A modeling and analysis method for giant magnetostrictive transducer considering the effects of temperature and loss

Through the multi-physical finite element modeling method, considering the influence of temperature and loss, a three-dimensional structure of the supermagnetized transducer was established, which solved the problem of failure to effectively consider the impact of temperature and loss in the prior art, and achieved accurate description and performance optimization of the supermagnetized transducer at different temperatures.

CN118332847BActive Publication Date: 2025-05-16HUNAN UNIV
View PDF 2 Cites 0 Cited by

Patent Information

Application Number
CN202410325058.7
Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2024-03-21
Publication Date
2025-05-16
Estimated Expiration
2044-03-21

AI Technical Summary

Technical Problem

The existing super magnetostrictive transducer modeling methods fail to effectively consider the influence of temperature and loss, resulting in a decrease in output performance and efficiency in high temperature environments, and it is difficult to accurately describe the electroacoustic characteristics under temperature changing conditions.

Method used

The multi-physical field finite element modeling method of electro-magnetic-machine-acoustic acoustic is adopted to establish a parameterized three-dimensional structure of supermagnetized transducer. Taking into account the influence of temperature field and loss, the frequency domain response at different temperatures is simulated through multi-physical field coupling calculation model, and the impedance and sound source level are calculated.

Benefits of technology

This method can accurately describe the output characteristics of super magnetostrictive transducers at different temperatures, guide the optimization design and the operation strategy regulation of optimal working performance, and improve the performance and efficiency of the transducer under different operating conditions.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN118332847B_ABST
    Figure CN118332847B_ABST
Patent Text Reader

Abstract

The present invention discloses a modeling and analysis method for a giant magnetostrictive transducer considering the influence of temperature and loss. First, an electro-magnetic-thermal simulation model of a giant magnetostrictive transducer is established, and the temperature field of the giant magnetostrictive transducer is analyzed to obtain the axial temperature distribution difference and temperature rise variation range of the giant magnetostrictive rod; then, for the main electromagnetic-mechanical model parameters [s], [d] and [μ] that affect the giant magnetostrictive transducer, complex parameters are introduced to characterize the three energy losses of the giant magnetostrictive transducer, and the temperature influence is taken into account by the function fitting method based on the experimental data of the temperature characteristics of the giant magnetostrictive material, and a frequency domain calculation model of the electroacoustic transducer is built to simulate the electroacoustic output characteristics of the transducer at different temperatures, so as to achieve accurate simulation of the impedance and sound source level curves at different temperatures, thereby guiding the optimization design of the electroacoustic transducer and the operation strategy regulation of the best working performance.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] The invention relates to the technical field of giant magnetostrictive transducer measurement, and in particular to a giant magnetostrictive transducer modeling and analysis method taking into account the influence of temperature and loss. Background Art

[0002] With the rise of new materials, giant magnetostrictive materials have gradually occupied the traditional piezoelectric material market with their excellent performance advantages such as large strain, high energy density and fast response speed. The giant magnetostrictive rod can be driven to vibrate reciprocatingly by a high-frequency periodic magnetic field. Based on this characteristic, it can be used to develop a giant magnetostrictive transducer. However, the giant magnetostrictive material is a ferromagnetic material. It will produce eddy current effect under the influence of the alternating magnetic field. Its eddy current loss will increase significantly with the increase of frequency, and it will generate serious heat after long-term operation. At the same time, many scholars have found through research that giant magnetostrictive materials are temperature sensitive. Small temperature changes will have a great impact on their performance parameters. Temperature disturbances will introduce nonlinear changes, and the study of transducer output characteristics will be more difficult. Domestic and foreign researchers often use equivalent circuit method and impedance analysis method to model the overall transducer and characterize the output characteristics of the system. The formula derivation of the equivalent circuit method is complex, and the parameter identification is difficult. It is easy to fall into the local optimal solution, and the parameters are difficult to be universal and for various working conditions; the impedance model established by the finite element method is more intuitive, and has rich three-dimensional information, with clear physical meaning, suitable for the analysis of the electroacoustic characteristics of transducers with complex structures. In the energy conversion process of the giant magnetostrictive transducer, there are magnetic energy losses, magneto-mechanical coupling losses and mechanical losses. However, the existing modeling methods based on the real number domain ignore the influence of losses and it is difficult to effectively predict the transducer impedance. In addition, the electroacoustic transducer is highly sealed, has few heat dissipation paths, and has a high internal temperature. The output performance of the giant magnetostrictive rod is highly sensitive to temperature. High temperature environment will seriously reduce the output performance and efficiency of the transducer. However, the existing modeling methods have not yet involved the influence of temperature and cannot accurately describe the output characteristics of the giant magnetostrictive transducer under variable temperature conditions. Therefore, constructing a giant magnetostrictive electroacoustic characteristic analysis method that considers the influence of temperature and loss is the key to effectively mastering the output characteristics of the electroacoustic transducer, and can guide the optimization design of the electroacoustic transducer and the operation strategy regulation of the best working performance. Summary of the invention

