, the present invention corrects the injection pressure provided by the injection device through the distance between the air extraction port and the glue inlet, the difference between the negative pressure value of the air extraction port and the injection pressure provided by the injection device, and the temperature, etc., to improve the accuracy of the actual injection pressure entering the injection port when calculating the permeability, so as to achieve the purpose of improving the calculation accuracy. Optionally, the correction of the injection pressure ΔP is:

[0067]

[0068] Wherein, ΔP0 is the theoretical injection pressure; H is the average distance between the multiple air extraction ports and the injection port; H0 is the preset distance; P1 is the injection pressure provided by the injection device; P2 is the negative pressure value of the air extraction port; P3 is the preset pressure difference; μ(T) is the viscosity at the real-time temperature; μ ref is the reference viscosity at the reference temperature; γ, β and δ are preset coefficients.

[0069] Optionally, when |H - H0| is less than the preset lower limit value, it indicates that the distance between the glue inlet and the air extraction port has little influence on the actual injection pressure P entering the injection port, and γ is 0. When |H - H0| is greater than the preset upper limit value, the position of the air extraction port is reset. When |P1 - P2| is less than the preset lower limit value, it indicates that the sealing problem affects the normal progress of the experiment, and the edge seal needs to be reset. When the absolute value of the deviation between the real-time temperature T and Tre is greater than 5°C, the test process is paused and the ambient temperature is adjusted by other means; when the absolute value of the deviation between the real-time temperature T and Tre is less than 5°C, the test continues.

[0070] Example 3:

[0071] This embodiment provides a method for testing the in-plane permeability of fibers, using the in-plane permeability testing device for fibers described in Embodiment 1 and the method in Embodiment 2. In this embodiment, a calculation program for permeability and porosity is compiled in MATLAB language to achieve efficient and rapid calculation. Traditional calculation of permeability and porosity is usually carried out by pen and paper or in an Excel spreadsheet, with low calculation efficiency. As Figure 10 shown, this embodiment realizes the one-key conversion of "experimental data → calculation results" through MATLAB language, greatly improving the calculation efficiency. The method of this embodiment includes:

[0072] S1. Clean the working environment: Close all figure windows, clear the command line history, and clear the variables in memory to ensure a fresh start.

[0073] S2. Specify the data file path: The user needs to provide the Excel file path of the actual test data.

[0074] S3. Load the parameter table: Read the data (denoted as data1) from the "Permeability Calculation" worksheet of the file, including parameters such as time and the position of the flow front.

[0075] Read the data (denoted as data2) from the "Porosity Calculation" worksheet, including the fiber layer thickness, number of layers, areal density, and fiber density.

[0076] S4. Extract parameters: Include the time series t, the resin flow front r x in the x direction, the resin flow front r y in the y direction, the single-layer thickness a, the number of fiber layers b, the areal density c, and the fiber density d, etc.

[0077] S5. Calculate the cavity thickness:

[0078] h = ab;

[0079] S6. Calculate the porosity:

[0080]

[0081] Among them, the numerator is the total mass of the fibers, and the denominator is the combined parameter of the cavity thickness and the fiber density.

[0082] S7. Set the injection parameters: The radius r r of the injection port, unit: meter; the resin viscosity u, and the injection pressure p.

[0083] S8. Process the flow front data: Convert the flow front positions r1 and r2 in the x and y directions from centimeters to meters.

[0084] S9. Determine the ply type, calculate the difference in the flow fronts in the x and y directions (r3 = r1 - r2), and count the number of times r5 that the difference exceeds 2 cm. If the number of times is less than 1, it is regarded as a quasi-isotropic ply; otherwise, it is treated as anisotropic.

[0085] S10. Calculate:

[0086] For a quasi-isotropic ply where r5 < 1, use a single permeability formula:

[0087]

[0088] where t = T × 60 (convert the time unit to seconds).

[0089] For an anisotropic ply (r5 > 1), calculate the permeabilities in the x and y directions (Kx and Ky) respectively:

[0090]

[0091] For the correction of the injection pressure, see Example 2 and will not be elaborated here.

