Fiber porous material three-dimensional orientation calculation method and system based on two-dimensional image

Abstract

The invention discloses a fiber porous material three-dimensional orientation calculation method and system based on a two-dimensional image, and belongs to the field of material structure analysis, and the method comprises the following steps: S1, obtaining a microscopic cross section picture of a fiber porous material through a microscopic characterization means; s2, calibrating a fiber segment in the microscopic cross section picture by using image processing software; s3, calibrating a main direction vector of fiber arrangement in the microscopic section pictures, calculating an included angle between a fiber section and the main direction vector, counting a standard deviation SD2D of the included angle, averaging statistical results of the plurality of microscopic section pictures of the section of the fiber porous material, s4, according to the fiber orientation overall distribution standard deviation # imgabs0 # in the microscopic cross section picture, calculating to obtain the fiber space orientation distribution standard deviation SD3D of the fiber porous material according to the fiber orientation overall distribution standard deviation # imgabs1 # in the microscopic cross section picture. According to the method for obtaining the fiber space orientation statistical characteristics by utilizing the two-dimensional microcosmic picture and based on the fiber porous material space distribution prior information, the method has the characteristics of low cost and high accuracy, the material analysis efficiency is remarkably improved, and the engineering application value is relatively high.

Description

Technical Field

[0001] The present invention relates to the field of material structure analysis, and in particular to a method and system for calculating the three-dimensional orientation of a fiber porous material based on a two-dimensional image. Background Art

[0002] As a typical porous material, fiber porous materials have excellent thermal and acoustic properties, such as fluid permeability, filtration, heat insulation and sound insulation, and have been widely used in various fields. Fiber porous materials are often used as filter materials (high permeability, low specific surface area per unit volume, high mechanical properties), thermal insulation materials (high mechanical properties, low thermal conductivity, low specific surface area per unit volume), sound insulation and sound absorption materials (high open porosity, uniform pore distribution, wide pore size) and shock absorption materials (high porosity, high mechanical properties).

[0003] The pores of fibrous porous materials are introduced by the mutual support of the fiber skeleton formed by the cross-linking of fibers. Therefore, the performance of fibrous porous materials not only depends on the fiber system of the parent material, but also is affected by the spatial distribution of the fibers. It has very excellent designability and is the most widely used artificial material. Therefore, the spatial distribution of fibrous porous materials, including the length, orientation, arrangement and other characteristics of the fibers, is a key parameter affecting its mechanical and conductive properties. Among them, the orientation of the fiber is a typical three-dimensional characteristic parameter, which is generally calculated and counted by CT scanning and professional software. The experimental and calculation costs are high, and the microstructural characteristics obtained by relatively cheap planar microscopic characterization methods such as SEM cannot obtain three-dimensional statistical information. Therefore, another new method for calculating fiber orientation is urgently needed. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of existing fiber orientation calculation methods and provide a method and system for calculating the three-dimensional orientation of fiber porous materials based on two-dimensional images, thereby improving material analysis efficiency and reducing analysis costs.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] In a first aspect, a method for calculating the three-dimensional orientation of a fibrous porous material based on a two-dimensional image is provided, comprising the following steps:

[0007] S1. Obtain microscopic cross-sectional photos of fibrous porous materials by microscopic characterization methods;

[0008] S2, using image processing software to calibrate the fiber segments in the microscopic cross-sectional photograph;

[0009] S3. Calibrate the main direction vector of the fiber arrangement in the microscopic cross-section photo, calculate the angle between the fiber segment and the main direction vector, and calculate the standard deviation SD of the angle 2D, the statistical results of multiple microscopic cross-sectional photos of the fiber porous material cross section are averaged to obtain the standard deviation of the overall distribution of fiber orientation in the microscopic cross-sectional photos

[0010] S4, based on the standard deviation of the overall distribution of fiber orientation in the microscopic cross-section photograph The standard deviation SD of the fiber spatial orientation distribution of the fibrous porous material is calculated. 3D .

[0011] In some embodiments, in step S1, the microscopic cross-sectional photos acquired by the microscopic characterization method include at least three photos of different parts of the same cross-section.

[0012] In some embodiments, in step S3, the calibration of the main direction vector of the fiber arrangement in the microscopic cross-sectional photograph is determined by calculating the mean of all calibrated fiber segments, wherein all vector directions are adjusted to be consistent by a vector inversion adjustment method.

