Rock dynamic crushing residual kinetic energy measuring device and method based on piezoelectric array

Abstract

The invention discloses a rock dynamic crushing residual kinetic energy measuring device and method based on a piezoelectric array. The device comprises a cylindrical cavity capable of being opened and closed, a piezoelectric film array arranged on the inner wall of the cylindrical cavity capable of being opened and closed, a circular support capable of being opened and closed which is arranged in the cylindrical cavity capable of being opened and closed and used for fixing a rock sample, and an incident bar inserted into one end of the cylindrical cavity capable of being opened and closed, the piezoelectric film array is arranged at one end of the openable cylindrical cavity, the transmission rod is inserted into the other end of the openable cylindrical cavity, the information processing module is arranged outside the openable cylindrical cavity and connected with the piezoelectric film array, and the PC is arranged outside the openable cylindrical cavity and connected with the information processing module. The method is realized based on the device. The device has the advantages that the operation is simple and convenient, the practicability is high, electric signals generated when the fragments impact on the inner wall of the cavity can be captured in real time, and the residual kinetic energy of the fragments can be accurately measured.

Description

Technical Field

[0001] The present invention relates to the technical field of rock dynamic mechanical property testing, and in particular to a device and method for measuring rock dynamic crushing residual kinetic energy based on a piezoelectric array. Background Art

[0002] The study of the dynamic crushing mechanism of rocks is of great significance to fields such as mining, tunneling and underground engineering construction. In the above-mentioned engineering scenarios, rocks are frequently subjected to dynamic loads, and their crushing process involves complex energy conversion. Residual kinetic energy, as a direct characterization parameter of the kinetic energy of fragments, plays a key role in revealing the laws of energy transfer and dissipation. The Hypo-Hopkinson bar (SHPB) experiment can effectively obtain macroscopic mechanical responses such as dynamic compressive strength and strain rate sensitivity through the three-wave method. However, there is still a certain technical gap in the measurement of the residual kinetic energy of fragments after crushing. Since the residual kinetic energy directly reflects the conversion efficiency of stress wave energy to fragment motion, its accurate measurement is of great value to improving the energy conservation analysis model and establishing a rock crushing efficiency evaluation system.

[0003] Among traditional measurement methods, high-speed camera image analysis typically requires simultaneous capture by multiple high-frame-rate cameras and a high-power lighting system. This method suffers from low accuracy in environments with high dust concentrations or insufficient light. Furthermore, due to the pixel precision limitations of high-speed cameras and inadequate edge detection technology, this method often faces a high risk of missed detection when monitoring small-sized debris. Furthermore, this method requires frame-by-frame image analysis, which cannot meet real-time monitoring requirements. High equipment costs also severely restrict its applicability. Another indirect method, strain gauge measurement, uses an elastic rod and strain gauge combination to indirectly infer kinetic energy. However, this method's mechanical structure is relatively complex, and friction losses between the elastic rod and the loose-leaf assembly reduce energy transfer efficiency. Particularly when monitoring low kinetic energy, the low signal-to-noise ratio makes it difficult to accurately capture data from lightweight debris, leading to biased energy assessments. Therefore, there is an urgent need to develop a cost-effective residual kinetic energy measurement device that is adaptable to complex working conditions and can provide data support for blasting energy utilization assessment, rock fragmentation prediction, and intelligent construction decision-making. Summary of the Invention

[0004] The present invention aims to address the deficiencies in the existing technology and propose a rock dynamic crushing residual kinetic energy measurement device and its use method that are simple to operate and highly practical. Through a piezoelectric film array, the electrical signals generated when fragments collide with the inner wall of the cavity are captured in real time, thereby accurately measuring the residual kinetic energy of the fragments and solving the problem that the residual kinetic energy of sample fragments cannot be effectively measured in the Hopkinson bar experiment.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] On the one hand, the present invention provides a rock dynamic crushing residual kinetic energy measuring device based on a piezoelectric array, comprising an openable cylindrical cavity and a piezoelectric film array arranged on the inner wall of the openable cylindrical cavity, an openable circular bracket arranged inside the openable cylindrical cavity and used to fix the rock sample, an incident rod inserted at one end of the openable cylindrical cavity and used to fully fit with one end of the rock sample, a transmission rod inserted at the other end of the openable cylindrical cavity and used to fully fit with the other end of the rock sample, an information processing module arranged outside the openable cylindrical cavity and connected to the piezoelectric film array, and a PC arranged outside the openable cylindrical cavity and connected to the information processing module.