[0092] Figure 11 As shown, it is the simulation calculation result of resin flow for 9000 s, Figure 12 and it is the experimental result of resin flow for 9000 s. Table 1 is the comparison table of simulation results and experiments.

[0093] Table 3 Comparison Table of Simulation Results and Experiments

[0094]

[0095]

[0096] Through Figure 12 it can be found that when the resin is diverted for about 9000 s, it basically reaches the boundary of the circular contour. From Table 3, it can be analyzed that for the 400 g / m 2 glass fiber square cloth, the moving speeds in the X and Y directions are almost the same as a whole, which conforms to the characteristics of plain weave fabric, thus verifying the correctness of the experiment. The reason for the error is the deformation between fiber bundles during laying. Through the comparison between experiment and simulation, the minimum error is 12.9%, the maximum error is 15%, and the average error is 17.9%, which is less than 20%, meeting the requirements in this direction, thus verifying the correctness of this analysis method.

[0097] In some embodiments, during the process of analyzing fiber permeability, due to a large amount of test data, the computational workload is large and prone to calculation errors. Therefore, the permeability results are programmed using the Matlab language, with the intrinsic characteristics of the raw material as the input end and the permeability results as the output end, to achieve fast, efficient, and multi-sample calculations. Submitting the calculation, the calculation results are shown in Table 4, and the permeability calculation path program is as follows:

[0098] clc; close all; clear;

[0099] filename = ('Enter the actual test data location'); % Set the test data location;

[0100] data1 = readtable(filename, 'Sheet', 'Permeability calculation'); % Read the test parameters;

[0101] data2 = readtable(filename, 'Sheet', 'Porosity calculation'); % Read the test parameters;

[0102] %% Calculate the porosity;

[0103] T = data1(:, 1); % Read the table time parameter;

[0104] rx = data1(:, 2); % Read the resin flow profile front in the x direction;

[0105] ry = data1(:, 3); % Read the resin flow profile front in the y direction;

[0106] a = data2(:, 1); % Read the single-layer thickness;

[0107] b = data2(:, 2); % Read the number of fiber layers;

[0108] c = data2(:, 3); % Read the areal density of the fiber;

[0109] d = data2(:, 4); % Read the fiber density;

[0110] t = a.Variables.*b.Variables; % Calculate the cavity thickness;

[0111] b1 = b.Variables; % Convert the data type;

[0112] c1 = c.Variables; % Convert the data type;

[0113] d1 = d.Variables; % Convert the data type;

[0114] fai = 1 - (1 / (2 * t)) * (sum(b1.*c1. / d1));

[0115] rr = 0.01; % Input the size of the injection port;

[0116] u = 0.75; % Input the fluid viscosity;

[0117] p = 100000; % Input the injection pressure;

[0118] r1 = rx.Variables / 100; % Convert the data type;

[0119] r2 = ry.Variables / 100; % Convert the data type;

[0120] %% Calculate the permeability;

[0121] r3 = r1 - r2;

[0122] r4 = r3 > 2;

[0123] r5 = sum(r4);

[0124] if r5 < 1 % Quasi-isotropic ply;

[0125] e1 = r1 / rr;

[0126] f1 = log(e1);

[0127] t1 = T.Variables * 60;

[0128] K = ((r1.*r1).*(f1.*2 - 1) + (rr*rr)).*(u*fai. / (4.*t1.*p)); else % Other plies;

[0129] e1 = r1 / rr;

[0130] e2 = r2 / rr;

[0131] f1 = log(e1);

[0132] f2 = log(e2);

[0133] t1 = T.Variables * 60;

[0134] Kx = ((r1.*r1).*(f1.*2 - 1) + (rr*rr)).*(u*fai. / (4.*t1.*p)); Ky = ((r2.*r2).*(f2.*2 - 1) + (rr*rr)).*(u*fai. / (4.*t1.*p)); End.

