A rock multi-scale and multi-source damage and fracture monitoring method and system

Abstract

The present invention provides a method and system for monitoring multi-scale and multi-source rock damage and fracture. The method comprises: obtaining a rock specimen and performing a loading process on the rock specimen; performing imaging scanning on the rock specimen using a pre-configured imaging module to obtain multi-scale digital images of the rock specimen at different stages of 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; extracting multi-scale crack image features from the multi-scale digital image, performing a multi-scale damage and fracture process analysis on the rock specimen, and obtaining an analysis result. The present invention achieves synchronous monitoring and time-series imaging of multi-scale rock damage and fracture features, solving the problems of existing rock damage and fracture monitoring technologies, such as the inability to perform multi-scale monitoring and imaging, and poor efficiency and accuracy.

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 and fracture of rocks. Background Art

[0002] The multi-scale damage and fracture process of rocks seriously affects the recovery rate of deep rock reservoir resources and the development of mining technology. It also seriously affects the safety and stability of deep rock reservoir resource mining and CO2-nuclear waste deep burial projects. Therefore, the development of rock damage and fracture monitoring technology has broad practical application value and huge economic benefits.

[0003] Existing rock damage and fracture monitoring technologies mainly include non-intuitive monitoring technology and intuitive visual monitoring technology. The former mainly includes conventional damage and fracture mechanics testing technologies, such as stress-strain testing, ultrasonic and acoustic emission testing technologies. 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 visual monitoring technologies have problems such as only targeting a single scale, being unable to conduct multi-scale joint monitoring and testing, being time-consuming and expensive, etc., which can be specifically divided into the following aspects:

[0004] (1) Non-intuitive monitoring technology cannot image the damage and fracture process specifically, and it is difficult to visually display the specific location and failure characteristics of the damage and fracture;

[0005] (2) Although intuitive visual monitoring technology can reveal the damage and fracture process in detail and intuitively, it is only targeted at a specific scale and cannot monitor the damage and fracture process at multiple scales. In addition, due to the imaging resolution limitation of intuitive visual monitoring technology, the damage and fracture process of large-scale specimens has problems such as long time consumption and insufficient resolution for capturing damage features.

[0006] (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, taking a long time to test, being expensive, and being unable to achieve cross-scale monitoring of rock damage and fracture.

[0007] Therefore, existing rock damage and fracture monitoring technologies have problems such as the inability to conduct multi-scale joint monitoring, long testing time, high cost, and the inability to achieve cross-scale monitoring of rock damage and fracture. These problems seriously limit the revelation of multi-scale damage and fracture behaviors and mechanisms of multiple rocks, thereby affecting the efficiency of deep-earth resource exploitation, the development of mining technology, and the safety and stability of deep engineering.

[0008] There is currently no effective solution to the problems that existing rock damage and fracture monitoring technologies are unable to perform multi-scale monitoring imaging and have poor efficiency and accuracy. Summary of the Invention

[0009] The present invention provides a method and system for monitoring multi-scale and multi-source rock damage and fracture, which is used to solve the defects of existing rock damage and fracture monitoring technologies, such as the inability to perform multi-scale monitoring imaging and the poor efficiency and accuracy, and realizes synchronous time-series imaging of multi-scale rock damage and fracture characteristics.

[0010] In a first aspect, the present invention provides a method for monitoring multi-scale and multi-source damage and fracture in rock, comprising:

[0011] Obtaining a rock specimen and performing a loading process on the rock specimen;

[0012] Performing multi-scale imaging scanning on the rock specimen using 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;

[0013] 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.

[0014] According to a rock multi-scale and multi-source damage and fracture monitoring method provided by the present invention, a rock specimen is obtained and loaded, comprising:

[0015] Obtaining rock raw materials to be analyzed, and making the rock specimens from the rock raw materials according to preset dimensions;

[0016] The rock specimen is subjected to a loading process.

