Rock multi-scale multi-source damage fracture monitoring method and system

Abstract

The invention provides a rock multi-scale multi-source damage fracture monitoring method and system.The rock multi-scale multi-source damage fracture monitoring method comprises the steps that a rock test piece is obtained, and loading treatment is conducted on the rock test piece; performing imaging scanning on the rock test piece through a pre-configured imaging module to obtain multi-scale digital images of the rock test piece in different stages in the loading treatment process; the imaging module comprises at least two of an X-mu CT control and imaging module, an NMR control scanning and imaging module and an HSC-DIC control imaging module; and extracting multi-scale crack image features of the multi-scale digital image, and carrying out multi-scale damage fracture process analysis on the rock test piece to obtain an analysis result. According to the invention, synchronous monitoring and time sequence imaging of multi-scale rock damage and fracture characteristics are realized, and the problems of incapability of multi-scale monitoring and imaging and poor efficiency and precision of the existing rock damage and fracture monitoring technology are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of rock analysis, and in particular to a method and system for monitoring multi-scale and multi-source damage fracture of rocks. Background Art

[0002] The multi-scale damage fracture process of rocks seriously affects the recovery rate of deep rock reservoir resources and the development of mining technologies, and at the same time seriously affects the safety and stability of deep rock reservoir resource mining and CO 2 - the safety and stability of the nuclear waste deep burial project. Therefore, the development of rock damage fracture monitoring technology has extensive practical application value and huge economic benefits.

[0003] The existing rock damage fracture monitoring technologies mainly include two categories: non-intuitive monitoring technologies and intuitive visualization monitoring technologies. The former mainly includes conventional damage fracture mechanics testing technologies, such as stress-strain testing, ultrasonic and acoustic emission testing technologies, etc. The latter mainly includes testing technologies such as Scanning electron microscope (SEM), Nuclear magnetic resonance (NMR), Computed Tomography (CT) scanning imaging, and digital photography. However, both non-intuitive and intuitive visualization monitoring technologies have problems such as only targeting a single scale, being unable to conduct multi-scale joint monitoring, long testing time, and high cost. Specifically, it can be divided into the following aspects: (1) Non-intuitive monitoring technologies cannot specifically image the damage fracture process, and it is difficult to intuitively display the specific location and damage characteristics of the damage fracture; (2) Although intuitive visualization monitoring technologies can finely and intuitively reveal the damage fracture process, they only target a specific scale, cannot conduct multi-scale damage fracture process monitoring, and due to the imaging resolution limitation of intuitive visualization monitoring technologies, there are problems such as long testing time and insufficient resolution for capturing damage characteristics in the damage fracture process of large-scale specimens; (3) Both non-intuitive and intuitive visualization monitoring technologies have problems such as only targeting a single scale, being unable to conduct multi-scale joint monitoring, long testing time, high cost, and being unable to achieve cross-scale monitoring of rock damage fracture.

[0004] Thus, the existing rock damage fracture monitoring technologies all have problems such as being unable to conduct multi-scale joint monitoring, long testing time, high cost, and being unable to achieve cross-scale monitoring of rock damage fracture, which severely restricts the revelation of multi-rock multi-scale damage fracture behaviors and mechanisms, and further affects the deep earth resource mining efficiency, the development of mining technologies, and the safety and stability of deep engineering.

[0005] For the problems that existing rock damage and fracture monitoring technologies cannot perform multi-scale monitoring imaging and have poor efficiency and accuracy, no effective solutions have been proposed yet. Summary of the Invention

[0006] The present invention provides a multi-scale and multi-source rock damage and fracture monitoring method and system to solve the defects that existing rock damage and fracture monitoring technologies cannot perform multi-scale monitoring imaging and have poor efficiency and accuracy, and realizes synchronous time-series imaging of multi-scale rock damage and fracture characteristics.

