Experimental device and experimental method for researching magnetic characteristics of ferromagnetic cavity

Abstract

The invention relates to an experimental device and an experimental method for researching the physical magnetic characteristics of a ferromagnetic cavity, and the experimental device and the experimental method provided by the invention measure the change of a space magnetic field of a specified point outside the ferromagnetic cavity under different background magnetic fields and different pressures through a sensor array; the device is suitable for researching the magnetic characteristics of the ferromagnetic cavity under two working conditions that the background magnetic field is changed by fixed pressure and the pressure is changed by the fixed background magnetic field, and has the advantages of miniaturization, flexible layout, large pressure change range, adjustable background magnetic field, accurate measurement and the like.

Description

Technical Field

[0001] The invention relates to an experimental device and an experimental method for studying the force and magnetic characteristics of a ferromagnetic cavity, and belongs to the technical field of physical performance analysis and testing. Background Art

[0002] Deep-sea magnetic detection technology is mainly used to find and locate ferromagnetic targets in the deep sea, such as submarines, sunken ships and submarine pipelines. This technology relies on the magnetic anomalies generated by the target in the earth's magnetic field. The magnetic field generated by ferromagnetic materials can be divided into fixed magnetic fields and induced magnetic fields. The size and distribution of the fixed magnetic field are affected by factors such as the material's magnetism, shape, the geomagnetic field of the construction area, and the manufacturing process. The induced magnetic field is mainly related to the ferromagnetic material's own properties, shape, and background magnetic field. The spatial magnetic field anomalies caused by ferromagnetic materials can be detected by magnetic detection instruments, thereby realizing the detection and positioning of targets.

[0003] Ferromagnetic cavities such as various functional pipelines and underwater vehicles are usually made of ferromagnetic materials. The magnetoelastic coupling effect of ferromagnetic materials will cause the magnetic field they generate to change with the change of force, thereby reducing the accuracy of deep-sea magnetic detection. Therefore, it is very necessary to study the magnetoelastic properties of ferromagnetic cavities. The study of magnetoelastic coupling effect began in 1945. After decades of development, a series of theoretical models such as Jiles-Atherton theory have gradually been formed and applied to simulation models. However, current experimental research on magnetoelastic coupling mainly focuses on rods. Due to the huge volume of deep-sea ferromagnetic cavities, they are not suitable for research as experimental objects. Summary of the invention

[0004] The invention discloses an experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure, the experimental device comprising an inner ferromagnetic cavity, an outer pressurized container, a pressurizing pump, a compensating current regulating system, a sensor array and a pressure relief valve;

[0005] The inner ferromagnetic cavity is the object of the magnetomechanical property experiment. When the background magnetic field is 0, its residual magnetism will generate a fixed magnetic field in the external space; when it is subjected to pressure, the magnetic field in the external space will change due to the magnetomechanical coupling effect.

[0006] The outer layer pressurized container is coated on the outer side of the inner layer ferromagnetic cavity, and is used to pressurize the inner layer ferromagnetic cavity;

[0007] The pressure pump is used to fill the cavity between the inner ferromagnetic cavity and the outer pressure container with water, and then pressurize the cavity between the inner ferromagnetic cavity and the outer pressure container through the water filling valve, and stop working when the pressure reaches the set pressure value;

[0008] The compensation current adjustment system is used to adjust the compensation current in the three directions of x, y and z, thereby adjusting the background magnetic field in the inner ferromagnetic cavity;

[0009] The sensor array is used to measure the magnetic field component of the corresponding point in the outer space of the inner ferromagnetic cavity, and can measure both absolute and relative quantities. The absolute quantity is the actual magnetic field component of the spatial point where the sensor is located, and the relative quantity is the change in the magnetic field component of the spatial point where the sensor is located.

[0010] The pressure relief valve is used to relieve pressure in the ferromagnetic cavity. After completing the magnetomechanical property research experiment, the ferromagnetic cavity needs to be relieved of pressure to ensure safety.

