Calculation method of contact magnetoelectric coupling variables of piezoelectric substrates containing piezomagnetic particles

Abstract

This invention discloses a method for calculating the contact magnetoelectric coupling variables of a piezoelectric matrix containing piezoelectric magnetic particles. This method, which pertains to the field of novel contact applications for magnetoelectric functional devices, includes a general model for achieving the functional properties of MEE composite materials through contact loading. Using a contact model of a MEE composite material containing piezoelectric magnetic particles in a piezoelectric matrix as an example, the method employs finite element numerical simulation based on the constitutive models of the piezomagnetic and piezoelectric phases and multi-physics field coupling theory to systematically reveal the mechanism by which the magnetoelectric coupling variables are controlled by force loading.

Description

Technical Field

[0001] The present invention belongs to the field of contact applications of novel magnetoelectric functional devices, and in particular relates to a method for calculating magnetoelectric coupling variables of a piezoelectric substrate containing piezoelectric magnetic particles. Background Art

[0002] Piezoelectric-piezomagnetic (MEE) multiferroic composites have broad application prospects in realizing large-capacity disk storage, nanogenerators, contact-type magnetoelectric sensors and other fields. All of the above applications are realized through contact. Therefore, it is urgent to develop a computational model that is suitable for solving how MEE composites adjust magnetoelectric coupling variables under contact, or a computational model for the change law of magnetoelectric coupling variables during the contact process of MEE composites.

[0003] Existing contact models for piezoelectric-piezomagnetic multiferroic composites often ignore the microstructure of MEE composites. However, in fact, the contact performance of MEE composites is closely related to their microstructure. Therefore, existing models are limited to solving the macroscopic manifestation of magneto-electro-elastic properties during the contact process of MEE composites, but lack research on the intrinsic mechanism of how MEE materials regulate the conversion of force-magnetism-electricity through contact.

[0004] Patent CN118228550A proposes a method for calculating the magnetoelectric coefficients of multilayer nonlinear magnetostrictive-piezoelectric composite materials. This method of calculating the magnetoelectric conversion coefficients directly by magnetically driving MEE materials is more inclined to applications in the fields of magnetoelectric sensors, magnetoelectric energy storage devices, electromagnetic antennas, etc.; although the article states that its results are applicable to the MEE composite material contact model, it is obviously more reasonable to directly establish the MEE composite material contact model to solve the magnetoelectric coupling variables. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a method for calculating the contact magnetoelectric coupling variables of a piezoelectric matrix containing piezomagnetic particles, comprising:

[0006] The actual contact situation of the composite material is simplified to the contact model between the rigid indenter and the half-space MEE composite material;

[0007] Based on the MEE composite material contact model, a force-magnetic coupling constitutive model is established, and the magnetic and mechanical physical quantities in the piezomagnetic contact process are solved according to the elastic field and magnetic field control equations and the magnetic and mechanical boundaries;

[0008] Based on the MEE composite material contact model, a force-electric coupling constitutive model is established, and the electrical and mechanical physical quantities in the piezoelectric contact process are solved according to the elastic field and electric field control equations and the electrical and mechanical boundaries;

[0009] Based on the solutions of the magnetic and mechanical physical quantities and the solutions of the electrical and mechanical physical quantities, a contact geometry model of the piezomagnetic particle-piezoelectric matrix composite material considering the microstructure is established;

[0010] Discretizing the contact geometric model of the piezomagnetic particle-piezoelectric matrix composite material considering the microstructure, and assigning material properties to the discretized geometric model of the piezomagnetic particle-piezoelectric matrix composite material;

[0011] Apply load to the model after assigning material properties, complete the finite element numerical model solution, perform post-processing, and obtain magnetoelectric coupling variables.

