CN113129275A - Rock-soil mass material-based digital image three-dimensional structure characterization method - Google Patents

Rock-soil mass material-based digital image three-dimensional structure characterization method Download PDF

Info

Publication number
CN113129275A
CN113129275A CN202110346356.0A CN202110346356A CN113129275A CN 113129275 A CN113129275 A CN 113129275A CN 202110346356 A CN202110346356 A CN 202110346356A CN 113129275 A CN113129275 A CN 113129275A
Authority
CN
China
Prior art keywords
digital image
filling
radius
sphere
dimensional
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202110346356.0A
Other languages
Chinese (zh)
Other versions
CN113129275B (en
Inventor
刘江峰
马士佳
倪宏阳
林远健
李震
孙晨皓
尹乾
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
China University of Mining and Technology CUMT
Original Assignee
China University of Mining and Technology CUMT
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by China University of Mining and Technology CUMT filed Critical China University of Mining and Technology CUMT
Priority to CN202110346356.0A priority Critical patent/CN113129275B/en
Publication of CN113129275A publication Critical patent/CN113129275A/en
Application granted granted Critical
Publication of CN113129275B publication Critical patent/CN113129275B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00Image analysis
    • G06T7/0002Inspection of images, e.g. flaw detection
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T17/00Three dimensional [3D] modelling, e.g. data description of 3D objects
    • G06T5/70
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00Image analysis
    • G06T7/10Segmentation; Edge detection
    • G06T7/136Segmentation; Edge detection involving thresholding
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00Indexing scheme for image analysis or image enhancement
    • G06T2207/10Image acquisition modality
    • G06T2207/10072Tomographic images
    • G06T2207/10081Computed x-ray tomography [CT]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/30Assessment of water resources

Abstract

The invention discloses a rock-soil body material-based digital image three-dimensional structure representation method, and relates to the technical field of three-dimensional image processing. And reconstructing a three-dimensional model by adopting the computer microscopic digital image of the rock-soil mass material and measuring and calculating the distribution conditions of pores with different sizes to represent the three-dimensional pore structure of the target material. Acquiring a computer digital image of a material to be detected, and acquiring a binary image by adopting a threshold segmentation and image filtering method; superposing the binary images along the normal direction of the binary images in the original sample to obtain a binary three-dimensional model; calculating the space distance based on the binary three-dimensional model; selecting a sphere with a proper radius to fill the pore by taking a pore voxel corresponding to the maximum value in the distance values as a sphere center; recording the radius of the used sphere, and updating the three-dimensional model until all pores are filled; and summarizing and counting the radius value and the number of the spheres to generate a visual result. The method has stable and reliable measuring and calculating results and wide application range, and can provide powerful support for microscopic research of target materials.