[0007] In the first aspect, the present invention provides a multi-scale and multi-source rock damage and fracture monitoring method, including: Obtain a rock specimen and perform a loading process on the rock specimen; Perform multi-scale imaging scanning on the rock specimen through a pre-configured imaging module to obtain multi-scale digital images of different stages of the rock specimen during the loading process; the imaging module includes at least two of an X-μCT control and imaging module, an NMR control scanning and imaging module, and an HSC-DIC control imaging module; Extract multi-scale crack image features of the multi-scale digital images, analyze the multi-scale damage and fracture process of the rock specimen, and obtain an analysis result.

[0008] According to the multi-scale and multi-source rock damage and fracture monitoring method provided by the present invention, obtaining a rock specimen and performing a loading process on the rock specimen includes: Obtain a rock raw material to be analyzed and make the rock raw material into the rock specimen according to a preset size; Perform a loading process on the rock specimen.

[0009] According to the multi-scale and multi-source rock damage and fracture monitoring method provided by the present invention, configuring the imaging module includes: Set the imaging resolution of the X-μCT control and imaging module; And / or, set the imaging resolution of the NMR control scanning and imaging module; And / or, set the imaging frequency of the HSC-DIC control imaging module.

[0010] According to the multi-scale and multi-source rock damage and fracture monitoring method provided by the present invention, extracting multi-scale crack image features of the multi-scale digital images includes: Convert the multi-scale digital images into a 2D image matrix and determine the histogram distribution of the 2D image matrix; Based on the histogram distribution, determine the segmentation threshold between cracks and the background in the multi-scale digital images; Extract the multi-scale crack image features of the multi-scale digital image according to the segmentation threshold between the crack and the background in the multi-scale digital image, and generate the crack and background image corresponding to the multi-scale digital image.

[0011] According to a rock multi-scale multi-source damage and fracture monitoring method provided by the present invention, convert the multi-scale digital image into a 2D image matrix, and determine the histogram distribution of the 2D image matrix, including: Convert the multi-scale digital image into the 2D image matrix; Obtain the image pixels and image dimensions of the multi-scale digital image, and determine the histogram distribution of the 2D image matrix.

[0012] According to a rock multi-scale multi-source damage and fracture monitoring method provided by the present invention, based on the histogram distribution, determine the segmentation threshold between the crack and the background in the multi-scale digital image, including: Obtain the gray scale values of the image pixels of the image matrices of the maximum value and the minimum value in the histogram distribution, and calculate the average value; Based on the average value, determine the segmentation threshold between the crack and the background in the multi-scale digital image.

[0013] In a second aspect, the present invention also provides a rock multi-scale multi-source damage and fracture monitoring system, including: A mechanical control loading module for performing a loading process on the rock specimen; An imaging module for performing multi-scale imaging scans on the rock specimen to obtain multi-scale digital images of different stages during the loading process of the rock specimen; the imaging module includes at least two of an X-μCT control and imaging module, an NMR control scan and imaging module, and an HSC-DIC control imaging module; A data analysis and processing module for extracting the multi-scale crack image features of the multi-scale digital image, analyzing the multi-scale damage and fracture process of the rock specimen, and obtaining an analysis result.

[0014] According to a rock multi-scale multi-source damage and fracture monitoring system provided by the present invention, the mechanical control loading module includes an upper bearing platform and a lower bearing platform, and a loading chamber is arranged between the upper bearing platform and the lower bearing platform; Loading pressure plates and loading bearing plates are symmetrically arranged in the loading chamber, a specimen gripper is arranged between the loading pressure plates and the loading bearing plates, and a sensor is installed on the specimen gripper; A servo loading motor is arranged on the top of the upper bearing platform, an output shaft of the servo loading motor is connected to the loading pressure plate through a loading rod; the servo loading motor is connected to the data analysis and processing module through a motor control wire.