[0012] Preferably, the process of simplifying the actual contact situation of the composite material to the contact model of the rigid contact indenter and the half-space MEE composite material includes:

[0013] A rectangular coordinate system is established with the contact point between the rigid indenter and the half-space MEE composite material as the coordinate origin. The rigid indenter contacts the MEE composite material under the action of longitudinal load and transverse load, and a contact model of the rigid contact indenter and the half-space MEE composite material is constructed.

[0014] Preferably, the process of solving the magnetic and mechanical physical quantities during the piezomagnetic contact process includes:

[0015] Construct a force-magnetic coupling constitutive model based on the linear force-magnetic coupling relationship;

[0016] The elastic field and magnetic field control equations as well as the magnetic and mechanical boundary conditions are substituted into the force-magnetic coupling constitutive model to solve the magnetic and mechanical physical quantities in the piezomagnetic contact process.

[0017] Preferably, the process of solving the electrical and mechanical physical quantities during the piezoelectric contact process includes:

[0018] Construct a mechanoelectric coupling constitutive model based on the linear mechanoelectric coupling relationship;

[0019] The elastic field and magnetic field control equations as well as the electrical and mechanical boundary conditions are substituted into the force-electric coupling constitutive model to solve the electrical and mechanical physical quantities in the piezoelectric contact process.

[0020] Preferably, the Voigt form of the force-magnetic coupling constitutive model can be expressed as:

[0021] ;

[0022] in, 、 、 、 、 、 represents the piezoresistance force, 、 、 represents the magnetic field strength, 、 、 represents the magnetic flux, 、 、 、 、 、 represents the piezomagnetic strain, represents the elastic coefficient of the piezomagnetic material, represents the piezomagnetic coupling coefficient, Represents magnetic permeability.

[0023] The elastic field, magnetic field control equations and magnetic and mechanical boundary conditions are expressed as follows:

[0024] ;

[0025] In the formula 、 、 、 、 、 represents the piezoresistance force, 、 、 、 、 、 represents the piezomagnetic strain, 、 、 represents the magnetic flux, 、 、 represents the magnetic flux density, represents the magnetic potential at the grid nodes, represents the displacement component on the piezomagnetic phase grid node, ” is the symbol for partial differential.

[0026] Preferably, the Voigt form of the mechanical-electrical coupling constitutive model can be expressed as:

[0027] ;

[0028] in, 、 、 、 、 、 represents the piezoelectric response stress, 、 、 represents the electric field strength, 、 、 represents the electric displacement, 、 、 、 、 represents the piezoelectric response, represents the elastic coefficient of the piezomagnetic material, represents the piezoelectric coupling coefficient, Indicates conductivity.

[0029] The elastic field, electric field control equations and electrical and mechanical boundary conditions are expressed as follows:

[0030] ;

[0031] In the formula 、 、 、 、 、 represents the piezoelectric response stress, 、 、 、 、 represents the piezoelectric response, 、 、 represents the electric displacement, 、 、 represents the electric field strength, represents the electric potential on the grid nodes, represents the displacement component on the piezoelectric phase grid node, ” represents the partial differential symbol.

[0032] Preferably, the piezomagnetic particle-piezoelectric matrix composite material considering the microstructure: the radius of the piezomagnetic particles follows a normal distribution, and the proportion of the piezoelectric matrix is expressed as:

[0033] ;

[0034] Where, represents the volume fraction of piezomagnetic particles, represents the side length of a regular cube sampling interval, represents the radius of a piezomagnetic particle in the sampling interval, Indicates the number of the piezomagnetic particle.

[0035] Preferably, the model material properties include: stiffness coefficient, piezoelectric coupling coefficient, and dielectric constant of piezoelectric materials; elastic coefficient, piezomagnetic coupling coefficient, and magnetic permeability of piezomagnetic materials.

[0036] Preferably, the load includes: longitudinal load, transverse load, electrical load and magnetic load, and the load in the contact area is:

[0037] ;

[0038] In the formula represents the matrix-corresponding force component (i=m,p), represents the tangential force on the mesh nodes in the contact area, Normal force on mesh nodes in the contact region, represents the total tangential load, represents the total normal load, represents the electric displacement component, represents the magnetic flux component, g represents the electric load, and q represents the magnetic load.