Description

Rock-soil mass material-based digital image three-dimensional structure characterization method
Technical Field
The invention relates to the technical field of three-dimensional image processing, in particular to a rock-soil body material-based digital image three-dimensional structure characterization method.
Background
In the related field of capital construction, the rock-soil mass material is widely applied in the production and is also the key point of scientific research. The pore network randomly and widely distributed in the material determines the pore size distribution and the connectivity of the material, and further influences important technical indexes such as permeability, water retention and the like, so that the method has important significance in scientifically and efficiently measuring, calculating and representing the three-dimensional structure of the pore network. The three-dimensional structures of the current measurement and characterization rock-soil body are roughly divided into two types: one is based on physical actual measurement methods, such as mercury intrusion method, neutron scattering and the like, but the methods have the defects of narrow applicable scale range, sample damage, non-uniform and non-standard test operation flow and the like; the other method is to measure and calculate based on a computer digital image, such as Computed Tomography (CT), Scanning Electron Microscope (SEM) focused ion beam, scanning electron microscope (FIB-SEM) dual beam system, etc., but in the existing research, a two-dimensional calculation method is mostly used for measuring and calculating, and only a two-dimensional plane is represented, and defects such as irregular pore representation misalignment exist; and a small amount of three-dimensional calculation methods are adopted, the characterization results of different two-dimensional plane measurement and calculation are simply accumulated, the difference between the characterization results and the actual situation is large, and the three-dimensional pore structure of the target material cannot be truly characterized. In addition, when the three-dimensional pore space with different radiuses is described and characterized based on the digital image, the characterization error is increased to a certain extent due to the characteristic of digital image rasterization and the error between the calculated volume and the actual volume based on the digital image.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a new characterization method, which is used for measuring and calculating the distribution condition of a characterized pore structure in a three-dimensional space based on a rock-soil body material computer digital image reconstruction three-dimensional model and solving the problem that the three-dimensional pore can not be accurately and reliably measured by the existing method; meanwhile, in order to overcome the rasterization characteristics of the digital image, the representation schemes of spheres with different radiuses are optimized so as to greatly reduce the volume error when describing the spheres with different radiuses. The measuring and calculating result is stable and reliable, the application range is wide, and powerful technical support can be provided for other subsequent works.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a rock-soil mass material digital image-based three-dimensional structure characterization method comprises the following steps:
s1: acquiring a computer digital image of a material to be detected, and acquiring a clear noiseless binary image only containing pores and a skeleton by adopting a threshold segmentation and image filtering method, wherein 1 represents a skeleton region, and 0 represents a pore region;
s2: superposing the binary images obtained in the step S1 along the normal direction of the binary images in the original sample to obtain a binary three-dimensional model with the same length and width as the collected images and the same height as the number of the images;
s3: calculating the spatial distance based on the binary three-dimensional model, calculating the distance between each pore voxel and the nearest skeleton voxel, and marking the distance value at the corresponding position of the pore voxel, namely acquiring a three-dimensional array which has the same size with the original model and each element representing the distance between the corresponding position of the original three-dimensional model and the nearest skeleton voxel;
s4: filling the pore by taking the pore voxel corresponding to the maximum value in the marked distance values as the center of a sphere and taking the maximum value as the radius of the sphere; if the ball used for filling does not interfere with the existing framework region, filling is finished; if the filled ball interferes with the existing framework region, the position of the center of the ball is kept still, the radius is continuously reduced until the ball does not interfere with the existing framework region, and then filling is finished.
S5: recording the radius of the ball used when the filling is finished in S4, updating the three-dimensional model, and combining the area covered by the ball for filling and the existing skeleton area as a new skeleton area; the unfilled void region remains a void region;
s6: repeating S4-S5 on the updated three-dimensional model until all pores of the three-dimensional model are filled; summarizing the radiuses and the corresponding numbers of the spheres used in the filling process, counting the percentage of the respective volumes of the spheres with different radiuses in the total pore area volume, and converting the actual distances in the three-dimensional model in the corresponding display of the different radiuses according to the scaling of the original digital image.
Further, based on the size of the ball used in the filling process, summarizing the size and the corresponding number of all the balls used for filling, and converting the voxel distance into an actual distance to obtain a three-dimensional structure representation result; the unit conversion method is as follows:
r=ri×L
wherein r isiThe radius is a certain size of a filling sphere, L is the length of a 1 voxel in a mesoscopic digital image acquired by S1 corresponding to the reality, r is the radius value of a sphere with the radius in the three-dimensional reconstruction model in the reality, and the unit is consistent with L;
the method for calculating the distribution frequency of pores with different sizes in the three-dimensional structure comprises the following steps:
Figure BDA0003000838670000021
wherein, PiRefers to the distribution frequency, r, of pores of that size in a three-dimensional structureiRefers to a certain size, n, of the ball for fillingiRefers to the number of balls of that size, V, during the filling processiRefers to the total volume, V, of the ball filling of that sizeglobalRefers to the total volume of the void region.
Further, in step S4, in order to reduce the volume error based on the spheres with different radii of the digital image and the reality, the sphere characterization schemes with different radii are modified: calculating the number n of voxels occupied by a sphere with the radius r in the digital image, and combining the voxel with the center of the sphere and the nearest n-1 voxels to obtain a representation scheme of the sphere with the radius r in the digital image;
Figure BDA0003000838670000022