[0003] The purpose of the present invention is to provide an electroacoustic characteristic analysis method of a giant magnetostrictive transducer taking into account the influence of temperature and loss in view of the deficiencies in the prior art. Through finite element modeling calculation of the multi-physics field of electro-magnetic-mechanical-acoustic, the sound source level and impedance curves at different temperatures are obtained, thereby guiding the study of the output characteristics of the giant magnetostrictive transducer at different temperatures.

[0004] In order to achieve the purpose of the present invention, the technical solution adopted by the present invention is:

[0005] A modeling and analysis method for a giant magnetostrictive transducer considering the influence of temperature and loss comprises the following steps:

[0006] S1. Establish a parameterized three-dimensional structure of the giant magnetostrictive transducer and simplify the details, confirm the geometric size parameters of the giant magnetostrictive transducer, and define global variables: semi-major axis a, semi-minor axis b, shell thickness e, shell height c, giant magnetostrictive rod radius r1 and height h1;

[0007] S2. Establish an electromagnetic field calculation model based on the simplified three-dimensional structure of the giant magnetostrictive transducer;

[0008] Wherein: the driving coil is regarded as a uniform multi-turn, the number of turns N and the input current I are determined, and the currents of the two driving coils are defined as being in opposite directions, and a continuous magnetic circuit is formed through the magnetic silicon steel yoke;

[0009] At the same time, a sectional vibrator structure of rod-permanent magnet-rod is adopted to establish the piezomagnetic effect model of the giant magnetostrictive rod and define the main axis direction of magnetization.

[0010] Among them: the direction of the permanent magnet remanence is the same as the direction of the coil excitation magnetic field, which serves as the excitation source of the giant magnetostrictive rod bias magnetic field;

[0011] S3. Establish a temperature field calculation model based on the simplified three-dimensional structure of the giant magnetostrictive transducer, simulate the transient temperature rise of the giant magnetostrictive transducer as a whole based on the loss results, analyze the axial distribution of the giant magnetostrictive rod, and obtain the temperature rise range of the giant magnetostrictive transducer and the spatial distribution of the axial temperature;

[0012] Among them: the calculation of the electric-magnetic-thermal multi-physics field of the giant magnetostrictive transducer is involved, and the main losses of the giant magnetostrictive transducer are calculated, including the AC loss of the coil, the eddy current loss and hysteresis loss of the giant magnetostrictive rod;

[0013] S4. Build a temperature characteristics experimental test platform for giant magnetostrictive materials, obtain experimental test results based on the temperature characteristics of giant magnetostrictive materials, and fit the main material parameters that affect the output characteristics through the polynomial fitting method to minimize the error and function The temperature-dependent complex function of the giant magnetostrictive material is obtained, and the complex domain function is obtained to characterize the loss through parameter inversion;

[0014] S5. Based on the electromagnetic field calculation model established in S2, a magnetostrictive model of the giant magnetostrictive rod is constructed, the temperature-related complex function of the giant magnetostrictive material obtained in S4 is used as the matrix parameter of the magnetostrictive model, the magnetic-mechanical output characteristics of the giant magnetostrictive rod are obtained by iterative calculation of the linear piezomagnetic equation, and the mechanical output is used as the initial condition for the acoustic-solid coupling calculation;

