Design method of stress sensing detection device based on high-throughput micromagnetic simulation screening

Abstract

The present invention discloses a stress sensing detection device design method based on high-throughput micromagnetic simulation screening, including: obtaining magnetic parameters of different magnetostrictive materials, designing a reasonable multi-component magnetostrictive material device model for the drawbacks of eddy current loss and component damage that may occur during stress sensing detection; writing a corresponding high-throughput micromagnetic simulation program, calculating and analyzing the magnetization intensity response of different materials under stress drive, and screening out the composition range of excellent piezomagnetic materials; selecting excellent piezomagnetic materials as magnetoelastic elements, constructing a stress sensing detection device, clarifying the response relationship of magnetization intensity in the device with stress changes, and further optimizing the response capability under low stress fields; reasonably designing the magnetic circuit and using Hall elements or coils to obtain the changes in the magnetic field near the magnetoelastic element under stress, and realizing stress sensing detection. The present invention has broad application prospects in medical detection, wall crack monitoring, rock formation and mine pressure warning, etc.

Description

Technical Field

[0001] The invention relates to the field of high-performance magnetostrictive material screening and stress sensor device design, and in particular to a stress sensor detection device design method based on high-throughput micromagnetic simulation screening. Background Art

[0002] With the continuous advancement of science and technology and the rapid development of society, the demand for stress sensing detection is also increasing day by day. High-performance stress sensing detection devices are required in human health detection, industrial electronic weighing, landslide and earthquake monitoring, mine collapse warning and other aspects. However, traditional piezoresistive stress sensors have the disadvantages of complex structure, short service life, poor accuracy and stability, and are usually active detection, which limits their application scope. The stress sensing detection device based on the piezomagnetic effect of magnetostrictive materials has the advantages of simple structure, high sensitivity and good stability, and is expected to become an ideal candidate device for stress sensing detection. Since the stress signal can directly modulate the magnetization intensity of the piezomagnetic material, this type of device has the characteristics of passive probe and can realize passive detection. At the same time, the magnetic field signal emitted is harmless to the human body and has good penetration ability, which can be used in medical detection, wall crack monitoring, rock formation and mine pressure warning and other aspects.

[0003] It is obvious that the magnetization intensity response ability of piezomagnetic materials with different compositions under external stress is very different. However, due to the lack of corresponding experimental data on the piezomagnetic effect, we cannot yet grasp the evolution law of the piezomagnetic properties of materials with composition. If the traditional phenomenological method based on the linear coupling piezomagnetic model is used to analyze the piezomagnetic properties of materials, it cannot effectively reflect the multi-field coupling phenomenon of materials under stress, and it is inevitable that the piezomagnetic effect of materials cannot be accurately characterized. If the traditional experimental trial and error method is used for material screening, a long R&D cycle and high R&D cost are required. If the first-principles calculation method is used to predict the correlation between material composition and piezomagnetic properties, it not only takes a lot of time and computing resources, but also often has great difficulties when calculating multi-component or polycrystalline materials, which is obviously not conducive to quickly optimizing the composition range of ideal piezomagnetic materials. Micromagnetic simulation can effectively deal with complex multi-body problems through quasi-classical numerical calculation methods, and can simulate the changes in magnetization intensity under multi-field coupling such as magnetic field and stress field, providing an important solution for calculating the piezomagnetic properties of materials. However, this method can only simulate materials of a single component point each time, and cannot quickly calculate the piezomagnetic properties of multi-component magnetostrictive materials. Summary of the invention

[0004] Purpose of the invention: In view of the shortcomings of the prior art mentioned above, the present invention proposes a design method for a stress sensing detection device based on high-throughput micromagnetic simulation screening. The present invention can quickly and accurately predict the details of the magnetization intensity response of multi-component magnetostrictive materials under stress, which helps to screen out the composition range of magnetostrictive materials with excellent piezomagnetic properties, thereby filling the gap in the prediction method of multi-component piezomagnetic materials; the piezomagnetic stress sensing detection device designed by the present invention has the advantages of high sensitivity, good environmental stability, and passive probe; at the same time, the magnetic signal induced by stress is harmless to the human body and has good penetration ability.