[0013] In some embodiments, in step S3, the angle between the fiber segment and the main direction vector is in the range of 0° to 90°. If the angle exceeds the range, the supplementary angle is used.

[0014] In some embodiments, in step S3, the angle data between the fiber segment and the main direction vector is processed to symmetrize the source angle data, that is, another set of angle data is obtained by mapping with the function f(x)=180-x, and the new angle data is formed with the source angle data, and then the standard deviation SD is calculated. 2D .

[0015] In some embodiments, step S4 specifically includes:

[0016] Firstly, the prior distribution characteristics of the three-dimensional orientation of the fibers are determined;

[0017] Then, according to the prior distribution characteristics, the standard deviation SD of the fiber spatial orientation distribution is generated by mathematical random experiment. 3D The standard deviation of the overall distribution of fiber orientation Discrete relations between

[0018] Finally, the discrete relationship is used to interpolate or fit the measured standard deviation of the dimensional orientation distribution. Solve the standard deviation SD of fiber spatial orientation distribution 3D .

[0019] In some embodiments, the prior distribution characteristics refer to the statistical distribution characteristics of the zenith angle and azimuth angle of the fiber spatial orientation described according to the spherical coordinate system.

[0020] Preferably, the sample size of the mathematical random test is more than 100,000, and the standard deviation SD of the fiber spatial orientation distribution is 3D The sampling points are at least 1° apart.

[0021] In some embodiments, the fiber spatial orientation distribution standard deviation SD 3D The standard deviation of the overall distribution of fiber orientation The relationship between them is as follows:

[0022]

[0023] In a second aspect, a system for calculating the three-dimensional orientation of a fiber porous material based on a two-dimensional image is provided, comprising:

[0024] A microscopic cross-sectional photo acquisition module is used to obtain microscopic cross-sectional photos of fibrous porous materials by means of microscopic characterization;

[0025] A fiber segment calibration module, used to calibrate the fiber segments in the microscopic cross-section photo using image processing software;

[0026] The fiber orientation overall distribution calculation module is used to calibrate the main direction vector of the fiber arrangement in the microscopic cross-section photo, calculate the angle between the fiber segment and the main direction vector, and calculate the standard deviation SD of the angle 2D , the statistical results of multiple microscopic cross-sectional photos of the fiber porous material cross section are averaged to obtain the standard deviation of the overall distribution of fiber orientation in the microscopic cross-sectional photos

[0027] The fiber spatial orientation distribution calculation module is used to calculate the fiber spatial orientation distribution standard deviation based on the overall fiber orientation distribution standard deviation in the microscopic cross-section photo. The standard deviation SD of the fiber spatial orientation distribution of the fibrous porous material is calculated. 3D .

[0028] It should be further explained that the technical features corresponding to the above options can be combined or replaced with each other to form a new technical solution if there is no conflict.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention utilizes two-dimensional microscopic photographs to obtain the statistical characteristics of fiber spatial orientation based on prior information on the spatial distribution of fibrous porous materials. Compared with CT analysis, this method significantly reduces experimental costs, obtains results based on statistics, has the characteristics of high accuracy, significantly improves material analysis efficiency, and has high engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A flow chart of a method for calculating three-dimensional orientation of a fiber porous material based on a two-dimensional image according to an embodiment of the present invention;

[0032] Figure 2 A schematic diagram for describing fiber orientation according to an embodiment of the present invention;

[0033] Figure 3 θ is shown in the embodiment of the present invention Axis The variance of θ Projection The relationship between the variance of

[0034] Figure 4 This is a schematic diagram of the cross-sectional measurement of sample 1 shown in an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the cross-sectional measurement of sample 2 shown in an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the cross-sectional measurement of sample 3 shown in an embodiment of the present invention;

[0037] Figure 7 This is a schematic diagram of the cross-sectional measurement of sample 4 shown in an embodiment of the present invention;

[0038] Figure 8 This is a schematic diagram of the cross-sectional measurement of sample 5 shown in an embodiment of the present invention;

[0039] Fig. 9 Schematic diagram of the fiber orientation statistics method of the cross-sectional SEM image shown in an embodiment of the present invention ((a) original calibration data; (b) determination of the main direction of the material in the image; (c) adjusted data);

[0040] Fig.10 This is a schematic diagram of Micro-CT measurement results shown in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various configurations. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] It should be noted that the defects existing in the solutions in the above-mentioned prior art are the results obtained by the inventor after practice and careful research. Therefore, the discovery process of the above-mentioned problems and the solutions proposed in the embodiments of the present application for the above-mentioned problems below should all be the contributions made by the inventor to the present application in the process of invention and creation, and should not be understood as technical contents known to technical personnel in this field.