[0015] According to a multi-scale and multi-source damage fracture monitoring system for rock provided by the present invention, the X-μCT control and imaging module includes a longitudinal track disposed on the lower bearing platform. A circular track is provided on the moving part of the longitudinal track, and the specimen holder is disposed in the middle of the circular track. A movable X-ray probe and a detection panel are provided on the circular track, and the detection panel is composed of a plurality of block detectors. The X-ray probe is connected to the data analysis and processing module through a probe control wire, and the detection panel is connected to the data analysis and processing module through a panel control wire. The NMR control scanning and imaging module includes a magnet assembly disposed outside the specimen holder, and the magnet assembly includes a plurality of magnetic poles. The NMR control scanning and imaging module further includes a nuclear magnetic resonance radio frequency generator, a digital-to-analog converter, and a signal amplifier, and the data analysis and processing module, the nuclear magnetic resonance radio frequency generator, the magnet assembly, the digital-to-analog converter, and the signal amplifier are connected in sequence to form a closed loop. The HSC-DIC control imaging module includes a supplementary light searchlight and a high-speed camera disposed between the upper bearing platform and the lower bearing platform, and the high-speed camera is connected to the data analysis and processing module through a camera control wire.

[0016] According to a multi-scale and multi-source damage fracture monitoring system for rock provided by the present invention, the X-μCT control and imaging module and the NMR control scanning and imaging module are distributed in a cross shape, and the HSC-DIC control imaging module is located between the empty window distance centers of the X-μCT control and imaging module and the NMR control scanning and imaging module.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The multi-scale and multi-source damage fracture monitoring method for rock provided by the present invention scans a rock specimen through a multi-source imaging module, breaks through the scale limitations of the rock specimen scale and the scale of the rock damage fracture process, realizes synchronous time-series imaging of multi-scale rock damage fracture characteristics, and solves the problems of the existing rock damage fracture monitoring technology that cannot perform multi-scale monitoring imaging and has poor efficiency and accuracy. Moreover, the above process can finely capture the damage fracture characteristics of different positions of the rock specimen without replacing the rock specimen, and realizes an intuitive display of the cross-scale damage fracture characteristics of the rock specimen. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the attached drawings required for use in the embodiments or the description of the prior art. Obviously, the attached drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other attached drawings can also be obtained based on these attached drawings.

[0019] Figure 1 is a flowchart of the multi-scale and multi-source damage fracture monitoring method for rocks provided by the present invention; Figure 2 are the multi-scale digital images of rock crack propagation and crack segmentation images at different scales of sandstone in the embodiments of the present invention; Figure 3 is a schematic structural diagram of the multi-scale and multi-source damage fracture monitoring system for rocks provided by the present invention; Figure 4 is the XOZ plane sectional view of the mechanical control loading module in the embodiments of the present invention; Figure 5 is the XOY plane sectional view of the mechanical control loading module in the embodiments of the present invention; Figure 6 is a schematic diagram of the X-μCT control and imaging module in the embodiments of the present invention.

[0020] Reference numerals: 1: upper bearing platform; 2: loading bin; 3: magnet assembly; 4: fastening bolt; 5: loading pressing plate; 6: loading rod; 7: servo loading motor; 8: specimen holder; 9: sensor; 10: detection panel; 11: supplementary light searchlight; 12: high-speed camera; 13: probe control wire; 14: motor control wire; 15: panel control wire; 16: camera control wire; 17: data analysis and processing module; 18: NMR output wire; 19: NMR input wire; 20: nuclear magnetic resonance radio frequency generator; 21: digital-to-analog converter; 22: signal amplifier; 23: rock specimen; 24: magnetic pole; 25: circular track; 26: X-ray probe; 27: longitudinal track; 28: specimen transparent protective sleeve; 29: instrument bearing platform column; 30: lower bearing platform; 31: loading bearing plate; 32: open segmented detector; 33: closed segmented detector; 34: sandstone X-μCT microscopic image; 35: sandstone NMR mesoscopic image; 36: sandstone high-speed camera macroscopic image; 37: sandstone X-μCT microscopic crack segmentation image; 38: sandstone NMR mesoscopic crack segmentation image; 39: sandstone high-speed camera macroscopic crack segmentation image. Detailed implementation manners

