Rock scratch test device based on true triaxial stress

Abstract

This application provides a rock scratch testing device based on true triaxial stress, relating to the field of rock performance testing technology. The rock scratch testing device based on true triaxial stress includes: a support base; at least two lateral loading mechanisms, which are arranged opposite each other along the width direction of the support base, and at least one lateral loading mechanism is arranged along the length direction of the support base, with the at least two lateral loading mechanisms respectively used to apply lateral pressure to opposite sides of the rock sample; two axial loading mechanisms, which are used to apply pressure to the end faces of both ends of the rock sample; and a scratching mechanism to scratch the side surface of the rock sample. By setting at least two lateral loading mechanisms to apply corresponding lateral pressure to the side surfaces of different areas of the rock sample, and by applying pressure to the end faces of the rock sample through the axial loading mechanisms, the pressure on the rock sample is simulated, making the test results more accurate and reducing test errors.

Description

Technical Field

[0001] This application relates to the field of rock performance testing technology, and in particular to a rock scratch testing device based on true triaxial stress. Background Technology

[0002] Rocks are heterogeneous structures formed by one or more minerals or aggregates of minerals, containing bedding / lamination and lithological interfaces with varying mechanical properties. These bedding / lamination and lithological interfaces affect rock strength under complex stress fields, and rock strength is crucial for wellbore stability and hydraulic fracturing research. Therefore, accurately characterizing the mechanical response of rocks and their strong heterogeneity (including matrix, bedding / lamination, and lithological interfaces) is essential for ensuring safe and efficient subsequent development.

[0003] In related technologies, a rock scratch testing device is used to measure the mechanical parameters of rocks. The rock scratch testing device includes a confining pressure loading mechanism and a scratching mechanism. The confining pressure loading mechanism abuts against the axial and lateral surfaces of the rock sample to apply confining pressure to the rock sample in the axial and lateral directions. The scratching mechanism is used to scratch the surface of the rock test.

[0004] However, the confining stress on rocks at different depths below the strata varies, leading to errors in the test results. Summary of the Invention

[0005] This application provides a rock scratch testing device based on true triaxial stress to overcome the errors in test results caused by the different confining pressure stresses on rocks at different depths below the strata in the prior art.

[0006] In a first aspect, embodiments of this application provide a rock scratch testing device based on true triaxial stress, comprising: a support base for supporting a rock sample; at least two lateral loading mechanisms disposed on the support base, the at least two lateral loading mechanisms being disposed opposite each other along the width direction of the support base, and at least one lateral loading mechanism being disposed along the length direction of the support base, the at least two lateral loading mechanisms being respectively used to apply lateral pressure to opposite sides of the rock sample; two axial loading mechanisms disposed on the support base, the two axial loading mechanisms being respectively used to apply pressure to the end faces at both ends of the rock sample; and a scratching mechanism connected to the support base, the scratching mechanism being movable relative to the support base and scratching the side surface of the rock sample.

[0007] In one possible implementation, the lateral loading mechanism includes a first driving member and a first pressing block. The first pressing block includes a first pressing portion and a second pressing portion connected to the first pressing portion. The side of the rock sample includes a first side and a second side. The first pressing portion is mounted on the first side, and the second pressing portion is mounted on the second side connected to the first side. The output end of the first driving member is connected to the first pressing block. The first driving member is used to drive the first pressing block to apply lateral pressure to the side of the rock sample.

[0008] In one possible implementation, the first block has a loading surface, which is either an arc-shaped surface or a plane, and the loading surface is in contact with the side of the rock sample.

[0009] In one possible implementation, the axial loading mechanism includes a second drive member and a second pressure block, the output end of the second drive member being connected to the second pressure block, and the second drive member being used to drive the second pressure block to apply axial pressure to the end face of the rock sample.

[0010] In one possible implementation, a guiding mechanism is further included, comprising a guiding frame, two parallel guide rails, and a driving component. The guiding frame is slidably connected to both guide rails, the perpendicular line between the two guide rails forms the width direction of the support, and the extension direction of the guide rails forms the length direction of the support. The driving component is connected to the guiding frame and is used to drive the guiding frame to slide along the extension direction of the guide rails. The scribing mechanism is connected to the guiding frame.