[0017] According to a rock multi-scale and multi-source damage and fracture monitoring method provided by the present invention, the imaging module is configured to include:

[0018] Set the imaging resolution of the X-μCT control and imaging module;

[0019] and / or, setting the imaging resolution of the NMR control scanning and imaging module;

[0020] And / or, setting the imaging frequency of the HSC-DIC control imaging module.

[0021] According to a rock multi-scale multi-source damage and fracture monitoring method provided by the present invention, extracting multi-scale crack image features of the multi-scale digital image includes:

[0022] Converting the multi-scale digital image into a 2D image matrix and determining a histogram distribution of the 2D image matrix;

[0023] Determining a segmentation threshold for cracks and background in the multi-scale digital image based on the histogram distribution;

[0024] According to the segmentation threshold of the crack and background in the multi-scale digital image, the multi-scale crack image features of the multi-scale digital image are extracted to generate the crack and background images corresponding to the multi-scale digital image.

[0025] According to a rock multi-scale and multi-source damage and fracture monitoring method provided by the present invention, the multi-scale digital image is converted into a 2D image matrix, and the histogram distribution of the 2D image matrix is determined, including:

[0026] Converting the multi-scale digital image into the 2D image matrix;

[0027] Image pixels and image dimensions of the multi-scale digital image are obtained, and a histogram distribution of the 2D image matrix is determined.

[0028] According to a rock multi-scale multi-source damage and fracture monitoring method provided by the present invention, based on the histogram distribution, determining the segmentation threshold of the crack and background in the multi-scale digital image, comprising:

[0029] Obtaining grayscale values of image pixels of the image matrix of maximum and minimum values in the histogram distribution, and calculating an average value;

[0030] A segmentation threshold for cracks and background in the multi-scale digital image is determined based on the average value.

[0031] In a second aspect, the present invention further provides a rock multi-scale and multi-source damage and fracture monitoring system, comprising:

[0032] A mechanical control loading module, used for performing loading processing on the rock specimen;

[0033] An imaging module, configured 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 comprises 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;

[0034] The data analysis and processing module is used to extract the 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.

[0035] According to a rock multi-scale and multi-source damage and fracture monitoring system provided by the present invention, the mechanical control loading module includes an upper platform and a lower platform, and a loading chamber is provided between the upper platform and the lower platform;

[0036] A loading pressure plate and a loading pressure plate are symmetrically arranged in the loading chamber, a specimen holder is arranged between the loading pressure plate and the loading pressure plate, and a sensor is installed on the specimen holder;

[0037] A servo loading motor is provided on the top of the upper support platform, and the 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.

[0038] According to a multi-scale and multi-source rock damage and fracture monitoring system provided by the present invention, the X-μCT control and imaging module includes a longitudinal track provided on the lower support platform, the movable portion of the longitudinal track is provided with a circular track, and the specimen holder is provided 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 segmented detectors; the X-ray probe is connected to the data analysis and processing module via a probe control wire, and the detection panel is connected to the data analysis and processing module via a panel control wire;

[0039] The NMR control scanning and imaging module includes a magnet assembly arranged outside the specimen holder, and the magnet assembly includes a plurality of magnetic poles; the NMR control scanning and imaging module also 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 sequentially connected to form a closed loop;

[0040] The HSC-DIC controlled imaging module includes a fill light searchlight and a high-speed camera arranged between the upper supporting platform and the lower supporting platform. The high-speed camera is connected to the data analysis and processing module through a camera control wire.