[0011] Furthermore, the experimental device for studying the magnetomechanical characteristics of the ferromagnetic cavity under external pressure includes an operating platform; the operating platform is used to control the pressurization speed and pressure value, read the internal real-time pressure through the pressure sensor, and generate a time-pressure table and curve;

[0012] The operating platform can perform experiments under the condition of changing pressure with a fixed background magnetic field:

[0013] A three-phase fluxgate sensor is placed at the point to be tested to obtain compensation current data corresponding to the target background magnetic field and the fixed magnetic field distribution of the ferromagnetic cavity;

[0014] After adjusting the compensation current to make the background magnetic field zero, the ferromagnetic cavity is placed at the point to be measured, the data of the sensor array is read, and the fixed magnetic field distribution of the ferromagnetic cavity is measured;

[0015] Control the compensation current, adjust the background magnetic field to the target magnetic field, and keep the compensation current unchanged;

[0016] Fill the cavity with water until it is full and pressurize it, then reduce the pressure to 0 after reaching the preset pressure, and repeat the cycle twice;

[0017] The sensor array data is read to obtain the change in magnetic field components under different pressures. Based on the relationship between the change and the background magnetic field and the intracavity pressure, the force and magnetic characteristics are analyzed.

[0018] Furthermore, the operating platform can perform experiments under the condition of changing the background magnetic field with a fixed pressure:

[0019] A three-phase fluxgate sensor is placed at the point to be tested to obtain compensation current data corresponding to the target background magnetic field and the fixed magnetic field distribution of the ferromagnetic cavity;

[0020] After adjusting the compensation current to make the background magnetic field zero, the ferromagnetic cavity is placed at the point to be measured, the data of the sensor array is read, and the fixed magnetic field distribution of the ferromagnetic cavity is measured;

[0021] Fill the cavity with water until it is full, and pressurize it to keep the pressure inside the cavity constant;

[0022] Control the compensation current to adjust the background magnetic field so that the background magnetic field in the x, y, and z directions is within the range (0, B max ,0) changes twice;

[0023] The sensor array data is read to obtain the change in magnetic field components corresponding to different background magnetic fields under a fixed pressure.

[0024] Furthermore, the experimental device for studying the magnetomechanical properties of the ferromagnetic cavity under external pressure also includes a water tank and a water filling valve; the water tank is used to store water, and water is filled into the cavity between the inner ferromagnetic cavity and the outer pressurized container through the water filling valve before pressurization.

[0025] Furthermore, the experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure also includes a water reservoir and a drain valve; the water reservoir is used to store water discharged through the drain valve after pressure relief is completed, and when drainage is completed, the drain valve is closed and the experiment ends.

[0026] Furthermore, the experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure also includes a power supply system; the power supply system supplies power to a pressure pump, an operating platform, a compensation current regulation system, and a sensor array.

[0027] Furthermore, the sensor array includes 5 measuring lines, the distance between adjacent measuring lines is 200 mm, and 12 three-phase fluxgate sensors are distributed on each measuring line, and the distance between adjacent sensors is 200 mm; each three-phase fluxgate sensor can measure the absolute value and change of the magnetic field component at its spatial point.

[0028] Furthermore, the compensation current adjustment system is used to adjust the compensation current in the x, y, and z directions, thereby adjusting the background magnetic field in the ferromagnetic cavity; three groups of coils are distributed outside the measurement space and are respectively linked to the x, y, and z axes, called x coils, y coils, and z coils, respectively. The currents in the coils are independent of each other and are superimposed to generate a background magnetic field.

[0029] A method for studying the force and magnetic properties of a ferromagnetic cavity is also provided. The method is used to conduct an experiment under the condition of changing the pressure in a fixed background magnetic field. The method comprises the following steps:

[0030] Step 11, placing the ferromagnetic cavity at the far end to ignore its influence on the background magnetic field of the measuring point, placing a three-phase fluxgate sensor at the point to be measured, reading the magnetic field at the point as the background magnetic field of the measuring environment; controlling the compensation current in the x, y, and z directions to adjust the background magnetic field to the target value, and recording the compensation current data corresponding to different target magnetic fields;

[0031] Step 12, remove the three-phase fluxgate sensor at the test point, adjust the compensation current to make the background magnetic field zero, place the ferromagnetic cavity at the test point, read the data of the sensor array, and measure the fixed magnetic field distribution of the ferromagnetic cavity;