[0043] In view of the technical problems pointed out in the background technology, the embodiments provided by the present invention are as follows:

[0044] Reference Figure 1 In an exemplary embodiment, a method for calculating the three-dimensional orientation of a fibrous porous material based on a two-dimensional image is provided, comprising the following steps:

[0045] S1. Obtain a microscopic cross-sectional photograph of the fibrous porous material (sample) by microscopic characterization means;

[0046] S2. calibrating the fiber segments in the microscopic cross-sectional photograph using image processing software; defining a Cartesian coordinate system in the image plane, obtaining the endpoint coordinates of the fiber segments, and then exporting the endpoint data of each fiber segment for statistics;

[0047] S3. Calibrate the main direction vector of the fiber arrangement in the microscopic cross-section photo, calculate the angle between the fiber segment and the main direction vector, and calculate the standard deviation SD of the angle 2D , the statistical results of multiple microscopic cross-section photos of the sample cross section are averaged to obtain the standard deviation of the overall distribution of fiber orientation in the sample microscopic cross-section photos

[0048] S4, based on the standard deviation of the overall distribution of fiber orientation in the microscopic cross-section photograph Calculate the standard deviation SD of the fiber spatial orientation distribution of the sample 3D The calculation method is as follows:

[0049] First, determine the prior distribution characteristics of the fiber three-dimensional orientation, and then use mathematical random experiments to generate the standard deviation SD of the fiber spatial orientation distribution based on the distribution characteristics. 3D The standard deviation of the overall distribution of fiber orientation Finally, the discrete relationship is used to interpolate or fit the measured fiber orientation distribution standard deviation. Solve the standard deviation SD of fiber spatial orientation distribution 3D .

[0050] Furthermore, in step S1, the microscopic cross-sectional photographs obtained by the microscopic characterization means should contain a sufficient number of fiber segments and be able to clearly distinguish the main direction of the fiber arrangement; in order to ensure statistical accuracy, the microscopic cross-sectional photographs obtained by the microscopic characterization means should include at least 3 photographs of different parts of the same cross-section.

[0051] Furthermore, in step S2, the calibration process has no sequence constraints, and the orientation of the fiber segment is arbitrary.

[0052] Further, in step S3, the main direction of fiber arrangement in the cross-sectional photo refers to the main direction of material preferential orientation; the calibration of the main direction vector of the fiber arrangement in the cross-sectional photo is determined by calculating the mean of all calibration line segments, in order to avoid the uncertainty of statistical results caused by the difference in the direction of the starting end point position of the fiber in the statistical process, to ensure that the fiber is always oriented in the same direction and the statistical results are reliable, all vector directions are adjusted to be consistent through the vector reverse adjustment method, and the main direction of the material in the cross-sectional photo is calculated thereby;

[0053] Furthermore, when the distribution information of the angle is counted, the angle between the fiber segment and the main direction should be in the range of 0° to 90°. If the angle exceeds this range, the supplementary angle is taken. In addition, the angle data between the fiber segment and the main direction needs to be processed, and the source angle data needs to be symmetric, that is, another set of angle data is mapped using the function f(x) = 180-x, and the new angle data is formed with the source angle data, and then the standard deviation SD is calculated. 2D ;

[0054] Furthermore, in step S3, the measurement statistical results of multiple photo samples of the sample cross section are averaged, and the mean of the standard deviation of the angle in each photo is calculated to obtain the overall distribution standard deviation of the fiber orientation in the sample photo.