[0015] S6. According to the electromagnetic-mechanical multi-physics field coupling calculation model of the giant magnetostrictive transducer three-dimensional model established in S5, the electroacoustic characteristic simulation model of the giant magnetostrictive transducer three-dimensional model is established in combination with the acoustic-solid coupling, the calculation variables of the external field sound pressure are defined, the medium domain of the sound field calculation is set, and a perfect matching layer (PML) is added as an infinite domain, and the infinite boundary condition is used as the sound absorption boundary to enhance the convergence and accuracy of the model iteration;

[0016] S7. Based on the temperature rise range of the giant magnetostrictive transducer and the spatial distribution of the axial temperature obtained in S3, the temperature range to be simulated is selected, the frequency domain response of the giant magnetostrictive transducer at different temperature points is simulated through the electroacoustic characteristic simulation model established in S6, the calculation results of the external field sound pressure are saved, and the sound source level is calculated according to the calculation results;

[0017] S8. Calculate the impedance and sound source level at different temperatures through AC impedance and external field sound pressure to obtain the corresponding curve.

[0018] Furthermore, the expression of the electromagnetic field calculation model in S2 is that the line integral of the magnetic field H of the closed path is equal to the algebraic sum of the currents passing through the area enclosed by the loop:

[0019] ∮H·dl=∑I k

[0020] After simplification, the magnetic field of the coil follows the expression:

[0021] Hl=NI

[0022] Where: H is the magnetic field strength provided by the coil, I is the coil current, N is the total number of turns of the coil, and l is the axial length of the coil;

[0023] The magnetic field distribution of the giant magnetostrictive rod satisfies Maxwell's equations:

[0024]

[0025] Where J, D, and B satisfy the following equation:

[0026] J = σE;

[0027] D = εE;

[0028] B=μH=μ0μ r H

[0029] Where: J is the current density of the giant magnetostrictive rod, D is the electric displacement, E is the electric field intensity, B is the magnetic induction intensity of the giant magnetostrictive rod, μ0 is the vacuum magnetic permeability, μ r is the relative magnetic permeability.

[0030] Furthermore, in S3, the temperature field calculation model established is as follows:

[0031]

[0032] Where: Q e is the electromagnetic loss, which is caused by the resistive loss and magnetic losses Composition. * is the conjugate complex number of the electric field strength, H * is the conjugate complex number of the external magnetic field, and ω is the angular frequency.

[0033] Furthermore, the principle of the method for obtaining the temperature-dependent complex function of the giant magnetostrictive material in S4 is as follows:

[0034] There are n groups of experimental data on the temperature characteristics of the main parameters of giant magnetostrictive materials, and the sample points used for fitting are as follows:

[0035] {(T1,s1,d1,μ1),(T2,s2,d2,μ2)…(T n ,s n ,d n ,μ n )}

[0036] In the parameter matrices [s], [d], and [μ], the sample point distribution of each element conforms to a quadratic polynomial:

[0037]

[0038] The sum of squared errors is used as the objective function:

[0039]

[0040] The minimum value of ∈ is obtained to obtain the best fitting coefficients a0, a1 and a2. The complex domain temperature correlation function of the giant magnetostrictive material is obtained by parameter inverse optimization as follows:

[0041]

[0042] Among them: a s0 is the constant fitting coefficient of the compliance coefficient, a s1 is the first-order fitting coefficient of the compliance coefficient, a s2 is the quadratic fitting coefficient of the compliance coefficient, a d0 is the constant fitting coefficient of the piezomagnetic coefficient, a d1 is the first-order fitting coefficient of the piezomagnetic coefficient, a d2 is the quadratic fitting coefficient of the piezomagnetic coefficient, a μ0 is the constant fitting coefficient of magnetic permeability, a μ1 is the first-order fitting coefficient of magnetic permeability, aμ2 is the fitting coefficient of the quadratic term of magnetic permeability.

[0043] Furthermore, the control equation of the magnetostrictive model of the giant magnetostrictive rod in S5 is as follows:

[0044] Among them, the real-domain linear expression of the piezomagnetic model of the giant magnetostrictive transducer is as follows:

[0045]

[0046] ε is strain, s H is the compliance coefficient under constant magnetic field, d is the piezomagnetic coefficient, μ σ is the magnetic permeability under constant stress.

