An indoor blasting model experiment system and experiment method

Abstract

The application discloses an indoor blasting model experiment system, which comprises a seismic source system, wherein the seismic source system comprises a high-energy releaser, the high-energy releaser is electrically connected with a controller and a monitor and a capacitor box respectively, a power supply system is electrically connected with the controller and the monitor respectively, the high-energy releaser is electrically connected with a transmitting probe through a discharge cable, the end of the transmitting probe is located in an electrolyte solution, and the transmitting probe is wrapped with an elastic material outside, the system further comprises a measuring system, the measuring system comprises a PVDF piezoelectric film sensor, the PVDF piezoelectric film sensor is electrically connected with a dynamic signal test analyzer through a micro impedance changer, and the dynamic signal test analyzer is connected with a computer. The application further discloses an experiment method of the indoor blasting model experiment system. The application solves the problems of the existing measuring system, such as large vibration frequency of the seismic source system, and the piezoelectric film being easily interfered by electromagnetic waves.

Description

Technical Field

[0001] This invention belongs to the field of blasting vibration technology and relates to an indoor blasting model experimental system and experimental method. Background Technology

[0002] Vibration sources for indoor blasting models can be broadly categorized into explosive and non-explosive sources. With increasingly stringent regulations on explosives, using explosives as vibration sources for indoor blasting models has become increasingly difficult. Therefore, researchers have adopted non-explosive sources to replace traditional explosive sources. The source system is one of the most commonly used non-explosive sources, primarily consisting of a high-energy release device, capacitor box, power supply system, transmitting probe, and cables. Compared to traditional explosive sources, the source system is smaller, more portable, safer, and more environmentally friendly, and can generate stable, synchronous, high-resolution, and high signal-to-noise ratio stress waves. Depending on the requirements of different experimental schemes, an experimental measurement system is needed to monitor the stress wave vibration and propagation caused by the source system. This measurement system mainly consists of a PVDF piezoelectric film sensor, a miniature impedance changer, a dynamic signal test and analyzer, a synchronization generator, data transmission lines, and a computer. The PVDF piezoelectric film is a flexible element with characteristics such as softness, lightness, high toughness, high sensitivity, and wide bandwidth, making it suitable for measuring stress changes caused by vibration.

[0003] However, when using an experimental measurement system to monitor stress changes in blast stress waves caused by a seismic source system, the following drawbacks exist: (1) Compared with traditional explosives, the vibration frequency caused by the seismic source system is relatively high; (2) When the piezoelectric film is placed inside the object being measured, it is easily damaged by corrosion and other factors; (3) When using a piezoelectric film for monitoring, at the moment of discharge, the high-energy release device and the transmitting probe generate electromagnetic pulses at the moment of explosion, which causes the piezoelectric film to be interfered with by electromagnetic pulse signals, seriously affecting the accuracy of the experimental results. In view of this, it is urgent to improve the existing measurement system to reduce the vibration frequency of the seismic source system, making it more consistent with the actual blast vibration frequency, and at the same time to effectively shield the piezoelectric film electromagnetically, so that the experimental data are more effective and reliable. Summary of the Invention

[0004] To achieve the above objectives, this invention provides an indoor blasting model experimental system and method, which solves problems such as the excessive vibration frequency of the source system and the susceptibility of the piezoelectric film to electromagnetic interference in existing measurement systems.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is an indoor blasting model experimental system, including a seismic source system, wherein the seismic source system includes:

[0006] A high-energy release device is used to release the electrical energy released from the capacitor bank to the transmitting probe;

[0007] The controller is used to control the charging and discharging of the capacitor bank.

[0008] A capacitor bank is used to absorb and release electrical energy from a power supply system.

[0009] The monitoring instrument is used to monitor the charging and discharging process of the capacitor bank;

[0010] The power supply system is used to provide electrical energy to the seismic source system;

[0011] The transmitting probe is used to receive the energy released by the high-energy releaser and react with the electrolyte solution to discharge.