[0021] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] The present invention provides a method for monitoring multi-scale and multi-source damage fracture of rocks. Figure 1 It is a flow chart of the method for monitoring multi-scale and multi-source damage fracture of rocks provided by the present invention. As Figure 1 shown, the method includes the following steps: Step S101: Obtain a rock specimen and perform a loading process on the rock specimen. Step S102: Perform multi-scale imaging scanning on the rock specimen through a pre-configured imaging module to obtain multi-scale digital images of different stages during the loading process of the rock specimen; the imaging module includes at least two of an X-μCT control and imaging module, an NMR control scanning and imaging module, and an HSC-DIC control imaging module. Step S103: Extract the multi-scale crack image features of the multi-scale digital images, analyze the multi-scale damage fracture process of the rock specimen, and obtain an analysis result.

[0023] In this method, first, place the rock specimen in a loading device and perform a loading process on the rock specimen. During the loading process, scan and image the rock specimen through at least two imaging modules to obtain multi-scale digital images of different scales of the rock specimen. Finally, extract the multi-scale crack image features of all the multi-scale digital images, analyze the rock specimen, and obtain a final analysis result. In the above process, scan the rock specimen through a multi-source imaging module, breaking through the scale limitations of the rock specimen scale and the scale of the rock damage fracture process, realizing synchronous time-series imaging of multi-scale rock damage fracture characteristics, and solving the problems that the existing rock damage fracture monitoring technology cannot perform multi-scale monitoring imaging and has poor efficiency and accuracy. Moreover, in the above process, it is possible to finely capture the damage fracture characteristics of different positions of the rock specimen without replacing the rock specimen, and directly display the cross-scale damage fracture characteristics of the rock specimen.

[0024] In some of the embodiments, step S101, obtaining a rock specimen and performing a loading process on the rock specimen, includes: obtaining a rock raw material to be analyzed and fabricating the rock raw material into a rock specimen according to a preset size; performing a loading process on the rock specimen.

[0025] Exemplarily, according to the test purpose, standard rock specimens are prepared using rock raw materials, with dimensions of length × width × height = 160 mm × 80 mm × 30 mm. The rock specimens are fixedly installed on the loading device, and a uniaxial compression loading process is carried out on the rock specimens.

[0026] For the above three different imaging modules, configure the imaging module, including: setting the imaging resolution of the X-μCT control and imaging module; and / or, setting the imaging resolution of the NMR control scanning and imaging module; and / or, setting the imaging frequency of the HSC-DIC control imaging module.

[0027] Exemplarily, the imaging resolution of the X-μCT control and imaging module is 5 μm, the imaging resolution of the NMR control scanning and imaging module is 0.1 mm, and the imaging frequency of the HSC-DIC control imaging module is 2000 frames per second. During the uniaxial compression loading process of the rock specimens, synchronous temporal X-μCT, NMR, and HSC-DIC multi-scale imaging is performed on different stages of rock specimen damage and fracture to capture the multi-scale characteristics of rock damage and fracture, and multi-scale digital images of X-μCT, NMR, and HSC-DIC at different stages are generated.

[0028] In some of these embodiments, in step S103, extracting the multi-scale crack image features of the multi-scale digital images includes: converting the multi-scale digital images into 2D image matrices and determining the histogram distribution of the 2D image matrices; based on the histogram distribution, determining the segmentation threshold between cracks and the background in the multi-scale digital images; according to the segmentation threshold between cracks and the background in the multi-scale digital images, extracting the multi-scale crack image features of the multi-scale digital images to generate crack and background images corresponding to the multi-scale digital images.

[0029] In this embodiment, converting the multi-scale digital images into 2D image matrices and determining the histogram distribution of the 2D image matrices includes: converting the multi-scale digital images into 2D image matrices; obtaining the image pixels and image dimensions of the multi-scale digital images and determining the histogram distribution of the 2D image matrices.

[0030] Based on the histogram distribution, determining the segmentation threshold between cracks and the background in the multi-scale digital images includes: obtaining the gray-level values of the image pixels of the image matrices of the maximum and minimum values in the histogram distribution and calculating the average value; based on the average value, determining the segmentation threshold between cracks and the background in the multi-scale digital images.