where n is the number of voxels that a sphere of radius r occupies in the digital image, [. sup. ] denoting rounding down.
Has the advantages that: the method provided by the invention can measure and calculate the real three-dimensional pore structure of the characterization target material, but the existing method is mostly limited to a two-dimensional plane, and the characterization result is difficult to be close to the real situation. Meanwhile, the measuring range is comprehensive, and the method can be suitable for the irregular pores such as 'ink bottle type' and the like. And the representation scheme of spheres with different radiuses is improved, so that the error between the pore volumes with different radiuses and the reality caused by the adoption of digital image rasterization is greatly reduced, and the accuracy is improved. Compared with the existing experimental means, the method can quickly and accurately construct and characterize the real three-dimensional structure for measuring and calculating various scaling scales under the condition of not damaging the sample.
Drawings
FIG. 1 is a flow chart of a characterization method;
FIG. 2 is a schematic of a three-dimensional reconstruction;
FIG. 3 is a three-dimensional structure characterization measurement;
fig. 4 is a visual filling result.
Detailed Description
The technical solution of the present invention is further described below with reference to the accompanying drawings and examples.
The invention relates to a rock-soil mass material-based digital image three-dimensional structure characterization method, which has a specific flow shown in figure 1 and comprises the following steps:
s1: and (6) obtaining a binary image. Acquiring a computer digital image of a material to be detected, and acquiring a clear noiseless binary image only containing pores and a skeleton by adopting a threshold segmentation and image filtering method, wherein 1 represents a skeleton region, and 0 represents a pore region; the computer digital image is obtained by acquiring images of different cross sections in the same normal direction of a sample to be detected by adopting microscopic digital image acquisition technologies such as CT, FIB-SEM and the like. In this embodiment, 500 × 500 voxels are selected to collect a microscopic image of a certain coal sample by FIB-SEM, and binary images are obtained by using methods such as threshold segmentation and median filtering.
S2: and (4) three-dimensional reconstruction. Superposing the binary images obtained in the step S1 along the normal direction of the binary images in the original sample to obtain a binary three-dimensional model with the same length and width as the collected images and the same height as the number of the images; in the stack of the three-dimensional model, 1 represents a skeleton region and 0 represents a pore region. In this embodiment, 500 binary images are sequentially superimposed along the normal direction of the image, so as to obtain 500 × 500 array stacks, i.e., a three-dimensional reconstruction model of the material to be measured, as shown in fig. 2.
S3: and calculating the space distance. Calculating the spatial distance based on the binary three-dimensional model, calculating the distance between each pore voxel and the nearest skeleton voxel, and marking the distance value at the corresponding position of the pore voxel, namely acquiring a three-dimensional array which has the same size with the original model and each element representing the distance between the corresponding position of the original three-dimensional model and the nearest skeleton voxel;
the distance calculation method is shown in formula (1):
Figure BDA0003000838670000031
wherein x isi,yi,ziRepresenting measured pore voxels, x1,y1,z1Representing the skeleton voxel closest thereto, DiRepresenting the distance to its nearest skeletal voxel.
S4: and (6) filling. Filling the pore by taking the pore voxel corresponding to the maximum value in the marked distance values as the center of a sphere and taking the maximum value as the radius of the sphere; if the ball used for filling does not interfere with the existing skeleton region, namely the ball does not cover any skeleton voxel, the filling is finished; if the filled ball interferes with the existing skeleton area, namely the ball covers a certain skeleton voxel, the position of the center of the ball is kept still, the radius is continuously reduced until the ball does not interfere with the existing skeleton area, and then filling is finished.
The characterization scheme of spheres with different radii is as follows: calculating the number n of voxels occupied by a sphere with the radius r in a digital image, and combining the voxel with the center of the sphere and the nearest n-1 voxels to obtain a representation scheme of the sphere with the radius r in the digital image;
Figure BDA0003000838670000032
where n is the number of voxels that a sphere of radius r occupies in the digital image, [. sup. ] denoting rounding down.
S5: recording the radius of the ball used when the filling is finished in S4, updating the three-dimensional model, and combining the area covered by the ball for filling and the existing skeleton area as a new skeleton area; the unfilled void region remains a void region.
S6: repeating S4-S5 on the updated three-dimensional model until all pores of the three-dimensional model are filled (the three-dimensional model is all skeleton voxels, and the element values in the stack are all 1); summarizing the radiuses and the corresponding numbers of the spheres used in the filling process, counting the percentage of the respective volumes of the spheres with different radiuses in the total pore area volume, and converting the actual distances in the three-dimensional model in the corresponding display of the different radiuses according to the scaling of the original digital image.
And (3) summarizing statistics and generating a visual result: the three-dimensional structure representation result is the pores with different sizes and the corresponding distribution frequency in the three-dimensional structure. The visual filling result is that the original pore areas filled by the spheres with different sizes are displayed in different colors after the filling is finished. And summarizing the sizes and the corresponding numbers of all the balls for filling based on the sizes of the balls for recording in the filling process, thereby finishing a three-dimensional structure characterization result (such as figure 3) and a visual filling result (such as figure 4) after converting the voxel distance into an actual distance. In the present embodiment, the unit conversion method is as follows:
r=ri×L
wherein r isiThe radius is a certain size of a filled sphere, L is a length of a 1 voxel in the mesoscopic digital image acquired at S1 corresponding to the real world, r is a radius value of a sphere with the radius in the three-dimensional reconstruction model in the real world, and the unit is consistent with L.
The method for calculating the distribution frequency of pores with different sizes in the three-dimensional structure comprises the following steps:
Figure BDA0003000838670000041
wherein r isiRefers to a certain size, n, of the ball for fillingiRefers to the number of balls of that size, V, during the filling processiRefers to the total volume, V, of the ball filling of that sizeglobalTotal volume of finger hole area, PiRefers to the frequency of distribution of pores of that size in a three-dimensional structure.
The foregoing is a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims (3)