[0032] Step 13, controlling the compensation current, adjusting the background magnetic field to the target magnetic field, and keeping the compensation current unchanged. At this time, the magnetic field in the measured space is the target magnetic field;

[0033] Step 14: Close the drain valve, open the water filling valve, and fill the cavity with water from the water tank until it is full; open the operating platform, and adjust the pressurization rate and the upper limit of the pressure stabilization P. max ; Start the air pump to pressurize to P max After that, turn off the air pump and the pressure valve, open the pressure relief valve to release the pressure until the pressure in the cavity is 0, and repeat the above operation twice;

[0034] Step 15, reading the sensor array data to obtain the variation of the magnetic field components under different pressures, and performing force and magnetic characteristics analysis based on the relationship between the variation, the background magnetic field, and the intracavity pressure;

[0035] Step 16, determine whether the experimental goal is completed. If not, return to step 13, change the background magnetic field and repeat steps 14 and 15. If it is completed, open the drain valve and close the drain valve after drainage is completed, and the experiment ends.

[0036] A method for studying the force and magnetic properties of a ferromagnetic cavity is also provided. The method is used to conduct an experiment under the condition of changing the pressure in a fixed background magnetic field. The method comprises the following steps:

[0037] Step 21, placing the ferromagnetic cavity at a remote end to ignore its influence on the background magnetic field of the measuring point, placing a three-phase fluxgate sensor at the point to be measured, and reading the magnetic field at the point as the background magnetic field of the measuring environment; controlling the compensation current in the x, y, and z directions to adjust the background magnetic field to the target value, and recording the compensation current data corresponding to different target magnetic fields;

[0038] Step 22, remove the three-phase fluxgate sensor at the test point, adjust the compensation current to make the background magnetic field zero, place the ferromagnetic cavity at the test point, read the data of the sensor array, and measure the fixed magnetic field distribution of the ferromagnetic cavity;

[0039] Step 23, close the drain valve, open the water filling valve, and fill the cavity with water from the water tank until it is full. Open the operating platform and adjust the pressurization rate and the upper limit of the pressure stabilization P max ; Start the air pump to pressurize to P max After that, the pressure in the cavity is kept constant;

[0040] Step 24, combining the demagnetization current corresponding to different background magnetic fields, according to the experimental requirements, control the compensation current to adjust the background magnetic field so that the background magnetic field in the x, y, and z directions is within the range (0, B max ,0) changes twice;

[0041] Step 25, reading the sensor array data to obtain the change in magnetic field components corresponding to different background magnetic fields under a fixed pressure;

[0042] Step 26, determine whether the experimental goal has been achieved. If not, return to step 23, change the pressure and repeat steps 24 and 25. If it has been completed, close the pressurizing valve, open the pressure relief valve to release the pressure, open the drain valve after the pressure relief is completed, and close the drain valve after the drainage is completed. The experiment ends.

[0043] The beneficial effects achieved by the present invention are:

[0044] The experimental device for studying the magnetomechanical properties of ferromagnetic cavities provided by the present invention has the advantages of miniaturization and flexible layout. The experimental device and experimental method adopt the idea of ​​analogy research, which solves the problem that large ferromagnetic cavities are not suitable for research as experimental objects;

[0045] The ferromagnetic cavity mechanical and magnetic property research experimental device provided by the present invention has the advantage of a large pressure variation range. The ferromagnetic cavity used in the experiment is designed according to the actual pressure magnitude of the outer wall of the deep-sea ferromagnetic cavity. The pressure of the ferromagnetic cavity can be displayed and recorded in real time, and the maximum pressure can reach MPa level.

[0046] The experimental device for studying the magnetomechanical properties of a ferromagnetic cavity provided by the present invention is applicable to two working conditions: changing the background magnetic field with a fixed pressure and changing the pressure with a fixed background magnetic field. The change in the magnetic field in the outer space of the ferromagnetic cavity is mainly related to the pressure in the cavity and the background magnetic field. The device adopts the idea of ​​the control variable method, supports the exploration of the relationship between a single independent variable and a dependent variable, and is conducive to the study of the magnetomechanical properties of the ferromagnetic cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of an experimental device for studying the mechanical and magnetic properties of a ferromagnetic cavity according to the present invention;

[0048] Figure 2 It is a method flow chart of the experimental method for studying the magnetomechanical properties of a ferromagnetic cavity of the present invention under the condition of changing the pressure in a fixed background magnetic field;

[0049] Figure 3 It is a method flow chart of the experimental method for studying the magnetomechanical properties of a ferromagnetic cavity of the present invention under the condition of changing the background magnetic field at a fixed pressure. DETAILED DESCRIPTION

[0050] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer as the description proceeds. However, these embodiments are exemplary only and do not constitute any limitation to the scope of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solution of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the scope of protection of the present invention.