[0135] Table 4 Calculation Results

[0136]

[0137]

[0138] In summary, taking the in-plane two-dimensional permeability of 400 g / m2 fiberglass plain weave fabric as an example, the present invention optimizes the design of the traditional test device, improves the application scenario of the test device, and enhances the universality of the test method. Combining with the two-dimensional isotropic porous medium test method of Darcy's law, the in-plane two-dimensional permeability test method is summarized, and the accuracy of the device is verified by simulation. The present invention provides a test method for in-plane fiber permeability, a method for analyzing permeability data, and a test device, providing a theoretical basis for studying the movement of resin matrix in fiber reinforcement. The calculation method provided by the present invention can quickly calculate the permeability during the flow process of resin in various composite materials. The test results of the present invention are used as a key parameter in the simulation of the liquid composite molding (LCM) process, providing the most basic theoretical basis for predicting the resin flow state and the design of the runner. At the same time, the test device of the present invention is easy to disassemble and install, improving the application scenario of the test, saving the permeability data for cross-regional testing, and providing the test efficiency.

[0139] The above are only the preferred embodiments of this example and are not used to limit this example. For those skilled in the art, this example can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this example shall be included within the protection scope of this example.

Claims

1. A fiber in-plane permeability testing device, characterized in that: It includes a first mold, a second mold, and an edge seal arranged between the first mold and the second mold; the first mold and the second mold are made of transparent materials, a glue injection port is arranged at the center of the second mold, and multiple air extraction ports are arranged at the edge of the second mold.

2. A fiber in-plane permeability testing device as claimed in claim 1, characterized in that: The first mold and the second mold are transparent acrylic plates.

3. A fiber in-plane permeability testing device as claimed in claim 1, characterized in that: The edge sealing is a sealing strip.

4. A fiber in-plane permeability testing device as claimed in claim 1, characterized in that: The second mold is symmetrically provided with two air extraction ports.

5. A fiber in-plane permeability testing method, characterized in that: A fiber in-plane permeability testing device as described in any one of claims 1 to 4 is used, comprising: placing a fiber sample between the first mold and the second mold, and sealing the edges of the first mold and the second mold using the edge sealing; injecting resin into the injection port at a preset injection pressure, and exhausting air through the exhaust port at a preset exhaust pressure, measuring the flow front of the resin in the x direction and the flow front of the y direction within a preset time; and calculating the permeability based on the flow front of the resin in the x direction and the flow front of the resin in the y direction.

6. A fiber in-plane permeability testing method as claimed in claim 5, characterized in that: When calculating the permeability, the permeability K in the x direction is xx , and the permeability K in the y direction yy They are: Where, μ is the resin viscosity; ε is the porosity; t is the time; ΔP is the injection pressure; r xe is the resin flow front in the x direction; r0 is the injection port radius; r ye is the resin flow front in the y direction.

7. A fiber in-plane permeability testing method as claimed in claim 6, characterized in that: The porosity ε is: Wherein, b is the number of fiber layers; c is the surface density; d is the fiber density; and h is the thickness of the cavity between the first mold and the second mold.

8. A fiber in-plane permeability testing method as claimed in claim 6, characterized in that: The injection pressure ΔP is corrected as follows: Among them, ΔP0 is the theoretical injection pressure; H is the average distance between multiple suction ports and the injection port; H0 is the preset distance; P1 is the injection pressure provided by the injection equipment; P2 is the negative pressure value of the suction port; P3 is the preset pressure difference value; μ(T) is the viscosity at the real-time temperature; μ ref is the reference viscosity at the reference temperature; γ, β and δ are preset coefficients.

9. A fiber in-plane permeability testing method as claimed in claim 8, characterized in that: When |H-H0| is less than the preset lower limit, γ is 0, and when |H-H0| is greater than the preset upper limit, the position of the air extraction port is reset.

10. A fiber in-plane permeability testing method as claimed in claim 8, characterized in that: When |P1-P2| is less than the preset lower limit, reset the edge banding.

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