[0011] In one possible implementation, the guide frame includes a top rod and two support rods, the top rod connecting the two support rods, and the support rods being slidably connected to the guide rail; the scribing mechanism is slidably connected to the top rod.

[0012] In one possible implementation, the drive assembly includes a lead screw, a connecting block, and a drive motor. The connecting block is threadedly connected to the lead screw and connected to the guide frame. The output end of the drive motor is connected to the end of the lead screw. The drive motor is used to drive the lead screw to rotate, so that the connecting block slides along the extension direction of the guide rail.

[0013] In one possible implementation, the scribing mechanism includes a scribing tool holder, a scribing tool, a scribing tool driver, a laser rangefinder, and a laser scanner. The scribing tool holder is connected to the guide frame. The scribing tool driver, the laser rangefinder, and the laser scanner are all mounted on the scribing tool holder. The output end of the scribing tool driver is connected to the scribing tool. The scribing tool driver is used to drive the scribing tool to vibrate and scribble on the rock sample. The laser rangefinder is used to test the depth of the scribing tool on the rock sample. The laser scanner is used to detect the relationship between the position of each scribing point and its corresponding data point when the scribing tool scribbles on the rock sample.

[0014] In one possible implementation, the scribing mechanism further includes a lifting assembly, which includes a lifting frame, a lifting motor, and a lifting rod. The lifting frame is connected to the guide frame, the lifting motor is mounted on the lifting frame, and the scribing tool holder is threadedly connected to the lifting rod. The lifting motor is used to drive the lifting rod to rotate, thereby driving the scribing tool to rise and fall through the scribing tool holder, so as to adjust the scribing depth of the scribing tool on the rock sample.

[0015] In one possible implementation, a grinding mechanism is also included, which includes a grinding disc, a grinding drive, and a grinding bracket. The grinding bracket is connected to the scribing mechanism, the grinding drive is mounted on the grinding bracket, and the output end of the grinding drive is connected to the grinding disc. The grinding disc is used to grind the rock sample.

[0016] The rock scratch testing device based on true triaxial stress provided in this application embodiment uses a support base to support the rock sample and sets up at least two lateral loading mechanisms. At least two lateral loading mechanisms are arranged opposite each other along the width direction of the support base, and at least one lateral loading mechanism is arranged along the length direction of the support base. This allows for the application of corresponding lateral pressure to the sides of different areas of the rock sample according to the actual pressure experienced by the rock at different depths. The axial loading mechanism applies pressure to the end faces of both ends of the rock sample to simulate the pressure experienced by the rock sample. This makes the test results of the scratch testing of the rock sample by the scratching mechanism more accurate and effectively reduces the error of the test results. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] Figure 1 A top view of the rock scratch testing device based on true triaxial stress provided in this application;

[0019] Figure 2 for Figure 1A side view of the rock scratch testing device based on true triaxial stress provided in the image;

[0020] Figure 3 for Figure 1 The front view of the rock scratch testing device based on true triaxial stress provided in the image;

[0021] Figure 4 for Figure 1 The schematic diagram of the drive component of the rock scratch test device based on true triaxial stress provided in the paper.

[0022] Explanation of reference numerals in the attached figures:

[0023] 100-Support base;

[0024] 200 - Lateral loading mechanism; 210 - First driving component; 220 - First pressing block; 221 - First pressing part; 222 - Second pressing part;

[0025] 300 - Axial loading mechanism; 310 - Second driving component; 320 - Second pressure block;

[0026] 400 - Engraving mechanism; 410 - Engraving tool holder; 420 - Engraving tool; 430 - Engraving tool drive component; 440 - Lifting assembly; 441 - Lifting frame; 442 - Lifting motor; 443 - Lifting rod;

[0027] 500 - Grinding mechanism; 510 - Grinding disc; 520 - Grinding drive component; 530 - Grinding support;

[0028] 600-Rock sample;

[0029] 700-Guide mechanism; 710-Guide frame; 711-Top rod; 712-Support rod; 720-Guide rail; 730-Drive assembly; 731-Lead screw; 732-Connecting block; 733-Drive motor.