[0051] Embodiment 1

[0052] As attached Figure 1 As shown, the present invention provides an experimental device for studying the magnetomechanical properties of a ferromagnetic cavity. The experimental device is suitable for two working conditions: changing the pressure with a fixed background magnetic field and changing the background magnetic field with a fixed pressure. It includes an inner ferromagnetic cavity, an outer pressurized container, a water tank, a pressure pump, a water reservoir, an operating platform, a compensating current regulation system, a power supply system, a sensor array, a pressure relief valve, a water injection valve and a drain valve.

[0053] The inner ferromagnetic cavity is the object of the magnetoelastic property experiment. It is made of ferromagnetic material. The relationship between its magnetization intensity and the background magnetic field can be described by a hysteresis loop. When the background magnetic field is 0, its remanent magnetism will generate a fixed magnetic field in the external space. When it is subjected to pressure, the magnetic field in the external space will change due to the magnetoelastic coupling effect.

[0054] The outer pressure container is coated on the outer side of the inner ferromagnetic cavity, and is used for pressurizing the inner ferromagnetic cavity, and is made of low magnetic material.

[0055] The water tank is used to store water. Before pressurization, water is injected into the cavity between the inner ferromagnetic cavity and the outer pressurized container through the water injection valve until it is full.

[0056] The booster pump is used to fill the cavity between the inner ferromagnetic cavity and the outer pressurized container with water, and then pressurize the cavity between the inner ferromagnetic cavity and the outer pressurized container through the water filling valve, and stop working when the pressure reaches the set pressure value.

[0057] The operating platform is used to control the pressurization speed and pressure value, read the internal real-time pressure through the pressure sensor, and generate time-pressure tables and curves.

[0058] The compensation current adjustment system is used to adjust the compensation current in the x, y, and z directions, thereby adjusting the background magnetic field of the inner ferromagnetic cavity. The three compensation currents flow in three sets of coils that are interlinked with the x, y, and z axes respectively, independently of each other, and are superimposed to generate a background magnetic field;

[0059] The sensor array is used to measure the magnetic field components of corresponding points in the space outside the inner ferromagnetic cavity. It can measure both absolute and relative quantities. The absolute quantity is the actual magnetic field component of the spatial point where the sensor is located, and the relative quantity is the change in the magnetic field component of the spatial point where the sensor is located.

[0060] The power supply system is a general term for a series of power supplies, which provide power for modules and systems that require power, such as booster pumps, operating platforms, compensation current regulation systems, and sensor arrays.

[0061] The pressure relief valve is used to relieve the pressure of the ferromagnetic cavity. After completing the magnetomechanical property research experiment, the ferromagnetic cavity needs to be depressurized to ensure safety;

[0062] The water reservoir is used to store the water discharged through the drain valve after the pressure relief is completed. When the drainage is completed, the drain valve is closed and the experiment is over.

[0063] Embodiment 2

[0064] In order to make the experimental method for studying the magnetic properties of the ferromagnetic cavity proposed in the present invention more clear, the following will be combined with Figure 2 The experimental method is further explained.

[0065] As attached Figure 2 As shown, this embodiment provides an experimental method for studying the magnetomechanical properties of a ferromagnetic cavity. The experimental method is conducted under the condition of changing the pressure in a fixed background magnetic field. The experimental method includes the following steps:

[0066] Step 11, place the ferromagnetic cavity at the far end to ignore its influence on the background magnetic field of the measuring point, place a three-phase fluxgate sensor at the point to be measured, and read the magnetic field at the point as the background magnetic field of the measuring environment. Control the compensation current in the x, y, and z directions to adjust the background magnetic field to the target value, and record the compensation current data corresponding to different target magnetic fields;

[0067] Step 12, remove the three-phase fluxgate sensor at the test point, adjust the compensation current to make the background magnetic field zero, place the ferromagnetic cavity at the test point, read the data of the sensor array, and measure the fixed magnetic field distribution of the ferromagnetic cavity;

[0068] Step 13, controlling the compensation current, adjusting the background magnetic field to the target magnetic field, and keeping the compensation current unchanged. At this time, the magnetic field in the measured space is the target magnetic field.