[0039] On the other hand, the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program implements the method when executed by a processor.

[0040] Compared with the prior art, the present invention has the following advantages and technical effects:

[0041] This paper establishes a universal model for achieving the functional properties of MEE composites through contact interactions. Using a MEE composite material containing piezoelectric particles in a piezoelectric matrix as an example, the authors systematically reveal the mechanism by which force loads regulate magnetoelectric coupling variables through multi-physics coupling theory and finite element numerical simulation.

[0042] Its characteristics are that it takes into account the microstructure of MEE composite materials (such as the size of piezomagnetic particles r and volume fraction vf) and macroscopic contact parameters (indenter radius R, pressure amount ω, and control parameters of actual working conditions during the contact process of MEE composite materials), combines the constitutive equations of piezoelectric and piezomagnetic phases with the actual working condition boundaries, and successfully realizes the force load control of magnetoelectric coupling variables. Prediction of objective laws. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0044] Figure 1Schematic diagram of the contact model of the MEE (0-3 type) composite material according to an embodiment of the present invention;

[0045] Figure 2 Schematic diagram of the probability distribution of piezomagnetic particle size according to an embodiment of the present invention;

[0046] Figure 3 Schematic diagram of the contact geometry model of the MEE (0-3) composite material according to an embodiment of the present invention;

[0047] Figure 4 Schematic diagram of the contact discrete model of the MEE (0-3) composite material according to an embodiment of the present invention;

[0048] Figure 5 The FEM solution results of the xz cross section along the negative z-axis of the MEE composite material (type 0-3) according to an embodiment of the present invention under contact, including (a) von Mises stress, (b) electric potential φ, (c) electric field normE, and (d) magnetic flux normB.

[0049] Figure 6 The FEM solution results of the contact surface of the MEE composite material (type 0-3) of the embodiment of the present invention under contact action include (a) contact pressure pm, (b) electric potential φ, and (c) magnetic field Hz;

[0050] Figure 7 The parameters of the embodiment of the present invention are the magnetoelectric coefficient components Schematic diagram, where (a) piezomagnetic particle radius, (b) piezomagnetic particle volume fraction, (c) indenter radius;

[0051] Figure 8 The parameters of the embodiment of the present invention are the magnetoelectric coefficient components Schematic diagram, where (a) piezomagnetic particle radius, (b) piezomagnetic particle volume fraction, (c) indenter radius; DETAILED DESCRIPTION

[0052] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0053] It should be noted that the attached diagram shows an example of solving the magnetoelectric coupling variables of the contact mechanics model of longitudinal load loading of a piezoelectric matrix containing piezoelectric magnetic particles taking into account the microstructure. This method is also applicable to piezoelectric particles-piezomagnetic matrix, piezomagnetic fibers (piezoelectric fibers)-piezoelectric matrix (piezomagnetic matrix) and arbitrary shape particle-matrix composite material structure types; at the same time, it is not limited to independent longitudinal load loading methods, but is also applicable to solving magnetoelectric coupling variables of independent and combined loading methods of transverse loads, magnetic loads, and electric loads.

[0054] Example 1

[0055] This embodiment provides a method for calculating contact magnetoelectric coupling variables of a piezoelectric substrate containing piezomagnetic particles, including:

[0056] The actual contact situation of the composite material is simplified to the contact model between the rigid indenter and the half-space MEE composite material;

[0057] Based on the MEE composite material contact model, a force-magnetic coupling constitutive model is established, and the magnetic and mechanical physical quantities in the piezomagnetic contact process are solved according to the elastic field and magnetic field control equations and the magnetic and mechanical boundaries;