[0007] Furthermore, the openable and closable cylindrical cavity body includes an upper semicircular cavity body and a lower semicircular cavity body, and the upper semicircular cavity body and the lower semicircular cavity body are locked together by two snap-fit ​​locks respectively arranged on the left and right sides of the openable and closable cylindrical cavity body.

[0008] Furthermore, each of the snap-fit ​​locks consists of a lock body fixed on the outer wall of the upper semicircular cavity and a buckle fixed on the outer wall of the lower semicircular cavity and matched with the lock body.

[0009] Furthermore, the piezoelectric film array is composed of a plurality of upper piezoelectric films respectively arranged on the inner wall of the upper semicircular cavity and a plurality of lower piezoelectric films respectively arranged on the inner wall of the lower semicircular cavity.

[0010] Furthermore, the retractable circular bracket is composed of an upper U-shaped bracket arranged at the center position of the inner wall of the upper semicircular cavity and a lower U-shaped bracket arranged at the center position of the inner wall of the lower semicircular cavity.

[0011] Furthermore, a protective layer is provided on the surface of each of the upper piezoelectric film and the lower piezoelectric film, and the protective layer is fixed to the surface of the upper piezoelectric film or the lower piezoelectric film by an adhesive. The protective layer is made of wear-resistant material and is used to protect the upper piezoelectric film and the lower piezoelectric film from direct impact of rock fragments. The adhesive is a quick-drying epoxy resin.

[0012] Furthermore, an insulating layer is provided between each upper piezoelectric film and the inner wall of the upper semicircular cavity, and between each lower piezoelectric film and the inner wall of the lower semicircular cavity. The insulating layer is made of polytetrafluoroethylene and is used to isolate the direct contact between the upper piezoelectric film and the inner wall of the upper semicircular cavity and the lower piezoelectric film and the inner wall of the lower semicircular cavity, so as to prevent the electrical signals generated by the upper piezoelectric film and the lower piezoelectric film from being interfered with by the outside world.

[0013] Furthermore, each of the upper piezoelectric film and the lower piezoelectric film is connected to a flexible wire, and the end of each flexible wire is connected to a connector, and each connector is connected to the information processing module;

[0014] The upper semicircular cavity and the lower semicircular cavity are both provided with a plurality of reserved holes for passing flexible wires; among them, the plurality of reserved holes provided on the upper semicircular cavity correspond one-to-one to the plurality of upper piezoelectric films provided on the inner wall of the upper semicircular cavity; the plurality of reserved holes provided on the lower semicircular cavity correspond one-to-one to the plurality of lower piezoelectric films provided on the inner wall of the lower semicircular cavity.

[0015] Furthermore, the information processing module includes a PCB circuit board and a charge amplifier, a data acquisition card, a computing unit, a wire interface and a signal line interface arranged on the PCB circuit board. The charge amplifier is connected to the data acquisition card, the computing unit and the wire interface respectively. The data acquisition card and the computing unit are both connected to the signal line interface. The signal line interface is connected to a PC, and the wire interface is connected to a connector.