[0069] Step 14: Close the drain valve, open the water filling valve, and fill the cavity with water from the water tank until it is full. Open the operating platform and adjust the pressurization rate and the upper limit of the pressure stabilization P. max . Open the pressure valve, close the pressure relief valve, and start the air pump to pressurize. Pressurize to P max After that, turn off the air pump and the pressure valve, open the pressure relief valve to release the pressure until the pressure in the cavity is 0, and repeat the above operation twice;

[0070] Step 15, read the sensor array data to obtain the change of the magnetic field component under different pressures, and perform magnetomechanical characteristic analysis based on the relationship between the change and the background magnetic field and the intracavity pressure.

[0071] Step 16, determine whether the experimental goal is completed. If not, return to step 13, change the background magnetic field and repeat steps 14 and 15. If it is completed, open the drain valve and close the drain valve after drainage is completed, and the experiment ends.

[0072] Embodiment 3

[0073] As attached Figure 3 As shown, the present embodiment provides an experimental method for studying the magnetomechanical properties of a ferromagnetic cavity. The experiment is conducted under the condition of changing the background magnetic field at a fixed pressure. The experimental method includes the following steps:

[0074] Step 21, place the ferromagnetic cavity at the far end to ignore its influence on the background magnetic field of the measuring point, place a three-phase fluxgate sensor at the point to be measured, and read the magnetic field at the point as the background magnetic field of the measuring environment. Control the compensation current in the x, y, and z directions to adjust the background magnetic field to the target value, and record the compensation current data corresponding to different target magnetic fields;

[0075] Step 22, remove the three-phase fluxgate sensor at the test point, adjust the compensation current to make the background magnetic field zero, place the ferromagnetic cavity at the test point, read the data of the sensor array, and measure the fixed magnetic field distribution of the ferromagnetic cavity;

[0076] Step 23, close the drain valve, open the water filling valve, and fill the cavity with water from the water tank until it is full. Open the operating platform and adjust the pressurization rate and the upper limit of the pressure stabilization P max . Open the pressure valve, close the pressure relief valve, and start the air pump to pressurize. Pressurize to P max After that, the pressure in the cavity is kept constant;

[0077] Step 24, combining the demagnetization current corresponding to different background magnetic fields, according to the experimental requirements, control the compensation current to adjust the background magnetic field so that the background magnetic field in the x, y, and z directions is within the range (0, B max ,0) changes twice; B max is the maximum preset magnetic field strength;

[0078] Step 25, reading the sensor array data to obtain the change in magnetic field components corresponding to different background magnetic fields under a fixed pressure;

[0079] Step 26, determine whether the experimental goal has been achieved. If not, return to step 23, change the pressure and repeat steps 24 and 25. If it has been completed, close the pressurizing valve, open the pressure relief valve to release the pressure, open the drain valve after the pressure relief is completed, and close the drain valve after the drainage is completed. The experiment ends.

[0080] The present invention is not limited to the above-mentioned specific implementation modes. A person skilled in the art may implement the present invention in various other specific implementation modes according to the embodiments and the disclosure of the drawings. Therefore, any design that adopts the design structure and concept of the present invention and makes some simple transformations or changes shall fall within the scope of protection of the present invention.