[0047] In order to consider the influence of magnetic energy loss, magnetic-mechanical coupling loss and mechanical loss, the expression of complex parameters is introduced as follows:

[0048]

[0049] Where θ is the phase delay between stress σ and strain ε under a constant external magnetic field; is the phase delay between the magnetic field H and the strain ε or the stress σ and the magnetic induction intensity B;

[0050] Since the giant magnetostrictive rod is a columnar structure with a tetragonal symmetry, the compliance matrix contains 6 independent variables. The piezomagnetic matrix and the permeability matrix use the IEEE standard z-axis polarization direction to define the full parameter matrix form of the giant magnetostrictive rod, as follows:

[0051]

[0052] The variable relationship follows, s′ 66 =(s′ 11 +s′ 12 ) / 2, s″ 66 =(s″ 11 +s″ 12 ) / 2; where: s ij is the element of the compliance coefficient matrix, d ij Elements of the piezomagnetic coefficient matrix, μ ij is the element of the magnetic permeability matrix, ' represents the real part, and " represents the imaginary part.

[0053] Furthermore, the frequency domain expression of the acoustic-solid coupling model in S6 is:

[0054]

[0055] Among them, ρ represents the density of the sound transmission medium, q v represents the volume force of a domain, c represents the speed of sound, ω represents the angular frequency, Qm represents the contributing source causing the pressure change, p t is the total sound pressure, p b is the background sound pressure, p is the sound pressure, and the subscript c indicates that the material property is a complex value.

[0056] The acoustic boundary is regarded as a boundary condition where the normal component of the acceleration is zero, and the expression is as follows:

[0057]

[0058] The external field calculation formula calculates the pressure field at any distance outside the domain. The expression is as follows:

[0059]

[0060] in,

[0061] The sound source level of the giant magnetostrictive transducer is obtained through post-processing calculation. The calculation formula of the sound source level is as follows:

[0062]

[0063] The effective sound pressure p is the external sound pressure at 1m, p ref is the reference sound pressure, when p ref =20×10 -6 Pa, used in auditory measurements or measurements of sound levels and noise in the air; when p ref =10 -6 Pa, it is used in the calibration of underwater acoustic transducers and the measurement of sound pressure levels in liquids.

[0064] Compared with the prior art, the advantages of the present invention are:

[0065] The electroacoustic characteristics analysis method of the giant magnetostrictive transducer considering the influence of temperature and loss proposed in the present invention can be used to establish a finite element model for transducer systems of different complex structures. The model can consider the electroacoustic characteristics of the transducer under different temperatures and under the influence of losses, which is conducive to mastering the output characteristics of the electroacoustic transducer under different working conditions, and can guide the optimization design of the electroacoustic transducer and the regulation of the operating strategy for the best working performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 The overall flow chart of multi-physics field simulation modeling of the giant magnetostrictive transducer in the present invention;

[0067] Figure 2 It is a schematic diagram of the temperature distribution of the oscillator of the giant magnetostrictive transducer in the present invention;

[0068] Figure 3It is a schematic diagram of the main process of function fitting of main material parameters in the present invention;

[0069] Figure 4 The resistance curves of the giant magnetostrictive transducer simulated at different temperatures in the present invention;

[0070] Figure 5 The reactance curves of the giant magnetostrictive transducer simulated at different temperatures in the present invention;

[0071] Figure 6 The sound source level curves of the giant magnetostrictive transducer simulated at different temperatures in the present invention. DETAILED DESCRIPTION

[0072] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose, the modeling and analysis method of the giant magnetostrictive transducer considering the influence of temperature and loss proposed by the present invention is described in detail below in combination with the accompanying drawings and preferred examples:

[0073] Step 1: Parameterize and establish a three-dimensional model of the giant magnetostrictive transducer. Globally define variables: semi-major axis a, semi-minor axis b, shell thickness e, shell height c, giant magnetostrictive rod radius r1 height h1 and other main parameters. Ignore model details such as threaded holes, multi-turn coils and through holes to improve simulation efficiency.

[0074] The corresponding material properties and parameters are defined according to the physical fields required to be calculated for the giant magnetostrictive transducer.

[0075] Basic material properties for electromagnetic field calculations: relative permeability, relative permittivity, and electrical conductivity.

[0076] Basic material properties for temperature field calculations: thermal conductivity, heat capacity at constant pressure, and density.