[0030] To facilitate understanding of the embodiments of this application, the spline curves and arrows used in the reference numerals in the accompanying drawings are explained below: the components indicated by spline curves without arrows can be solid components, that is, components with solid structures; the components indicated by spline curves with arrows can be virtual components, that is, components without solid structures; in some cases, the components indicated by spline curves with arrows can also be assemblies with solid structures or virtual structures.

[0031] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0032] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0033] The terms "first," "second," "third," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.

[0034] Secondly, it should be noted that in the description of this application, the terms "inner", "outer", "first direction", "second direction", etc., which indicate the direction or positional relationship, are based on the direction or positional relationship shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0035] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0036] As shown in the background art, in related technologies, a rock scratch testing device is used to measure the mechanical parameters of rocks. The rock scratch testing device includes a confining pressure loading mechanism and a scratching mechanism. The confining pressure loading mechanism abuts against the axial surface and the side surface of the rock sample, respectively, and is used to apply confining pressure to the rock sample in the axial and lateral directions. The scratching mechanism is used to scratch the surface of the rock test.

[0037] However, rocks are heterogeneous structures, and the confining stresses on rocks at different depths and with different mechanical properties are different, leading to errors in the test results.

[0038] To address the aforementioned technical problems, this application provides a rock scratch testing device based on true triaxial stress, comprising: a support base for supporting a rock sample; at least two lateral loading mechanisms disposed on the support base, the at least two lateral loading mechanisms being arranged opposite each other along the width direction of the support base, and at least one lateral loading mechanism being disposed along the length direction of the support base, the at least two lateral loading mechanisms being respectively used to apply lateral pressure to opposite sides of the rock sample; two axial loading mechanisms disposed on the support base, the axial loading mechanisms being used to apply pressure to the end faces of both ends of the rock sample respectively; and a scratching mechanism connected to the support base, the scratching mechanism being movable relative to the support base and scratching the side surface of the rock sample.

[0039] The rock scratch testing device based on true triaxial stress provided in this application embodiment uses a support base to support the rock sample and sets up at least two lateral loading mechanisms. At least two lateral loading mechanisms are arranged opposite each other along the width direction of the support base, and at least one lateral loading mechanism is arranged along the length direction of the support base. This allows for the application of corresponding lateral pressure to the sides of different areas of the rock sample according to the actual pressure experienced by the rock at different depths. The axial loading mechanism applies pressure to the end faces of both ends of the rock sample to simulate the pressure experienced by the rock sample. This makes the test results of the scratch testing of the rock sample by the scratching mechanism more accurate and effectively reduces the error of the test results.

[0040] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0041] This application provides a rock scratch testing device based on true triaxial stress, combined with... Figures 1 to 4 As shown, it includes: a support base 100, which is used to support the rock sample 600.

[0042] At least two lateral loading mechanisms 200 are provided on the support base 100. The at least two lateral loading mechanisms 200 are arranged opposite each other along the width direction of the support base 100. At least one lateral loading mechanism 200 is provided along the length direction of the support base 100. The at least two lateral loading mechanisms 200 are respectively used to apply lateral pressure to opposite sides of the rock sample 600.

[0043] Two axial loading mechanisms 300 are mounted on the support base 100. The two axial loading mechanisms 300 are used to apply pressure to the end faces of both ends of the rock sample 600.

[0044] The scribing mechanism 400 is connected to the support base 100. The scribing mechanism 400 moves relative to the support base 100 and scribes the side of the rock sample 600.

[0045] It is understandable that rocks have a heterogeneous structure, and the stresses experienced by the rocks at different depths and with different mechanical properties at the lithological interfaces are different. Therefore, the rock sample 600 can be divided into multiple different regions based on its burial depth, with adjacent regions set along the extension direction of the rock sample 600. Each region is equipped with a pressure device to simulate the stresses experienced by the rocks beneath the strata, so that the rock's hardness, toughness, and other mechanical parameters can be calculated based on the indentation data.