[0005] The technical solution adopted by the present invention is a stress sensing detection device design method based on high-throughput micromagnetic simulation screening, comprising the following steps:

[0006] Step 1: Obtain the magnetic parameters of multi-component magnetostrictive materials, including magnetostriction coefficient, magnetocrystalline anisotropy constant and exchange stiffness coefficient, and design a reasonable device configuration for different application scenarios in stress sensing detection;

[0007] Step 2: Construct a high-throughput micromagnetic simulation program for predicting the piezomagnetic effect of multi-component magnetostrictive materials, calculate and analyze the changes in the magnetization intensity of magnetostrictive materials with different components under stress, and thus select the most ideal piezomagnetic material composition range;

[0008] Step 3: Based on the screening results of step 2, select one of the material components with excellent piezomagnetic properties, analyze the response relationship between magnetization intensity and stress and the device sensitivity, and start designing the stress sensing detection device.

[0009] Furthermore, the step 1 is specifically divided into the following steps:

[0010] Step 1-1: Obtain magnetic parameters of a multi-component magnetostrictive material, such as a saturation magnetostriction coefficient, a magnetocrystalline anisotropy constant, and an exchange stiffness coefficient;

[0011] Step 1-2: Pre-set possible drawbacks during stress sensing testing: When the stress on the material changes, the changing magnetization intensity will often induce eddy currents on the material surface, leading to problems such as excessive temperature; when the impact stress detected is large, the piezomagnetic material may break;

[0012] Step 1-3: Designing a polycrystalline model to reduce the error loss caused by the situation described in step 1-2; in the model, each grain is bonded together by means of a non-magnetic insulating adhesive; the non-magnetic insulating adhesive can effectively reduce the eddy current loss generated when the magnetization intensity of the material changes, and can also improve the mechanical properties of the material against fracture;

[0013] Step 1-4: Use the Voronoi partitioning method to construct a polycrystalline model, and simulate the effect of the non-magnetic insulating adhesive between the grains by reducing the magnetic exchange coupling strength between the grains.

[0014] Furthermore, the step 2 is specifically divided into the following steps:

[0015] Step 2-1: By writing an additional stress-induced uniaxial magnetocrystalline anisotropy energy, the change of the internal energy of the material under the action of uniaxial stress is simulated, and the Landau-Lifshitz-Gibert (LLG) equation is further solved to calculate the response relationship of the material magnetization intensity to the stress change, and a feasible model that can simulate the piezomagnetic effect is obtained;

[0016] Step 2-2: Design and develop a high-throughput micromagnetic simulation program to enable the computer to generate a large number of running scripts in parallel according to the selected material composition range and stress application range, and perform 10 2 Concurrent automatic micromagnetic calculations of the order of magnitude, with fully automatic image rendering and data processing;

[0017] Step 2-3: Use the high-throughput micromagnetic simulation program designed in step 2-2 to simulate the response relationship between the magnetization intensity of the multi-component magnetostrictive material and the stress change in step 1-1, and finally screen out the composition range of the magnetostrictive material with excellent piezomagnetic properties.

[0018] Furthermore, the step 3 is specifically divided into the following steps:

[0019] Step 3-1: Based on the high-throughput screening results of step 2-3, select excellent piezomagnetic materials as magnetoelastic elements, further fit the response relationship between its magnetization intensity and stress, and determine the stress required when the element has the maximum sensitivity. Then, in the process of material preparation, high-pressure annealing, thermal interface control and other technologies are used to apply corresponding prestress, which can further improve the response ability of magnetoelastic elements under low stress fields;

[0020] Step 3-2: Design a stress detection device: Place the magnetoelastic element on the device base, and set up two semi-arc magnetic blocks of the same shape and material composition as the magnetoelastic element on both sides thereof, wherein there is a certain air gap between the semi-arc magnetic blocks and the magnetoelastic element; place a small permanent magnet on each side of the semi-arc magnetic blocks to provide a horizontal bias magnetic field parallel to the surface of the magnetoelastic element so that the magnetization intensity of the magnetoelastic element tends to saturation along the external field direction; connect the permanent magnets through magnetic steel to form a closed magnetic circuit, thereby reducing magnetic leakage.

[0021] Step 3-3: Place the Hall element on the side of the magnetoelastic element so that it can more accurately sense the magnitude of the magnetic field around the magnetoelastic element under different stresses and convert the stress magnitude into a corresponding voltage value;

[0022] Step 3-4: Use an operational amplifier and an analog-to-digital converter to convert the Hall voltage value obtained in step 3-3 into a corresponding digital signal (original code); use standard stress to perform multiple measurements and calibrate the original code value under different stresses;

[0023] Step 3-5: Integrate the prefabricated single-chip microcomputer and display into a reading device, and decode and display the original code value under the standard stress in step 3-4. By comparing the measured value with the standard value, the stress detection device is further calibrated to achieve accurate stress measurement.