[0055] Furthermore, the prior distribution characteristics of the three-dimensional fiber orientation in step S4 refer to the statistical distribution characteristics of the zenith angle and azimuth angle of the fiber spatial orientation described according to the spherical coordinate system;

[0056] Furthermore, the sample size considered in the mathematical random test in step S4 should be large enough, generally more than 100,000, and the standard deviation SD of the fiber spatial orientation distribution should be 3D The sampling points should be sufficient to obtain relatively smooth discrete points, with an interval of at least 1°;

[0057] Furthermore, in step S4, the standard deviation SD of the fiber spatial orientation distribution is obtained. 3D The principle is:

[0058] If the spatial orientation of the fiber is described by a spherical coordinate system, such as Figure 2 As shown, the azimuth angle is defined as θ Plane , whose distribution probability density function is f1, and the angle between the fiber and the positive z-axis is defined as θ Axis , its distribution probability density function is f2, and the two are independent of each other.

[0059] Considering the projection of the fiber in the plane of the cross-sectional photo, define θ Projection is the angle between the projection line segment and the main direction of the projection plane material, that is, θ Projection is θ Axis The complementary angle of the projection angle in the photo plane, θProjection is the angle between the fiber segment and the main direction of the material in the image plane. Axis ,θ Plane The probability distribution density function can be used to obtain θ Projection Expected to be:

[0060] E(θ Projection ) = ∫∫cot -1 (tanθ Axis sinθ Plane )f1f2dθ Axi sdθ Plane

[0061] And θ Projection The variance of is:

[0062] D(θ Projection )=∫∫(cot -1 (tanθ Axis sinθ Plane )) 2 f1f2dθ Axis dθ Plane -(E(θ Proiection )) 2

[0063] In practical applications, E(θ Projection ) and D(θ Projection ) does not necessarily have an analytical form. Therefore, using the random experiment method, we can get θ Axis Variance SD 3D With θ Projection Variance The discrete relationship between them is obtained, so that the variance of the angle between the fiber and the main direction of the material in the image plane is measured, and the spatial orientation variance of the corresponding fiber is solved with considerable accuracy.

[0064] In particular, in step S4, if the azimuth angle θ of the fiber orientation is Plane Approximately uniform distribution between 0° and 360°, the zenith angle of fiber orientation θ Axis If it satisfies the normal distribution, then θ Axis Variance SD 3D With θ Projection Variance The discrete relationship between Figure 3 As shown, the curve can be accurately fitted by a five-parameter logistic function (Logistic5 function):

[0065]

[0066] Using the above formula (1), after measuring the variance of the angle between the fiber and the main direction of the material in the image plane, the standard deviation SD of the fiber spatial orientation distribution of the corresponding fiber can be obtained: 3D .

[0067] In one example, based on the practical application of the above method, the method of obtaining the statistical characteristics of fiber spatial orientation based on the prior information of the spatial distribution of fiber porous materials has significantly reduced the amount of experiments and calculations compared with the method of obtaining the statistical information of fiber orientation through CT scanning and large-scale calculation. Taking a ceramic fiber porous material as an example, the specific implementation method is as follows:

[0068] Step S1, obtaining a microscopic cross-section photograph of the fiber porous material by microscopic characterization means;

[0069] Among them, as for the microscopic characterization method, this embodiment uses SEM to obtain microscopic photos of the material cross section, and the obtained microscopic photos are as follows: Figures 4 to 8 shown.

[0070] Step S2, using image processing software to calibrate the fiber segments in the cross-sectional photograph, define a Cartesian coordinate system in the image plane, obtain the endpoint coordinates of the fiber segments, and then export the endpoint data of each fiber segment for statistics;

[0071] In the case where the quality of the photo is low and the accuracy of the automatic fiber orientation recognition of the image processing software is not high, the method of manual auxiliary calibration can be used to calibrate the fiber segment in the image. The initial coordinate axes of the calibration are the x-axis and y-axis of the image. The calibration process has no sequence constraints and the orientation of the fiber segment is arbitrary. The calibrated fiber segment in this embodiment is as follows: Figures 4 to 8 Shown as the blue line in the middle.