[0016] On the other hand, the present invention also provides a method for using a device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array, comprising the following steps:

[0017] S1. Launch a calibration projectile to impact the openable cylindrical cavity and record the voltage signal , calculate the calibration coefficient , and stored in the database; among them, ,here, To calibrate the mass of the projectile, To calibrate the projectile's launch velocity;

[0018] S2. Process the rock material to be studied into a standard cylindrical rock specimen with a parallelism of the upper and lower end faces ≤ 0.05 mm, a flatness of the end face ≤ 0.02 mm, a diameter of 50 mm, and a height of 35 mm according to the ISMR test procedure;

[0019] S3. Open the retractable cylindrical cavity, place the standard cylindrical rock sample prepared in step S2 on the lower U-shaped bracket, move the incident rod and the transmission rod to ensure that the incident rod and the transmission rod are completely aligned with the two ends of the standard cylindrical rock sample, and then close the retractable cylindrical cavity to completely fix the standard cylindrical rock sample;

[0020] S4. Lead the wires of the piezoelectric film array out from the reserved holes on the openable cylindrical cavity and connect them to the information processing module;

[0021] S5. Initiating a Hopkinson bar impact test to break the standard cylindrical rock sample in the openable cylindrical cavity to generate rock fragments;

[0022] S6. The piezoelectric film array on the inner wall of the openable cylindrical cavity receives the impact of the rock fragments. When the rock fragments hit the piezoelectric film array on the inner wall of the openable cylindrical cavity, the piezoelectric film array is subjected to force to generate an electrical signal and transmit the electrical signal to the signal processing module through a flexible wire.

[0023] S7. Processing and analyzing the received electrical signal through a signal processing module to calculate the kinetic energy of the rock fragments and display the experimental results;

[0024] S8. Open the retractable cylindrical cavity, take out the rock sample fragments, and clean and recycle them.

[0025] Compared with the prior art, the present invention provides a device and method for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array, which has the following advantages and beneficial effects:

[0026] (1) The present invention evenly arranges a piezoelectric film array on the inner wall of a cylindrical openable cavity, which can capture the electrical signals generated when rock fragments collide with the inner wall of the cavity in real time, thereby calculating and outputting a cloud map of the residual kinetic energy distribution of the rock fragments, thereby solving the problem that the Hopkinson bar test cannot effectively measure the residual kinetic energy of rock sample fragments.

[0027] (2) The present invention adopts an openable cylindrical cavity design, which facilitates the installation and removal of rock samples, is easy to operate, and improves test efficiency. After the cylindrical cavity is closed, it forms a confined space, and the energy of rock fragments splashing is completely absorbed by the inner wall sensor. Compared with the traditional high-speed camera image analysis method, the present invention shows an extremely low missed detection rate when detecting tiny fragments. After the test, the cavity can be opened to directly recover 100% of the fragments, solving the cleaning problem of traditional devices.

[0028] (3) The present invention uses a piezoelectric film array to axially cover the inner wall of the cavity, constructing a three-dimensional measurement space and achieving effective directional decoupling. Within this space, a single impact event can be synchronously and accurately captured by multiple piezoelectric films, which greatly eliminates the influence of the debris's flight direction on the measurement results. In addition, this method does not have any physical contact with the debris, thus avoiding potential interference with the debris's trajectory.

[0029] (4) The present invention is based on the voltage square integration method, which effectively reduces noise interference and improves the signal-to-noise ratio. At the same time, it integrates the time domain threshold filtering and spatial domain trajectory tracking method to eliminate the interference of multiple rebound signals, making the measurement results more accurate and reliable.

[0030] (5) The signal processing module of the present invention is highly integrated, integrating multiple functions such as charge amplification, data acquisition, and integral calculation. It can output the residual kinetic energy value very quickly after the test is completed. Compared with the image analysis method and the traditional strain gauge method, its processing efficiency is significantly improved. In addition, compared with the high-speed camera method that requires at least two cameras arranged at multiple angles, the hardware complexity of the device of the present invention is greatly reduced, the cost is more economical, and there is no need for precise calibration of camera positions and demanding optical environment settings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solution in this embodiment, the following is a brief introduction to the drawings required for describing the embodiment. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] Figure 1 1 is a schematic structural diagram of a device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array according to an embodiment of the present invention;

[0033] Figure 2 is a schematic cross-sectional view of an openable and closable cylindrical cavity according to an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the structure of the retractable cylindrical cavity body involved in the embodiment of the present invention. Figure 1 ;

[0035] Figure 4 This is a schematic diagram of the structure of the retractable cylindrical cavity body involved in the embodiment of the present invention. Figure 2 ;

[0036] Figure 5 is a schematic structural diagram of an information processing module involved in an embodiment of the present invention;

[0037] Explanation of the accompanying symbols: 1. Openable and closable cylindrical cavity; 101. Upper semicircular cavity; 102. Lower semicircular cavity; 103. Snap-fit ​​lock; 104. Reserved hole; 2. Piezoelectric film array; 201. Upper piezoelectric film; 202. Lower piezoelectric film; 3. Openable and closable circular bracket; 301. Upper U-shaped bracket; 302. Lower U-shaped bracket; 303. Rubber pad; 4. Incident rod; 5. Transmission rod; 6. Flexible wire; 7. Connector; 8. Information processing module; 801. PCB circuit board; 802. Charge amplifier; 803. Data acquisition card; 804. Computing unit; 805. Wire interface; 806. Signal line interface; 9. PC; 10. Rock sample. DETAILED DESCRIPTION

[0038] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the following further describes how the present invention is implemented in conjunction with the accompanying drawings and specific implementation methods.

[0039] like Figure 1 As shown, an embodiment of the present invention provides a rock dynamic crushing residual kinetic energy measuring device based on a piezoelectric array, comprising an openable cylindrical cavity 1 and a piezoelectric film array 2 arranged on the inner wall of the openable cylindrical cavity 1, an openable circular bracket 3 arranged inside the openable cylindrical cavity 1 and used to fix the rock sample 10, an incident rod 4 inserted at one end of the openable cylindrical cavity 1 and used to fully fit with one end of the rock sample 10, a transmission rod 5 inserted at the other end of the openable cylindrical cavity 1 and used to fully fit with the other end of the rock sample 10, an information processing module 8 arranged outside the openable cylindrical cavity 1 and connected to the piezoelectric film array 2, and a PC 9 arranged outside the openable cylindrical cavity 1 and connected to the information processing module 8. Among them, the openable cylindrical cavity body 1 can be made of low elongation and high strength steel materials, such as alloy steel, high carbon steel and stainless steel, which can have little shape change when used for a long time or under heavy loads, which helps to maintain the geometric accuracy and stability of the openable cylindrical cavity body 1.

[0040] Specifically, in the embodiment of the present invention, Figure 2 As shown, the openable and closable cylindrical cavity body 1 includes an upper semicircular cavity body 101 and a lower semicircular cavity body 102, and the upper semicircular cavity body 101 and the lower semicircular cavity body 102 are locked together by two snap-fit ​​locks 103 respectively arranged on the left and right sides of the openable and closable cylindrical cavity body 1, forming an openable and closable cylindrical cavity structure.

[0041] Specifically, in the embodiment of the present invention, Figure 2 As shown, each snap-fit ​​lock 103 consists of a lock body 103a fixed to the outer wall of the upper semicircular cavity 101 and a buckle 103b fixed to the outer wall of the lower semicircular cavity 102 and cooperating with the lock body 103a. By snapping the lock body 103a and the buckle 103b together, the upper semicircular cavity 101 and the lower semicircular cavity 102 can be closed, thus forming an openable and closable cylindrical cavity structure.

[0042] Specifically, in the embodiment of the present invention, Figure 1As shown, the piezoelectric film array 2 is composed of a plurality of upper piezoelectric films 201 disposed on the inner wall of the upper semicircular cavity 101, and a plurality of lower piezoelectric films 202 disposed on the inner wall of the lower semicircular cavity 102. It should be noted that the shape, size, and number of the upper and lower piezoelectric films 201, 202 are optimized based on the geometric dimensions of the inner wall of the retractable cylindrical cavity 1. This is to ensure that the piezoelectric films can cover most of the inner wall of the retractable cylindrical cavity 1, thereby improving the sensitivity and accuracy of the device's measurement.

[0043] Specifically, in the embodiment of the present invention, Figure 3 As shown, the retractable circular bracket 3 consists of an upper U-shaped bracket 301 disposed at the center of the inner wall of the upper semicircular cavity 101, and a lower U-shaped bracket 302 disposed at the center of the inner wall of the lower semicircular cavity 102. The upper U-shaped bracket 301 and the lower U-shaped bracket 302 are preferably made of aluminum alloy, which has excellent strength and lightness, can effectively fix the rock sample 10, and ensure the stability and reliability of the test.

[0044] In order to protect the piezoelectric film array 2 from direct impact by rock fragments, based on the above-mentioned embodiment of the rock dynamic crushing residual kinetic energy measurement device based on the piezoelectric array, the present application provides an improved example 1: that is, a protective layer (not shown in the figure) is provided on the surface of each upper piezoelectric film 201 and the lower piezoelectric film 202, and the protective layer is fixed to the surface of the upper piezoelectric film 201 or the lower piezoelectric film 202 by an adhesive.

[0045] Specifically, in this improved example 1, the protective layer is made of wear-resistant material, and the thickness is preferably 0.5 mm; the adhesive is a quick-drying epoxy resin, which has high strength and high temperature resistance after curing.

[0046] In order to prevent the electrical signal generated by the piezoelectric film array 2 from being interfered with by the outside world, based on the above-mentioned embodiment of the rock dynamic crushing residual kinetic energy measuring device based on the piezoelectric array, the present application provides an improved example 2: that is, an insulating layer (not shown in the figure) is provided between each upper piezoelectric film 201 and the inner wall of the upper semicircular cavity 101, and between each lower piezoelectric film 202 and the inner wall of the lower semicircular cavity 102.

[0047] Specifically, in this improved example 2, the insulating layer is made of polytetrafluoroethylene, and the thickness is preferably 0.2 mm. Polytetrafluoroethylene has good insulation properties and high temperature resistance, and can effectively isolate the direct contact between the upper piezoelectric film 201 and the inner wall of the upper semicircular cavity 101 and the lower piezoelectric film 202 and the inner wall of the lower semicircular cavity 102, thereby preventing the electrical signals generated by the upper piezoelectric film 201 and the lower piezoelectric film 202 from being interfered with by the outside world.

[0048] In order to reduce the additional impact on the rock sample during the experiment, based on the above embodiment of the rock dynamic crushing residual kinetic energy measurement device based on the piezoelectric array, this application provides an improved example 3: Figure 4 As shown, rubber pads 303 are provided on the inner surfaces of the upper U-shaped bracket 301 and the lower U-shaped bracket 302 .

[0049] Specifically, in the present modified example 3, the thickness of the rubber pad 303 is preferably 1.0 mm.

[0050] In order to ensure the stability of the rock sample 10 during the impact process, based on the above-mentioned improvement example 3, the present application has made further improvements, that is, an anti-slip texture is provided on the inner surface of the openable and closable circular bracket 3 to increase the friction between the rock sample 10 and the openable and closable circular bracket 3 to ensure the stability of the rock sample 10 during the impact process.

[0051] Specifically, in the above-mentioned embodiments and improved examples 1 to 3, in order to facilitate the timely transmission of the electrical signals generated by the piezoelectric film array 2 to the external information processing module 8, each upper piezoelectric film 201 and the lower piezoelectric film 202 are connected to a flexible wire 6, and the end of each flexible wire 6 is connected to a connector 7, and each connector 7 is used to connect to the information processing module 8; the upper semicircular cavity 101 and the lower semicircular cavity 102 are both provided with a number of reserved holes 104 for passing the flexible wires 6; among them, the several reserved holes 104 opened on the upper semicircular cavity 101 correspond one-to-one to the several upper piezoelectric films 201 arranged on the inner wall of the upper semicircular cavity 101; the several reserved holes 104 opened on the lower semicircular cavity 102 correspond one-to-one to the several lower piezoelectric films 202 arranged on the inner wall of the lower semicircular cavity 102. During use, after all the flexible wires 6 of the piezoelectric films are led out from the corresponding reserved holes 104 , they will be gathered at one end of the openable cylindrical cavity 1 and connected to the information processing module 8 through the connector 7 respectively.

[0052] Specifically, in the above-described embodiment and Modifications 1-3, to ensure reliable connection of the flexible conductors 6, each flexible conductor 6 is fixed to the center of the corresponding upper piezoelectric film 201 or lower piezoelectric film 202 by welding. The flexible conductors 8 are preferably made of silver-plated copper wire, which has excellent conductivity and flexibility, effectively preventing interference during signal transmission and ensuring stable and reliable signal transmission.

[0053] Specifically, in the above embodiment and modified examples 1 to 3, Figure 5As shown, the information processing module 8 includes a PCB circuit board 801 and a charge amplifier 802, a data acquisition card 803, a computing unit 804, a wire interface 805 and a signal line interface 806 arranged on the PCB circuit board 801. The charge amplifier 802 is connected to the data acquisition card 803, the computing unit 804 and the wire interface 805 respectively. The data acquisition card 803 and the computing unit 804 are both connected to the signal line interface 806. The signal line interface 806 is connected to the PC 9, and the wire interface 805 is connected to the connector 7. The wire interface 805 is used to receive the charge signal generated when the piezoelectric film is impacted by rock fragments and transmit it to the charge amplifier 802. The charge amplifier 802 is used to convert the received charge signal into voltage data and transmit it to the computing unit 804 for calculation. The data acquisition card 803 is used to record the voltage data converted by the charge amplifier 802. The signal line interface 806 is used to transmit the data recorded by the data acquisition card 803 and the calculation result of the computing unit 804 to the PC 9 for display. The data acquisition card 803 is used to record voltage data at a sampling rate of 1.0 MHz and set a reasonable time window (e.g., 0.1 ms). For example, if the same piezoelectric film is triggered multiple times within the window, it is considered as a continuous rebound of the same fragment, and only the first impact signal is recorded; the calculation unit 804 is used to execute the voltage square integral algorithm ( ), the residual kinetic energy of the fragments is obtained, where is the calibration coefficient, determined by calibration experiment, The voltage data.

[0054] During use, the rock dynamic crushing residual kinetic energy measuring device based on a piezoelectric array provided by the present invention first places the rock sample 10 on the lower U-shaped bracket 302 inside the lower semicircular hollow body 102. After ensuring that the end faces of the incident rod 4 and the projection rod 5 completely overlap with the two ends of the rock sample 10, the upper semicircular hollow body 101 is closed to completely fix the rock sample 10. Then, the Hopkinson bar impact test is started to cause the rock sample 10 to be crushed in the retractable cylindrical hollow body 1. When the sample fragments hit the piezoelectric film on the inner wall of the retractable cylindrical hollow body 1, the piezoelectric film will be subjected to force to generate an electrical signal and transmit it to the signal processing module 8 through the flexible wire 6. The signal processing module 8 then processes and analyzes the electrical signal, calculates the kinetic energy of the fragments, and finally obtains the experimental results. After the test is completed, all the fragments can be easily removed by simply opening the retractable cylindrical hollow body 1. The operation is simple. The kinetic energy of the fragments can be measured in real time during the test, effectively solving the problem of the inability to accurately measure the residual kinetic energy of the fragments in the prior art.

[0055] Based on the above embodiments of the present invention, the present application further provides a method for using a device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array, which specifically includes the following steps:

[0056] S1. Launch a calibration projectile to impact the openable cylindrical cavity 1 and record the voltage signal. , calculate the calibration coefficient , and stored in the database; among them, ,here, To calibrate the mass of the projectile, To calibrate the projectile's launch velocity;

[0057] S2. Process the rock material to be studied into a standard cylindrical rock specimen with a parallelism of the upper and lower end faces ≤ 0.05 mm, a flatness of the end face ≤ 0.02 mm, a diameter of 50 mm, and a height of 35 mm according to the ISMR test procedure;

[0058] S3. Open the retractable cylindrical hollow body 1, place the standard cylindrical rock sample prepared in step S2 on the lower U-shaped bracket, move the incident rod 4 and the transmission rod 5, ensure that the incident rod 4 and the transmission rod 5 are completely aligned with the two ends of the standard cylindrical rock sample, and then close the retractable cylindrical hollow body 1 to completely fix the standard cylindrical rock sample;

[0059] S4. Lead the flexible wire 6 of the piezoelectric film array 2 out of the reserved hole 10 on the openable cylindrical cavity 1 and connect it to the information processing module 8;

[0060] S5. Start the Hopkinson bar impact test to break the standard cylindrical rock sample in the openable cylindrical cavity 1 to generate rock fragments;

[0061] S6. The piezoelectric film array 2 on the inner wall of the openable cylindrical cavity 1 receives the impact of the rock fragments. When the rock fragments hit the piezoelectric film array 2 on the inner wall of the openable cylindrical cavity 1, the piezoelectric film array 2 is subjected to force to generate an electrical signal and transmit the electrical signal to the signal processing module 8 through the flexible wire 8;

[0062] S7, processing and analyzing the received electrical signal through the signal processing module 8, calculating the kinetic energy of the rock fragments, and displaying the experimental results;

[0063] S8. Open the retractable cylindrical cavity 1, take out the rock sample fragments, and clean and recycle them.

[0064] Finally, it should be noted that the above description is only an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array, characterized by: The invention comprises an openable cylindrical cavity (1) and a piezoelectric film array (2) arranged on the inner wall of the openable cylindrical cavity (1), an openable circular bracket (3) arranged inside the openable cylindrical cavity (1) and used to fix the rock sample (10), an incident rod (4) inserted at one end of the openable cylindrical cavity (1) and used to completely fit with one end of the rock sample (10), a transmission rod (5) inserted at the other end of the openable cylindrical cavity (1) and used to completely fit with the other end of the rock sample (10), an information processing module (8) arranged outside the openable cylindrical cavity (1) and connected to the piezoelectric film array (2), and a PC (9) arranged outside the openable cylindrical cavity (1) and connected to the information processing module (8).

2. The device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array according to claim 1 is characterized by: The retractable cylindrical cavity (1) comprises an upper semicircular cavity (101) and a lower semicircular cavity (102), wherein the upper semicircular cavity (101) and the lower semicircular cavity (102) are locked together by two snap-fit ​​locks (103) respectively provided on the left and right sides of the retractable cylindrical cavity (1).

3. The device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array according to claim 2 is characterized by: Each of the snap-fit ​​locks (103) consists of a lock body (103a) fixed on the outer wall of the upper semicircular cavity (101) and a buckle (103b) fixed on the outer wall of the lower semicircular cavity (102) and matched with the lock body (103a).

4. The device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array according to claim 2 is characterized in that: The piezoelectric film array (2) is composed of a plurality of upper piezoelectric films (201) arranged on the inner wall of the upper semicircular cavity (101) and a plurality of lower piezoelectric films (202) arranged on the inner wall of the lower semicircular cavity (102).

5. The device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array according to claim 2 is characterized in that: The retractable circular bracket (3) is composed of an upper U-shaped bracket (301) arranged at the center of the inner wall of the upper semicircular cavity (101) and a lower U-shaped bracket (302) arranged at the center of the inner wall of the lower semicircular cavity (102).

6. The device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array according to claim 4 is characterized in that: A protective layer is provided on the surface of each of the upper piezoelectric film (201) and the lower piezoelectric film (202), and the protective layer is fixed to the surface of the upper piezoelectric film (201) or the lower piezoelectric film (202) by an adhesive. The protective layer is made of a wear-resistant material and is used to protect the upper piezoelectric film (201) and the lower piezoelectric film (202) from direct impact by rock fragments. The adhesive is a quick-drying epoxy resin.

7. The device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array according to claim 4 is characterized in that: An insulating layer is provided between each upper piezoelectric film (201) and the inner wall of the upper semicircular cavity (101), and between each lower piezoelectric film (202) and the inner wall of the lower semicircular cavity (102). The insulating layer is made of polytetrafluoroethylene and is used to isolate the upper piezoelectric film (201) from direct contact with the inner wall of the upper semicircular cavity (101) and the lower piezoelectric film (202) from direct contact with the inner wall of the lower semicircular cavity (102), so as to prevent the electrical signals generated by the upper piezoelectric film (201) and the lower piezoelectric film (202) from being interfered with by the outside world.

8. The device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array according to claim 4 is characterized in that: Each of the upper piezoelectric film (201) and the lower piezoelectric film (202) is connected to a flexible wire (6), the end of each flexible wire (6) is connected to a connector (7), and each connector (7) is connected to an information processing module (8); The upper semicircular cavity (101) and the lower semicircular cavity (102) are both provided with a plurality of reserved holes (104) for passing the flexible wires (6); wherein the plurality of reserved holes (104) provided on the upper semicircular cavity (101) correspond one-to-one to the plurality of upper piezoelectric films (201) provided on the inner wall of the upper semicircular cavity (101); and the plurality of reserved holes (104) provided on the lower semicircular cavity (102) correspond one-to-one to the plurality of lower piezoelectric films (202) provided on the inner wall of the lower semicircular cavity (102).

9. The device for measuring residual kinetic energy of rock dynamic crushing based on a piezoelectric array according to claim 8 is characterized by: The information processing module (8) comprises a PCB circuit board (801) and a charge amplifier (802), a data acquisition card (803), a calculation unit (804), a wire interface (805) and a signal line interface (806) arranged on the PCB circuit board (801); the charge amplifier (802) is connected to the data acquisition card (803), the calculation unit (804) and the wire interface (805) respectively; the data acquisition card (803) and the calculation unit (804) are both connected to the signal line interface (806); the signal line interface (806) is connected to the PC (9); and the wire interface (805) is connected to the connector (7).

10. A method for using a rock dynamic crushing residual kinetic energy measurement device based on a piezoelectric array, characterized in that: The steps include: S1. Launch a calibration projectile to impact the openable cylindrical cavity (1) and record the voltage signal. , calculate the calibration coefficient , and stored in the database; among them, ,here, To calibrate the mass of the projectile, To calibrate the projectile's launch velocity; S2. Process the rock material to be studied into a standard cylindrical rock specimen with a parallelism of the upper and lower end faces ≤ 0.05 mm, a flatness of the end face ≤ 0.02 mm, a diameter of 50 mm, and a height of 35 mm according to the ISMR test procedure; S3, opening the retractable cylindrical hollow body (1), placing the standard cylindrical rock sample prepared in step S2 on the lower U-shaped bracket, moving the incident rod (4) and the transmission rod (5), ensuring that the incident rod (4) and the transmission rod (5) are completely aligned with both ends of the standard cylindrical rock sample, and then closing the retractable cylindrical hollow body (1) to completely fix the standard cylindrical rock sample; S4, leading the wires of the piezoelectric film array (2) out of the reserved holes on the openable cylindrical cavity (1) and connecting them to the information processing module (8); S5, starting the Hopkinson bar impact test to break the standard cylindrical rock sample in the openable cylindrical cavity (1) to generate rock fragments; S6. The piezoelectric film array (2) on the inner wall of the openable cylindrical cavity (1) receives the impact of the rock fragments. When the rock fragments hit the piezoelectric film array (2) on the inner wall of the openable cylindrical cavity (1), the piezoelectric film array (2) is subjected to force to generate an electrical signal and transmits the electrical signal to the signal processing module (8) through the flexible wire (8); S7, processing and analyzing the received electrical signal through the signal processing module (8), calculating the kinetic energy of the rock fragments, and displaying the experimental results; S8. Open the retractable cylindrical cavity (1), take out the rock sample fragments, and clean and recycle them.

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