[0031] Exemplarily, the obtained rock X-μCT microscopic multi-scale digital images, NMR mesoscopic numerical images, and HSC-DIC macroscopic multi-scale digital images are converted into 2D image matrices, as Figure 2 shown. Figure 2They are the multi-scale digital images of rock crack propagation and crack segmentation images of sandstone at different scales in the embodiments of the present invention. In the figure, 34 is the X-μCT microscopic image of sandstone, 35 is the NMR mesoscopic image of sandstone, 36 is the high-speed camera macroscopic image of sandstone, 37 is the X-μCT microscopic crack segmentation image of sandstone, 38 is the NMR mesoscopic crack segmentation image of sandstone, and 39 is the high-speed camera macroscopic crack segmentation image of sandstone. The element units of the 2D image matrix E gl take values in the range of 0 - 255, and calculate their corresponding histogram distributions. The expression is as follows:

[0032] Among them, PDF his (·) represents the histogram distribution function of the 2D image matrix, represents the counter, represents the image pixel, N represents the image dimension, E gl represents the element unit. Calculate and make PDF his (·) obtain the image pixel values of the image matrix where the maximum and minimum values are obtained, and average them to obtain the segmentation thresholds between cracks and the background in the segmented rock X-μCT microscopic multi-scale digital images, NMR mesoscopic numerical images, and HSC-DIC macroscopic multi-scale digital images. The expression is as follows:

[0033] Among them, represents the minimum value calculation function, represents the maximum value calculation function, represents making PDF his (·) obtain the value of the element unit of the image matrix where the minimum value of the element unit of the image matrix is obtained, represents making PDF his (·) obtain the value of the element unit of the image matrix where the maximum value of the element unit of the image matrix is obtained, represents the segmentation threshold between cracks and the background in the multi-scale digital images. According to the obtained segmentation thresholds between cracks and the background in the multi-scale digital images, obtain the crack and background images of the rock X-μCT microscopic multi-scale digital images, NMR mesoscopic numerical images, and HSC-DIC macroscopic multi-scale digital images. The expression is as follows:

[0034] Among them, is the crack and background image of the X-μCT microscopic multi-scale digital image, It is the crack and background images of the NMR microscopic numerical image, It is the crack and background images of the HSC-DIC macroscopic multi-scale digital image, where 0 represents black for the crack and 1 represents white for the background.

[0035] The present invention also provides a rock multi-scale multi-source damage fracture monitoring system. The rock multi-scale multi-source damage fracture monitoring system provided by the present invention will be described below. The rock multi-scale multi-source damage fracture monitoring system described below can be correspondingly referred to the rock multi-scale multi-source damage fracture monitoring method described above. Figure 3 It is a schematic structural diagram of the rock multi-scale multi-source damage fracture monitoring system provided by the present invention, as Figure 3 shown. The system includes: A mechanical control loading module for loading the rock specimen 23; An imaging module for performing multi-scale imaging scans on the rock specimen 23 to obtain multi-scale digital images of different stages of the rock specimen 23 during the loading process; the imaging module includes at least two of an X-μCT control and imaging module, an NMR control scanning and imaging module, and an HSC-DIC control imaging module; A data analysis and processing module 17 for extracting multi-scale crack image features of the multi-scale digital images, analyzing the multi-scale damage fracture process of the rock specimen 23, and obtaining an analysis result.

[0036] When this system is in use, first, place the rock specimen 23 in the loading device and perform a loading process on the rock specimen 23. During the loading process, scan and image the rock specimen 23 through at least two imaging modules to obtain multi-scale digital images of different scales of the rock specimen 23. Finally, extract the multi-scale crack image features of all the multi-scale digital images, analyze the rock specimen 23, and obtain the final analysis result. In the above process, scan the rock specimen 23 through a multi-source imaging module, breaking through the scale limitations of the rock specimen 23 scale and the rock damage fracture process scale, realizing synchronous time-series imaging of multi-scale rock damage fracture characteristics, and solving the problems that the existing rock damage fracture monitoring technology cannot perform multi-scale monitoring imaging and has poor efficiency and accuracy. Moreover, in the above process, it is possible to finely capture the damage fracture characteristics of different positions of the rock specimen 23 without replacing the rock specimen 23, and directly display the cross-scale damage fracture characteristics of the rock specimen 23.