[0058] Based on the MEE composite material contact model, a force-electric coupling constitutive model is established, and the electrical and mechanical physical quantities in the piezoelectric contact process are solved according to the elastic field and electric field control equations and the electrical and mechanical boundaries;

[0059] Based on the solution process of the magnetic and mechanical physical quantities and the solution process of the electrical and mechanical physical quantities, a contact geometry model of the piezomagnetic particle-piezoelectric matrix composite material considering the microstructure is established;

[0060] Discretizing the contact geometric model of the piezomagnetic particle-piezoelectric matrix composite material considering the microstructure, and assigning material properties to the discretized geometric model of the piezomagnetic particle-piezoelectric matrix composite material;

[0061] Apply load to the model after assigning material properties, complete the finite element numerical model solution, perform post-processing, and obtain magnetoelectric coupling variables.

[0062] Mechanical model establishment:

[0063] Achieving the functional properties of MEE composites through contact has numerous applications, but the contact region is always localized. Therefore, a general model for MEE composite contact can be developed to calculate the magnetoelectric coupling variables during the contact process. The actual contact situation of composite materials is simplified to a contact model consisting of a rigid contact indenter (one of four types: insulating indenter, PE indenter, FE indenter, and MEE indenter) and a half-space MEE composite. The rigid indenter transfers the mechanical, electrical, and magnetic loads during the actual contact process of the MEE composite. Under the influence of mechanical loads, the magnetoelectric coupling variables can be controlled through contact.

[0064] like Figure 1Figure 2 shows a contact theory model for the microstructure of an MEE composite (piezomagnetic particles in a piezoelectric matrix). The matrix is a piezoelectric (PE) phase, and the particles are a piezomagnetic (PM) phase. A rectangular coordinate system is established with the point of contact between a rigid indenter and the MEE composite in a half-space as the coordinate origin. The indenter radius is R, and the indenter contacts the MEE composite under the action of a longitudinal load Pz and a transverse load Px. (If the indenter is a PE material, the electric load g must be considered; if it is a PM material, the magnetic load q must be considered; if it is an MEE material, both the electric load g and the magnetic load q must be considered.) The electric (magnetic) potential at infinity is considered to be grounded.

[0065] Distribution of piezomagnetic particles in the piezoelectric matrix:

[0066] The piezomagnetic particles-piezoelectric matrix composite material was prepared by sol-gel method. The cross section of MEE composite material was observed by Aspex scanning electron microscope to obtain the distribution of piezomagnetic particles in piezoelectric matrix and the probability distribution of particle size. Figure 2 As shown in Figure 2, the probability distribution of piezomagnetic particle size conforms to the normal distribution. The ratio of piezomagnetic particles to piezoelectric matrix can be defined as:

[0067] ;

[0068] Where, represents the volume fraction of piezomagnetic particles, represents the side length of a regular cube sampling interval, represents the radius of a piezomagnetic particle in the sampling interval, Indicates the number of the piezomagnetic particle.

[0069] Magnetoelectric coupling variables for the MEE composite contact model:

[0070] The process of force load regulating magnetoelectric coupling variables: When the force load acts on the rigid pressure head, the force load is transferred through the contact action; the force-electricity conversion is achieved through the force-electricity coupling property of the piezoelectric phase (PE), generating an induced potential; the conversion of the induced potential and the magnetic potential is achieved through the transmission of stress / strain at the interface between the piezoelectric matrix and the piezomagnetic particles, that is, magnetoelectric coupling. The magnetoelectric coupling effect of the contact process of MEE composite materials is usually expressed by magnetoelectric coupling variables. measure, It can be expressed as:

[0071] ;

[0072] Where, 、 are the PE phase electric field component and PM phase magnetic field component in the contact area of the MEE composite material. The MEE composite material is a transversely isotropic material. According to the properties of transversely isotropic materials: i=j, (i=1,2,3). If the xoy plane is a transversely isotropic plane, then ,when hour, In the following steps, we will describe in detail how to establish the MEE composite material contact model through finite element numerical simulation and solve the magnetoelectric coupling variables. , Specific process.