[0012] The high-energy release device is electrically connected to the controller, the monitor, and the capacitor box respectively; the power supply system is electrically connected to the controller and the monitor respectively; the high-energy release device is electrically connected to the transmitting probe through a discharge cable; the end of the transmitting probe is located in the electrolyte solution, and the outside of the transmitting probe is wrapped with a ring of elastic material;

[0013] The indoor blasting model experimental system also includes a measurement system, which includes a PVDF piezoelectric thin film sensor. The PVDF piezoelectric thin film sensor is electrically connected to a dynamic signal test and analyzer via a miniature impedance changer; the dynamic signal test and analyzer is connected to a computer.

[0014] The measurement system and the seismic source system are electrically connected via a synchronization generator;

[0015] The synchronization generator is used to ensure coordinated operation between the high-energy releaser and the dynamic signal test analyzer, waking up the dynamic signal test analyzer before the PVDF piezoelectric film sensor senses vibration, thus preparing it for signal reception.

[0016] Furthermore, the transmitting probe includes a cathode and an anode, with the anode located at the center of the cathode forming a circle. Polyethylene material is filled between the cathode and the anode, and the outer ring of the cathode is wrapped with polyethylene material. The ends of the cathode and the anode are exposed with polyethylene material. The exposed ends of the cathode and the anode are in contact with the electrolyte solution. The outer side of the transmitting probe is wrapped with an elastic material, and the cathode and the anode are exposed from the top.

[0017] Furthermore, the PVDF piezoelectric film sensor includes a PVDF piezoelectric film, with transmission layers disposed on the upper and lower sides of the PVDF piezoelectric film, and the PVDF piezoelectric film and transmission layers are located inside the metal shell.

[0018] Furthermore, the PVDF piezoelectric film includes an intermediate layer, the intermediate layer being made of a piezoelectric film material with piezoelectric properties; protective layers are disposed on the upper and lower surfaces of the intermediate layer, and a shielding layer is disposed on the outer side of the protective layers; electrode leads are disposed on the outer side of the PVDF piezoelectric film.

[0019] Furthermore, when selecting the material for the transfer layer, a material whose elastic modulus is closest to that of the object being tested should be chosen.

[0020] Furthermore, the protective layer is composed of an acrylic coating layer and a polyester film, wherein the acrylic coating layer is coated on both sides of the piezoelectric film material, and the polyester film covers the surface of the acrylic coating layer.

[0021] Furthermore, the material of the shielding layer is copper foil.

[0022] Furthermore, the electrolyte solution is a sodium chloride solution, and the mass concentration of the sodium chloride solution is 1.0% to 3.0%.

[0023] This invention also discloses an experimental method for an indoor blasting model experimental system, comprising the following steps:

[0024] S1. Connect the high-energy release device, controller, monitor, capacitor box, power supply system, transmitting probe and discharge cable to the corresponding electrical components; connect the synchronous generator and the dynamic signal test and analyzer; connect one end of the dynamic signal test and analyzer to the computer, and the other end to the PVDF piezoelectric film sensor through a miniature impedance changer; place the PVDF piezoelectric film sensor at the measurement point of the object being tested and fix it in place.

[0025] S2. Use a container filled with electrolyte solution to seal the transmitting probe tightly, and then place the sealed transmitting probe inside the object being tested.

[0026] S3. Charge the capacitor box. After charging is completed, the controller controls the capacitor box and releases energy to the transmitting probe through the high-energy release device. At this time, an electric arc spark is generated between the cathode and anode on the transmitting probe, and stress waves are emitted outward from the center of the transmitting probe.

[0027] S4. The PVDF piezoelectric film on the object under test generates unequal amounts of charge according to the magnitude of stress. The charge is transferred to the miniature impedance changer through the lead wire. The miniature impedance changer converts the charge signal into a voltage signal proportionally and transmits it to the dynamic signal test and analysis instrument. Then, the required real signal is obtained in the computer.