[0024] Furthermore, the Hall element in step 3-3 is replaced with an induction coil, and an operational amplifier and a light-emitting diode are connected in sequence. The light-emitting diode can be used to determine whether the stress changes at this time, thereby realizing stress sensing and early warning. The device is a stress sensing detector.

[0025] Beneficial effects of the present invention:

[0026] 1. The present invention provides a new method for simulating the piezomagnetic effect of giant magnetostrictive materials based on the microscopic intrinsic mechanism of stress modulation on magnetic domains.

[0027] 2. The present invention can rapidly and accurately predict the magnetization intensity response of multi-component magnetostrictive materials under stress, and can screen out the composition range of magnetostrictive materials with excellent piezomagnetic properties, thus filling the gap in the prediction method of multi-component piezomagnetic materials.

[0028] 3. The piezomagnetic stress sensing device designed by the present invention has the advantages of high sensitivity, good environmental stability, and passive probe. At the same time, the magnetic signal induced by stress is harmless to the human body and has good penetrating ability. It has broad application prospects in medical detection, wall crack monitoring, rock formation and mine pressure warning, etc.

[0029] In the embodiment of the present invention, the changes in the magnetization intensity of various Tb-Dy-Fe samples with different compositions under external stress were calculated by high-throughput micromagnetic simulation, and it was predicted that when the Tb composition ranged from 0.26 to 0.32 and the Fe composition ranged from 1.93 to 1.97, the Tb x Dy 1-x Fe y The alloy exhibits excellent piezomagnetic response under stress of 0-200MPa. 0.26 Dy 0.74 Fe 1.97 The magnetoelastic element is subjected to a prestress of 100 MPa, which enables it to have a sensitivity of up to 11.87 mT / MPa at a relatively low pressure, showing excellent device response performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The high-throughput micromagnetic simulation screening results in the embodiments of the present invention;

[0031] Figure 2 and Figure 3 The material composition selected in the embodiment of the present invention is Tb 0.26 Dy 0.74 Fe 1.97 , simulation results with internal stress of 100MPa;

[0032] Figure 4 Schematic diagram of a stress detection device in an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of a stress sensing detector in an embodiment of the present invention;

[0034] The numbers in the figure are as follows: 1. magnetoelastic element; 2. base; 3 and 4. semi-arc magnetic blocks; 5 and 6. permanent magnets; 7. magnetic steel; 8. Hall element; 9. reading device; 10. induction coil; 11. amplifier circuit; 12. light-emitting diode. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0036] In this embodiment, the method is specifically used to accurately and quickly predict the piezomagnetic properties of Tb-Dy-Fe-based rare earth giant magnetostrictive materials and design a stress detector with excellent response capability. The specific operation steps are as follows:

[0037] Step 1: Obtain the magnetic parameters of multi-component Tb-Dy-Fe-based rare earth giant magnetostrictive materials, such as magnetostriction coefficient, magnetocrystalline anisotropy constant and exchange stiffness coefficient, and design a reasonable device configuration for different application scenarios in stress sensing detection; specifically including:

[0038] Step 1-1: Obtaining magnetic parameters of a multi-component Tb-Dy-Fe-based rare earth giant magnetostrictive material, such as magnetostriction coefficient, magnetocrystalline anisotropy constant and exchange stiffness coefficient;

[0039] Step 1-2: Pre-set the possible drawbacks in stress sensing detection. For example, 1. When the stress on the material changes, the changing magnetization intensity will often induce eddy currents on the surface of the material, leading to problems such as overheating; 2. When the impact stress detected is large, the piezomagnetic material may break;

[0040] Step 1-3: Design a polycrystalline model to reduce the error loss caused by the situation described in step 1-2. In the model, each grain is bonded together with the help of a non-magnetic insulating adhesive. The non-magnetic insulating adhesive can effectively reduce the eddy current loss generated by the material when the magnetization intensity changes, and can also improve the mechanical properties of the material to resist fracture;

[0041] Step 1-4: Use the Voronoi partitioning method to construct a polycrystalline model, and simulate the effect of the non-magnetic insulating adhesive between the grains by reducing the magnetic exchange coupling strength between the grains.