[0041] According to a rock multi-scale and multi-source damage and fracture monitoring system 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-shaped manner, and the HSC-DIC control imaging module is located between the center of the window distance between the X-μCT control and imaging module and the NMR control scanning and imaging module.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The multi-scale, multi-source rock damage and fracture monitoring method provided by this invention uses multi-source imaging modules to scan rock specimens. This method overcomes the limitations of the rock specimen scale and the scale of the rock damage and fracture process, achieving simultaneous time-series imaging of multi-scale rock damage and fracture characteristics. This addresses the limitations of existing rock damage and fracture monitoring technologies, including the inability to perform multi-scale monitoring and imaging, and the low efficiency and accuracy. Furthermore, this process allows for precise capture of damage and fracture characteristics at different locations on a rock specimen without requiring replacement of the rock specimen, enabling intuitive display of cross-scale damage and fracture characteristics within the rock specimen. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 This is a flow chart of the rock multi-scale and multi-distance damage and fracture monitoring method provided by the present invention;

[0046] Figure 2 These are multi-scale digital images of rock crack propagation and crack segmentation images at different scales of sandstone in an embodiment of the present invention;

[0047] Figure 3 This is a schematic structural diagram of the rock multi-scale and multi-source damage and fracture monitoring system provided by the present invention;

[0048] Figure 4 is a cross-sectional view of the XOZ plane of the mechanical control loading module according to an embodiment of the present invention;

[0049] Figure 5 is an XOY plane cross-sectional view of a mechanically controlled loading module according to an embodiment of the present invention;

[0050] Figure 6 Schematic diagram of the X-μCT control and imaging module in an embodiment of the present invention.

[0051] Reference numerals:

[0052] 1: Upper platform; 2: Loading chamber; 3: Magnet assembly; 4: Fastening bolts; 5: Loading plate; 6: Loading rod; 7: Servo loading motor; 8: Specimen holder; 9: Sensor; 10: Detection panel; 11: Filling 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: NMR RF generator; 21: Digital-to-analog converter; 22: Signal amplifier; 23: Rock specimen; 24: Magnetic pole; 25: Annular track; 26: X-ray probe; 27: Longitudinal track; 28: Transparent protective cover for specimen; 29: Instrument support column; 30: Lower support; 31: Loading pressure plate; 32: Block detector on; 33: Block detector off; 34: Sandstone X-μCT microscopic image; 35: Sandstone NMR mesoscopic image; 36: Sandstone high-speed camera macroscopic image; 37: Sandstone X-μCT microcrack segmentation image; 38: Sandstone NMR mesocrack segmentation image; 39: Sandstone high-speed camera macrocrack segmentation image. DETAILED DESCRIPTION

[0053] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0054] The present invention provides a rock multi-scale and multi-source damage and fracture monitoring method. Figure 1 This is a flow chart of the rock multi-scale and multi-distance damage and fracture monitoring method provided by the present invention. Figure 1 As shown, the method includes the following steps:

[0055] Step S101, obtaining a rock specimen and performing a loading process on the rock specimen;

[0056] Step S102, performing multi-scale imaging scanning on the rock specimen using 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;

[0057] Step S103 , extracting multi-scale crack image features of the multi-scale digital image, performing multi-scale damage and fracture process analysis on the rock specimen, and obtaining analysis results.

[0058] In this method, first, a rock specimen is placed in a loading device and loaded. During the loading process, the rock specimen is scanned and imaged by at least two imaging modules to obtain multi-scale digital images of the rock specimen at different scales. Finally, the multi-scale crack image features of all multi-scale digital images are extracted, and the rock specimen is analyzed to obtain the final analysis results. In the above process, the rock specimen is scanned by a multi-source imaging module, breaking through the scale limitation of the rock specimen scale and the rock damage and fracture process, realizing the synchronous time-series imaging of multi-scale rock damage and fracture characteristics, and solving the problem that the existing rock damage and fracture monitoring technology cannot perform multi-scale monitoring imaging and has poor efficiency and accuracy. Moreover, the above process can achieve the fine capture of the damage and fracture characteristics of different positions of the rock specimen without changing the rock specimen, and realize the intuitive display of the cross-scale damage and fracture characteristics of the rock specimen.