[0028] Furthermore, the outer side of the launching probe is wrapped with a ring of rubber as an elastic material, and the relationship between the thickness T of the rubber and the required explosion vibration frequency f is determined as follows:

[0029] If the density ρ of the object being measured, the rubber wave velocity C, the rubber density ρ1, and the sound wave velocity C1 of the object being measured are determined, then the relationship between the vibration frequency f and the rubber thickness T can be determined by the following formula:

[0030]

[0031] In the formula, D is the distance from the explosion center, Q is the discharge energy, and K1, α, and β are constants. γ and θ are constants, obtained by fitting and calculating the monitoring data of blasting vibration;

[0032] If only the density ρ of the object being measured and the rubber wave velocity C are determined, the relationship between the vibration frequency f and the rubber thickness T can be determined by the following formula:

[0033]

[0034] In the formula, K2, α, and β are constants, where,

[0035] The beneficial effects of this invention are:

[0036] This invention can simulate actual blasting conditions, reveal the relationship of blasting vibrations, and allow for intuitive observation of the amplitude and frequency of blasting vibrations. In this way, the intensity and frequency characteristics of blasting vibrations can be understood more clearly, which helps to optimize blasting parameters.

[0037] This invention effectively extends the service life of the piezoelectric film by adding a transmission layer and a metal shell. By wrapping the two sides of the piezoelectric film with a copper foil, the influence of electromagnetic pulses caused by other factors on the piezoelectric film is largely shielded. At the same time, by wrapping the transmitter probe with an elastic material, the vibration frequency of the explosion vibration is reduced, making the obtained explosion vibration curve more consistent with reality. This greatly improves the accuracy of the measurement and provides strong support for the reliability and validity of the experimental data. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the seismic source system and measurement system according to an embodiment of the present invention.

[0040] Figure 2 This is a schematic diagram of the discharge circuit of the vibration source system according to an embodiment of the present invention.

[0041] Figure 3 This is a schematic diagram of the transmitting probe structure of the seismic source system according to an embodiment of the present invention.

[0042] Figure 4 This is a cross-sectional view of the PVDF piezoelectric thin film sensor according to an embodiment of the present invention.

[0043] Figure 5 This is a top view of the PVDF piezoelectric thin film sensor according to an embodiment of the present invention.

[0044] Figure 6 This is a schematic diagram of the structure of the PVDF piezoelectric film according to an embodiment of the present invention; wherein, (a) is a planar cross-sectional view of the PVDF piezoelectric film, and (b) is an exploded side view of the PVDF piezoelectric film.

[0045] Figure 7 These are stress data diagrams obtained using the experimental system of the present invention in this embodiment of the invention; wherein, a) is a stress data diagram with the explosion point as the first point, and b) is a stress data diagram with the explosion point as the second point.

[0046] Figure 8 These are stress data diagrams obtained in embodiments of the present invention without using the experimental system of the present invention; wherein, a) is a stress data diagram with the explosion point as the first point, and b) is a stress data diagram with the explosion point as the second point.

[0047] In the diagram, 1. High-energy release device, 2. Controller, 3. Monitor, 4. Capacitor box, 5. Power supply system, 6. Transmitting probe, 7. Discharge cable, 8. PVDF piezoelectric film sensor, 9. Miniature impedance changer, 10. Dynamic signal test and analyzer, 11. Synchronizer, 12. Computer, 13. Polyethylene material, 14. Cathode, 15. Anode, 16. Elastic material, 17. Electrolyte solution, 18. PVDF piezoelectric film, 19. Transfer layer, 20. Metal shell, 21. Protective layer, 22. Shielding layer, 23. Electrode pins, 24. Screw position, 25. Intermediate layer. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] like Figures 1-6 As shown, this invention provides an indoor blasting model experimental system, including a seismic source system and a measurement system, wherein:

[0050] The seismic source system includes a high-energy release device 1, a controller 2, a monitoring instrument 3, a capacitor box 4, a power supply system 5, a transmitting probe 6, and a discharge cable 7.

[0051] The measurement system includes a PVDF piezoelectric film sensor 8, a miniature impedance changer 9, a dynamic signal test and analyzer 10, a synchro generator 11, and a computer 12.

[0052] In the seismic source system, to ensure a more stable and concentrated discharge path between the cathode 14 and anode 15 of the transmitting probe 6, the transmitting probe 6 is coupled to the electrolyte solution 17 for discharge. The discharge principle of the seismic source system in this field is as follows: Figure 2 As shown, the power supply system 5 boosts and rectifies the electrical signal and charges the high-voltage energy storage pulse capacitor box C (i.e., capacitor box 4) through the current-limiting resistor R. After charging is completed, switch S1 is opened and the system waits for the trigger signal. When switch S2 is closed, the source system is excited, and the energy on the high-voltage energy storage pulse capacitor box C is released in the transmitting probe 6 through the discharge cable 7. At this time, an electric arc spark is generated between the cathode 14 and anode 15 on the transmitting probe 6, and stress waves are emitted outward from the transmitting probe 6 as the center. The duration of the entire discharge process is only 0.1ms.

[0053] Controller 2 controls the charging and discharging of capacitor box 4, monitor 3 monitors the charging and discharging process, power system 5 is the power system for the entire device, and high-energy release device 1 releases energy. Controller 2 has charging and discharging buttons. When capacitor box 4 is charging, the monitor 3 displays the voltage. Clicking the button again stops the charging process when the required voltage is reached. Clicking the button again releases energy from the capacitor box to the transmitting probe 6 via high-energy release device 1.

[0054] In the source system, capacitor box 4 mainly serves as an energy storage element: during the charging phase, capacitor box 4 will quickly store electrical energy; when it is necessary to discharge, capacitor box 4 will quickly release the stored electrical energy according to the control command to supply the high-energy release device 1.

[0055] The high-energy release device 1 is a key component of the seismic source system. Its main function is to rapidly and centrally release the stored high-voltage electrical energy to the transmitting probe 6 in a very short time, forming a high-energy, high-frequency discharge phenomenon. This discharge phenomenon generates a high-temperature and high-pressure zone in the medium, which in turn forms a shock wave, becoming the source of the vibration wave.

[0056] For experiments with short time scales, high precision, and the need for multiple devices to work together, it is difficult to coordinate the operation of different devices through manual operation. In such cases, the synchronizing generator 11 can ensure the coordinated operation between the vibration source system and the dynamic signal test and analyzer 10 by generating a synchronizing voltage signal. It wakes up the dynamic signal test and analyzer 10 before the PVDF piezoelectric film sensor 8 senses the vibration, thus preparing it to receive the signal.

[0057] In some implementations, such as Figure 3 As shown, the transmitting probe 6 of the seismic source system includes a cathode 14 and an anode 15. The anode 15 is located at the center of the cathode 14, which forms a ring around it. Polyethylene material 13 is filled between the cathode 14 and the anode 15, and the outer ring of the cathode 14 is wrapped with polyethylene material 13. The ends of the cathode 14 and the anode 15 are exposed outside the polyethylene material 13. An elastic material 16 is wrapped around the outside of the transmitting probe 6, and the cathode 14 and the anode 15 are exposed from the top. In use, a container filled with electrolyte solution 17 is used. The end of the transmitting probe 6 that exposes the cathode 14 and the anode 15 is immersed in the electrolyte solution 17, and then the upper end of the container is tied above the transmitting probe 6.

[0058] Electrolyte solution 17 is preferably a sodium chloride solution, which has the advantages of being easy to prepare and relatively stable. In the laboratory, a sodium chloride solution with a mass concentration in the range of 1.0% to 3.0% is usually used, preferably a 2.0% sodium chloride solution, with a specific mass ratio of sodium chloride to water of 1:49.

[0059] As an artificially controlled seismic source, the discharge energy of the source system is determined by the capacitance and charging voltage of capacitor box 4, and is calculated using the following formula:

[0060] In previous measurements, the piezoelectric film lacked shielding and protection, making it susceptible to corrosion from the environment or damage from other factors. Furthermore, the collected data showed that the piezoelectric film was affected by two electromagnetic pulses during the excitation of the source system: the first pulse was generated when capacitor box 4 discharged, and the second pulse was generated by the breakdown discharge of cathode 14 and anode 15 of transmitting probe 6. To ensure the accuracy of the experimental results, appropriate measures should be taken to protect the piezoelectric film and prevent electromagnetic pulse interference.

[0061] To avoid damage to the piezoelectric film and the effects of electromagnetic pulses, such as Figure 4 As shown, the PVDF piezoelectric film sensor 8 in this embodiment of the invention includes a PVDF piezoelectric film 18, a transmission layer 19, and a metal shell 20. The PVDF piezoelectric film 18 is placed in the middle, with the transmission layers 19 above and below it, and the outermost layer is protected and fixed by the metal shell 20.

[0062] In some implementations, see Figure 6As shown in (a) and (b), the PVDF piezoelectric film 18 includes an intermediate layer 25 composed of a piezoelectric film material with piezoelectric properties, and protective layers 21 on both sides of the piezoelectric film material composed of an acrylic coating layer and a polyester film. The acrylic coating layer is coated on both sides of the piezoelectric film material, and the polyester film covers the surface of the acrylic coating layer. The piezoelectric film material is polyvinylidene fluoride. The two electrode pins 23 of the PVDF piezoelectric film 18 are respectively connected to the outer conductor and inner conductor of the coaxial cable. Waterproof tape is wrapped around the electrode pins 23, and the upper and lower sides of the PVDF piezoelectric film 18 are wrapped with copper foil with a thickness of 0.06 mm. The copper foil serves as a shielding layer 22, and the coaxial discharge cable 7 serves as the lead wire of the PVDF piezoelectric film sensor 8.

[0063] In some implementations, the material of the transmission layer 19 is selected such that its elastic modulus is similar to that of the surrounding soil being measured, meaning that their elastic moduli are well matched, which helps to effectively transmit vibration energy. This ensures better coupling between the sensor and the soil, and more accurate sensing of soil vibration, thereby guaranteeing a more realistic and reliable measured frequency signal. It can also reduce interface effects and signal attenuation between the sensor and the soil, thus improving the sensor's sensitivity and measurement accuracy.

[0064] By wrapping the PVDF piezoelectric film 18 with copper foil and adding an external transmission layer 19 and a metal shell 20, the signal of the PVDF piezoelectric film 18 can remain stable and unaffected by electromagnetic pulse interference when the source system is excited, and the service life of the PVDF piezoelectric film 18 can be extended.

[0065] Because the elastic modulus of the tested soil and rock masses varies in the field, the PVDF piezoelectric film sensor 8 is designed to be detachable, allowing for the selection of a suitable material for the transfer layer 19 based on the elastic modulus of the soil and rock mass. Specific materials are selected for different soil and rock masses: soft rubber material for cohesive soil, cork board material for sandy soil, carbon fiber reinforced polymer material for rock, and cement-based polymer mixture for concrete. The material for the transfer layer 19 can be chosen more appropriately based on the measured elastic modulus of the soil and rock mass. The upper and lower transfer layers 19 and the PVDF piezoelectric film are designed as three independent parts for easy removal and reloading. See also Figure 5 The PVDF piezoelectric film sensor 8 is a convex circular device with four screw positions 24 at both ends for installation.

[0066] In some embodiments, an elastic material 16 surrounding the transmitting probe 6 can reduce the vibration frequency. Preferably, it is elastic rubber. The elastic material 16 can undergo elastic deformation. When the source system is excited, the vibration is transmitted to the elastic material 16, causing it to deform elastically. During this deformation, some energy is absorbed, thereby reducing the vibration frequency.

[0067] Because blasting vibration is a transient random signal with numerous influencing factors, it is extremely difficult to establish equations that comprehensively consider all factors. Therefore, several key factors affecting the vibration frequency are selected as physical quantities for establishing the similarity criterion equation. Thus, Q (discharge energy), T (rubber thickness), D (blast center distance), ρ (density of the measured object), ρ1 (rubber density), C1 (sound wave velocity of the measured object), and C (rubber wave velocity) are chosen as the main physical quantities affecting the blasting vibration frequency f.

[0068] First, let's establish the π term: π = Q α T β C γ f, In the formula, π1~π4 represent the defined functions, and α, β, γ, α1~α4, β1~β4, and γ1~γ4 are all unknown terms that need to be determined by calculation. The values ​​of constants α1~α4, β1~β4, and γ1~γ4 are obtained by the principle of dimensional harmony and the method of undetermined coefficients, and the obtained constants are substituted into the above formula to obtain:

[0069]

[0070] For example, by substituting the formula representing the three basic dimensions of Q, T, and C into π, setting the degree to 0, we can obtain the exponents α, β, and γ. Then, by substituting these exponents into π, we can obtain the expression for π. The same applies to π2 to π4.

[0071] The similarity equations are as follows:

[0072] π=φ(π1, π2, π3, π4);

[0073] In the formula, φ is an intermediate function and has no practical meaning.

[0074] Substituting the result of the π-term into the similarity index equation, we obtain the following equation:

[0075]

[0076] If the site (which can affect certain properties of the soil being measured, such as density and sound wave velocity) and the rubber material are determined, then ρ, C, ρ1, and C1 are all constants. By simplifying the above equation, we can finally obtain:

[0077]

[0078] In the formula, θ is a constant, which is obtained by fitting the monitoring data of blasting vibration. Under the same site, multiple monitoring points are selected for subsequent fitting analysis to obtain θ and K2. In computer 12, the relationship between rubber thickness T and blasting vibration frequency f can be obtained through Fourier transform.

[0079] Alternatively, selecting discharge energy Q, rubber thickness T, and wave velocity C as the basic physical quantities, and blast vibration frequency f as the dependent variable, we can formulate the π-term: π = Q α T β C γ f, The exponent values ​​are obtained using the principle of dimensional harmony and the method of undetermined coefficients, and then substituted into the above formula to obtain:

[0080]

[0081] The similarity equations are listed below:

[0082] π = φ(π1, π2).

[0083] Substituting the result of the π-term into the similarity index equation, we obtain the following equation:

[0084]

[0085] If the measurement site is fixed, and the density and wave velocity of the object being measured are constants, simplifying the above equation, we get:

[0086]

[0087] In the formula, α and β are constants, obtained by fitting the monitoring data of blasting vibration; under the same site, multiple monitoring points are selected for subsequent fitting analysis to obtain α, β, and K2; in computer 12, the relationship between rubber thickness T and blasting vibration frequency f can be obtained through Fourier transform.

[0088] The above provides two calculation methods. The appropriate formula can be selected based on the different parameters of different known materials in reality, so as to choose the appropriate thickness of the rubber as the elastic material 16 according to the required blasting vibration frequency.

[0089] This invention also provides an indoor blasting model experiment method, the specific steps of which are as follows:

[0090] S1. Connect the high-energy release device 1, capacitor box 4, power supply system 5, transmitting probe 6, and discharge cable 7 in sequence, connect them to the synchronizing generator 11, and then connect them to the dynamic signal test and analyzer 10. One end of the dynamic signal test and analyzer 10 is connected to the computer 12, and the other end is connected to the PVDF piezoelectric film sensor 8 through the miniature impedance changer 9. Place the PVDF piezoelectric film sensor 8 at the measurement point and fix it in place.

[0091] S2. At the transmitting probe 6, use a container filled with sodium chloride solution to seal the transmitting probe 6 tightly to create a specific conductive environment, and then place the transmitting probe 6 inside the object being measured.

[0092] S3, the 220V household power supply is boosted and rectified by the power system 5 and then charged through the capacitor box 4. After charging is completed, the switch is turned off and waits for the trigger signal. When the discharge switch is closed, the source system is excited, and the electrical energy on the capacitor box 4 is released in the transmitting probe 6 through the high-energy release device 1 and the discharge cable 7. At this time, an electric arc spark is generated between the cathode 14 and the anode 15 on the transmitting probe 6, and stress waves are emitted outward from the transmitting probe 6 as the center. The duration of the entire discharge process is only 0.1ms.

[0093] S4. When the source system is excited, stress waves are emitted outward from the center of the transmitting probe 6. The PVDF piezoelectric film 18 on the object under test generates unequal amounts of charge according to the magnitude of the stress. These charges are transmitted to the micro impedance changer 9 through the lead wire. The micro impedance changer 9 converts the charge signal into a voltage signal proportionally and transmits it to the dynamic signal test and analysis instrument 10. Then, the required real signal is obtained in the computer 12.

[0094] Example

[0095] In this embodiment, two rounds of blasting simulation experiments are set up. One round of experiments is conducted using the experimental system of the present invention, and the other round of experiments is conducted using an existing commercially available seismic source system (i.e., the experimental system of the present invention is not used). The locations of the two rounds of experiments are basically the same.

[0096] The experiment was conducted with a discharge voltage of approximately 2000V, and the object being tested was a rectangular marble slab. Figure 7 The stress data of blasting vibration measured using the apparatus of this application, Figure 8 These are the stress data from previously measured blasting vibrations. Among them, Figure 7 (a) and (b) in the figure are the data measured in the first round of experiments. The points in (a) and (b) are the points selected on two adjacent sides of the marble. Figure 8 Figures (a) and (b) show the data obtained in the second round of experiments. The selected points in figures (a) and (b) are... Figure 7 The selected points in (a) and (b) are basically the same.

[0097] Electrical spark discharges or electromagnets release large amounts of energy in a very short time, typically on the order of milliseconds or microseconds. This rapidly released energy results in very high-frequency vibrations. Under the same electrical spark discharge conditions, the higher the vibration frequency produced by the source system, the larger the peak value of the stress wave is likely to be.

[0098] By comparison Figure 7 (a) and Figure 8 (a) in the middle, and the comparison Figure 7 (b) and Figure 8 In (b), it can be observed that the peak value of the stress data measured by the existing electric spark source device during blasting is significantly higher than that of the standard. Figure 7 The peak value measured after using the experimental system of the present invention decreased by approximately 20%. This demonstrates that the experimental system of the present invention can significantly reduce the vibration frequency of the seismic source, making it more closely resemble the actual blasting vibration frequency.

[0099] Additionally, it should be noted that all circuit connection methods not mentioned in this invention are conventional connection methods that can be implemented by those skilled in the art based on their professional expertise.

[0100] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0101] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. An indoor blasting model experimental system, comprising a seismic source system, characterized in that, The seismic source system includes: High-energy release device (1) is used to release the electrical energy released by the capacitor box (4) to the transmitting probe (6); The controller (2) is used to control the charging and discharging of the capacitor bank (4); Capacitor box (4) is used to absorb and release electrical energy from the power supply system (5); The monitoring instrument (3) is used to monitor the charging and discharging process of the capacitor box (4); The power supply system (5) is used to provide electrical energy to the source system; The transmitting probe (6) is used to receive the energy released by the high-energy releaser (1) and react with the electrolyte solution (17) to discharge; The high-energy release device (1) is electrically connected to the controller (2), the monitor (3), and the capacitor box (4) respectively; the power supply system (5) is electrically connected to the controller (2) and the monitor (3) respectively; the high-energy release device (1) is electrically connected to the emission probe (6) through the discharge cable (7); the end of the emission probe (6) is located in the electrolyte solution (17), and the outer side of the emission probe (6) is wrapped with a ring of elastic material (16); The indoor blasting model experimental system also includes a measurement system, which includes a PVDF piezoelectric thin film sensor (8). The PVDF piezoelectric thin film sensor (8) is electrically connected to a dynamic signal test and analyzer (10) via a miniature impedance changer (9). The dynamic signal test and analyzer (10) is connected to a computer (12). The measurement system and the seismic source system are electrically connected via a synchronous generator (11); The synchronization generator (11) is used to ensure coordinated operation between the high-energy releaser (1) and the dynamic signal test analyzer (10), and to wake up the dynamic signal test analyzer (10) before the PVDF piezoelectric film sensor (8) senses vibration, so as to prepare for receiving signals.

2. The indoor blasting model experimental system according to claim 1, characterized in that, The transmitting probe (6) includes a cathode (14) and an anode (15). The anode (15) is located at the center of the cathode (14) which is enclosed in a circle. Polyethylene material (13) is filled between the cathode (14) and the anode (15), and the outer ring of the cathode (14) is wrapped with polyethylene material (13). The ends of the cathode (14) and the anode (15) are exposed to the polyethylene material (13). The exposed ends of the cathode (14) and the anode (15) are in contact with the electrolyte solution (17). The outer side of the transmitting probe (6) is wrapped with an elastic material (16), and the cathode (14) and the anode (15) are exposed from the top.

3. The indoor blasting model experimental system according to claim 1, characterized in that, The PVDF piezoelectric film sensor (8) includes a PVDF piezoelectric film (18), and a transfer layer (19) is provided on the upper and lower sides of the PVDF piezoelectric film (18). The PVDF piezoelectric film (18) and the transfer layer (19) are located inside the metal shell (20).

4. The indoor blasting model experimental system according to claim 3, characterized in that, The PVDF piezoelectric film (18) includes an intermediate layer (25), the material of which is a piezoelectric film material with piezoelectric properties; a protective layer (21) is provided on the upper and lower surfaces of the intermediate layer (25), and a shielding layer (22) is provided on the outside of the protective layer (21); an electrode pin (23) is provided on the outside of the PVDF piezoelectric film (18).

5. The indoor blasting model experimental system according to claim 3, characterized in that, When selecting the material for the transfer layer (19), the material whose elastic modulus is closest to that of the object being tested should be selected.

6. The indoor blasting model experimental system according to claim 4, characterized in that, The protective layer (21) is composed of an acrylic coating layer and a polyester film, wherein the acrylic coating layer is coated on both sides of the piezoelectric film material, and the polyester film covers the surface of the acrylic coating.

7. The indoor blasting model experimental system according to claim 4, characterized in that, The material of the shielding layer (22) is copper foil.

8. The indoor blasting model experimental system according to claim 1, characterized in that, The electrolyte solution (17) is a sodium chloride solution with a mass concentration of 1.0% to 3.0%.

9. An experimental method for an indoor blasting model experimental system as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Connect the high-energy release device (1), controller (2), monitor (3), capacitor box (4), power system (5), transmitting probe (6), and discharge cable (7) to the corresponding electrical connections; connect to the synchronous generator (11) and connect to the dynamic signal test and analyzer (10); connect one end of the dynamic signal test and analyzer (10) to the computer (12), and the other end to the PVDF piezoelectric film sensor (8) through the miniature impedance changer (9); place the PVDF piezoelectric film sensor (8) at the measurement point of the object being measured and fix it in place; S2. Use a container containing electrolyte solution (17) to seal the transmitting probe (6) tightly, and then place the sealed transmitting probe (6) inside the object to be tested. S3. Charge the capacitor box (4). After charging is completed, control the capacitor box (4) through the controller (2) and release energy to the transmitting probe (6) through the high energy release device (1). At this time, an electric arc spark is generated between the cathode (14) and anode (15) on the transmitting probe (6), and stress waves are emitted outward from the center of the transmitting probe (6). S4. The PVDF piezoelectric film (18) on the object under test generates unequal charges according to the magnitude of the stress. The charges are transferred to the micro impedance changer (9) through the lead wire. The micro impedance changer (9) converts the charge signal into a voltage signal proportionally and transmits it to the dynamic signal test and analyzer (10). Then, the required real signal is obtained in the computer (12).

10. The experimental method of the indoor blasting model experimental system according to claim 9, characterized in that, The outer side of the transmitting probe (6) is wrapped with a ring of rubber as an elastic material (16), and the relationship between the thickness T of the rubber and the explosion vibration frequency f required for the experiment is determined in the following way: If the density ρ of the object being measured, the rubber wave velocity C, the rubber density ρ1, and the sound wave velocity C1 of the object being measured are determined, then the relationship between the vibration frequency f and the rubber thickness T can be determined by the following formula: In the formula, D is the distance from the explosion center, Q is the discharge energy, and K1, α, and β are constants. γ and θ are constants, obtained by fitting and calculating the monitoring data of blasting vibration; If only the density ρ of the object being measured and the rubber wave velocity C are determined, the relationship between the vibration frequency f and the rubber thickness T can be determined by the following formula: In the formula, K2, α, and β are constants, where,

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