[0046] Specifically, in combination Figures 1 to 4 As shown, a rock sample 600 is supported by a support base 100, and at least two lateral loading mechanisms 200 are provided. At least two lateral loading mechanisms 200 are arranged opposite each other along the width direction of the support base 100, and at least one lateral loading mechanism 200 is arranged along the length direction of the support base 100. This allows for the application of corresponding lateral pressure to the sides of different areas of the rock sample 600 based on the actual pressure experienced by the rock at different depths. Furthermore, pressure is applied to the end faces of both ends of the rock sample 600 by an axial loading mechanism 300 to simulate the pressure experienced by the rock sample 600. This makes the scratch test results of the scratching mechanism 400 on the rock sample more accurate and effectively reduces the error in the test results.

[0047] In addition, combined Figure 1 As shown, at least two lateral loading mechanisms 200 are arranged opposite each other along the width direction of the support 100. This arrangement ensures uniform pressure is applied to the side of the rock sample 600, avoiding uneven pressure and ensuring accurate test results. The first driving component 210 can be a hydraulic cylinder or a pneumatic cylinder, as long as it can drive the first pressure block 220 to apply lateral pressure towards the side of the rock sample 600.

[0048] In addition, the rock sample 600 can be divided into multiple regions according to the burial depth of the rock. Each region is provided with a lateral loading mechanism 200 on its side. Different pressures can be applied through the corresponding lateral loading mechanism 200, thereby obtaining the strength difference of the rock sample 600 corresponding to different regions based on the scratch test.

[0049] Of course, multiple zones can be divided according to the different depths the rock extends into the ground, or they can be flexibly adjusted according to specific test requirements.

[0050] In one possible implementation, such as Figure 1As shown, the lateral loading mechanism 200 includes a first driving member 210 and a first pressing block 220. The first pressing block 220 includes a first pressing part 221 and a second pressing part 222 connected to the first pressing part 221. The side of the rock sample 600 includes a first side and a second side. The first pressing part 221 is installed on the first side, and the second pressing part 222 is installed on the second side connected to the first side. The output end of the first driving member 210 is connected to the first pressing block 220. The first driving member 210 is used to drive the first pressing block 220 to apply lateral pressure to the side of the rock sample 600.

[0051] Specifically, such as Figure 1 As shown, the rock sample 600 may include a first side and a second side, which are connected to each other to form the side of the rock sample 600. The first pressing block 220 may include a first pressing part 221 and a second pressing part 222, wherein the first pressing part 221 is installed on the first side and the second pressing part 222 is installed on the second side. The second pressing part 222 is connected to the first pressing part 221 to fit against the side of the rock sample 600. The first driving member 210 can drive the first pressing block 220 to apply lateral pressure to the side of the rock sample 600 to achieve pressure on the rock sample 600 in the y and z directions.

[0052] The first pressing block 220 mentioned above can be a one-piece molded structure.

[0053] Furthermore, refer to Figure 1 As shown, the first pressure block 220 has a loading surface, which is an arc-shaped surface or a plane, and the loading surface is in contact with the side of the rock sample 600.

[0054] Specifically, such as Figure 1 As shown, the rock sample 600 can be a cylindrical or cuboid structure, and the first pressing block 220 has a loading surface. The loading surface can be a curved surface that can fit against the side of the rock sample 600; and the loading surface can also be a plane, which is the loading surface of the first pressing part and the second pressing part mentioned above, so that the first pressing block 220 can always fit against the side of the rock sample 600.

[0055] In one possible implementation, such as Figure 1 As shown, the axial loading mechanism 300 includes a second driving member 310 and a second pressure block 320. The output end of the second driving member 310 is connected to the second pressure block 320. The second driving member 310 is used to drive the second pressure block 320 to apply axial pressure to the rock sample 600.

[0056] Specifically, such as Figure 1As shown, the second pressure block 320 can be a loading pressure block. The loading pressure blocks of the two axial loading mechanisms 300 are respectively disposed on two opposite end faces of the rock sample 600 along the axial direction, and the pressing surfaces of the two loading pressure blocks are in contact with the surface of the rock sample 600. The second driving member 310 can be a hydraulic cylinder. The output end of the second driving member 310 is connected to the loading pressure block. The second driving member 310 can drive the second pressure block 320 to apply axial pressure toward the end face of the rock sample 600, that is, to apply pressure to the rock sample 600 in the x direction.

[0057] Of course, in other embodiments, the second driving member 310 can also be a cylinder, not limited to a hydraulic cylinder, as long as it can drive the second pressure block 320 to apply pressure toward the rock sample 600.