Claims

1. An experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure, characterized in that: The experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure comprises an inner ferromagnetic cavity, an outer pressurized container, a pressurizing pump, a compensating current regulating system, a sensor array and a pressure relief valve; The inner ferromagnetic cavity is the object of the magnetomechanical property experiment. When the background magnetic field is 0, its residual magnetism will generate a fixed magnetic field in the external space; when it is subjected to pressure, the magnetic field in the external space will change due to the magnetomechanical coupling effect. The outer layer pressurized container is coated on the outer side of the inner layer ferromagnetic cavity, and is used to pressurize the inner layer ferromagnetic cavity; The pressure pump is used to fill the cavity between the inner ferromagnetic cavity and the outer pressure container with water, and then pressurize the cavity between the inner ferromagnetic cavity and the outer pressure container through the water filling valve, and stop working when the pressure reaches the set pressure value; The compensation current adjustment system is used to adjust the compensation current in the three directions of x, y and z, thereby adjusting the background magnetic field in the inner ferromagnetic cavity; The sensor array is used to measure the magnetic field component of the corresponding point in the outer space of the inner ferromagnetic cavity, and can measure both absolute and relative quantities. The absolute quantity is the actual magnetic field component of the spatial point where the sensor is located, and the relative quantity is the change in the magnetic field component of the spatial point where the sensor is located. The pressure relief valve is used to relieve pressure in the ferromagnetic cavity. After completing the magnetomechanical property research experiment, the ferromagnetic cavity needs to be relieved of pressure to ensure safety.

2. According to the experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure as described in claim 1, it is characterized in that: The experimental device for studying the magnetomechanical characteristics of a ferromagnetic cavity under external pressure comprises an operating platform; the operating platform is used to control the pressurization speed and pressure value, read the internal real-time pressure through a pressure sensor, and generate a time-pressure table and curve; The operating platform can perform experiments under the condition of changing pressure with a fixed background magnetic field: A three-phase fluxgate sensor is placed at the point to be tested to obtain compensation current data corresponding to the target background magnetic field and the fixed magnetic field distribution of the ferromagnetic cavity; After adjusting the compensation current to make the background magnetic field zero, the ferromagnetic cavity is placed at the point to be measured, the data of the sensor array is read, and the fixed magnetic field distribution of the ferromagnetic cavity is measured; Control the compensation current, adjust the background magnetic field to the target magnetic field, and keep the compensation current unchanged; Fill the cavity with water until it is full and pressurize it, then reduce the pressure to 0 after reaching the upper limit of the stable pressure, and repeat the cycle twice; The sensor array data is read to obtain the change in magnetic field components under different pressures. Based on the relationship between the change and the background magnetic field and the intracavity pressure, the force and magnetic characteristics are analyzed.

3. The experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure according to claim 2 is characterized in that: The operating platform can perform experiments under the condition of changing the background magnetic field with a fixed pressure: A three-phase fluxgate sensor is placed at the point to be tested to obtain compensation current data corresponding to the target background magnetic field and the fixed magnetic field distribution of the ferromagnetic cavity; After adjusting the compensation current to make the background magnetic field zero, the ferromagnetic cavity is placed at the point to be measured, the data of the sensor array is read, and the fixed magnetic field distribution of the ferromagnetic cavity is measured; Fill the cavity with water until it is full, and pressurize it to keep the pressure inside the cavity constant; Control the compensation current to adjust the background magnetic field so that the background magnetic field in the x, y, and z directions is within the range (0, B max ,0) changes twice; The sensor array data is read to obtain the change in magnetic field components corresponding to different background magnetic fields under a fixed pressure.

4. The experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure according to claim 1 is characterized in that: The experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure also includes a water tank and a water injection valve; the water tank is used to store water, and water is injected into the cavity between the inner ferromagnetic cavity and the outer pressurized container through the water injection valve before pressurization.

5. The experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure according to claim 1 is characterized in that: The experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure also includes a water reservoir and a drain valve; the water reservoir is used to store water discharged through the drain valve after pressure relief is completed, and the drain valve is closed after drainage is completed, and the experiment ends.

6. The experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure according to claim 2, characterized in that: The experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure also includes a power supply system; the power supply system supplies power to a pressure pump, an operating platform, a compensation current regulation system, and a sensor array.

7. The experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure according to claim 1, characterized in that: The sensor array includes 5 measuring lines, the distance between adjacent measuring lines is 200mm, and 12 three-phase fluxgate sensors are distributed on each measuring line, and the distance between adjacent sensors is 200mm; each three-phase fluxgate sensor can measure the absolute value and change of the magnetic field component at its spatial point.

8. The experimental device for studying the magnetomechanical properties of a ferromagnetic cavity under external pressure according to claim 1, characterized in that: The compensation current adjustment system is used to adjust the compensation current in the three directions of x, y and z, so as to adjust the background magnetic field in the ferromagnetic cavity; three groups of coils are distributed outside the measurement space, which are respectively linked with the three axes of x, y and z, and are called x coil, y coil and z coil respectively. The currents in the coils are independent of each other and are superimposed to generate a background magnetic field.

9. An experimental method for studying the magnetomechanical properties of a ferromagnetic cavity, characterized in that: The experimental method for studying the magnetomechanical properties of a ferromagnetic cavity is used to conduct an experiment under the condition of changing the pressure in a fixed background magnetic field, and the experimental method comprises the following steps: Step 11, placing the ferromagnetic cavity at the far end to ignore its influence on the background magnetic field of the measuring point, placing a three-phase fluxgate sensor at the point to be measured, reading the magnetic field at the point as the background magnetic field of the measuring environment; controlling the compensation current in the x, y, and z directions to adjust the background magnetic field to the target value, and recording the compensation current data corresponding to different target magnetic fields; Step 12, remove the three-phase fluxgate sensor at the test point, adjust the compensation current to make the background magnetic field zero, place the ferromagnetic cavity at the test point, read the data of the sensor array, and measure the fixed magnetic field distribution of the ferromagnetic cavity; Step 13, controlling the compensation current, adjusting the background magnetic field to the target magnetic field, and keeping the compensation current unchanged. At this time, the magnetic field in the measured space is the target magnetic field; Step 14: Close the drain valve, open the water filling valve, and fill the cavity with water from the water tank until it is full; open the operating platform, and adjust the pressurization rate and the upper limit of the pressure stabilization P. max ; Start the air pump to pressurize to P max After that, turn off the air pump and the pressure valve, open the pressure relief valve to release the pressure until the pressure in the cavity is 0, and repeat the above operation twice; Step 15, reading the sensor array data to obtain the variation of the magnetic field components under different pressures, and performing force and magnetic characteristics analysis based on the relationship between the variation, the background magnetic field, and the intracavity pressure; Step 16, determine whether the experimental goal is completed. If not, return to step 13, change the background magnetic field and repeat steps 14 and 15. If it is completed, open the drain valve and close the drain valve after drainage is completed, and the experiment ends.

10. An experimental method for studying the magnetomechanical properties of a ferromagnetic cavity, characterized in that: The experimental method for studying the magnetomechanical properties of a ferromagnetic cavity is used to conduct an experiment under the condition of changing the pressure in a fixed background magnetic field, and the experimental method comprises the following steps: Step 21, placing the ferromagnetic cavity at a remote end to ignore its influence on the background magnetic field of the measuring point, placing a three-phase fluxgate sensor at the point to be measured, and reading the magnetic field at the point as the background magnetic field of the measuring environment; controlling the compensation current in the x, y, and z directions to adjust the background magnetic field to the target value, and recording the compensation current data corresponding to different target magnetic fields; Step 22, remove the three-phase fluxgate sensor at the test point, adjust the compensation current to make the background magnetic field zero, place the ferromagnetic cavity at the test point, read the data of the sensor array, and measure the fixed magnetic field distribution of the ferromagnetic cavity; Step 23, close the drain valve, open the water filling valve, and fill the cavity with water from the water tank until it is full. Open the operating platform and adjust the pressurization rate and the upper limit of the pressure stabilization P max ; Start the air pump to pressurize to P max After that, the pressure in the cavity is kept constant; Step 24, combining the demagnetization current corresponding to different background magnetic fields, according to the experimental requirements, control the compensation current to adjust the background magnetic field so that the background magnetic field in the x, y, and z directions is within the range (0, B max ,0) changes twice; Step 25, reading the sensor array data to obtain the change in magnetic field components corresponding to different background magnetic fields under a fixed pressure; Step 26, determine whether the experimental goal has been achieved. If not, return to step 23, change the pressure and repeat steps 24 and 25. If it has been completed, close the pressurizing valve, open the pressure relief valve to release the pressure, open the drain valve after the pressure relief is completed, and close the drain valve after the drainage is completed. The experiment ends.

Images