[0037] Specifically, Figure 4 It is the XOZ plane sectional view of the mechanical control loading module in the embodiment of the present invention, Figure 5 It is the XOY plane sectional view of the mechanical control loading module in the embodiment of the present invention, as Figure 4 and Figure 5As shown in the figure, the mechanical control loading module includes an upper bearing platform 1 and a lower bearing platform 30. A loading chamber 2 is arranged between the upper bearing platform 1 and the lower bearing platform 30. Loading pressure plates 5 and loading bearing plates 31 are symmetrically arranged in the loading chamber 2. A specimen holder 8 is arranged between the loading pressure plate 5 and the loading bearing plate 31. A sensor 9 is installed on the specimen holder 8. A servo loading motor 7 is arranged on the top of the upper bearing platform 1. The output shaft of the servo loading motor 7 is connected to the loading pressure plate 5 through a loading rod 6. The servo loading motor 7 is connected to the data analysis and processing module 17 through a motor control wire 14. The data analysis and processing module 17 outputs the mechanical loading stress required for the test, which is transmitted to the loading pressure plate 5 through the loading rod 6 and then transmitted to the rock specimen 23 to conduct the mechanical control loading process.

[0038] Among them, the external port of the specimen holder 8 adopts a thread design. Its upper part is connected to the loading pressure plate 5 through the loading chamber 2, and its lower part is connected to the loading bearing plate 31. A telescopic groove slightly larger than the diameter of the loading rod 6 is opened at the top of the loading chamber 2 to facilitate the progress of loading. The loading bearing plate 31 is connected to the bottom instrument bearing platform by a fastening bolt 4. A circular card slot is arranged at the internal port of the specimen holder 8 to place the specimen transparent protective sleeve 28, which is used to soak the specimen when imaging the non-wet saturated specimen by the NMR nuclear magnetic resonance control and imaging system, and can prevent the specimen fragments from splashing and damaging the instrument. The lower bearing platform 30 and the upper bearing platform 1 are connected by an instrument bearing platform column 29.

[0039] During use, according to the experimental purpose, a standard rock specimen 23 with dimensions of length × width × height = 160 mm × 80 mm × 30 mm is prepared. The rock specimen 23 is fixedly installed on the specimen holder 8 on which the sensors 9 (such as stress sensors and displacement sensors) have been installed, and the specimen holder 8 is installed between the loading pressure plate 5 and the loading bearing plate 31, and then the mechanical control loading module is started to conduct the uniaxial compression loading process on the rock specimen 23.

[0040] Figure 6 It is a schematic diagram of the X-μCT control and imaging module in the embodiment of the present invention. As Figure 6 shown, the X-μCT control and imaging module includes a longitudinal track 27 arranged on the lower bearing platform 30. A circular ring track 25 is arranged on the moving part of the longitudinal track 27. The specimen holder 8 is arranged in the middle of the circular ring track 25. A movable X-ray probe 26 and a detection panel 10 are arranged on the circular ring track 25. The detection panel 10 is composed of a number of segmented detectors. The X-ray probe 26 is connected to the data analysis and processing module 17 through a probe control wire 13, and the detection panel 10 is connected to the data analysis and processing module 17 through a panel control wire.