[0058] In one possible implementation, combining Figure 1 and Figure 2 As shown, it also includes a guide mechanism 700, which includes a guide frame 710, two parallel guide rails 720 and a drive assembly 730. The guide frame 710 is slidably connected to both guide rails 720. The perpendicular line between the two guide rails 720 forms the width direction of the support 100, and the extension direction of the guide rails 720 forms the length direction of the support 100.

[0059] The drive assembly 730 is connected to the guide frame 710 and is used to drive the guide frame 710 to slide along the extension direction of the guide rail 720. The scribing mechanism 400 is connected to the guide frame 710.

[0060] Understandably, referring to Figure 1 As shown, the lateral loading mechanism 200 and the axial loading mechanism 300 are disposed on the support base 100 and are in contact with the surface of the rock sample 600 to apply pressure. The guide mechanism 700 is disposed on the outer periphery of the support base 100 and can drive the scribing mechanism 400 to move relative to the rock sample 600 to scribing.

[0061] Specifically, in combination Figure 1 and Figure 2 As shown, two guide rails 720 are arranged parallel to each other, and the perpendicular lines of the two guide rails 720 form the width direction of the support base 100. That is, the two guide rails 720 are spaced apart on both sides of the rock sample 600, and the extension direction of the two guide rails 720 forms the length direction of the support base 100. The guide frame 710 is connected to the two guide rails 720, and the drive component 730 is connected to the guide frame 710. Under the action of the drive component 730, the guide frame 710 can be driven to move along the extension direction of the two guide rails 720. The scribing mechanism 400 is connected to the guide frame 710, thereby driving the scribing mechanism 400 to scribble on the rock sample 600.

[0062] The connection between the guide frame 710 and the two guide rails 720 can be a sliding connection. The two guide rails 720 have grooves, and a slider is installed on the side of the guide frame 710 facing the guide rails 720. The slider is installed in the groove.

[0063] Of course, in other embodiments, the connection method between the guide frame 710 and the two guide rails 720 is not specifically limited, as long as it can drive the guide frame 710 to move, thereby driving the scribing mechanism 400 to scribble on the rock sample 600.

[0064] Additionally, it should be noted that the aforementioned guide frame 710 can be a frame structure formed by multiple connecting rods, having a hollow space, in which the rock sample 600 is installed and passes through the guide frame 710.

[0065] Furthermore, refer to Figure 2 As shown, the guide frame 710 includes a top rod 711 and two support rods 712. The top rod 711 connects to the two support rods 712, and the support rods 712 are slidably connected to the guide rail 720.

[0066] The engraving mechanism 400 is slidably connected to the push rod 711.

[0067] Specifically, such as Figure 2 As shown, the guide frame 710 may include a top rod 711 and two support rods 712. One end of the support rod 712 is connected to the top rod 711, and the other end is slidably connected to the guide rail 720. The extension direction of the top rod 711 forms the width direction of the support base 100, and the top rod 711 is disposed above the support base 100, parallel to the support base 100 but not coplanar. The scribing mechanism 400 is connected to the top rod 711. Under the driving action of the driving member (not shown in the figure), the scribing mechanism 400 moves along the extension direction of the top rod 711 so that the scribing end of the scribing mechanism 400 is aligned with the scribing surface of the rock sample 600 to perform the scribing operation.

[0068] The connection between the scribing mechanism 400 and the top rod 711 can also be a sliding connection, so that the position of the scribing mechanism 400 can be adjusted according to the specific size of the rock sample 600 being tested, ensuring that the scribing end of the scribing mechanism 400 can be aligned with the surface of the rock sample 600 to be scribed.

[0069] It should be noted that the surface to be scratched is the side of the rock sample 600 that is not in contact with the first pressure block 220.

[0070] Furthermore, combined Figure 2 and Figure 4 As shown, the drive assembly 730 includes a lead screw 731, a connecting block 732, and a drive motor 733. The connecting block 732 is threadedly connected to the lead screw 731 and is connected to the guide frame 710. The output end of the drive motor 733 is connected to the end of the lead screw 731. The drive motor 733 is used to drive the lead screw 731 to rotate so that the connecting block 732 slides along the extension direction of the guide rail 720.