[0077] Poisson's ratio and Young's modulus in solid mechanics calculations, as well as the full parameter matrix required for magnetostriction calculations of giant magnetostrictive materials.

[0078] The medium sound velocity and sound pressure required for sound field calculation.

[0079] Step 2: Establish an electromagnetic field calculation model for the three-dimensional model of the giant magnetostrictive transducer, set a uniform multi-turn drive coil to provide an excitation magnetic field, determine the number of turns N and the input current I, define the magnetic fields of the two drive coils as opposite directions, and the vibrator and the magnetic silicon steel yoke form a continuous magnetic circuit. Establish a piezomagnetic effect model for the giant magnetostrictive rod and define the magnetization direction. The direction of the permanent magnet remanence is in the same direction as the coil excitation magnetic field, providing a bias magnetic field for the giant magnetostrictive rod.

[0080] Step 3: Establish a temperature field calculation model for the three-dimensional model of the giant magnetostrictive transducer, which mainly involves the electric-magnetic-thermal multi-physics field coupling calculation of the giant magnetostrictive transducer. Based on the electromagnetic loss value of the giant magnetostrictive transducer calculated in step 2, simulate the transient temperature rise of the giant magnetostrictive transducer as a whole through time domain calculation, analyze the axial distribution law of the giant magnetostrictive rod, obtain the temperature rise range of the giant magnetostrictive rod and save the result.

[0081] Step 4: Build a temperature characteristic test platform for giant magnetostrictive materials to obtain temperature-related material performance data of giant magnetostrictive materials. Based on the function fitting method, the temperature-related variation law of material parameters is obtained, and the error and function are minimized. Solve to get the best fitting coefficient combination [a s0 ,a s1 ,a s2 ; a d0 ,a d1 ,a d2 ; a μ0 ,a μ1 ,a μ2 ], and the obtained fitting function is separated into real and imaginary parts by reverse optimization of parameters.

[0082] Step 5: Establish the electromagnetic-mechanical multi-physics coupling calculation model of the three-dimensional model of the giant magnetostrictive transducer, which mainly involves the multi-field calculation of the electro-magnetic-mechanical of the giant magnetostrictive transducer. First, based on the electromagnetic model of the giant magnetostrictive transducer in step 2, the magnetostrictive model of the giant magnetostrictive rod is established based on the piezomagnetic equation. Define the magnetization vibration direction of the giant magnetostrictive rod, define the compliance coefficient matrix [s], piezomagnetic coefficient matrix [d] and magnetic permeability matrix [μ] according to the magnetization direction, and substitute the complex domain function related to the temperature of the giant magnetostrictive material into the calculation.

[0083] Step 6: By combining the acoustic-solid coupling with the electromagnetic-mechanical multi-physics field coupling calculation model of step 5, a simulation model of the electroacoustic characteristics of the giant magnetostrictive transducer is established, the calculation variables of the external field sound pressure are defined, and the infinite boundary condition is set as the sound absorption boundary to enhance the convergence and accuracy of the model iteration.

[0084] Step 7: Based on the analysis of the temperature field calculation results in step 3, according to the temperature rise range of the giant magnetostrictive rod and the spatial distribution of the axial temperature, select the temperature range to be simulated, simulate the frequency domain response of the giant magnetostrictive transducer at different temperature points, and save the calculation results of the intermediate variables.

[0085] Step 8: Calculate the impedance and sound source level at different temperatures through AC impedance and external field sound pressure, and draw the response curve.

[0086] In step 2, the expression of the electromagnetic field calculation model is:

[0087] The line integral of the magnetic field H of a closed path is equal to the algebraic sum of the currents passing through the area enclosed by the loop: ∮H·dl=∑I k , after simplification, the magnetic field of the coil follows the expression: Hl=NI.

[0088] The magnetic field distribution of the giant magnetostrictive transducer satisfies Maxwell's equations:

[0089]

[0090] Where J, D, and B satisfy the following equations: J = σE, D = εE, and B = μH = μ0μ r H.

[0091] In step 3, the control equation for calculating the temperature field of the electromagnetic heat of the giant magnetostrictive transducer is as follows:

[0092] The unsteady heat conduction differential equation with heat source satisfies the following relationship:

[0093]

[0094] Q e is the electromagnetic loss, and the resistive loss Q r and magnetic energy loss Q m composition.