[0042] Step 2: Construct a high-throughput micromagnetic simulation program for predicting the piezomagnetic effect of multi-component magnetostrictive materials, calculate and analyze the changes in the magnetization intensity of Tb-Dy-Fe magnetostrictive materials with different compositions under stress, and thus select the most ideal Tb-Dy-Fe material composition range; specifically, it includes:

[0043] Step 2-1: By writing an additional stress-induced uniaxial magnetocrystalline anisotropy energy, the change of the internal energy of the material under the action of uniaxial stress is simulated, and the Landau-Lifshitz-Gibert (LLG) equation is further solved to calculate the response relationship of the material magnetization intensity to the stress change, and a feasible model that can simulate the piezomagnetic effect is obtained;

[0044] Step 2-2: Design and develop a high-throughput micromagnetic simulation program to enable the computer to generate a large number of running scripts in parallel according to the selected material composition range and stress application range, and perform 10 2 Concurrent automatic micromagnetic calculations of the order of magnitude, with fully automatic image rendering and data processing;

[0045] Step 2-3: Use the high-throughput micromagnetic simulation program designed in step 2-2 to simulate the magnetization intensity response of the multi-component Tb-Dy-Fe magnetostrictive material under stress in step 1-1, and finally screen out the material composition range with excellent piezomagnetic properties. Figure 1 The high-throughput micromagnetic simulation results of the embodiment, Δ x It is defined as the magnitude of the stress-driven magnetization change, written as

[0046] Δ x =m x|-500MPa -m x|500MPa

[0047] Where m x|-500MPa It represents the magnetization intensity in the x direction of the material under 500MPa compressive stress, m x|500MPa It represents the magnetization intensity in the x direction of the material under the tensile stress of 500MPa.

[0048] Step 3: Based on the screening results of step 2, select one of the Tb-Dy-Fe material components with excellent piezomagnetic properties, analyze the response relationship between magnetization intensity and stress and the device sensitivity, and carry out the design of stress sensing detection devices. Specifically include:

[0049] Step 3-1: Based on the high-throughput screening results of step 2-3, select excellent piezomagnetic materials as magnetoelastic elements, further fit the response relationship between its magnetization intensity and stress, and determine the stress required when the element sensitivity is maximum. Then, in the material preparation process, high-pressure annealing, thermal interface control and other technologies are used to apply corresponding prestress, which can further improve the response ability of magnetoelastic elements under low stress fields. Figure 2 and 3 The material composition selected in the embodiment of the present invention is Tb 0.26 Dy 0.74 Fe 1.97 , simulation results with internal stress of 100MPa;

[0050] Step 3-2: Design a stress detection device: Tb 0.26 Dy 0.74 Fe 1.97 The magnetoelastic element 1 is placed on the device base 2, and two semi-arc magnetic blocks 3 and 4 of the same shape and the same material composition as the magnetoelastic element are set on both sides thereof, wherein there is a certain air gap between the magnetic blocks and the magnetoelastic element; a small permanent magnet 5 and 6 are respectively placed on the other side of the semi-arc magnetic blocks 3 and 4 to provide a horizontal bias magnetic field (with a magnitude between 0.04 and 0.07 T) parallel to the surface of the magnetoelastic element, so that the magnetization intensity of the magnetoelastic element tends to saturation along the external field direction; the permanent magnets 5 and 6 are connected by a magnetic steel 7 to form a closed magnetic circuit, thereby reducing magnetic leakage;

[0051] Step 3-3: Place the Hall element 8 on the side of the magnetoelastic element and parallel to the direction of the bias magnetic field, so that it can more accurately sense the magnitude of the magnetic field around the magnetoelastic element under different stresses and convert the stress magnitude into a corresponding voltage value;

[0052] Step 3-4: Use an operational amplifier and an analog-to-digital converter to convert the Hall voltage value obtained in step 3-3 into a corresponding digital signal (original code); use standard stress to perform multiple measurements and calibrate the original code value under different stresses;

[0053] Step 3-5: Integrate the prefabricated single-chip microcomputer and display into a reading device 9, and decode and display the original code value under the standard stress in step 3-4. By comparing the measured value with the standard value, the stress detection device is further calibrated to achieve accurate stress measurement. Figure 4 As shown;

[0054] Step 3-6: If the Hall element 8 in 3-3 is replaced with an induction coil 10, and the operational amplifier 11 and the light-emitting diode 12 are connected in sequence, the light-emitting diode can be used to determine whether the stress changes at this time, thereby realizing stress sensing and early warning. Figure 5 shown.