[0071] Specifically, in combination Figure 2 and Figure 4 As shown, the extension direction of the lead screw 731 forms the length direction of the support base 100, that is, the lead screw 731 extends along the length direction of the rock sample 600. The connecting block 732 is threadedly connected to the lead screw 731 and is connected to the guide frame 710. The drive motor 733 can drive the lead screw 731 to rotate, so that the connecting block 732 can move along the extension direction of the lead screw 731, driving the guide frame 710 to move along the length direction of the rock sample 600, thereby realizing that the engraving knife 420 (which will be described below) moves smoothly along the tangential direction of the rock sample 600 to perform engraving.

[0072] In one possible implementation, combining Figure 2 and Figure 3 As shown, the scribing mechanism 400 includes a scribing tool holder 410, a scribing tool 420, a scribing tool driver 430, a laser rangefinder, and a laser scanner. The scribing tool holder 410 is connected to the guide frame 710. The scribing tool driver 430, the laser rangefinder, and the laser scanner are all mounted on the scribing tool holder 410. The output end of the scribing tool driver 430 is connected to the scribing tool 420. The scribing tool driver 430 is used to drive the scribing tool 420 to vibrate and scribble on the rock sample 600. The laser rangefinder is used to test the depth of the scribing tool 420 on the rock sample 600. The laser scanner is used to detect the relationship between the position of each scribing point and its corresponding data point when the scribing tool 420 scribbles on the rock sample 600.

[0073] Specifically, in combination Figure 2 and Figure 3 As shown, the engraving blade holder 410 is connected to the top rod 711 of the guide frame 710. The engraving blade drive unit 430 is mounted on the engraving blade holder 410. The engraving blade drive unit 430 can drive the engraving blade 420 to vibrate in order to engrave the surface of the rock sample 600. The engraving blade drive unit 430 can control the engraving rate of the engraving blade 420 to continuously engrave the surface of the rock sample 600.

[0074] The engraving tool holder 410 is also equipped with a laser rangefinder and a laser scanner. The laser rangefinder detects the distance from each engraving point to the engraving tool 420 and the engraving depth of the tool when it engraves the rock sample 600, allowing for direct detection of the engraving depth and preventing errors. The laser scanner acquires the position of each engraving point and its corresponding data point when the engraving tool 420 engraves the rock sample 600, enabling it to work in conjunction with the laser rangefinder to optimize engraving accuracy and reduce errors.

[0075] Furthermore, refer to Figure 2 As shown, it also includes a lifting assembly 440, which includes a lifting frame 441, a lifting motor 442, and a lifting rod 443. The lifting frame 441 is connected to the guide frame 710, the lifting motor 442 is mounted on the lifting frame 441, the lifting rod 443 extends vertically, and the engraving knife support 410 is threadedly connected to the lifting rod 443. The lifting motor 442 is used to drive the lifting rod 443 to rotate, so as to drive the engraving knife 420 to rise and fall through the engraving knife support 410, so as to adjust the engraving depth of the engraving knife 420 on the rock sample 600.

[0076] Understandably, in combination Figure 2 As shown, the scratching depth affects the mechanical parameters of the rock being studied. Therefore, the lifting assembly 440 can be connected to the cutting tool holder 410, and the scratching depth of the cutting tool 420 in the normal direction of the rock sample 600 can be adjusted by the lifting assembly 440.

[0077] Specifically, the lifting rod 443 can be a lead screw. The lifting rod 443 is used to extend vertically toward the rock sample 600. The engraving knife holder 410 has a connecting part, which is threadedly connected to the lifting rod 443. The lifting motor 442 can drive the lifting rod 443 to rotate, thereby driving the engraving knife holder 410 to move along the extension direction of the lifting rod 443, so as to control and adjust the engraving knife 420 along the normal direction of the rock sample 600, and use a laser rangefinder to monitor the engraving depth of the engraving knife 420 in the normal direction of the rock sample 600.

[0078] Of course, the scratch depth can be greater than 0 mm and less than 5 mm to achieve non-destructive testing and preserve the structural integrity of the rock sample 600 to the greatest extent.

[0079] Furthermore, it should be noted that a force sensor can be installed at the cutting tool 420. The force sensor can monitor and record the force on the cutting tool 420 in real time during the cutting process. This allows the cutting tool 420 to accurately obtain force data in multiple directions, including tangential, normal, and lateral directions, when continuously scratching the surface of the rock sample 600 at the set cutting depth and cutting rate. This facilitates the subsequent calculation of key mechanical parameters of the rock sample 600, such as tangential strength, normal strength, hardness, and toughness, providing reliable data support for the non-destructive mechanical characterization of rocks.

[0080] In one possible implementation, combining Figure 2 and Figure 3 As shown, it also includes a grinding mechanism 500, which includes a grinding disc 510, a grinding drive 520, and a grinding bracket 530. The grinding bracket 530 is connected to the scribing mechanism 400, the grinding drive 520 is mounted on the grinding bracket 530, and the output end of the grinding drive 520 is connected to the grinding disc 510. The grinding disc 510 is used to grind the circumferential surface of the rock sample 600 that is not covered.

[0081] Understandably, depending on the specific needs of different rock scratch tests, the grinding mechanism 500 can be used to grind the surface of the rock sample 600. If the core objective of the rock scratch test is to study its physical properties in its natural state (such as hardness and abrasion resistance), then the grinding mechanism 500 is unnecessary to avoid altering the original structure of the rock sample 600's surface (such as crack distribution and the degree of mineral particle exposure), so that the test results can truly reflect the rock properties in the geological environment. If the core objective of the rock scratch test is to detect the mechanical parameters such as the hardness and toughness of the minerals inside the rock sample 600, then the grinding mechanism 500 must be used to grind the rock sample 600 to eliminate interference from the surface medium.

[0082] Specifically, in combination Figure 2 and Figure 3 As shown, the grinding bracket 530 can be connected to the lifting component 440 of the scribing mechanism 400. The grinding drive 520 is installed on the grinding bracket 530. The output end of the grinding drive 520 is connected to the grinding disc 510. The distance between the grinding disc 510 and the uncovered circumferential surface (the surface to be scribed) of the rock sample 600 can be adjusted by the lifting component 440. This allows for adjustment of whether the grinding disc 510 performs grinding operations on the uncovered circumferential surface of the rock sample 600 according to the changes in different rock scratch tests, providing high flexibility.

[0083] The specific usage method of this rock scratch testing device based on true triaxial stress is as follows:

[0084] First, select the surface of the rock sample 600 to be scratched, fix the rock sample 600 on the support base 100, and set it below the top rod 711 of the guide frame 710, with the rock sample 600 and the top rod 711 being parallel to each other.

[0085] Secondly, before scratching, depending on the requirements of different rock scratch tests, the surface of the rock sample 600 can be polished using the polishing mechanism 500.

[0086] Then, lateral pressure is applied to different areas of the rock sample 600 through the lateral loading mechanism 200, and axial pressure is applied to the rock sample 600 through the axial loading mechanism 300. A reasonable scratching depth and scratching rate are set based on the strength estimate of the rock sample 600, and a scratching test is performed on the rock sample 600 using the scratching mechanism 400. Furthermore, while maintaining consistency in the scratching start point, scratching surface, scratching depth, and scratching rate, the scratching test is repeated at least three times to reduce the impact of experimental repeatability and local heterogeneity of the rock sample 600 on data fluctuations.