[0095] In step 4, the principle of the complex function fitting method of the temperature dependence of the giant magnetostrictive material of the main material parameters is as follows:

[0096] There are n sets of experimental data on the temperature characteristics of the main parameters of giant magnetostrictive materials, and the sample points used for fitting are as follows

[0097] {(T1,s1,d1,μ1),(T2,s2,d2,μ2)…(T n ,s n ,d n ,μ n )}

[0098] It can be observed that the distribution of sample points of each element in the material parameter matrices [s], [d], and [μ] roughly conforms to the quadratic polynomial

[0099]

[0100] The error sum of squares is used as the objective function

[0101]

[0102] The minimum value of ∈ is obtained to obtain the best fitting coefficients a0, a1 and a2. The complex domain temperature correlation function of the giant magnetostrictive material is obtained through parameter inverse optimization as follows.

[0103]

[0104] In step 5, the governing equation of the magnetostrictive model of the giant magnetostrictive rod is as follows:

[0105] Among them, the real-domain linear expression of the piezomagnetic model of the giant magnetostrictive transducer is as follows:

[0106]

[0107] In order to consider the influence of magnetic energy loss, magnetic-mechanical coupling loss and mechanical loss, the expression of complex parameters is introduced as follows:

[0108]

[0109] Where θ is the phase delay between stress σ and strain ε under a constant external magnetic field; It is the phase delay between the external magnetic field H and the strain ε or the stress σ and the magnetic induction intensity B.

[0110] Since the giant magnetostrictive rod is a columnar structure with a tetragonal symmetry, the compliance matrix contains 6 independent variables. The piezomagnetic matrix and the permeability matrix use the IEEE standard z-axis polarization direction to define the full parameter matrix form of the giant magnetostrictive rod, as follows:

[0111]

[0112] The variable relationship follows: s′ 66 =(s′ 11 +s′ 12 ) / 2, s″ 66 =(s″ 11 +s″ 12 ) / 2.

[0113] The governing equation in the frequency domain of the acoustic-solid coupling model is:

[0114]

[0115] Among them, ρ represents the density of the sound transmission medium, q v represents the volume force of a domain, c represents the speed of sound, ω represents the angular frequency, Q m represents the contributing source causing the pressure change, p t is the total sound pressure, p b is the background sound pressure, p is the sound pressure, and the subscript c indicates that the material property can be complex-valued.

[0116] The acoustic boundary is regarded as a boundary condition where the normal component of the acceleration is zero, and the expression is as follows:

[0117]

[0118] The external field calculation formula calculates the pressure field at any distance outside the domain. The expression is as follows:

[0119]

[0120] in,

[0121] The sound source level of the giant magnetostrictive transducer can be obtained by post-processing calculation using the following formula. The calculation formula for the sound source level is as follows:

[0122]

[0123] in, p ref is the reference sound pressure, when p ref =20×10 -6 Pa, used in auditory measurements or measurements of sound levels and noise in the air; when p ref =10 -6 Pa, it is used in the calibration of underwater acoustic transducers and the measurement of sound pressure levels in liquids.

[0124] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any technician familiar with the profession, without departing from the scope of the technical solution of the present invention, makes any simple modifications, equivalent changes and modifications to the above embodiments based on the technical essence of the present invention, which still fall within the scope of the technical solution of the present invention.