[0072] Step S3, calibrate the main direction vector of the fiber arrangement in the cross-sectional photo, calculate the angle between the fiber segment and the main direction vector, and calculate the standard deviation SD of the angle 2D , the measurement statistical results of multiple photo samples of the sample cross section are averaged to obtain the standard deviation of the overall distribution of fiber orientation in the sample photo

[0073] In the statistical process, the acquired fiber segment endpoint coordinates are first converted into vectors, as shown in Fig. 9 (a) The original calibration vector data shown;

[0074] In order to avoid the uncertainty of statistical results caused by the difference in the direction of the starting and ending points of the fibers during the statistical process, and to ensure that the fibers are always oriented in the same direction and the statistical results are reliable, all vector directions are adjusted to be consistent through the vector reverse adjustment method, and the main direction of the material in the cross-sectional SEM photo is calculated, such as Fig. 9 (b)

[0075] Finally, all vectors are transformed according to the main direction vector of the material, the main direction vector is transformed to the positive y-axis of the image, and the angle between all vectors and the main direction vector is ensured to be between 0° and 90°, as shown in the following figure: Fig. 9 (c) shows the results.

[0076] Finally, the angle between the statistical vector and the main direction vector, that is, the distribution information of the angle between the fiber and the main direction, is obtained, corresponding to the zenith angle of the spherical coordinate system, and the angle between the fiber and the main direction of the material in the image is obtained, such as Figures 4 to 8 Shown in the medium blue histogram.

[0077] Since the obtained angle information is not symmetrical, the original data is processed, the data is symmetrically copied, and statistical calculations are performed on this basis to obtain the following: Figures 4 to 8 The statistical results are shown in the green histogram. At this time, the histogram is symmetrically distributed. The mean and standard deviation of the SEM photo samples of different sample cross sections can be obtained by calculation, as shown in the following table.

[0078] Table 1 Statistical data of fiber orientation in photos

[0079] Data Source Mean(°) Standard deviation (°) Sample 1 90 33.291 Sample 2 90 34.581 Sample 3 90 32.439 Sample 4 90 35.007 Sample 5 90 36.423 Mean 90 34.348

[0080] The measurement statistical results were averaged to obtain an overall distribution mean of fiber orientation in the sample of 90.00° and a standard deviation of 34.35°.

[0081] Step S4: According to relevant literature, for this type of ceramic fiber porous material, the azimuth angle θ of the fiber orientation is Plane Approximately uniform distribution between 0 and 360°, the zenith angle of fiber orientation θ Axis The distribution of can be described by normal distribution, and the standard deviation SD of the spatial orientation distribution of the sample fiber can be calculated according to formula (1): 3D . Figures 4 to 8 The standard deviation of the fiber orientation photographs of the samples shown in is 34.35°, then the standard deviation SD of the fiber spatial orientation distribution of the sample is 3D It is 18.37°.

[0082] In addition, the samples were measured by Micro-CT, e.g. Fig.10 As shown, the measurement results were statistically analyzed using image processing software, and the statistical result of the fiber spatial orientation distribution was obtained to have a standard deviation of 18.56°, which was only -1.02% different from the result calculated by this method.

[0083] In another exemplary embodiment, based on the same inventive concept as the method, a system for calculating the three-dimensional orientation of a fibrous porous material based on a two-dimensional image is provided, comprising:

[0084] A microscopic cross-sectional photo acquisition module is used to obtain microscopic cross-sectional photos of fibrous porous materials by means of microscopic characterization;

[0085] A fiber segment calibration module, used to calibrate the fiber segments in the microscopic cross-section photo using image processing software;

[0086] The fiber orientation overall distribution calculation module is used to calibrate the main direction vector of the fiber arrangement in the microscopic cross-section photo, calculate the angle between the fiber segment and the main direction vector, and calculate the standard deviation SD of the angle 2D , the statistical results of multiple microscopic cross-sectional photos of the fiber porous material cross section are averaged to obtain the standard deviation of the overall distribution of fiber orientation in the microscopic cross-sectional photos

[0087] The fiber spatial orientation distribution calculation module is used to calculate the fiber spatial orientation distribution standard deviation based on the overall fiber orientation distribution standard deviation in the microscopic cross-section photo. The standard deviation SD of the fiber spatial orientation distribution of the fibrous porous material is calculated. 3D .

[0088] It should be noted that each module of the system implements the functions corresponding to each step in the method, and its specific implementation means are not elaborated here.