[0059] In some embodiments, step S101, obtaining a rock specimen and performing a loading process on the rock specimen, includes: obtaining rock raw materials to be analyzed, and making the rock raw materials into rock specimens according to preset sizes; and performing a loading process on the rock specimen.

[0060] For example, according to the test purpose, a standard rock specimen is prepared using rock raw materials with dimensions of length × width × height = 160 mm × 80 mm × 30 mm. The rock specimen is fixedly mounted on a loading device, and a uniaxial compression loading process is performed on the rock specimen.

[0061] For the three different imaging modules mentioned above, configuring the imaging module includes: 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.

[0062] For example, the X-μCT control and imaging module has an imaging resolution of 5 μm, the NMR control scanning and imaging module has an imaging resolution of 0.1 mm, and the HSC-DIC control imaging module has an imaging frequency of 2,000 images per second. During uniaxial compression loading of a rock specimen, synchronized time-series X-μCT, NMR, and HSC-DIC multiscale imaging is performed at different stages of damage and fracture of the rock specimen, capturing the multiscale characteristics of rock damage and fracture, and generating multiscale digital images of these images at different stages using X-μCT, NMR, and HSC-DIC.

[0063] In some embodiments, step S103, 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; determining a segmentation threshold for cracks and background in the multi-scale digital image based on the histogram distribution; extracting multi-scale crack image features of the multi-scale digital image according to the segmentation threshold for cracks and background in the multi-scale digital image, and generating a crack and background image corresponding to the multi-scale digital image.

[0064] In this embodiment, converting a multi-scale digital image into a 2D image matrix and determining a histogram distribution of the 2D image matrix include: converting the multi-scale digital image into a 2D image matrix; obtaining image pixels and image dimensions of the multi-scale digital image, and determining a histogram distribution of the 2D image matrix.

[0065] Based on the histogram distribution, a segmentation threshold of cracks and background in a multi-scale digital image is determined, including: obtaining grayscale values of image pixels of an image matrix of maximum and minimum values in the histogram distribution and calculating an average value; and determining the segmentation threshold of cracks and background in the multi-scale digital image based on the average value.

[0066] For example, the obtained rock X-μCT microscopic multi-scale digital image, NMR microscopic numerical image and HSC-DIC macroscopic multi-scale digital image are converted into a 2D image matrix, such as Figure 2 As shown, Figure 2 The multi-scale digital images and crack segmentation images of rock crack propagation at different scales of sandstone in the embodiment of the present invention are shown. In the figure, 34 is a sandstone X-μCT microscopic image, 35 is a sandstone NMR microscopic image, 36 is a sandstone high-speed camera macroscopic image, 37 is a sandstone X-μCT microscopic crack segmentation image, 38 is a sandstone NMR microscopic crack segmentation image, and 39 is a sandstone high-speed camera macroscopic crack segmentation image. The element unit of the 2D image matrix E gl The value range of is 0-255, and its corresponding histogram distribution is calculated. The expression is as follows:

[0067]

[0068] in, PDF his (·) represents the histogram distribution function of the 2D image matrix, Represents a counter, represents image pixels, N represents the image dimension, E gl Represents an element unit. Calculation order PDF his(·) Obtain the image pixel values of the image matrix with the maximum and minimum values and calculate the average value. The segmentation threshold for segmenting cracks and background in rock X-μCT microscopic multi-scale digital images, NMR mesoscopic numerical images, and HSC-DIC macroscopic multi-scale digital images can be obtained. The expression is as follows:

[0069]

[0070] in, represents the minimum value calculation function, represents the maximum value calculation function, Indication command PDF his (·) Obtain the value of the image matrix element unit with the minimum value of the image matrix element unit, Indication command PDF his (·) Get the value of the image matrix element unit with the maximum value of the image matrix element unit, Represents the segmentation threshold of cracks and background in the multi-scale digital image. Based on the obtained segmentation threshold of cracks and background in the multi-scale digital image, the crack and background images of the rock X-μCT microscopic multi-scale digital image, NMR mesoscopic numerical image, and HSC-DIC macroscopic multi-scale digital image are obtained. The expression is as follows:

[0071]

[0072] in, The crack and background images of the X-μCT microscopic multi-scale digital image are shown in Figure 2. are the crack and background images of the NMR microscopic numerical image, The crack and background images of the HSC-DIC macroscopic multi-scale digital image, where 0 represents the crack in black and 1 represents the background in white.