Claims

1. A modeling and analysis method for a giant magnetostrictive transducer considering the influence of temperature and loss, characterized in that: The following steps are involved: S1. Establish a parameterized three-dimensional structure of the giant magnetostrictive transducer and simplify the details, confirm the geometric size parameters of the giant magnetostrictive transducer, and define global variables: semi-major axis a, semi-minor axis b, shell thickness e, shell height c, giant magnetostrictive rod radius r1 and height h1; S2. Establish an electromagnetic field calculation model based on the simplified three-dimensional structure of the giant magnetostrictive transducer; Wherein: the driving coil is regarded as a uniform multi-turn, the number of turns N and the input current I are determined, and the currents of the two driving coils are defined as being in opposite directions, and a continuous magnetic circuit is formed through the magnetic silicon steel yoke; At the same time, a sectional vibrator structure of rod-permanent magnet-rod is adopted to establish the piezomagnetic effect model of the giant magnetostrictive rod and define the main axis direction of magnetization. Among them: the direction of the permanent magnet remanence is the same as the direction of the coil excitation magnetic field, which serves as the excitation source of the giant magnetostrictive rod bias magnetic field; S3. Establish a temperature field calculation model based on the simplified three-dimensional structure of the giant magnetostrictive transducer, simulate the transient temperature rise of the giant magnetostrictive transducer as a whole based on the loss results, analyze the axial distribution of the giant magnetostrictive rod, and obtain the temperature rise range of the giant magnetostrictive transducer and the spatial distribution of the axial temperature; Among them: the calculation of the electric-magnetic-thermal multi-physics field of the giant magnetostrictive transducer is involved, and the main losses of the giant magnetostrictive transducer are calculated, including the AC loss of the coil, the eddy current loss and hysteresis loss of the giant magnetostrictive rod; S4. Build a temperature characteristics experimental test platform for giant magnetostrictive materials, obtain experimental test results based on the temperature characteristics of giant magnetostrictive materials, and fit the main material parameters that affect the output characteristics through the polynomial fitting method to minimize the error and function The temperature-dependent complex function of the giant magnetostrictive material is obtained, and the imaginary part representing the loss is obtained by parameter inversion; S5. Based on the electromagnetic field calculation model established in S2, a magnetostrictive model of the giant magnetostrictive rod is constructed, the temperature-related complex function of the giant magnetostrictive material obtained in S4 is used as the matrix parameter of the magnetostrictive model, the magnetic-mechanical output characteristics of the giant magnetostrictive rod are obtained by iterative calculation of the linear piezomagnetic equation, and the mechanical output is used as the initial condition for the acoustic-solid coupling calculation; S6. According to the electromagnetic-mechanical multi-physics field coupling calculation model of the giant magnetostrictive transducer three-dimensional model established in S5, the electroacoustic characteristic simulation model of the giant magnetostrictive transducer three-dimensional model is established in combination with the acoustic-solid coupling, the calculation variables of the external field sound pressure are defined, the medium domain of the sound field calculation is set, and the perfect matching layer (PML) is added as the infinite domain, and the infinite boundary condition is used as the sound absorption boundary to enhance the convergence and accuracy of the model iteration; S7. Based on the temperature rise range of the giant magnetostrictive transducer and the spatial distribution of the axial temperature obtained in S3, the temperature range to be simulated is selected, the frequency domain response of the giant magnetostrictive transducer at different temperature points is simulated through the electroacoustic characteristic simulation model established in S6, the calculation results of the external field sound pressure are saved, and the sound source level is calculated according to the calculation results; S8. Calculate the impedance and sound source level at different temperatures through AC impedance and external field sound pressure to obtain the corresponding curve.

2. The giant magnetostrictive transducer modeling and analysis method considering the influence of temperature and loss as claimed in claim 1, characterized in that: The expression of the electromagnetic field calculation model in S2 is that the line integral of the magnetic field H of the closed path is equal to the algebraic sum of the currents passing through the area enclosed by the loop: ∮H·dl=∑I k After simplification, the excitation magnetic field generated by the coil follows the expression: Hl=NI Where: H is the magnetic field strength provided by the coil, I is the coil current, N is the total number of turns of the coil, and l is the axial length of the coil; The magnetic field distribution of the giant magnetostrictive rod satisfies Maxwell's equations: Where J, D, and B satisfy the following equation: J = σE; D = εE; B=μH=μ0μ r H Where: J is the current density of the giant magnetostrictive rod, D is the electric displacement, E is the electric field intensity, B is the magnetic induction intensity of the giant magnetostrictive rod, μ0 is the vacuum magnetic permeability, μ r is the relative magnetic permeability.

3. The giant magnetostrictive transducer modeling and analysis method considering the influence of temperature and loss as claimed in claim 1, characterized in that: In S3, the temperature field calculation model established is as follows: Where: Q e is the electromagnetic loss, which is caused by the resistive loss and magnetic losses Composition, E * is the conjugate complex number of the electric field strength, H * is the conjugate complex number of the external magnetic field, and ω is the angular frequency.