[0073] Finite element model solution process:

[0074] Considering that the solution to the MEE composite material contact model problem is a multi-physics field coupling problem (magnetic field, electric field, elastic field and their mutual coupling), and that it also has strong boundary effects and size effects, a finite element numerical simulation program is written to solve it. The specific steps are as follows:

[0075] (1) Establish a force-magnetic coupling constitutive model to solve the magnetic and mechanical physical quantities during the PM phase contact process. Here, a linear piezomagnetic constitutive model is used to solve the linear piezomagnetic constitutive model. It is necessary to introduce the magnetic field and elastic field control equations and the corresponding magnetic field boundaries and mechanical boundaries;

[0076] (2) Establish a force-electric coupling constitutive model to solve the electrical and mechanical physical quantities during the PE contact process. Here, a linear piezoelectric constitutive model is used to solve the piezoelectric constitutive model. It is necessary to introduce the corresponding electric field and elastic field control equations and the corresponding electrical and mechanical boundaries;

[0077] (3) Establish the contact geometry model of the piezomagnetic particles-piezoelectric matrix composite material ( Figure 3 By writing a model script, the distribution of piezomagnetic particles in the piezoelectric matrix mentioned in the distribution of piezomagnetic particles in the piezoelectric matrix is realized.

[0078] (4) Discretize the geometric model established in (3) ( Figure 4 ). In order to improve the efficiency of finite element solution, the contact area mesh is refined to improve the calculation efficiency without affecting the solution accuracy. , further refining of the mesh has no effect on the solution results.

[0079] (5) Assigning material properties. Common piezoelectric materials (PE phase) used to prepare MEE materials include BaTiO3, PZT-x, piezoelectric polymer (PVDF), etc. The piezoelectric effect of piezoelectric materials is determined by the piezoelectric constant e 31 / e 33 / e 15Determined; Common piezomagnetic materials (PM phase) used to prepare MEE materials include Terfenol-D, CoFe2O4, ZnO, etc. The piezomagnetic effect of piezomagnetic materials is determined by the piezomagnetic constant q 31 / q 33 / q 15 The two together determine the magnetoelectric coupling variables of MEE composite materials under contact Typical materials were studied, and Table 1 and Table 2 give the material parameters of the piezoelectric material BaTiO3 and the piezomagnetic material CoFe2O4 respectively. p c ij represents the stiffness coefficient of the piezoelectric material, e ij represents the piezoelectric coupling coefficient, k ij represents the dielectric constant, m c ij represents the elastic coefficient of the piezomagnetic material, q ij represents the piezomagnetic coupling coefficient, μ ij Represents magnetic permeability, wherein Table 1 is the material parameters of the piezoelectric material BaTiO3, and Table 2 is the material parameters of the piezomagnetic material CoFe2O4;

[0080] Table 1

[0081] Parameter name Value <![CDATA[ p c 11 / p c 12 / p c 13 / p c 33 / p c 44 / p c 66 (×10 9 Pa)]]> 166 / 77 / 78 / 162 / 43 / 44.5 <![CDATA[e 31 / e 33 / e 15 (C / m 2 )]]> -4.4 / 18.6 / 11.6 <![CDATA[k 11 =k 22 / k 33 (10 -9 C 2 / (Nm 2 ))]]> 11.2 / 12.6

[0082] Table 2

[0083] Parameter name Value <![CDATA[ m c 11 / m c 12 / m c 13 / m c 33 / m c 44 / m c 66 (×10 9 Pa)]]> 286 / 173 / 170.5 / 269.5 / 45.3 / 59.5 <![CDATA[q 31 / q 33 / q 15 (N / (A•m))]]> 580.3 / 699.7 / 550 <![CDATA[μ 11 =μ 22 / μ 33 (10 -6 Us 2 / C 2 ))]]> 297.5 / 83.5

[0084] (6) Finite element solution and post-processing. Apply loads (longitudinal load Pz, transverse load Px, electric load g, magnetic load q) to the MEE composite contact model and perform finite element model solution. During the solution process, perform convergence judgment. If converged, perform post-processing, record the calculation results, and calculate the magnetoelectric coefficient. If not converged, check the above steps until convergence.