[0089] The above specific implementation methods are detailed descriptions of the present invention. It cannot be determined that the specific implementation methods of the present invention are limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions and substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A method for calculating the three-dimensional orientation of a fibrous porous material based on a two-dimensional image, characterized in that: The following steps are involved: S1. Obtain microscopic cross-sectional photos of fibrous porous materials by microscopic characterization methods; S2, using image processing software to calibrate the fiber segments in the microscopic cross-sectional photograph; S3. Calibrate the main direction vector of the fiber arrangement in the microscopic cross-section photo, calculate the angle between the fiber segment and the main direction vector, and calculate the standard deviation SD of the angle 2D , the statistical results of multiple microscopic cross-sectional photos of the fiber porous material cross section are averaged to obtain the standard deviation of the overall distribution of fiber orientation in the microscopic cross-sectional photos S4, based on the standard deviation of the overall distribution of fiber orientation in the microscopic cross-section photograph The standard deviation SD of the fiber spatial orientation distribution of the fibrous porous material is calculated. 3D .

2. The method for calculating the three-dimensional orientation of a fiber porous material according to claim 1, characterized in that: In the step S1, the microscopic cross-section photos obtained by the microscopic characterization means include at least three photos of different parts of the same cross-section.

3. The method for calculating the three-dimensional orientation of a fiber porous material according to claim 1, characterized in that: In step S3, the calibration of the main direction vector of the fiber arrangement in the microscopic cross-sectional photograph is determined by calculating the mean of all calibrated fiber segments, wherein all vector directions are adjusted to be consistent by a vector inversion adjustment method.

4. The method for calculating the three-dimensional orientation of a fiber porous material according to claim 1, characterized in that: In step S3, the angle between the fiber segment and the main direction vector is in the range of 0° to 90°. If the angle exceeds the range, the supplementary angle is used.

5. The method for calculating the three-dimensional orientation of a fiber porous material according to claim 1, characterized in that: In step S3, the angle data between the fiber segment and the main direction vector are processed to symmetrize the source angle data, that is, another set of angle data is obtained by mapping with the function f(x)=180-x, and the new angle data is formed with the source angle data, and then the standard deviation SD is calculated. 2D .

6. The method for calculating the three-dimensional orientation of a fiber porous material according to claim 1, characterized in that: The step S4 specifically includes: Firstly, the prior distribution characteristics of the three-dimensional orientation of the fibers are determined; Then, according to the prior distribution characteristics, the standard deviation SD of the fiber spatial orientation distribution is generated by mathematical random experiment. 3D The standard deviation of the overall distribution of fiber orientation Discrete relations between Finally, the discrete relationship is used to interpolate or fit the measured standard deviation of the dimensional orientation distribution. Solve the standard deviation SD of fiber spatial orientation distribution 3D .

7. The method for calculating the three-dimensional orientation of a fiber porous material according to claim 6, characterized in that: The prior distribution characteristics refer to the statistical distribution characteristics of the zenith angle and azimuth angle of the fiber spatial orientation described according to the spherical coordinate system.

8. The method for calculating the three-dimensional orientation of a fiber porous material according to claim 6, characterized in that: The sample size of the mathematical random test is more than 100,000, and the standard deviation of the fiber spatial orientation distribution SD 3D The sampling points are at least 1° apart.

9. The method for calculating the three-dimensional orientation of a fiber porous material according to claim 6, characterized in that: Fiber spatial orientation distribution standard deviation SD 3D The standard deviation of the overall distribution of fiber orientation The relationship between them is as follows:

10. A three-dimensional orientation calculation system for fiber porous materials based on two-dimensional images, characterized in that: include: A microscopic cross-sectional photo acquisition module is used to obtain microscopic cross-sectional photos of fibrous porous materials by means of microscopic characterization; A fiber segment calibration module, used to calibrate the fiber segments in the microscopic cross-section photo using image processing software; The fiber orientation overall distribution calculation module is used to calibrate the main direction vector of the fiber arrangement in the microscopic cross-section photo, calculate the angle between the fiber segment and the main direction vector, and calculate the standard deviation SD of the angle 2D , the statistical results of multiple microscopic cross-sectional photos of the fiber porous material cross section are averaged to obtain the standard deviation of the overall distribution of fiber orientation in the microscopic cross-sectional photos The fiber spatial orientation distribution calculation module is used to calculate the fiber spatial orientation distribution standard deviation based on the overall fiber orientation distribution standard deviation in the microscopic cross-section photo. The standard deviation SD of the fiber spatial orientation distribution of the fibrous porous material is calculated. 3D .

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