[0073] The present invention also provides a multi-scale and multi-source rock damage and fracture monitoring system. The multi-scale and multi-source rock damage and fracture monitoring system provided by the present invention is described below. The multi-scale and multi-source rock damage and fracture monitoring system described below and the multi-scale and multi-source rock damage and fracture monitoring method described above can be referenced to each other. Figure 3 This is a schematic diagram of the structure of the rock multi-scale and multi-source damage and fracture monitoring system provided by the present invention. Figure 3 As shown, the system includes:

[0074] A mechanical control loading module is used to perform loading processing on the rock specimen 23;

[0075] An imaging module is used to perform multi-scale imaging scanning on the rock specimen 23 to obtain multi-scale digital images of the rock specimen 23 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;

[0076] 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 23, and obtain analysis results.

[0077] When using this system, first, the rock specimen 23 is placed in the loading device and the rock specimen 23 is loaded. During the loading process, the rock specimen 23 is scanned and imaged by at least two imaging modules to obtain multi-scale digital images of the rock specimen 23 at different scales. Finally, the multi-scale crack image features of all multi-scale digital images are extracted, and the rock specimen 23 is analyzed to obtain the final analysis results. In the above process, the rock specimen 23 is scanned by multi-source imaging modules, breaking through the scale limitations of the rock specimen 23 and the rock damage and fracture process, realizing synchronous time-series imaging of multi-scale rock damage and fracture characteristics, and solving the problems of existing rock damage and fracture monitoring technologies that are unable to monitor and image at multiple scales and have poor efficiency and accuracy. Moreover, the above process can achieve precise capture of damage and fracture characteristics at different positions of the rock specimen 23 without replacing the rock specimen 23, realizing an intuitive display of cross-scale damage and fracture characteristics of the rock specimen 23.

[0078] Specifically, Figure 4 is a cross-sectional view of the XOZ plane of the mechanical control loading module according to an embodiment of the present invention, Figure 5 is an XOY plane cross-sectional view of the mechanical control loading module in an embodiment of the present invention, as shown in FIG. Figure 4 and Figure 5 As shown, the mechanical control loading module includes an upper support platform 1 and a lower support platform 30, and a loading chamber 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, and 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, and the output shaft of the servo loading motor 7 is connected to the loading pressure plate 5 through the loading rod 6; the servo loading motor 7 is connected to the data analysis and processing module 17 through the motor control wire 14, and 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 and then to the rock specimen 23 by the loading rod 6 to perform the mechanical control loading process.

[0079] Among them, the external port of the specimen holder 8 adopts a threaded design, the upper part of which is connected to the loading pressure plate 5 through the loading chamber 2, and the lower part is connected to the loading pressure plate 31. A retractable groove slightly larger than the diameter of the loading rod 6 is opened on the top of the loading chamber 2 to facilitate moving loading, and the loading pressure plate 31 is connected to the bottom instrument base with a fastening bolt 4; the internal port of the specimen holder 8 is provided with a circular card slot to accommodate the specimen transparent protective cover 28, which is used to immerse the specimen when the non-wet saturated specimen is imaged using the NMR nuclear magnetic resonance control and imaging system, and can prevent the specimen fragments from splashing and damaging the instrument; the lower base 30 and the upper base 1 are connected by the instrument base column 29.

[0080] 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 mounted on the specimen holder 8 on which sensors 9 (stress sensors and displacement sensors, etc.) are installed. The specimen holder 8 is installed between the loading plate 5 and the loading pressure plate 31, and the mechanical control loading module is started to perform a uniaxial compression loading process on the rock specimen 23.