[0085] Constitutive model:

[0086] The Voigt form of the force-magnetic constitutive model described in step (1) can be expressed as:

[0087] ;

[0088] in, 、 、 、 、 、 represents the piezoresistance force, 、 、 represents the magnetic field strength, 、 、 represents the magnetic flux, 、 、 、 、 、 represents the piezomagnetic strain, represents the elastic coefficient of the piezomagnetic material, represents the piezomagnetic coupling coefficient, Represents magnetic permeability.

[0089] The Voigt form of the mechanical-electrical constitutive model described in step (2) can be expressed as:

[0090] ;

[0091] in, 、 、 、 、 、 represents the piezoelectric response stress, 、 、 represents the electric field strength, 、 、 represents the electric displacement, 、 、 、 、 represents the piezoelectric response, represents the elastic coefficient of the piezomagnetic material, represents the piezoelectric coupling coefficient, Indicates conductivity.

[0092] Governing equations:

[0093] The elastic field, magnetic field, and electric field control equations involved in steps (1) and (2) can be expressed as:

[0094] ;

[0095] In the formula 、 、 、 、 、 represents the piezoresistance force, 、 、 、 、 、 represents the piezoelectric response stress, 、 、 represents the magnetic flux, 、 、 represents the electric field strength, ” is the symbol for partial differential.

[0096] The deformation of the MEE composite material considered in this embodiment under contact is still within the elastic range, satisfying the small deformation theory. At the same time, according to the magnetostatics and electrostatics theories:

[0097] ;

[0098] In the formula 、 、 、 、 、 represents the piezomagnetic strain, 、 、 、 、 represents the piezoelectric response, represents the magnetic flux density, 、 、 represents the electric field strength, represents the magnetic potential at the grid nodes, represents the electric potential on the grid nodes, represents the displacement component on the piezomagnetic phase grid node, represents the displacement component on the piezoelectric phase grid node, ” is the symbol for partial differential.

[0099] Boundary conditions:

[0100] The bottom edge of the MEE composite material is infinitely far away as the zero magnetic potential end and the ground end. At the same time, the displacement of the MEE composite material at infinity should be zero. Then the magnetic, mechanical, and electrical boundaries involved in steps (1) and (2) can be expressed as:

[0101] ;

[0102] Where, represents the displacement component on the piezomagnetic phase grid node, represents the displacement component on the piezoelectric phase grid node, represents the magnetic potential at the grid nodes, represents the electric potential at the mesh nodes.

[0103] Loading conditions of MEE composite materials in the contact area:

[0104] ;

[0105] In the formula represents the matrix-corresponding force component (i=m,p), represents the tangential force on the mesh nodes in the contact area, Normal force on mesh nodes in the contact region, represents the total tangential load, represents the total normal load, represents the electric displacement component, represents the magnetic flux component, g represents the electric load, and q represents the magnetic load.

[0106] Get a single parameter pair The influence of the law:

[0107] The magnetoelectric coupling variables of the MEE composite under contact load have a strong size effect. Considering the microstructure of the MEE material, such as the radius r of the piezomagnetic particles and the particle volume fraction v f , and combined with the actual working conditions during the contact process of MEE composite materials, considering the indenter radius R, the amount of pressure As an example (another way to express the longitudinal force load Pz, used to adjust the magnetoelectric coupling variable), change the above parameters to construct a finite element numerical model, and solve it according to the finite element solution process given in step 5.