1. A rock-soil mass material digital image-based three-dimensional structure characterization method is characterized by comprising the following steps of: the method comprises the following steps:
s1: acquiring a computer digital image of a material to be detected, and acquiring a clear noiseless binary image only containing pores and a skeleton by adopting a threshold segmentation and image filtering method, wherein 1 represents a skeleton region, and 0 represents a pore region;
s2: superposing the binary images obtained in the step S1 along the normal direction of the binary images in the original sample to obtain a binary three-dimensional model with the same length and width as the collected images and the same height as the number of the images;
s3: calculating the spatial distance based on the binary three-dimensional model, calculating the distance between each pore voxel and the nearest skeleton voxel, and marking the distance value at the corresponding position of the pore voxel, namely acquiring a three-dimensional array which has the same size with the original model and each element representing the distance between the corresponding position of the original three-dimensional model and the nearest skeleton voxel;
s4: filling the pore by taking the pore voxel corresponding to the maximum value in the marked distance values as the center of a sphere and taking the maximum value as the radius of the sphere; if the ball used for filling does not interfere with the existing framework region, filling is finished; if the filled ball interferes with the existing framework region, keeping the position of the center of the ball still, and continuously reducing the radius until the ball does not interfere with the existing framework region, and finishing filling;
s5: recording the radius of the ball used when the filling is finished in S4, updating the three-dimensional model, and combining the area covered by the ball for filling and the existing skeleton area as a new skeleton area; the unfilled void region remains a void region;
s6: repeating S4-S5 on the updated three-dimensional model until all pores of the three-dimensional model are filled; summarizing the radiuses and the corresponding numbers of the spheres used in the filling process, counting the percentage of the respective volumes of the spheres with different radiuses in the total pore area volume, and converting the actual distances in the three-dimensional model in the corresponding display of the different radiuses according to the scaling of the original digital image.
2. The rock-soil mass material digital image-based three-dimensional structure characterization method according to claim 1, wherein: based on the size of the ball used in the filling process, summarizing the size and the corresponding number of all the balls used for filling, and converting the voxel distance into an actual distance to obtain a three-dimensional structure representation result; the unit conversion method is as follows:
r=ri×L
wherein r isiThe radius is a certain size of a filling sphere, L is the length of a 1 voxel in a mesoscopic digital image acquired by S1 corresponding to the reality, r is the radius value of a sphere with the radius in the three-dimensional reconstruction model in the reality, and the unit is consistent with L;
the method for calculating the distribution frequency of pores with different sizes in the three-dimensional structure comprises the following steps:
Figure FDA0003000838660000011
wherein, PiRefers to the distribution frequency, r, of pores of that size in a three-dimensional structureiRefers to a certain size, n, of the ball for fillingiRefers to the number of balls of that size, V, during the filling processiRefers to the total volume, V, of the ball filling of that sizeglobalRefers to the total volume of the void region.
3. The rock-soil mass material digital image-based three-dimensional structure characterization method according to claim 1 or 2, wherein: in step S4, the sphere with radius r is characterized by: calculating the number n of voxels occupied by a sphere with the radius r in the digital image, and combining the voxel with the center of the sphere and the nearest n-1 voxels to obtain a representation scheme of the sphere with the radius r in the digital image;
Figure FDA0003000838660000021
where n is the number of voxels that a sphere of radius r occupies in the digital image, [. sup. ] denoting rounding down.
CN202110346356.0A 2021-03-31 2021-03-31 Three-dimensional structure characterization method based on rock-soil mass material digital image Active CN113129275B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110346356.0A CN113129275B (en) 2021-03-31 2021-03-31 Three-dimensional structure characterization method based on rock-soil mass material digital image