[0081] Figure 6 FIG is a schematic diagram of an X-μCT control and imaging module in an embodiment of the present invention. Figure 6 As shown, the X-μCT control and imaging module includes a longitudinal track 27 arranged on the lower support platform 30, the movable part of the longitudinal track 27 is provided with a circular track 25, and the specimen holder 8 is provided in the middle of the circular track 25; a movable X-ray probe 26 and a detection panel 10 are provided 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 through the probe control wire 13, and the detection panel 10 is connected to the data analysis and processing module 17 through the panel control wire.

[0082] Specifically, the detection panel 10 composed of the X-ray probe 26 and the block detectors that can be switched on and off independently 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 track 25 and the lower support 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 track 25 can also move freely along the circular track 25, so that the X-μCT control and imaging module can test different directions of the rock specimen 23, while not blocking 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 block detectors that can be switched on and off independently, so as to perform local magnified imaging in different positions and directions. Figure 6 In the example, 32 is to open the block detector, and 33 is to close the block detector.

[0083] 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.

[0084] Specifically, the N pole of the magnet assembly 3 is connected to the signal amplifier 22, the digital-to-analog converter 21 and the data analysis and processing module 17 through the nuclear magnetic resonance output wire 18; the data analysis and processing module 17 is connected to the nuclear magnetic resonance radio frequency generator 20 and the S pole of the magnet assembly 3 through the nuclear magnetic resonance input wire 19 to perform the nuclear magnetic resonance imaging process.

[0085] The HSC-DIC control imaging module includes 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 .

[0086] Furthermore, 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 window distance between the X-μCT control and imaging module and the NMR control scanning and imaging module, so that the three can maintain synchronous imaging without interfering with each other.

[0087] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0088] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for monitoring rock multi-scale and multi-source damage and fracture, 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 by using 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 an X-μCT control and imaging module, an NMR control scanning and imaging module, and an HSC-DIC control imaging module; Extracting multi-scale crack image features of the multi-scale digital image, performing multi-scale damage and fracture process analysis on the rock specimen, and obtaining analysis results; The X-μCT control and imaging module includes a longitudinal track (27) arranged on a lower support platform (30), a movable portion of the longitudinal track (27) is provided with a circular track (25), and a specimen holder (8) is provided in the middle of the circular track (25); a movable X-ray probe (26) and a detection panel (10) are provided 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) 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; The NMR control scanning and imaging module includes a magnet assembly (3) arranged outside the specimen holder (8), and the magnet assembly (3) includes a plurality of magnetic poles (24); 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 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 an upper support platform (1) and a 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).

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 specimens from the rock raw materials according to preset dimensions; The rock specimen is subjected to a loading process.

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, setting the imaging resolution of the NMR control scanning and imaging module; And, set 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; Determining a segmentation threshold for cracks and background in the multi-scale digital image based on the histogram distribution; According to the segmentation threshold of the crack and background in the multi-scale digital image, the multi-scale crack image features of the multi-scale digital image are extracted to generate the 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 maximum and minimum values 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 by: 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 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) 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; The X-μCT control and imaging module includes a longitudinal track (27) arranged on a lower support platform (30), a movable portion of the longitudinal track (27) is provided with a circular track (25), and a specimen holder (8) is provided in the middle of the circular track (25); a movable X-ray probe (26) and a detection panel (10) are provided 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) 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; The NMR control scanning and imaging module includes a magnet assembly (3) arranged outside the specimen holder (8), and the magnet assembly (3) includes a plurality of magnetic poles (24); 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 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 an upper support platform (1) and a 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).

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 chamber (2) is provided 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), and 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).

9. 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 arranged in a cross pattern, and the HSC-DIC control imaging module is located between the centers of the window distances between the X-μCT control and imaging module and the NMR control scanning and imaging module.

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