[0108] Figure 5 , Figure 6 is the finite element solution result, Figure 7 , Figure 8 is the relationship between the microstructure of MEE composite material and the indenter radius R and the pressing amount Magnetoelectric coefficient Influence.

[0109] Adjusting magnetoelectric coupling variables under force load Formula fitting:

[0110] Will Figure 7 , 8 parameters r, vf, R, pressure ω respectively affect the magnetoelectric coefficient The influence law is presented in the form of an analytical expression. At the microscopic scale, the radius of the piezomagnetic particles r∈[1μm, 50μm], the volume fraction of the piezomagnetic particles and the piezoelectric matrix vf∈[0,1], and the indenter radius R∈[0.1mm,1mm] are considered.

[0111] ;

[0112] This example establishes a general model for achieving the functional properties of MEE composites through contact interactions. Using a MEE composite material containing piezoelectric particles in a piezoelectric matrix as an example, the mechanism by which force loads regulate magnetoelectric coupling variables is systematically revealed through multi-physics coupling theory and finite element numerical simulation.

[0113] Its characteristics are that it takes into account the microstructure of MEE composite materials (such as the size of piezomagnetic particles r and volume fraction vf) and macroscopic contact parameters (indenter radius R, pressure amount ω, and control parameters of actual working conditions during the contact process of MEE composite materials), combines the constitutive equations of piezoelectric and piezomagnetic phases with the actual working condition boundaries, and successfully realizes the force load control of magnetoelectric coupling variables. Prediction of objective laws (obtained by substituting the indentation value ω under actual contact conditions of MEE composite materials into the expression).

[0114] Application scenarios: writing / clearing information on large-capacity disk storage. Its mechanical energy consumption is much lower than that of traditional disks, which can effectively extend the service life of the disk. This embodiment can be used for the equivalent calculation of the information writing rate of new disk storage made of MEE composite materials. Application of nanogenerators. By regulating the magnetoelectric coupling variables of MEE composite materials through contact action, an efficient and flexible conversion solution is provided for micro-nanogenerators, which increases the energy conversion rate by 10 to 20 percentage points compared with traditional piezoelectric materials. This embodiment can be directly used for numerical calculations of mechanical energy conversion into electrical energy in MEE composite nanogenerators. Micro contact magnetoelectric sensors. Contact sensors can adapt to complex environments. At the same time, MEE composite materials are small in size and light in weight. Their displacement detection resolution can reach the micron level, which can greatly promote the popularization of portable detection equipment. This embodiment can be used as a micro contact magnetoelectric sensor, pressure detection and packaging program development.