4. The giant magnetostrictive transducer modeling and analysis method considering the influence of temperature and loss as claimed in claim 1, characterized in that: The method principle of obtaining the temperature-dependent complex function of the giant magnetostrictive material in S4 is as follows: There are n groups of experimental data on the temperature characteristics of the main parameters of giant magnetostrictive materials, and the sample points used for fitting are as follows: {(T1,s1,d1,μ1),(T2,s2,d2,μ2)…(T n ,s n ,d n ,μ n )} In the parameter matrices [s], [d], and [μ], the sample point distribution of each element conforms to a quadratic polynomial: The sum of squared errors is used as the objective function: The minimum value of ∈ is obtained to obtain the best fitting coefficients a0, a1 and a2. The complex domain temperature correlation function of the giant magnetostrictive material is obtained by parameter inverse optimization as follows: Among them: a s0 is the constant fitting coefficient of the compliance coefficient, a s1 is the first-order fitting coefficient of the compliance coefficient, a s2 is the quadratic fitting coefficient of the compliance coefficient, a d0 is the constant fitting coefficient of the piezomagnetic coefficient, a d1 is the first-order fitting coefficient of the piezomagnetic coefficient, a d2 is the quadratic fitting coefficient of the piezomagnetic coefficient, a μ0 is the constant fitting coefficient of magnetic permeability, a μ1 is the first-order fitting coefficient of magnetic permeability, a μ2 is the fitting coefficient of the quadratic term of magnetic permeability.

5. The giant magnetostrictive transducer modeling and analysis method considering the influence of temperature and loss as claimed in claim 1, characterized in that: The governing equation of the magnetostrictive model of the giant magnetostrictive rod in S5 is as follows: Among them, the real-domain linear expression of the piezomagnetic model of the giant magnetostrictive transducer is as follows: ε is strain, s H is the compliance coefficient under constant magnetic field, d is the piezomagnetic coefficient, μ σ is the magnetic permeability under constant stress; In order to consider the influence of magnetic energy loss, magnetic-mechanical coupling loss and mechanical loss, the expression of complex parameters is introduced as follows: Where θ is the phase delay between stress σ and strain ε under a constant external magnetic field; is the phase delay between the magnetic field H and the strain ε or the stress σ and the magnetic induction intensity B; Since the giant magnetostrictive rod is a columnar structure with a tetragonal symmetry, the compliance matrix contains 6 independent variables. The piezomagnetic coefficient and permeability matrix both use the z-axis polarization direction form of the IEEE standard to define the full parameter matrix form of the giant magnetostrictive rod, as follows: The variable relationship follows, s′ 66 =(s′ 11 +s′ 12 ) / 2, s″ 66 =(s″ 11 +s″ 12 ) / 2; Where: s ij is the element of the compliance coefficient matrix, d ij Elements of the piezomagnetic coefficient matrix, μ ij is the element of the magnetic permeability matrix, ' represents the real part, and " represents the imaginary part.

6. The giant magnetostrictive transducer modeling and analysis method considering the influence of temperature and loss as claimed in claim 1, characterized in that: The frequency domain expression of the acoustic-solid coupling model in S6 is: Among them, ρ represents the density of the sound transmission medium, q v represents the volume force of a domain, c represents the speed of sound, ω represents the angular frequency, Q m represents the contributing source causing the pressure change, p t is the total sound pressure, p b is the background sound pressure, p is the sound pressure, and the subscript c indicates that the material property is a complex value; The acoustic boundary is regarded as a boundary condition where the normal component of the acceleration is zero, and the expression is as follows: The external field calculation formula calculates the pressure field at any distance outside the domain. The expression is as follows: in, The sound source level of the giant magnetostrictive transducer is obtained through post-processing calculation. The calculation formula of the sound source level is as follows: The effective sound pressure p is the external sound pressure at 1m, p ref is the reference sound pressure, when p ref =20×10 -6 Pa, used in auditory measurements or measurements of sound levels and noise in the air; when p ref =10 -6 Pa, it is used in the calibration of underwater acoustic transducers and the measurement of sound pressure levels in liquids.

Citation Information

Patent Citations

  • Method and system for identifying electromagnetic-mechanical coupling parameters of giant magnetostrictive transducer

    CN116822350A

  • Transducer dynamic characteristic rapid analysis optimization method and system based on deep learning

    CN117709162A