[0055] It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A stress sensing detection device design method based on high-throughput micromagnetic simulation screening, characterized in that: The following steps are involved: Step 1: Obtain the magnetic parameters of multi-component magnetostrictive materials, including magnetostriction coefficient, magnetocrystalline anisotropy constant and exchange stiffness coefficient, and design a reasonable device configuration for different application scenarios in stress sensing detection; Step 2: Construct a high-throughput micromagnetic simulation program for predicting the piezomagnetic effect of multi-component magnetostrictive materials, calculate and analyze the changes in the magnetization intensity of magnetostrictive materials with different components under stress, and thus select the most ideal piezomagnetic material composition range; Step 3: Based on the screening results of step 2, select one of the material components with excellent piezomagnetic properties, analyze the response relationship between magnetization intensity and stress and the device sensitivity, and carry out the design of stress sensing detection devices; In the step 1, it is specifically divided into the following steps: Step 1-1: Obtaining magnetic parameters of a multi-component magnetostrictive material, including a saturation magnetostriction coefficient, a magnetocrystalline anisotropy constant, and an exchange stiffness coefficient; Step 1-2: Pre-set possible drawbacks during stress sensing testing: When the stress on the material changes, the changing magnetization intensity will often induce eddy currents on the material surface, leading to overheating problems; when the impact stress detected is large, the piezomagnetic material may break; Step 1-3: Designing a polycrystalline model to reduce the error loss caused by the situation described in step 1-2; in the model, each grain is bonded together by a non-magnetic insulating adhesive; Step 1-4: Use the Voronoi partitioning method to construct a polycrystalline model, and simulate the effect of the non-magnetic insulating adhesive between the grains by reducing the magnetic exchange coupling strength between the grains; In step 2, the specific steps are as follows: Step 2-1: By writing an additional stress-induced uniaxial magnetocrystalline anisotropy energy, the change of the internal energy of the material under the action of uniaxial stress is simulated, and the LLG equation is further solved to calculate the response relationship of the material magnetization intensity to the stress change, so as to obtain a feasible model that can simulate the piezomagnetic effect; Step 2-2: Design and develop a high-throughput micromagnetic simulation program to enable the computer to generate a large number of running scripts in parallel according to the selected material composition range and stress application range, and perform 10 2 Concurrent automatic micromagnetic calculations of the order of magnitude, with fully automatic image rendering and data processing; Step 2-3: Use the high-throughput micromagnetic simulation program designed in step 2-2 to simulate the response relationship between the magnetization intensity of the multi-component magnetostrictive material and the stress change in step 1-1, and finally screen out the composition range of the magnetostrictive material with excellent piezomagnetic properties; In step 3, the specific steps are as follows: Step 3-1: Based on the high-throughput screening results of step 2-3, select excellent piezomagnetic materials as magnetoelastic elements, further fit the response relationship between its magnetization intensity and stress, and determine the stress required when the element sensitivity is maximum; and then use high-pressure annealing and thermal interface control technology to apply corresponding prestress during the material preparation process, which can further improve the response ability of the magnetoelastic element under low stress field; Step 3-2: Design a stress detection device: Place the magnetoelastic element on the device base, and set up two semi-arc magnetic blocks of the same shape and material composition as the magnetoelastic element on both sides, wherein there is a certain air gap between the semi-arc magnetic blocks and the magnetoelastic element; place a small permanent magnet on each side of the semi-arc magnetic blocks to provide a horizontal bias magnetic field parallel to the surface of the magnetoelastic element, so that the magnetization intensity of the magnetoelastic element tends to saturation along the external field direction; connect the permanent magnets through magnetic steel to form a closed magnetic circuit, thereby reducing magnetic leakage; Step 3-3: Place the Hall element on the side of the magnetoelastic element so that it can more accurately sense the magnitude of the magnetic field around the magnetoelastic element under different stresses and convert the stress magnitude into a corresponding voltage value; Step 3-4: Use an operational amplifier and an analog-to-digital converter to convert the Hall voltage value obtained in step 3-3 into a corresponding digital signal; use standard stress to perform multiple measurements and calibrate the original code value under different stresses; Step 3-5: Integrate the prefabricated single-chip microcomputer and display into a reading device, decode and display the original code value under the standard stress in step 3-4; by comparing the measured value with the standard value, further calibrate the stress detection device to achieve accurate stress measurement.

2. The method for designing a stress sensing detection device based on high-throughput micromagnetic simulation screening according to claim 1, characterized in that: By replacing the Hall element in step 3-3 with an induction coil, and connecting an operational amplifier and a light-emitting diode in sequence, it is possible to determine whether the stress changes at this time by the on and off of the light-emitting diode, thereby realizing stress sensing and early warning. This device is a stress sensing detector.

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