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110346356.0A CN113129275B (en) 2021-03-31 2021-03-31 Three-dimensional structure characterization method based on rock-soil mass material digital image

Publications (2)

Publication Number Publication Date
CN113129275A true CN113129275A (en) 2021-07-16
CN113129275B CN113129275B (en) 2024-04-19

Family

ID=76774335

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110346356.0A Active CN113129275B (en) 2021-03-31 2021-03-31 Three-dimensional structure characterization method based on rock-soil mass material digital image

Country Status (1)

Country Link
CN (1) CN113129275B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114565658A (en) * 2022-01-14 2022-05-31 武汉理工大学 Pore size calculation method and device based on CT technology
CN115872760A (en) * 2022-10-24 2023-03-31 西安鑫垚陶瓷复合材料股份有限公司 Filling method of strip holes in ceramic matrix composite prefabricated body

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015068686A1 (en) * 2013-11-06 2015-05-14 東レ株式会社 Method for manufacturing three-dimensional structure, method for manufacturing scintillator panel, three-dimensional structure, and scintillator panel
US20170372470A1 (en) * 2016-06-27 2017-12-28 Sun Yat-Sen University Method of separating, identifying and characterizing cracks in 3d space
CN107817199A (en) * 2016-09-14 2018-03-20 中国石油化工股份有限公司 A kind of construction method of tight sand multi-scale porosity model and application
CN112435288A (en) * 2020-10-28 2021-03-02 中国矿业大学 Pore feature calculation method based on image

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015068686A1 (en) * 2013-11-06 2015-05-14 東レ株式会社 Method for manufacturing three-dimensional structure, method for manufacturing scintillator panel, three-dimensional structure, and scintillator panel
US20170372470A1 (en) * 2016-06-27 2017-12-28 Sun Yat-Sen University Method of separating, identifying and characterizing cracks in 3d space
CN107817199A (en) * 2016-09-14 2018-03-20 中国石油化工股份有限公司 A kind of construction method of tight sand multi-scale porosity model and application
CN112435288A (en) * 2020-10-28 2021-03-02 中国矿业大学 Pore feature calculation method based on image

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DE\' AN SUN等: "AN ELASTO-PLASTIC MODEL FOR UNSATURATED SOIL IN THREE-DIMENSIONAL STRESSES", 《SOILS AND FOUNDATIONS》, vol. 40, no. 3, 30 June 2020 (2020-06-30), pages 17 - 28 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114565658A (en) * 2022-01-14 2022-05-31 武汉理工大学 Pore size calculation method and device based on CT technology
CN115872760A (en) * 2022-10-24 2023-03-31 西安鑫垚陶瓷复合材料股份有限公司 Filling method of strip holes in ceramic matrix composite prefabricated body

Also Published As

Publication number Publication date
CN113129275B (en) 2024-04-19

Similar Documents

Publication Publication Date Title
Zhou et al. Three-dimensional sphericity, roundness and fractal dimension of sand particles
Wiebicke et al. On the metrology of interparticle contacts in sand from x-ray tomography images
CN101639434A (en) Method for analyzing pore structure of solid material based on microscopic image
Lin et al. 3D characterization and analysis of particle shape using X-ray microtomography (XMT)
Thompson et al. Quantitative computer reconstruction of particulate materials from microtomography images
CN113129275A (en) Rock-soil mass material-based digital image three-dimensional structure characterization method
CN108459318A (en) Potential landslide EARLY RECOGNITION method based on remote sensing technology
CN109341626B (en) Straightness calculation method, and method for calculating difference between maximum diameter and minimum diameter of cross section
Lux et al. 3D characterization of wood based fibrous materials: an application
CN104619952A (en) Digital rock analysis systems and methods with reliable multiphase permeability determination
CN109242985B (en) Method for determining key parameters of pore structure from three-dimensional image
Felfer et al. Applying computational geometry techniques for advanced feature analysis in atom probe data
CN109100719B (en) Terrain map joint mapping method based on satellite-borne SAR (synthetic aperture radar) image and optical image
CN115235977A (en) Method and system for calculating shale multi-scale pore size distribution based on fractal characteristics
CN101980304A (en) Three-dimensional digital volume image distortion measuring method
CN112435288B (en) Image-based pore feature calculation method
Zhang et al. Three‐dimensional quantitative analysis on granular particle shape using convolutional neural network
CN109556542B (en) CT size measurement method for complex lattice hollow structure
CN110211091A (en) A kind of full resolution pricture reconstructing method, device and crack nondestructive detection system
US10290123B2 (en) Method of segmenting the image of an object reconstructed by three-dimensional reconstruction
Anusree et al. Characterization of sand particle morphology: state-of-the-art
Biswal et al. Towards precise prediction of transport properties from synthetic computer tomography of reconstructed porous media
CN116429295A (en) Method for evaluating contact stress distribution of rock mass structural plane
CN114396892B (en) Track curvature measuring method for track traffic curve
Bloom et al. Measurement of porosity in granular particle distributions using adaptive thresholding

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant