Method of determining internal damage of a test piece after testing

Abstract

The embodiment of the present application relates to the technical field of analyzing test materials, and particularly relates to a method for determining internal damage of a test piece after a test, which mainly comprises the following steps: measuring X-direction wave velocity and Z-direction wave velocity of multiple measuring points on the surface of the test piece; testing the test piece, measuring X-direction wave velocity and Z-direction wave velocity of the measuring points after the test, and determining X-direction wave velocity attenuation of the measuring points; determining the relationship between the X-direction wave velocity attenuation of the measuring points and Z coordinates of the measuring points; determining Z-direction wave velocity attenuation of any point in the test piece according to the relationship and the Z-direction wave velocity before and after the test; and determining internal damage of the test piece according to the Z-direction wave velocity attenuation. According to the embodiment of the present application, the relationship between the X-direction wave velocity attenuation and the Z coordinates is determined, and the Z-direction wave velocity before and after the test is combined, so that the Z-direction wave velocity attenuation of any point in the test piece is accurately determined, and then the internal damage of the test piece is accurately characterized according to the Z-direction wave velocity attenuation.

Description

Technical Field

[0001] The embodiments of this application relate to the technical field of analyzing and testing materials, and more specifically to a method for determining internal damage to a specimen after testing. Background Technology

[0002] The statements herein are provided merely as background information in connection with this application and do not necessarily constitute prior art.

[0003] Rock and concrete are two typical heterogeneous materials. When subjected to external loads, defects develop within them, which are defined as internal damage. With the rapid development of technologies such as tunnel boring machines (TBMs), frequent rock and concrete tests are necessary. However, during these tests, internal damage accumulates, leading to a decrease in self-supporting capacity and ultimately causing overall failure and loss of load-bearing capacity, thus affecting the stability and safety of underground engineering projects. Summary of the Invention

[0004] A brief overview of this application is provided below to offer a basic understanding of certain aspects thereof. It should be understood that this overview is not an exhaustive summary of the application. It is not intended to identify key or essential parts of the application, nor is it intended to limit its scope. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0005] In a first aspect, embodiments of this application provide a method for determining internal damage to a specimen after a test, the method comprising the following steps: S10: setting multiple velocity measuring points on the surface of the specimen, determining the XYZ coordinates of the multiple velocity measuring points, and measuring the X-axis wave velocity and Z-axis wave velocity of the velocity measuring points; S20: conducting a test on the specimen, measuring the X-axis wave velocity and Z-axis wave velocity of the velocity measuring points after the test, and determining the X-axis wave velocity attenuation of the velocity measuring points; S30: determining velocity measuring points on the surface of the specimen with the same XY coordinates; S40: determining the relationship between the X-axis wave velocity attenuation of the velocity measuring points and the Z-coordinate of the velocity measuring points; S50: determining the Z-axis wave velocity attenuation inside the specimen that is different from any point on the surface of the specimen, based on the relationship determined in step S40 and the Z-axis wave velocity before and after the test; S60: determining the internal damage of the specimen based on the Z-axis wave velocity attenuation.

[0006] In the embodiments of this application, by determining velocity measurement points with the same XY coordinates on the surface of the specimen and the X-direction wave velocity attenuation of the velocity measurement points, the non-uniform distribution of damage in the Z-direction of the specimen is considered, thereby determining the relationship between the X-direction wave velocity attenuation of the velocity measurement points and the Z-coordinate. Furthermore, by determining the relationship between the X-direction wave velocity attenuation and the Z-coordinate and the Z-direction wave velocity and attenuation of the velocity measurement points before and after the test, the X-direction wave velocity and Z-direction wave velocity at any point inside the specimen can be accurately determined by measuring the X-direction wave velocity and Z-direction wave velocity at the velocity measurement points on the specimen surface before and after the test. Therefore, by utilizing the Z-direction wave velocity attenuation at any point inside the specimen, accurate characterization of the internal damage of the specimen can be achieved.

[0007] Secondly, embodiments of this application provide a method for determining internal damage to a specimen after a test, the method comprising the following steps: S10: setting multiple velocity measuring points on the surface of the specimen, determining the XYZ coordinates of the multiple velocity measuring points, and measuring the X-axis wave velocity, Z-axis wave velocity, and Y-axis wave velocity of the velocity measuring points; S20: conducting a test on the specimen, measuring the X-axis wave velocity, Z-axis wave velocity, and Y-axis wave velocity of the velocity measuring points after the test, and determining the attenuation of the X-axis wave velocity of the velocity measuring points; S30: determining velocity measuring points on the surface of the specimen with the same XY coordinates; S40: determining the relationship between the attenuation of the X-axis wave velocity of the velocity measuring points and the Z-coordinate of the velocity measuring points; S50: measuring the velocity measuring points before and after the test according to the relationship determined in step S40. S60: Determine the Z-axis wave velocity, and determine the attenuation of the Z-axis wave velocity at any point inside the specimen that is different from the surface of the specimen; S70: Determine the relationship between the attenuation of the Z-axis wave velocity at the velocity measurement point and the Y-coordinate of the velocity measurement point; S80: Based on the relationship determined in step S70, measure the Y-axis wave velocity at the velocity measurement point before and after the test, and determine the attenuation of the Y-axis wave velocity at any point inside the specimen that is different from the surface of the specimen; S90: Based on the attenuation of the X-axis wave velocity at the velocity measurement point determined in step S20, the attenuation of the Z-axis wave velocity at any point inside the specimen determined in step S50, and the attenuation of the Y-axis wave velocity at any point inside the specimen determined in step S80, determine the internal damage of the specimen.

[0008] In the embodiments of this application, by determining the relationship between the X-axis wave velocity attenuation and the Z-coordinate of the velocity measurement point, the Z-axis wave velocity attenuation at any point inside the specimen can be accurately determined. Furthermore, after determining the Z-axis wave velocity attenuation at any point inside the specimen, the relationship between the Z-axis wave velocity attenuation and the Y-coordinate, as well as the relationship between the Z-axis wave velocity attenuation and the Y-coordinate, and the Y-axis wave velocity and attenuation at the velocity measurement points before and after the test, are further determined. Thus, by measuring the X-axis, Z-axis, and Y-axis wave velocities at the velocity measurement points on the specimen surface before and after the test, the X-axis, Z-axis, and Y-axis wave velocity attenuations at any point inside the specimen can be accurately determined. Finally, by using the wave velocity attenuation in three directions to characterize the internal damage of the specimen, the measurement blind zone of internal damage is eliminated, effectively avoiding the problem of missing internal damage due to single-direction characterization, and further improving the comprehensiveness and accuracy of the characterization of internal damage of the specimen. Attached Figure Description

[0009] Other objects and advantages of this application will become apparent from the following description of embodiments of this application with reference to the accompanying drawings, and will help to provide a comprehensive understanding of this application.

[0010] Figure 1 This is a flowchart of a method for determining internal damage to a specimen after testing, according to an embodiment of the first aspect of this application.

[0011] Figure 2 This is a schematic diagram of the arrangement of velocity measuring points on the specimen according to an embodiment of this application;

[0012] Figure 3 This is a schematic diagram showing the grouping of velocity measurement points on the surface of a specimen according to an embodiment of this application;

[0013] Figure 4 This is a graph showing the relationship between the X-axis wave velocity attenuation and the Z-coordinate of a velocity measuring point according to an embodiment of this application.

[0014] Figure 5 This is a flowchart of a method for determining internal damage to a specimen after testing, according to an embodiment of the second aspect of this application.

[0015] Explanation of reference numerals in the attached figures:

[0016] 10. Specimen; 11. Velocity measuring point; 12. Rock column X1; 13. Rock column X2; 14. Rock column X k ;141, Rock Block X k L1; 142, Rock Block X k L2; 143, Rock Block X k L i 15. Rock Column X n ;

[0017] 20. Speed ​​measuring equipment; 21. Probe; 22. Signal cable;

[0018] 30. The curve showing the relationship between X-axis wave velocity attenuation and Z-axis coordinate.

[0019] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are shown only in a schematic manner without affecting the reader's understanding. Detailed Implementation

[0020] Exemplary embodiments of this application will be described below with reference to the accompanying drawings. For clarity and brevity, not all features of actual implementations are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the development of any such actual embodiment to achieve the developer's specific goals, such as complying with constraints related to the system and business, and these constraints may vary depending on the implementation. Furthermore, it should be understood that while development work can be very complex and time-consuming, such development work is merely a routine task for those skilled in the art who benefit from the content of this application.

[0021] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the equipment structure and / or processing steps closely related to the solution according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0022] The inventors of this application have discovered that current methods for determining internal damage in rock or concrete specimens typically involve measuring the wave velocity attenuation on the upper and lower surfaces of the specimen and converting the measured wave velocity attenuation into a damage distribution map of the specimen using a wave velocity-damage formula. However, this method ignores the non-uniform distribution of damage in the depth direction of the specimen, as well as the spatial regional characteristics of the damage induced by the experiment. This makes it difficult for the measurement results to accurately reflect the actual internal damage of the specimen, thereby affecting the determination of the degree of impact of the internal damage of the specimen on the project during on-site construction.

[0023] Based on this, embodiments of this application provide a method for determining internal damage to a specimen after testing. Figure 1 This is a flowchart illustrating a method for determining internal damage to a specimen after testing, according to an embodiment of the first aspect of this application. Figure 1As shown, the method includes the following steps: S10: Set multiple velocity measurement points on the surface of the specimen, determine the XYZ coordinates of the multiple velocity measurement points, and measure the X-axis wave velocity and Z-axis wave velocity of the velocity measurement points; S20: Conduct a test on the specimen, measure the X-axis wave velocity and Z-axis wave velocity of the velocity measurement points after the test, and determine the X-axis wave velocity attenuation of the velocity measurement points; S30: Determine the velocity measurement points with the same XY coordinates on the surface of the specimen; S40: Determine the relationship between the X-axis wave velocity attenuation of the velocity measurement points and the Z-coordinate of the velocity measurement points; S50: Based on the relationship determined in step S40, as well as the Z-axis wave velocity before the test and the Z-axis wave velocity after the test, determine the Z-axis wave velocity attenuation of any point inside the specimen that is different from the surface of the specimen; S60: Determine the internal damage of the specimen based on the Z-axis wave velocity attenuation.

[0024] In the embodiments of this application, by determining velocity measurement points with the same XY coordinates on the surface of the specimen and the X-direction wave velocity attenuation of the velocity measurement points, the non-uniform distribution of damage in the Z-direction of the specimen is considered, thereby determining the relationship between the X-direction wave velocity attenuation of the velocity measurement points and the Z-coordinate. Furthermore, by determining the relationship between the X-direction wave velocity attenuation and the Z-coordinate and the Z-direction wave velocity and attenuation of the velocity measurement points before and after the test, the X-direction wave velocity and Z-direction wave velocity at any point inside the specimen can be accurately determined by measuring the X-direction wave velocity and Z-direction wave velocity at the velocity measurement points on the specimen surface before and after the test. Therefore, by utilizing the Z-direction wave velocity attenuation at any point inside the specimen, accurate characterization of the internal damage of the specimen can be achieved.

[0025] In some embodiments, in step S40, the attenuation of the X-axis wave velocity at the speed measuring point can be determined based on the X-axis wave velocity at the speed measuring point and the X-axis wave velocity at the speed measuring point after the test. Specifically, the X-axis wave velocity at the speed measuring point, the X-axis wave velocity at the speed measuring point after the test, and the attenuation of the X-axis wave velocity at the speed measuring point conform to the following relationship:

[0026] R = (V0 - V1) / V0 × 100%.

[0027] Where V1 is the X-axis wave velocity at the velocity measurement point after the test, in m / s; V0 is the X-axis wave velocity at the velocity measurement point before the test, in m / s; and R is the attenuation of the X-axis wave velocity at the velocity measurement point, in %.

[0028] Figure 2 This is a schematic diagram of the arrangement of speed measuring points 11 on the specimen 10 according to an embodiment of this application. Figure 3 This is a schematic diagram showing the grouping of velocity measuring points 11 on the surface of specimen 10 according to an embodiment of this application. Figure 2 and Figure 3As shown, in some embodiments, in step S40, the velocity measuring points 11 on the surface of the specimen 10 are divided into multiple groups based on their XY coordinates. The relationship between the X-axis wave velocity attenuation and the Z-coordinate of each group's velocity measuring points 11 is then determined. The XY coordinates of the velocity measuring points 11 within the same group are identical. In the embodiments of this application, by grouping the velocity measuring points 11 on the surface of the specimen 10 and determining the relationship between the X-axis wave velocity attenuation and the Z-coordinate for each group, the specificity of the relationship between the X-axis wave velocity attenuation and the Z-coordinate is effectively improved, and it is ensured that the X-axis wave velocity attenuation and the Z-coordinate of any point within the same group conform to the determined relationship between the X-axis wave velocity attenuation and the Z-coordinate.

[0029] For example, such as Figure 3 As shown, the XOY surface of specimen 10 can be divided into rock columns X112, X213, and X... k 14 and Rock Pillar X n 15, of which rock block X k L1141, Rock Block X k L2142, Rock Block X k L i 143 is a group.

[0030] In some embodiments, in step S40, the relationship between the X-axis wave velocity attenuation and the Z-coordinate of each group can be determined by fitting the X-axis wave velocity attenuation and Z-coordinate of the velocity measurement point 11 of each group, and obtaining, as shown below, Figure 4 The curve 30 shows the relationship between X-axis wave velocity attenuation and Z-coordinate. Furthermore, the X-axis wave velocity attenuation at any point inside the specimen 10 can be accurately determined using the curve 30 and the formula relating X-axis wave velocity attenuation to Z-coordinate. Figure 4 This is a graph showing the relationship between the X-axis wave velocity attenuation and the Z-axis of the velocity measuring point 11 according to an embodiment of this application, where the horizontal axis is the Z-axis (cm) and the vertical axis is the percentage of X-axis wave velocity attenuation.

[0031] In some embodiments, in step S50, the height of any point i in the Z direction is L. i According to height L i The average Z-axis wave velocity at velocity measurement point 11 and the average Z-axis wave velocity after the test at velocity measurement point 11, along with the relationship determined in step S40, determine the attenuation of the Z-axis wave velocity at any point i inside the specimen 10 that is different from the surface of the specimen 10.

[0032] In the embodiments of this application, the height of any point i in the Z direction is the Z coordinate of any point i. Therefore, based on the height L of any point i in the Z direction... i By understanding the relationship between X-axis wave velocity attenuation and Z-coordinate, the X-axis wave velocity attenuation at any point i inside specimen 10 can be determined.

[0033] In some embodiments, in step S50, the relationship determined in step S40 is set as f(Z), where Z is the value of the Z coordinate, f(Z) is the X-direction wave velocity attenuation, and L is the height L of any point i in the Z direction of the specimen 10. i The Z-axis average wave velocity at velocity measurement point 11, the Z-axis average wave velocity after the test at velocity measurement point 11, and the relationship determined in step S40 conform to the following formula:

[0034]

[0035] Among them, V B L is the average wave velocity in the Z direction after the test at velocity measurement point 11, in m / s; L is the height of specimen 10 in the Z direction, in m; L i L is the Z-axis height of any point i, in meters (m). i-1 Let W be the Z-axis height of any point i preceding point i-1; i V represents the percentage attenuation of the Z-axis wave velocity at any point i, where i takes any integer value from 1 to L; A The average wave velocity in the Z direction before the test at velocity measurement point 11 is expressed in m / s; K is a coefficient.

[0036] In the embodiments of this application, based on the conservation of sound wave propagation path time, that is, the sum of the time for the sound wave to pass through all the rock blocks in the specimen 10 is equal to the time for the sound wave to pass through the specimen 10, the relationship between the Z-direction height of the specimen 10, the Z-direction height difference between any point i and the previous point i-1, and the Z-direction wave velocity attenuation of any point i is established. At the same time, based on the relationship between X-direction wave velocity attenuation and Z coordinate, the Z-direction height of any point i and its previous point i-1, and the Z-direction height of the specimen 10, the coefficient K affecting the above relationship is determined, thereby ensuring the accuracy and reliability of determining the Z-direction wave velocity attenuation of any point i using the above relationship.

[0037] In some embodiments, the specimen 10 is configured as a hexahedron, and multiple speed measuring points 11 are provided on each face, with a predetermined distance between the speed measuring points 11. In the embodiments of this application, the predetermined distance between the speed measuring points 11 ensures that when adjacent speed measuring points 11 are separated by a predetermined distance, the speed measuring points 11 can achieve full coverage of the specimen 10, eliminate test blind spots, and ensure high test efficiency.

[0038] It is easy to understand that the greater the predetermined distance between the velocity measuring points 11, the lower the accuracy of the wave velocity measurement on the surface of the specimen 10. Therefore, those skilled in the art can flexibly adjust the predetermined distance between the velocity measuring points 11 according to actual measurement needs.

[0039] In some embodiments, the predetermined distance is set to be less than or equal to the minimum moving distance of the probe 21 to ensure the accuracy of the measurement results when adjacent speed measuring points 11 are separated by the predetermined distance. The minimum moving distance of the probe 21 can be the diameter of the probe 21. For example, the probe 21 is 5 cm, and the second predetermined distance is set to 5 cm.

[0040] like Figure 2 As shown, in some embodiments, the specimen 10 can be configured as a cuboid, and the three mutually perpendicular edges of the cuboid are the X-axis, Y-axis and Z-axis.

[0041] In some embodiments, step S10 further includes grinding and polishing the surface of the specimen 10 to reduce the flatness of the surface of the specimen 10, thereby further improving the tightness of the contact between the speed measuring device 20 and the speed measuring point 11. In some preferred embodiments, the flatness is set to less than 0.02 mm to ensure that the speed measuring device 20 can be tightly attached to the speed measuring point 11 at this flatness.

[0042] In some embodiments, the velocity measuring points 11 on two opposite surfaces are arranged on the same axis and parallel to the normals of the two opposite surfaces, so that the sound wave passes through the specimen 10 along the shortest path. In this case, the distance between the two opposite surfaces is the displacement of the sound wave in the specimen 10, simplifying the steps for determining the displacement of the sound wave in the specimen 10. Furthermore, when measuring the wave velocity in the same direction using this arrangement, the displacement of the sound wave in the specimen 10 is the same, thereby simplifying the calculation of the wave velocity at the velocity measuring points 11 in the same direction.

[0043] In some embodiments, a velocity measurement signal can be transmitted to a velocity measurement point 11 on one of two opposing surfaces, and the velocity measurement signal can be received at the corresponding velocity measurement point 11 on the opposing surface. It is easy to understand that the time difference between transmitting and receiving the velocity measurement signal is the time it takes for the sound wave to pass through the specimen 10. Therefore, the wave velocity at the velocity measurement point 11 can be determined by the time it takes for the sound wave to pass through the specimen 10 and the displacement of the sound wave through the specimen 10.

[0044] In some embodiments, the speed measurement signal can be a sound wave.

[0045] In some embodiments, during speed measurement, the speed measuring device 20 is configured to fit against the surface of the speed measuring point 11 to eliminate interference from the air medium between the speed measuring device 20 and the speed measuring point 11, ensuring that the sound wave can be effectively transmitted between the speed measuring point 11 and the speed measuring device 20, thereby improving the accuracy of the X-axis wave velocity and Z-axis wave velocity of the speed measuring point 11 before and after the test.

[0046] In some embodiments, the speed measuring device 20 is attached to the surface of the speed measuring point 11 via two probes 21. Specifically, the two probes 21 of the speed measuring device 20 are respectively disposed on the speed measuring points 11 on two opposite surfaces. In some embodiments, the two probes 21 can be a transmitting probe and a receiving probe, wherein the transmitting probe is configured to transmit a speed measuring signal, and the receiving probe is configured to receive a speed measuring signal.

[0047] In some embodiments, an ultrasonic coupling agent can be applied to the surfaces of the transmitting and receiving probes to further improve the tightness of the contact between the transmitting and receiving probes and the surface of the velocity measuring point 11 during the wave velocity measurement process, eliminate the gap between the transmitting and receiving probes and the surface of the velocity measuring point 11, and ensure the accuracy of the wave velocity measurement by the velocity measuring device 20.

[0048] Since rock or concrete specimens 10 typically require multiple or secondary tests, non-destructive testing of the internal damage of specimens 10 is necessary to ensure that the measurement of internal damage does not affect subsequent tests. In some embodiments, the measuring device 20 can be a rock ultrasonic detector. Rock ultrasonic detectors are convenient, efficient, and do not damage specimens 10. Therefore, non-destructive testing of internal damage in specimens 10 can be achieved using a rock ultrasonic detector, eliminating the need for core sampling and the risk of secondary damage to specimens 10 during the core sampling process.

[0049] In some embodiments, step S20 further includes setting parameters such as the gain, frequency, and delay time of the rock ultrasonic detector (including standard sample calibration) to improve the accuracy of wave velocity measurement. The settings of these parameters can be determined by those skilled in the art based on experience.

[0050] In some embodiments, the test is a blasting, laser, or temperature test, and after the test is completed, the specimen 10 is intact and there is no large-area peeling of the rock surface.

[0051] In the embodiments of this application, the test can be a blasting, laser, or temperature test to simulate pre-splitting blasting, laser pretreatment, and temperature pretreatment in on-site construction, respectively. Furthermore, ensuring the specimen 10 is intact and that there is no large-area peeling of the rock surface prevents the velocity measuring device 20 from being unable to adhere to the surface of the velocity measuring point 11 due to large-area rock surface peeling. Simultaneously, it avoids the specimen 10 breaking, which could affect the measurement accuracy of the X-axis and Z-axis wave velocities of the velocity measuring point 11 after the test.

[0052] In some embodiments, in step S20, the speed measuring points 11 on each pair of surfaces are tested before the speed measuring points 11 on the next pair of surfaces are tested, thereby avoiding repeated switching of the surfaces on which the speed measuring device 20 and the speed measuring points 11 are attached during the test, and thus improving the speed measuring efficiency of the speed measuring points 11.

[0053] In some embodiments, during speed measurement, the transmission of the speed measurement signal is stopped after a stable waveform appears in the wave speed measured by the testing equipment, and the signal is recorded as a measured value to ensure the stability and reliability of the measured value.

[0054] In some embodiments, the measured values ​​can be the amplitude and frequency of the waveform and the time it takes for the sound wave to pass through the specimen 10, thereby enabling the wave velocity at the velocity measuring point 11 to be determined based on the time it takes for the sound wave to pass through the specimen 10 and the displacement of the sound wave in the specimen 10.

[0055] In some embodiments, step S60 further includes: repeating steps S40-S50 to determine the Z-direction wave velocity attenuation distribution inside the specimen 10, constructing a Z-direction spatial damage map of the specimen 10 based on the Z-direction wave velocity attenuation distribution, and then performing a correspondence analysis between the test result data and the damage of the specimen 10 based on the Z-direction spatial damage map.

[0056] In some embodiments, the relationship between wave velocity attenuation and damage degree can be used to transform Z-axis wave velocity attenuation into Z-axis spatial damage. Specifically, wave velocity attenuation and damage degree conform to the following expression:

[0057] D = 1 - (1 - N) 2 .

[0058] N = (V0 - V1) / V0 × 100%.

[0059] Where D represents the degree of damage and N represents the wave velocity attenuation, in percentage (%).

[0060] The inventors of this application have discovered that the internal defects of rock and concrete specimens 10 are directional, and that sound waves are propagated along the most intact structure in specimens 10. Therefore, when the direction of sound wave propagation is the same as the direction of the crack surface, the existence of internal defects in specimens 10 cannot be detected, and thus it is difficult to fully and accurately reflect the internal damage of specimens 10.

[0061] Based on this, embodiments of this application also provide a method for determining the internal damage of the specimen 10 after the test. Figure 5 This is a flowchart illustrating a method for determining internal damage to specimen 10 after testing, according to an embodiment of the second aspect of this application. Figure 5As shown, the method includes the following steps: S10: Set multiple velocity measuring points 11 on the surface of the specimen 10, determine the XYZ coordinates of the multiple velocity measuring points 11, and measure the X-direction wave velocity, Z-direction wave velocity and Y-direction wave velocity of the velocity measuring points 11; S20: Conduct a test on the specimen 10, measure the X-direction wave velocity, Z-direction wave velocity and Y-direction wave velocity of the velocity measuring points 11 after the test, and determine the attenuation of the X-direction wave velocity of the velocity measuring points 11.

[0062] S30: Determine the velocity measurement point 11 with the same XY coordinates on the surface of specimen 10; S40: Determine the relationship between the X-axis wave velocity attenuation of velocity measurement point 11 and the Z-axis coordinate of velocity measurement point 11; S50: Based on the relationship determined in step S40, measure the Z-axis wave velocity of velocity measurement point 11 before and after the test, and determine the Z-axis wave velocity attenuation of any point inside specimen 10 that is different from the surface of specimen 10; S60: Determine the velocity measurement point 11 with the same XZ coordinates on the surface of specimen 10; S70: Determine the relationship between the X-axis wave velocity attenuation of velocity measurement point 11 and the Z-axis coordinate of velocity measurement point 11; The relationship between the Y coordinates of the velocity measurement points; S80: Based on the relationship determined in step S70, measure the Y-direction wave velocity of the velocity measurement point 11 before and after the test, and determine the Y-direction wave velocity attenuation of any point inside the specimen 10 that is different from the surface of the specimen 10; S90: Based on the X-direction wave velocity attenuation of the velocity measurement point 11 determined in step S20, the Z-direction wave velocity attenuation of any point inside the specimen 10 determined in step S50, and the Y-direction wave velocity attenuation of any point inside the specimen 10 determined in step S80, determine the internal damage of the specimen 10.

[0063] In the embodiments of this application, by determining the relationship between the X-axis wave velocity attenuation and the Z-coordinate of the velocity measurement point, the X-axis wave velocity attenuation at any point inside the specimen 10 can be accurately determined. Furthermore, after determining the Z-axis wave velocity attenuation at any point inside the specimen 10, the relationship between the Z-axis wave velocity attenuation and the Y-coordinate, as well as the relationship between the Z-axis wave velocity attenuation and the Y-coordinate, and the connection between the Y-axis wave velocity attenuation and the Y-axis wave velocity at the velocity measurement point 11 before and after the test, are further determined. Thus, by measuring the X-axis wave velocity, Z-axis wave velocity, and Y-axis wave velocity at the velocity measurement point 11 on the surface of the specimen 10 before and after the test, the X-axis wave velocity attenuation, Z-axis wave velocity attenuation, and Y-axis wave velocity at any point inside the specimen 10 can be accurately determined. Finally, by using the wave velocity attenuation in three directions to characterize the internal damage of the specimen 10, the measurement blind zone of internal damage is eliminated, effectively avoiding the problem of missing internal damage in the specimen 10 due to single-direction characterization, and further improving the comprehensiveness and accuracy of the characterization of internal damage in the specimen 10.

[0064] In some embodiments, in step S40, the attenuation of the X-direction wave velocity at speed measuring point 11 can be determined based on the X-direction wave velocity at speed measuring point 11 and the X-direction wave velocity at speed measuring point 11 after the test. Specifically, the X-direction wave velocity at speed measuring point 11, the X-direction wave velocity at speed measuring point 11 after the test, and the attenuation of the X-direction wave velocity at speed measuring point 11 conform to the following relationship:

[0065] R = (V0 - V1) / V0 × 100%.

[0066] Where V1 is the X-axis wave velocity at measurement point 11 after the test, in m / s; V0 is the X-axis wave velocity at measurement point 11 before the test, in m / s; and R is the attenuation of the X-axis wave velocity at measurement point 11, in m / s.

[0067] like Figure 2 and Figure 3 As shown, in some embodiments, in step S40, the velocity measuring points 11 on the surface of the specimen 10 are divided into multiple groups based on their XY coordinates. The relationship between the X-axis wave velocity attenuation and the Z-coordinate of each group's velocity measuring points 11 is then determined. The XY coordinates of the velocity measuring points 11 within the same group are identical. In the embodiments of this application, by grouping the velocity measuring points 11 on the surface of the specimen 10 and determining the relationship between the X-axis wave velocity attenuation and the Z-coordinate for each group, the specificity of the relationship between the X-axis wave velocity attenuation and the Z-coordinate is effectively improved, and it is ensured that the X-axis wave velocity attenuation and the Z-coordinate of any point within the same group conform to the determined relationship between the X-axis wave velocity attenuation and the Z-coordinate.

[0068] For example, such as Figure 3 As shown, the XOY surface of specimen 10 can be divided into rock columns X112, X213, and X... k 14 and Rock Pillar X n 15, of which rock block X k L1141, Rock Block X k L2142, Rock Block X k L i 143 is a group.

[0069] In some embodiments, in step S40, the relationship between the X-axis wave velocity attenuation and the Z-coordinate of each group can be determined by fitting the X-axis wave velocity attenuation and Z-coordinate of the velocity measurement point 11 of each group, and obtaining, as shown below, Figure 4 The curve 30 shows the relationship between X-axis wave velocity attenuation and Z-coordinate. Furthermore, the X-axis wave velocity attenuation at any point inside the specimen 10 can be accurately determined using the curve 30 and the formula relating X-axis wave velocity attenuation to Z-coordinate. Figure 4This is a graph showing the relationship between the X-axis wave velocity attenuation and the Z-axis of the velocity measuring point 11 according to an embodiment of this application, where the horizontal axis is the Z-axis (cm) and the vertical axis is the percentage of X-axis wave velocity attenuation.

[0070] In some embodiments, in step S50, the height of any point i in the Z direction is L. i According to height L i The average Z-axis wave velocity at velocity measurement point 11 and the average Z-axis wave velocity after the test at velocity measurement point 11, along with the relationship determined in step S40, determine the attenuation of the Z-axis wave velocity at any point i inside the specimen 10 that is different from the surface of the specimen 10.

[0071] In the embodiments of this application, the height of any point i in the Z direction is the Z coordinate of any point i. Therefore, based on the height L of any point i in the Z direction... i By understanding the relationship between X-axis wave velocity attenuation and Z-coordinate, the X-axis wave velocity attenuation at any point i inside specimen 10 can be determined, and thus the X-axis wave velocity attenuation distribution inside specimen 10 can be determined.

[0072] In some embodiments, in step S50, the relationship determined in step S40 is set as f(Z), where Z is the value of the Z coordinate, f(Z) is the X-direction wave velocity attenuation, and L is the height L of any point i in the Z direction of the specimen 10. i The Z-axis average wave velocity at velocity measurement point 11, the Z-axis average wave velocity after the test at velocity measurement point 11, and the relationship determined in step S40 conform to the following formula:

[0073]

[0074] Among them, V B L is the average wave velocity in the Z direction after the test at velocity measurement point 11, in m / s; L is the height of specimen 10 in the Z direction, in m; L i L is the Z-axis height of any point i, in meters (m). i-1 Let W be the Z-axis height of any point i preceding point i-1; i V represents the percentage attenuation of the Z-axis wave velocity at any point i, where i takes any integer value from 1 to L; A The average wave velocity in the Z direction before the test at velocity measurement point 11 is expressed in m / s; K is a coefficient.

[0075] In the embodiments of this application, based on the conservation of sound wave propagation path time, that is, the sum of the time for the sound wave to pass through all the rock blocks in the specimen 10 is equal to the time for the sound wave to pass through the specimen 10, the relationship between the Z-direction height of the specimen 10, the Z-direction height difference between any point i and the previous point i-1, and the Z-direction wave velocity attenuation of any point i is established. At the same time, based on the relationship between X-direction wave velocity attenuation and Z coordinate, the Z-direction height of any point i and its previous point i-1, and the Z-direction height of the specimen 10, the coefficient K affecting the above relationship is determined, thereby ensuring the accuracy and reliability of determining the Z-direction wave velocity attenuation of any point i using the above relationship.

[0076] In some embodiments, in step S70, the velocity measuring points 11 on the surface of the specimen 10 are divided into multiple groups according to their XZ coordinates. The relationship between the Z-axis wave velocity attenuation and the Y-coordinate of each group is determined based on the Z-axis wave velocity attenuation and the Y-coordinate of all velocity measuring points 11 in each group. The XZ coordinates of the velocity measuring points 11 within the same group are identical. In the embodiments of this application, by grouping the velocity measuring points 11 on the surface of the specimen 10 and determining the relationship between the Z-axis wave velocity attenuation and the Y-coordinate for each group, it is ensured that the Z-axis wave velocity attenuation and the Y-coordinate of any point within the same group conform to the determined relationship, thus improving the specificity and reliability of the determined relationship between the Z-axis wave velocity attenuation and the Y-coordinate.

[0077] In some embodiments, in step S70, the relationship between the Z-axis wave velocity attenuation and the Y-coordinate of each group can be determined by fitting the Z-axis wave velocity attenuation and the Y-coordinate of the velocity measurement point 11 of each group. In the embodiments of this application, by fitting the Z-axis wave velocity attenuation and the Y-coordinate of the velocity measurement point 11 of each group, the relationship curve and formula between the Z-axis wave velocity attenuation and the Y-coordinate of each group are obtained, and then the Y-axis wave velocity attenuation of any point inside the specimen 10 can be accurately determined according to the relationship curve and formula.

[0078] In some embodiments, in step S80, the height of any point i in the Y direction is M. i According to height M i The average Y-direction wave velocity at velocity measurement point 11 and the average Y-direction wave velocity after the test at velocity measurement point 11, along with the relationship determined in step S70, determine the attenuation of the Y-direction wave velocity at any point i inside the specimen 10 that is different from the surface of the specimen 10.

[0079] In the embodiments of this application, the height of any point i in the Y direction is the Y coordinate of any point i. Therefore, based on the height M of any point i in the Y direction... i By understanding the relationship between the Z-axis wave velocity attenuation and the Y-coordinate, the Z-axis wave velocity attenuation at any point i inside specimen 10 can be determined.

[0080] In some embodiments, in step S80, the relationship determined in step S70 is set as f(Y), where Y is the value of the Y coordinate, f(Y) is the wave velocity attenuation in the Z direction, and the height M of any point i in the Y direction is... i The average Y-axis wave velocity at velocity measurement point 11, the average Y-axis wave velocity after the test at velocity measurement point 11, and the relationship determined in step S70 conform to the following formula:

[0081]

[0082]

[0083] Among them, V D M is the average Y-axis wave velocity after the test at velocity measurement point 11, in m / s; M is the Y-axis height of specimen 10, in m. i M represents the Y-axis height of any point i, in meters (m). i-1 Let W be the Y-axis height of any point i preceding point i-1; i V represents the percentage of Y-axis wave velocity attenuation at any point i; i takes any integer value from 1 to M; C The average wave velocity in the Y direction at velocity measurement point 11 before the test is expressed in m / s; H is a coefficient.

[0084] In the embodiments of this application, based on the conservation of sound wave propagation path time, that is, the sum of the time for the sound wave to pass through all the rock blocks in the specimen 10 is equal to the time for the sound wave to pass through the specimen 10, the relationship between the Y-direction height of the specimen 10, the Y-direction height difference between any point i and the previous point i-1, and the Y-direction wave velocity attenuation of any point i is established. At the same time, based on the relationship between the Z-direction wave velocity attenuation and the Y coordinate, the Y-direction height of any point i and its previous point i-1, and the Y-direction height of the specimen 10, the coefficient H affecting the above relationship is determined, thereby ensuring the accuracy and reliability of determining the Y-direction wave velocity attenuation of any point i using the above relationship.

[0085] In some embodiments, the specimen 10 is configured as a hexahedron, and multiple speed measuring points 11 are provided on each face, with a predetermined distance between the speed measuring points 11. In the embodiments of this application, the predetermined distance between the speed measuring points 11 ensures that when adjacent speed measuring points 11 are separated by a predetermined distance, the speed measuring points 11 can achieve full coverage of the specimen 10, eliminate test blind spots, and ensure high test efficiency.

[0086] It is easy to understand that the greater the predetermined distance between the velocity measuring points 11, the lower the accuracy of the wave velocity measurement on the surface of the specimen 10. Therefore, those skilled in the art can flexibly adjust the predetermined distance between the velocity measuring points 11 according to actual measurement needs.

[0087] In some embodiments, the predetermined distance is set to be less than or equal to the minimum moving distance of the probe 21 to ensure the accuracy of the measurement results when adjacent speed measuring points 11 are separated by the predetermined distance. The minimum moving distance of the probe 21 can be the diameter of the probe 21. For example, the probe 21 is 5 cm, and the second predetermined distance is set to 5 cm.

[0088] like Figure 2 As shown, in some embodiments, the specimen 10 can be configured as a cuboid, and the three mutually perpendicular edges of the cuboid are the X-axis, Y-axis and Z-axis.

[0089] In some embodiments, step S10 further includes grinding and polishing the surface of the specimen 10 to reduce the flatness of the surface of the specimen 10, thereby further improving the tightness of the contact between the speed measuring device 20 and the speed measuring point 11. In some preferred embodiments, the flatness is set to less than 0.02 mm to ensure that the speed measuring device 20 can be tightly attached to the speed measuring point 11 at this flatness.

[0090] In some embodiments, the velocity measuring points 11 on two opposite surfaces are arranged on the same axis and parallel to the normals of the two opposite surfaces, so that the sound wave passes through the specimen 10 along the shortest path. In this case, the distance between the two opposite surfaces is the displacement of the sound wave in the specimen 10, simplifying the steps for determining the displacement of the sound wave in the specimen 10. Furthermore, when measuring the wave velocity in the same direction using this arrangement, the displacement of the sound wave in the specimen 10 is the same, thereby simplifying the calculation of the wave velocity at the velocity measuring points 11 in the same direction.

[0091] In some embodiments, a velocity measurement signal can be transmitted to a velocity measurement point 11 on one of two opposing surfaces, and the velocity measurement signal can be received at the corresponding velocity measurement point 11 on the opposing surface. It is easy to understand that the time difference between transmitting and receiving the velocity measurement signal is the time it takes for the sound wave to pass through the specimen 10. Therefore, the wave velocity at the velocity measurement point 11 can be determined by the time it takes for the sound wave to pass through the specimen 10 and the displacement of the sound wave through the specimen 10.

[0092] In some embodiments, the speed measurement signal can be a sound wave.

[0093] In some embodiments, during speed measurement, the speed measuring device 20 is configured to fit in contact with the surface of the speed measuring point 11 to eliminate interference from the air medium between the speed measuring device 20 and the speed measuring point 11, ensuring that the sound wave can be effectively transmitted between the speed measuring point 11 and the speed measuring device 20, thereby improving the accuracy of the X-axis wave velocity, Z-axis wave velocity and Y-axis wave velocity of the speed measuring point 11 before and after the test.

[0094] In some embodiments, the speed measuring device 20 is attached to the surface of the speed measuring point 11 via two probes 21. Specifically, the two probes 21 of the speed measuring device 20 are respectively disposed on the speed measuring points 11 on two opposite surfaces. In some embodiments, the two probes 21 can be a transmitting probe and a receiving probe, wherein the transmitting probe is configured to transmit a speed measuring signal, and the receiving probe is configured to receive a speed measuring signal.

[0095] In some embodiments, an ultrasonic coupling agent can be applied to the surfaces of the transmitting and receiving probes to further improve the tightness of the contact between the transmitting and receiving probes and the surface of the velocity measuring point 11 during the wave velocity measurement process, eliminate the gap between the transmitting and receiving probes and the surface of the velocity measuring point 11, and ensure the accuracy of the wave velocity measurement by the velocity measuring device 20.

[0096] Since rock or concrete specimens 10 typically require multiple or secondary tests, non-destructive testing of the internal damage of specimens 10 is necessary to ensure that the measurement of internal damage does not affect subsequent tests. In some embodiments, the measuring device 20 can be a rock ultrasonic detector. Rock ultrasonic detectors are convenient, efficient, and do not damage specimens 10. Therefore, non-destructive testing of internal damage in specimens 10 can be achieved using a rock ultrasonic detector, eliminating the need for core sampling and the risk of secondary damage to specimens 10 during the core sampling process.

[0097] In some embodiments, step S20 further includes setting parameters such as the gain, frequency, and delay time of the rock ultrasonic detector (including standard sample calibration) to improve the accuracy of wave velocity measurement. The settings of these parameters can be determined by those skilled in the art based on experience.

[0098] In some embodiments, the test is a blasting, laser, or temperature test, and after the test is completed, the specimen 10 is intact and there is no large-area peeling of the rock surface.

[0099] In the embodiments of this application, the test can be a blasting, laser, or temperature test to simulate pre-splitting blasting, laser pretreatment, and temperature pretreatment in on-site construction, respectively. Furthermore, ensuring the specimen 10 is intact and that there is no large-area peeling of the rock surface prevents the velocity measuring device 20 from being unable to adhere to the surface of the velocity measuring point 11 due to large-area rock surface peeling. Simultaneously, it avoids the specimen 10 breaking, which could affect the measurement accuracy of the X-axis wave velocity, Z-axis wave velocity, and Y-axis wave velocity at the velocity measuring point 11 after the test.

[0100] In some embodiments, in step S20, the speed measuring points 11 on each pair of surfaces are tested before the speed measuring points 11 on the next pair of surfaces are tested, thereby avoiding repeated switching of the surfaces on which the speed measuring device 20 and the speed measuring points 11 are attached during the test, and thus improving the speed measuring efficiency of the speed measuring points 11.

[0101] In some embodiments, during speed measurement, the transmission of the speed measurement signal is stopped after a stable waveform appears in the wave speed measured by the testing equipment, and the signal is recorded as a measured value to ensure the stability and reliability of the measured value.

[0102] In some embodiments, the measured values ​​can be the amplitude and frequency of the waveform and the time it takes for the sound wave to pass through the specimen 10, thereby enabling the wave velocity at the velocity measuring point 11 to be determined based on the time it takes for the sound wave to pass through the specimen 10 and the displacement of the sound wave in the specimen 10.

[0103] In some embodiments, step S60 further includes: repeating steps S40-S50 to determine the Z-direction wave velocity attenuation distribution inside the specimen 10, constructing a Z-direction spatial damage map of the specimen 10 based on the Z-direction wave velocity attenuation distribution, and then performing a correspondence analysis between the test result data and the damage of the specimen 10 based on the Z-direction spatial damage map.

[0104] In some embodiments, in step S90, calculation software can be used to perform differential processing on the Y-direction wave velocity attenuation, thereby further improving the accuracy of the Y-direction wave velocity attenuation data. Specifically, the differential processing of the Y-direction wave velocity attenuation can be performed by those skilled in the art based on experience.

[0105] In some embodiments, step S90 further includes: repeating steps S70-S80 to determine the Y-direction wave velocity attenuation distribution inside the specimen 10, and constructing a three-dimensional spatial damage map of the specimen 10 based on the X-direction wave velocity attenuation distribution, Z-direction wave velocity attenuation distribution and Y-direction wave velocity attenuation distribution inside the specimen 10, and then realizing the correspondence analysis between the test result data and the damage of the specimen 10 based on the three-dimensional spatial damage map of the specimen 10.

[0106] In some embodiments, the relationship between wave velocity attenuation and damage degree can be used to transform Z-axis wave velocity attenuation into Z-axis spatial damage. Specifically, wave velocity attenuation and damage degree conform to the following expression:

[0107] D = 1 - (1 - N) 2 .

[0108] Where D represents the degree of damage and N represents the wave velocity attenuation, in percentage (%).

[0109] In some embodiments, step S90 further includes: comparing the X-direction wave velocity attenuation distribution, Z-direction wave velocity attenuation distribution and Y-direction wave velocity attenuation distribution inside the specimen 10 to determine all internal damages of the specimen 10 and their directions.

[0110] The following specific examples further illustrate the process of using the method provided in the first aspect of this application to determine the internal damage of specimen 10 after testing.

[0111] The specimen 10 is made into a cuboid, and the X-axis, Y-axis and Z-axis of the specimen 10 are determined. The surface of the specimen 10 is polished. After the surface of the specimen 10 is polished, a velocity measuring point 11 is arranged every 5 cm on the six surfaces of the specimen 10, and it is ensured that the velocity measuring points 11 set on two opposite surfaces are arranged on the same axis and parallel to the normal of the two opposite surfaces.

[0112] Set the parameters of the ultrasonic rock detector and calibrate it. Connect the calibrated ultrasonic rock detector to the transmitting and receiving probes via signal line 22. Apply ultrasonic coupling agent to the surfaces of the transmitting and receiving probes, and connect them to velocity measurement points 11 on the ZOY surface and the surface opposite to the ZOY surface, respectively. Start the ultrasonic rock detector; the transmitting probe emits sound waves to velocity measurement points 11, and the receiving probe receives the sound waves transmitted from these points. Stop emitting sound waves once a stable waveform appears on the ultrasonic rock detector, and record the wave velocity V0 in the X direction before the test. After all velocity measurement points 11 on the ZOY surface have been tested, move to the XOY surface and the surface opposite to the XOY surface and repeat the above steps to obtain the wave velocity V0 in the Z direction before the test. A .

[0113] Specimen 10 was subjected to micro-blasting, laser, or temperature tests, ensuring its integrity and absence of large-area spalling on the rock surface. Then, the wave velocity at the ZOY surface and the surface velocity measurement point 11 opposite to the ZOY surface was measured following the same procedure. The X-axis wave velocity at the same measurement point after the test was recorded as V1. After all velocity measurement points 11 on the ZOY surface were tested, the process was repeated on the XOY surface and the surface opposite to the XOY surface, obtaining the Z-axis wave velocity at the same measurement point after the test and recording it as V. B Based on the X-axis wave velocity V0 before the test and the X-axis wave velocity V1 after the test at the same measuring point, the X-axis wave velocity attenuation at measuring point 11 is calculated.

[0114] Based on the XY coordinates of the velocity measurement point 11 on the surface of specimen 10, the velocity measurement point 11 is divided into multiple groups, and the XY coordinates of each group are the same. The X-direction wave velocity attenuation and Z-coordinate of all measurement points in each group are fitted to obtain the relationship curve and formula between the X-direction wave velocity attenuation and Z-coordinate of each group.

[0115] Based on the relationship curve and formula between the X-axis wave velocity attenuation and Z-coordinate of any point i in its group, and the average Z-axis wave velocity of the velocity measuring point 11 with the same XY coordinates as any point i before and after the test, determine the Z-axis wave velocity attenuation of any point i. Repeat the above steps to obtain the Z-axis wave velocity attenuation distribution inside the specimen 10.

[0116] Based on the Z-direction wave velocity attenuation distribution inside the specimen 10, the spatial damage in the Z-direction inside the specimen 10 is established, and based on the spatial damage, the internal damage of the specimen 10 after the test is determined.

[0117] The following specific example further illustrates the process of using the method provided in the second aspect of this application to determine the internal damage of specimen 10 after testing.

[0118] The specimen 10 is made into a cuboid, and the X-axis, Y-axis and Z-axis of the specimen 10 are determined. The surface of the specimen 10 is polished. After the surface of the specimen 10 is polished, a velocity measuring point 11 is arranged every 5 cm on the six surfaces of the specimen 10, and it is ensured that the velocity measuring points 11 set on two opposite surfaces are arranged on the same axis and parallel to the normal of the two opposite surfaces.

[0119] Set the parameters of the rock ultrasonic detector and calibrate it. Connect the calibrated rock ultrasonic detector to the transmitting and receiving probes via signal line 22. Apply ultrasonic coupling agent to the surfaces of the transmitting and receiving probes, and connect them to velocity measurement points 11 on the ZOY surface and the surface opposite to the ZOY surface, respectively. Start the rock ultrasonic detector; the transmitting probe emits sound waves to velocity measurement points 11, and the receiving probe receives the sound waves transmitted from these points. Stop emitting sound waves once a stable waveform appears on the rock ultrasonic detector, and record the wave velocity V0 in the X direction before the test. After all velocity measurement points 11 on the ZOY surface have been tested, proceed sequentially to the XOY surface and the surface opposite to the XOY surface, and the XOZ surface and the surface opposite to the XOZ surface, repeating the above steps to obtain the wave velocity V0 in the Z direction before the test. A And the wave velocity V before the Y-axis test C .

[0120] Specimen 10 was subjected to micro-blasting, laser, or temperature tests, ensuring its integrity and absence of large-area spalling on the rock surface. Then, the wave velocity at the ZOY surface and the surface velocity measurement point 11 opposite to the ZOY surface was measured following the same procedure. The X-axis wave velocity at the same measurement point after the test was recorded as V1. After all velocity measurement points 11 on the ZOY surface were tested, the process was repeated sequentially on the XOY surface and the surface opposite to the XOY surface, and the XOZ surface and the surface opposite to the XOZ surface, obtaining the Z-axis wave velocity V at the same measurement point after the test. B And the Y-axis wave velocity V after the experimentD Based on the X-axis wave velocity V0 before the test and the X-axis wave velocity V1 after the test at the same measuring point, calculate the X-axis wave velocity attenuation.

[0121] Based on the XY coordinates of the velocity measurement points 11 on the surface of specimen 10, the velocity measurement points 11 are divided into multiple groups, with each group having the same XY coordinates. The X-axis wave velocity attenuation and Z-coordinate of all measurement points in each group are fitted to obtain the relationship curves and formulas between the X-axis wave velocity attenuation and Z-coordinate for each group. The XYZ coordinates of any point i inside specimen 10 are determined, and the group to which point i belongs is also determined. Based on the relationship curves and formulas between the X-axis wave velocity attenuation and Z-coordinate of the group to which point i belongs, the X-axis wave velocity attenuation of point i is determined. The above steps are repeated to determine the distribution of X-axis wave velocity attenuation inside the specimen.

[0122] Based on the relationship curve and formula between the X-axis wave velocity attenuation and Z-coordinate of any point i in its group, and the average Z-axis wave velocity of the velocity measuring point 11 with the same XY coordinates as any point i before and after the test, determine the Z-axis wave velocity attenuation of any point i. Repeat the above steps to obtain the Z-axis wave velocity attenuation distribution inside the specimen 10.

[0123] Based on the XZ coordinates of the velocity measurement point 11 on the surface of specimen 10, the velocity measurement point 11 is divided into multiple groups, and the XZ coordinates of each group are the same. The Z-axis wave velocity attenuation and Y-coordinate of all measurement points in each group are fitted to obtain the relationship curve and formula between the Z-axis wave velocity attenuation and Y-coordinate of each group.

[0124] Based on the relationship curve and formula between the Z-axis wave velocity attenuation and the Y-coordinate of any point i's group, and the average Y-axis wave velocity before and after the test at velocity measuring point 11 with the same XZ coordinates as any point i, determine the Y-axis wave velocity attenuation of any point i. Repeat the above steps to obtain the Y-axis wave velocity attenuation distribution inside the specimen 10.

[0125] Based on the X-axis wave velocity attenuation distribution, Z-axis wave velocity attenuation distribution and Y-axis wave velocity attenuation distribution inside the specimen 10, a three-dimensional spatial damage model inside the specimen 10 is established. The Y-axis wave velocity attenuation of all points inside the specimen 10 is compared with the X-axis wave velocity attenuation and Z-axis wave velocity attenuation to determine all internal damages of the specimen 10 and their directions.

[0126] Regarding the embodiments of this application, it should also be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other to obtain new embodiments.

[0127] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A method for determining internal damage to a specimen after a test, characterized in that, S10: Set multiple velocity measuring points on the surface of the specimen, determine the XYZ coordinates of the multiple velocity measuring points, and measure the X-axis wave velocity and Z-axis wave velocity of the velocity measuring points; S20: Conduct a test on the specimen, measure the X-axis wave velocity and Z-axis wave velocity at the velocity measuring point after the test, and determine the attenuation of the X-axis wave velocity at the velocity measuring point. S30: Determine the velocity measuring points on the surface of the specimen that have the same XY coordinates; S40: Determine the relationship between the X-axis wave velocity attenuation of the velocity measuring point and the Z-coordinate of the velocity measuring point; S50: Based on the relationship determined in step S40, the Z-axis wave velocity before the test, and the Z-axis wave velocity after the test, determine the attenuation of the Z-axis wave velocity inside the specimen that is different from any point on the surface of the specimen. S60: Determine the internal damage of the specimen based on the Z-axis wave velocity attenuation; In step S40, the relationship between the X-axis wave velocity attenuation and the Z-coordinate of each velocity measuring point is determined by fitting the X-axis wave velocity attenuation and the Z-coordinate of the velocity measuring point. In step S50, the height of any point i in the Z direction is L. i , According to the height L i The average Z-axis wave velocity before the velocity measurement point test and the average Z-axis wave velocity after the velocity measurement point test, and the relationship determined in step S40, determine the attenuation of the Z-axis wave velocity at any point i inside the specimen that is different from the surface of the specimen. In step S50, the relationship determined in step S40 is set as f(Z), where Z is the value of the Z coordinate and f(Z) is the X-axis wave velocity attenuation. The height L of any point i in the Z direction i The Z-axis average wave velocity at the speed measuring point, the Z-axis average wave velocity after the speed measuring point test, and the relationship determined in step S40 conform to the following formula: ； ； in, The average wave velocity in the Z direction after the test at the velocity measurement point is expressed in m / s; L is the height of the specimen in the Z direction, expressed in m. The height of any point i in the Z direction, in meters (m). The height of the Z-axis of any point i preceding point i is given in meters. The Z-axis wave velocity attenuation percentage at any point i; i takes any integer value from 1 to L; The average wave velocity in the Z direction before the test at the velocity measurement point is expressed in m / s; K is a coefficient. Step S60 further includes: repeating steps S40-S50 to determine the Z-direction wave velocity attenuation distribution inside the specimen, and determining the Z-direction spatial damage map of the specimen based on the Z-direction wave velocity attenuation distribution, and then determining the correspondence between the test result data and the internal damage of the specimen based on the Z-direction spatial damage map.

2. A method for determining internal damage to a specimen after a test, characterized in that, S10: Set multiple velocity measuring points on the surface of the specimen, determine the XYZ coordinates of the multiple velocity measuring points, and measure the X-axis wave velocity, Z-axis wave velocity and Y-axis wave velocity of the velocity measuring points. S20: Test the specimen, measure the X-axis wave velocity, Z-axis wave velocity and Y-axis wave velocity at the velocity measuring point after the test, and determine the attenuation of the X-axis wave velocity at the velocity measuring point. S30: Determine the velocity measuring points on the surface of the specimen that have the same XY coordinates; S40: Determine the relationship between the X-axis wave velocity attenuation of the velocity measuring point and the Z-coordinate of the velocity measuring point; S50: Based on the relationship determined in step S40, measure the Z-axis wave velocity at the velocity measurement point before and after the test, and determine the attenuation of the Z-axis wave velocity inside the specimen that is different from any point on the surface of the specimen. S60: Determine the velocity measuring points that have the same XZ coordinates on the surface of the specimen; S70: Determine the relationship between the Z-axis wave velocity attenuation of the velocity measuring point and the Y-coordinate of the velocity measuring point; S80: Based on the relationship determined in step S70, measure the Y-axis wave velocity at the velocity measurement point before and after the test, and determine the attenuation of the Y-axis wave velocity inside the specimen that is different from any point on the surface of the specimen. S90: Determine the internal damage of the specimen based on the X-direction wave velocity attenuation of the velocity measuring point determined in step S20, the Z-direction wave velocity attenuation of any point inside the specimen determined in step S50, and the Y-direction wave velocity attenuation of any point inside the specimen determined in step S80. In step S40, the relationship between the X-axis wave velocity attenuation and the Z-coordinate of each velocity measuring point is determined by fitting the X-axis wave velocity attenuation and the Z-coordinate of the velocity measuring point. In step S50, the height of any point i in the Z direction is L. i , According to the height L i The average Z-axis wave velocity before the velocity measurement point test and the average Z-axis wave velocity after the velocity measurement point test, and the relationship determined in step S40, determine the attenuation of the Z-axis wave velocity at any point i inside the specimen that is different from the surface of the specimen. In step S50, the relationship determined in step S40 is set as f(Z), where Z is the value of the Z coordinate and f(Z) is the X-axis wave velocity attenuation. The height L of any point i in the Z direction i The Z-axis average wave velocity at the speed measuring point, the Z-axis average wave velocity after the speed measuring point test, and the relationship determined in step S40 conform to the following formula: ； ； in, The average wave velocity in the Z direction after the test at the velocity measurement point is expressed in m / s; L is the height of the specimen in the Z direction, expressed in m. The height of any point i in the Z direction, in meters (m). The height of the Z-axis of any point i preceding point i is given in meters. The Z-axis wave velocity attenuation percentage at any point i; i takes any integer value from 1 to L; The average wave velocity in the Z direction before the test at the velocity measurement point is expressed in m / s; K is a coefficient. In step S70, the relationship between the Z-axis wave velocity attenuation and the Y-coordinate of the velocity measuring point is determined by fitting the Z-axis wave velocity attenuation and the Y-coordinate of the velocity measuring point. In step S80, the relationship determined in step S70 is set as f(Y), where Y is the value of the Y coordinate, f(Y) is the wave velocity attenuation in the Z direction, and M is the height of any point i in the Y direction. i The average Y-axis wave velocity at the velocity measuring point, the average Y-axis wave velocity after the test at the velocity measuring point, and the relationship determined in step S70 conform to the following formula: ； ； in, The average wave velocity in the Y direction after the test at the velocity measurement point is in m / s; M is the height of the specimen in the Y direction in m. Let be the Y-axis height of any point i, in meters (m). Let be the Y-axis height of any point i preceding point i-1; Let be the percentage of Y-direction wave velocity attenuation at any point i; i can take any integer value from 1 to M. The average Y-axis wave velocity at the velocity measurement point before the test, in m / s; H is a coefficient. Step S90 further includes: repeating steps S70-S80 to determine the Y-direction wave velocity attenuation distribution inside the specimen, and determining the three-dimensional spatial damage map of the specimen based on the X-direction wave velocity attenuation distribution, Z-direction wave velocity attenuation distribution and Y-direction wave velocity attenuation distribution inside the specimen, and then determining the correspondence between the test result data and the internal damage of the specimen based on the three-dimensional spatial damage map of the specimen.

3. The method according to claim 1 or 2, characterized in that, in, The specimen is configured as a hexahedron, with multiple speed measuring points on each face, and the speed measuring points are spaced at a predetermined distance from each other.

4. The method according to claim 3, characterized in that, The speed measuring points set on two opposite surfaces are arranged on the same axis and parallel to the normals of the two opposite surfaces.

5. The method according to claim 1 or 2, characterized in that, During speed measurement, the speed measuring device is configured to fit in contact with the surface of the speed measuring point.

6. The method according to claim 1 or 2, characterized in that, The test is a blasting, laser, or temperature test, and after the test is completed, the specimen remains intact and there is no large-area peeling of the rock surface.

7. The method according to claim 1 or 2, characterized in that, In step S20, the speed measuring points on each pair of surfaces are tested before the speed measuring points on the next pair of surfaces are tested.

8. The method according to claim 7, characterized in that, During speed measurement, the transmission of the speed measurement signal is stopped after the wave speed measured by the testing equipment reaches a stable waveform, and the measured value is recorded.

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