[0041] Specifically, the detection panel 10 composed of the X-ray probe 26 and the independently switchable segmented detectors is connected to the data analysis and processing module 17 through the probe control wire 13 and the panel control wire 15 respectively. The circular ring-shaped track 25 and the lower bearing platform 30 are connected by the longitudinal track 27 so that the X-μCT control and imaging module can move up and down to test different positions of the rock specimen 23. The X-ray probes 26 and the detection panel 10 symmetrically distributed on the circular ring-shaped track 25 can also move freely along the circular ring-shaped track 25 so that the X-μCT control and imaging module can test the rock specimen 23 in different directions, and at the same time, it does not block the NMR control and imaging module and the HSC-DIC control imaging module from imaging the rock specimen 23. The detection panel 10 is composed of independently switchable segmented detectors for local magnified imaging at different positions and directions. Figure 6 In it, 32 is to turn on the segmented detector, and 33 is to turn off the segmented detector.

[0042] The NMR control scanning and imaging module includes a magnet assembly 3 arranged outside the specimen holder 8. The magnet assembly 3 includes a plurality of magnetic poles 24, and the magnetic poles 24 include an S pole and an N pole; the NMR control scanning and imaging module also includes a nuclear magnetic resonance radio frequency generator 20, a digital-to-analog converter 21, and a signal amplifier 22, and the data analysis and processing module 17, the nuclear magnetic resonance radio frequency generator 20, the magnet assembly 3, the digital-to-analog converter 21, and the signal amplifier 22 are connected in sequence to form a closed loop.

[0043] Specifically, the N pole of the magnet assembly 3 is connected to the signal amplifier 22, and the digital-to-analog converter 21 and the data analysis and processing module 17 are connected through the nuclear magnetic output wire 18; the data analysis and processing module 17 is also connected to the nuclear magnetic resonance radio frequency generator 20 and the S pole of the magnet assembly 3 through the nuclear magnetic input wire 19 for the nuclear magnetic resonance imaging process.

[0044] The HSC-DIC control imaging module includes a supplementary light searchlight 11 and a high-speed camera 12 arranged between the upper bearing platform 1 and the lower bearing platform 30. The high-speed camera 12 is connected to the data analysis and processing module 17 through the camera control wire 16.

[0045] Furthermore, the X-μCT control and imaging module and the NMR control scanning and imaging module are distributed in a cross shape, and the HSC-DIC control imaging module is located between the center of the empty window distance between the X-μCT control and imaging module and the NMR control scanning and imaging module, so that synchronous imaging can be maintained among the three without interference.

[0046] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0047] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rock multi-scale and multi-source damage and fracture monitoring method, characterized in that: include: Obtaining a rock specimen, and performing a loading process on the rock specimen; Performing multi-scale imaging scanning on the rock specimen through a pre-configured imaging module to obtain multi-scale digital images of the rock specimen at different stages during the loading process; the imaging module includes at least two of an X-μCT control and imaging module, an NMR control scanning and imaging module, and an HSC-DIC control imaging module; The multi-scale crack image features of the multi-scale digital image are extracted, and a multi-scale damage and fracture process analysis is performed on the rock specimen to obtain an analysis result.

2. The rock multi-scale and multi-source damage and fracture monitoring method according to claim 1 is characterized in that: Obtaining a rock specimen and performing a loading process on the rock specimen, including: Obtaining rock raw materials to be analyzed, and making the rock raw materials into the rock specimens according to preset sizes; The rock specimen is subjected to a loading treatment.

3. The rock multi-scale and multi-source damage and fracture monitoring method according to claim 1 is characterized in that: Configuring the imaging module includes: Set the imaging resolution of the X-μCT control and imaging module; and / or, setting the imaging resolution of the NMR control scanning and imaging module; And / or, setting the imaging frequency of the HSC-DIC control imaging module.

4. The rock multi-scale and multi-source damage and fracture monitoring method according to claim 1 is characterized in that: Extracting multi-scale crack image features of the multi-scale digital image includes: Converting the multi-scale digital image into a 2D image matrix and determining a histogram distribution of the 2D image matrix; Based on the histogram distribution, determining a segmentation threshold of cracks and background in the multi-scale digital image; According to the segmentation threshold of cracks and background in the multi-scale digital image, multi-scale crack image features of the multi-scale digital image are extracted to generate crack and background images corresponding to the multi-scale digital image.