[0087] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A rock scratch testing device based on true triaxial stress, characterized in that, include: Support (100) for supporting rock sample (600); At least two lateral loading mechanisms (200) are disposed on the support base (100). The at least two lateral loading mechanisms (200) are disposed opposite to each other along the width direction of the support base (100) and are used to apply lateral pressure to opposite sides of the rock sample (600). At least one lateral loading mechanism (200) is disposed along the length direction of the support base (100) and is used to apply different lateral pressures to different areas of the rock sample (600). The rock sample (600) is divided into multiple areas according to the burial depth, and a lateral loading mechanism (200) is disposed on the side of each area. The lateral loading mechanism (200) includes a first driving member (210) and a first pressing block (220). The first pressing block (220) includes a first pressing part (221) and a second pressing part (222) connected to the first pressing part (221). The side of the rock sample (600) includes a first side and a second side. The first pressing part (221) is installed on the first side, and the second pressing part (222) is installed on the second side connected to the first side. The output end of the first driving member (210) is connected to the first pressing block (220). The first driving member (210) is used to drive the first pressing block (220) to apply lateral pressure to the side of the rock sample (600). The first pressing block (220) has a loading surface, which is an arc-shaped surface or a plane, and the loading surface is in contact with the side of the rock sample (600). Two axial loading mechanisms (300) are provided on the support base (100), and the two axial loading mechanisms (300) are respectively used to apply pressure to the end faces of the two ends of the rock sample (600); A scribing mechanism (400) is connected to the support base (100). The scribing mechanism (400) moves relative to the support base (100) along the length direction of the rock sample (600) and scribes the surface of the rock sample (600) to be scribed. The surface to be scribed is the side of the rock sample (600) that is not in contact with the first pressure block (220). It also includes a guide mechanism (700), which includes a guide frame (710), two parallel guide rails (720) and a drive assembly (730). The guide frame (710) is slidably connected to the two guide rails (720). The perpendicular line between the two guide rails (720) forms the width direction of the support base (100), and the extension direction of the guide rails (720) forms the length direction of the support base (100). The guide frame (710) includes a top rod (711) and two support rods (712). The top rod (711) connects the two support rods (712), and the support rods (712) are slidably connected to the guide rail (720). The extension direction of the top rod (711) forms the width direction of the support base (100), and the top rod (711) is disposed above the support base (100). The engraving mechanism (400) is slidably connected to the top rod (711); The marking mechanism (400) includes a marking knife holder (410), a marking knife (420), a marking knife drive (430), a laser rangefinder, and a laser scanner. The marking knife holder (410) is connected to the top rod (711). The marking knife drive (430), the laser rangefinder, and the laser scanner are all mounted on the marking knife holder (410). The output end of the marking knife drive (430) is connected to the marking knife (420). The marking knife drive (430) is used to drive the marking knife (420) to vibrate in order to mark the rock sample (600). The laser rangefinder is used to test the depth of the marking knife (420) on the rock sample (600). The laser scanner is used to detect the relationship between the position of each marking point and its corresponding data point when the marking knife (420) marks the rock sample (600). The scoring mechanism (400) further includes a lifting assembly (440), which includes a lifting frame (441), a lifting motor (442), and a lifting rod (443). The lifting frame (441) is connected to the guide frame (710), and the lifting motor (442) is mounted on the lifting frame (441). The scoring knife support (410) is threadedly connected to the lifting rod (443). The lifting motor (442) is used to drive the lifting rod (443) to rotate, so as to drive the scoring knife (420) to rise and fall through the scoring knife support (410), thereby adjusting the scoring depth of the scoring knife (420) on the rock sample (600). It also includes a grinding mechanism (500), which includes a grinding disc (510), a grinding drive (520), and a grinding bracket (530). The grinding bracket (530) is connected to the lifting assembly (440), the grinding drive (520) is mounted on the grinding bracket (530), and the output end of the grinding drive (520) is connected to the grinding disc (510). The grinding disc (510) is used to grind the rock sample (600), and the lifting assembly (440) is used to adjust the distance between the grinding disc (510) and the rock sample (600).

2. The rock scratch testing device based on true triaxial stress according to claim 1, characterized in that, The axial loading mechanism (300) includes a second driving member (310) and a second pressure block (320). The output end of the second driving member (310) is connected to the second pressure block (320). The second driving member (310) is used to drive the second pressure block (320) to apply axial pressure to the end face of the rock sample (600).

3. The rock scratch testing device based on true triaxial stress according to claim 1, characterized in that, The drive assembly (730) is connected to the guide frame (710) and is used to drive the guide frame (710) to slide along the extension direction of the guide rail (720).

4. The rock scratch testing device based on true triaxial stress according to claim 1, characterized in that, The drive assembly (730) includes a lead screw (731), a connecting block (732), and a drive motor (733). The connecting block (732) is threadedly connected to the lead screw (731) and connected to the guide frame (710). The output end of the drive motor (733) is connected to the end of the lead screw (731). The drive motor (733) is used to drive the lead screw (731) to rotate so that the connecting block (732) slides along the extension direction of the guide rail (720).

Images