[0115] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for calculating the contact magnetoelectric coupling variable of a piezoelectric matrix containing piezoelectric magnetic particles, characterized in that: include: The actual contact situation of the composite material is simplified to the contact model between the rigid indenter and the half-space MEE composite material; Based on the MEE composite material contact model, a force-magnetic coupling constitutive model is established, and the magnetic and mechanical physical quantities in the piezomagnetic contact process are solved according to the elastic field and magnetic field control equations and the magnetic and mechanical boundaries; Based on the MEE composite material contact model, a force-electric coupling constitutive model is established, and the electrical and mechanical physical quantities in the piezoelectric contact process are solved according to the elastic field and electric field control equations and the electrical and mechanical boundaries; Based on the solutions of the magnetic and mechanical physical quantities and the solutions of the electrical and mechanical physical quantities, a contact geometry model of the piezomagnetic particle-piezoelectric matrix composite material considering the microstructure is established; Discretizing the contact geometric model of the piezomagnetic particle-piezoelectric matrix composite material considering the microstructure, and then assigning material properties to the discretized geometric model of the piezomagnetic particle-piezoelectric matrix composite material; Apply loads to the model after assigning material properties, complete the finite element numerical model solution, perform post-processing, and obtain magnetoelectric coupling variables; The process of solving the magnetic and mechanical physical quantities during the piezomagnetic contact process includes: Construct a force-magnetic coupling constitutive model based on the linear force-magnetic coupling relationship; Substituting the elastic field and magnetic field control equations and the magnetic and mechanical boundary conditions into the force-magnetic coupling constitutive model, the magnetic and mechanical physical quantities in the piezomagnetic contact process are solved. The process of solving the electrical and mechanical physical quantities during the piezoelectric contact process includes: Construct a mechanoelectric coupling constitutive model based on the linear mechanoelectric coupling relationship; Substituting the elastic field and magnetic field control equations and the electrical and mechanical boundary conditions into the force-electric coupling constitutive model, the electrical and mechanical physical quantities in the piezoelectric contact process are solved. The Voigt form of the force-magnetic coupling constitutive model can be expressed as: ； in, 、 、 、 、 、 represents the piezoresistance force, 、 、 represents the magnetic field strength, 、 、 represents the magnetic flux, 、 、 、 、 、 represents the piezomagnetic strain, represents the elastic coefficient of the piezomagnetic material, represents the piezomagnetic coupling coefficient, represents magnetic permeability; The elastic field, magnetic field control equations and magnetic and mechanical boundary conditions are expressed as follows: ； In the formula 、 、 、 、 、 represents the piezoresistance force, represents the magnetic flux density, represents the magnetic potential at the grid nodes, represents the displacement component on the grid node, " " represents the partial differential symbol; The Voigt form of the mechanical-electrical coupling constitutive model can be expressed as: ； in, 、 、 、 、 、 represents the piezoelectric response stress, 、 、 represents the electric field strength, 、 、 represents the electric displacement, 、 、 、 、 represents the piezoelectric response, represents the elastic coefficient of the piezomagnetic material, represents the piezoelectric coupling coefficient, represents conductivity; The elastic field, electric field control equations and electrical and mechanical boundary conditions are expressed as follows: ； In the formula 、 、 、 、 、 represents the piezoelectric response stress, 、 、 represents the electric field strength, represents the electric potential on the grid nodes, represents the displacement component on the grid node, " " represents the partial differential symbol; The expression for obtaining the magnetoelectric coupling variable is: ； in, represents the volume fraction of the piezomagnetic particles, R is the indenter radius, is the magnetoelectric coefficient, ω is the downward pressure, and r is the radius of the piezomagnetic particle.

2. The method according to claim 1, characterized in that The process of simplifying the actual contact situation of the composite material into a contact model between a rigid indenter and a half-space MEE composite material includes: A rectangular coordinate system is established with the contact point between the rigid indenter and the half-space MEE composite material as the coordinate origin. The rigid indenter contacts the MEE composite material under the action of longitudinal load and transverse load, and a contact model of the rigid indenter and the half-space MEE composite material is constructed.

3. The method according to claim 1, characterized in that The piezomagnetic particle radius of the piezomagnetic particle-piezoelectric matrix composite material contact geometry model follows a normal distribution and is expressed as the fraction of the piezoelectric matrix: ； Where, represents the volume fraction of piezomagnetic particles, represents the side length of a regular cube sampling interval, represents the radius of a piezomagnetic particle in the sampling interval, Indicates the number of the piezomagnetic particle.

4. The method according to claim 1, wherein The material properties of the contact geometric model of the piezomagnetic particle-piezoelectric matrix composite material include: stiffness coefficient, piezoelectric coupling coefficient, dielectric constant of the piezoelectric material, elastic coefficient, piezomagnetic coupling coefficient, and magnetic permeability of the piezomagnetic material.

5. The method according to claim 1, wherein The loads include longitudinal load, transverse load, electrical load and magnetic load. The loads in the contact area are: ； In the formula represents the matrix-corresponding force component (i=m,p), represents the tangential force on the mesh nodes in the contact area, Normal force on mesh nodes in the contact region, represents the total tangential load, represents the total normal load, represents the electric displacement component, represents the magnetic flux component, g represents the electric load, and q represents the magnetic load.

6. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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