5. The rock multi-scale and multi-source damage and fracture monitoring method according to claim 4 is characterized in that: Converting the multi-scale digital image into a 2D image matrix and determining a histogram distribution of the 2D image matrix comprises: Converting the multi-scale digital image into the 2D image matrix; Image pixels and image dimensions of the multi-scale digital image are obtained, and a histogram distribution of the 2D image matrix is ​​determined.

6. The rock multi-scale and multi-source damage and fracture monitoring method according to claim 4 is characterized in that: Determining a segmentation threshold of cracks and background in the multi-scale digital image based on the histogram distribution includes: Obtaining grayscale values ​​of image pixels of the image matrix of the maximum value and the minimum value in the histogram distribution, and calculating an average value; A segmentation threshold for cracks and background in the multi-scale digital image is determined based on the average value.

7. A rock multi-scale and multi-source damage and fracture monitoring system, characterized in that: include: A mechanical control loading module, used for performing loading processing on the rock specimen; An imaging module is used to perform multi-scale imaging scanning on the rock specimen to obtain multi-scale digital images of the rock specimen at different stages during the loading process; the imaging module includes at least two of an X-μCT control and imaging module, an NMR control scanning and imaging module, and an HSC-DIC control imaging module; The data analysis and processing module (17) is used to extract multi-scale crack image features of the multi-scale digital image, perform multi-scale damage and fracture process analysis on the rock specimen, and obtain analysis results.

8. The rock multi-scale and multi-source damage and fracture monitoring system according to claim 7 is characterized in that: The mechanical control loading module comprises an upper support platform (1) and a lower support platform (30), and a loading bin (2) is arranged between the upper support platform (1) and the lower support platform (30); A loading pressure plate (5) and a loading pressure plate (31) are symmetrically arranged in the loading chamber (2), a specimen holder (8) is arranged between the loading pressure plate (5) and the loading pressure plate (31), and a sensor (9) is installed on the specimen holder (8); A servo loading motor (7) is provided on the top of the upper support platform (1); an output shaft of the servo loading motor (7) is connected to the loading platen (5) via a loading rod (6); and the servo loading motor (7) is connected to the data analysis and processing module (17) via a motor control wire (14).

9. The rock multi-scale and multi-source damage and fracture monitoring system according to claim 8, characterized in that: The X-μCT control and imaging module comprises a longitudinal track (27) arranged on the lower support platform (30), the movable portion of the longitudinal track (27) is provided with a circular track (25), and the specimen holder (8) is arranged in the middle of the circular track (25); a movable X-ray probe (26) and a detection panel (10) are arranged on the circular track (25), and the detection panel (10) is composed of a plurality of block detectors; the X-ray probe (26) is connected to the data analysis and processing module (17) via a probe control wire (13), and the detection panel (10) is connected to the data analysis and processing module (17) via a panel control wire; The NMR control scanning and imaging module comprises a magnet assembly (3) arranged outside the specimen holder (8), the magnet assembly (3) comprising a plurality of magnetic poles (24); the NMR control scanning and imaging module further comprises a nuclear magnetic resonance radio frequency generator (20), a digital-to-analog converter (21) and a signal amplifier (22), and the data analysis and processing module (17), the nuclear magnetic resonance radio frequency generator (20), the magnet assembly (3), the digital-to-analog converter (21) and the signal amplifier (22) are sequentially connected to form a closed loop; The HSC-DIC controlled imaging module comprises a fill light searchlight (11) and a high-speed camera (12) arranged between the upper support platform (1) and the lower support platform (30); the high-speed camera (12) is connected to the data analysis and processing module (17) via a camera control wire (16).

10. The rock multi-scale and multi-source damage and fracture monitoring system according to claim 7, characterized in that: The X-μCT control and imaging module and the NMR control scanning and imaging module are cross-distributed, and the HSC-DIC control imaging module is located between the center of the empty window distance between the X-μCT control and imaging module and the NMR control scanning and imaging module.

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