Method for calculating dislocation structure energy based on discrete dislocation dynamics

Abstract

The invention relates to a method for calculating dislocation structure energy based on discrete dislocation kinetics, which comprises the following steps of: decomposing strain and stress generated by plastic deformation in a crystal into an elastic field generated by dislocation in an infinite continuous medium and an additional field used for correcting real boundary conditions; and the stress and strain states of the target crystal material under the actual plastic deformation condition can be accurately captured, so that the influence of a real boundary on the plastic deformation process is deeply reflected. Dynamic evolution of a large number of discrete dislocation sections is directly considered through the discrete dislocation dynamics theory, the plastic behavior of a material is essentially simulated, the evolution process of a dislocation substructure can be directly captured, the plastic deformation mechanism of the material is essentially reproduced, and then a calculation formula of dislocation structure energy is deduced; the calculation precision of dislocation structure energy is improved, and the internal mechanism of different plastic deformation behaviors of the crystal material can be deeply understood.

Description

Technical Field

[0001] The invention relates to the field of material science, and in particular to a method for calculating dislocation structural energy based on discrete dislocation dynamics. Background Art

[0002] Dislocation structure plays a key role in the generation of crystal defects such as twin nucleation, fatigue crack initiation and propagation. The irreversibility of crack propagation stems from the dissipation generated by dislocation motion, and crack propagation is the result of the evolution of dislocation structure near the crack tip. Therefore, it is crucial to quantify the contribution of dislocation structure to plastic deformation and even fatigue failure.

[0003] During the plastic deformation of metals, most of the plastic work is dissipated in the form of heat, sound, etc., and the rest is stored in the material. The stored energy includes recoverable elastic strain energy and undissipated plastic work. In the absence of deformation damage, the undissipated plastic work includes the energy associated with a single isolated dislocation (dislocation line energy) and the dislocation structural energy generated by the interaction between dislocations. The dislocation structural energy is mainly caused by the change in lattice curvature caused by geometrically required dislocations. It is elastically stored inside the material and is the result of the interaction between dislocation stress fields. It is also a supplement to the sum of all dislocation line energies.

[0004] Existing methods for calculating dislocation structural energy are mainly based on the finite element theory of crystal plasticity. The consideration of dislocations is based on the statistical average theory. There is a certain phenomenology in the mathematical description, and it cannot consider the influence of the discreteness and randomness of dislocation motion at the microstructural scale on the plastic deformation of crystal materials. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0007] As a preferred embodiment of the present invention, the present invention provides a method for calculating dislocation structural energy based on discrete dislocation dynamics, comprising: obtaining crystallographic information of a target crystal material and constructing a discrete dislocation dynamics geometric model of the target crystal material; simulating the dynamic evolution process of dislocations of the target crystal material during plastic deformation according to the geometric model and based on the dislocation evolution mechanism; the dynamic evolution process is used to describe the dynamic distribution and morphological changes of dislocations in the target crystal material; based on the discrete dynamics theory, decomposing the stress and strain of the target crystal material due to plastic deformation into an elastic field generated by dislocations in an infinite continuous medium and an additional field used to correct the real boundary conditions, so as to obtain the stress and strain generated during the actual plastic deformation of the target crystal material; and deriving the dislocation structural energy in the target crystal material using a free energy calculation formula based on the obtained stress and strain generated during the actual plastic deformation of the target crystal material.

[0008] In some possible implementations, according to the geometric model and based on the dislocation evolution mechanism, the dynamic evolution process of dislocations of the target crystal material during plastic deformation is simulated, including: determining the initial dislocation configuration of the target crystal material, and applying a preset shear stress to the discrete dislocation dynamics model. ;When the shearing stress After the dislocation source intensity exceeds the preset time, the Burgers vector is The edge dislocation nucleates from the dislocation source and continues to slide along the corresponding slip plane. The dislocation nucleation time for:

[0009] ;

[0010] in is a constant related to the dislocation drag coefficient, is the length of the dislocation source. When the attraction between dislocations is equal to the applied shear stress nuc At equilibrium, the diameter of the initial dislocation ring is for:

[0011] ;

[0012] where G is the shear modulus, v is Poisson's ratio, is the dislocation source strength, which is obtained through experimental data. The sliding speed of dislocations between pinning obstacles is for:

[0013] ;

[0014] in, is the Boltzmann constant, is the representative distance of cooperative dislocation slip, is the atomic vacancy volume, It is the temperature The vacancy equilibrium concentration under is the vacancy diffusion coefficient.

[0015] In some possible implementations, the stress and strain generated during the actual plastic deformation of the target crystal material are respectively the superposition of the corresponding elastic field and the additional field; the strain generated during the actual plastic deformation is expressed as:

[0016] ;

[0017] in, For strain, is the strain field of the dislocation, is the additional field of strain; the stress generated during actual plastic deformation is expressed as:

[0018] ;

[0019] in, is the actual stress, is the stress field of the dislocation, is the additional field of stress.

[0020] In some possible implementations, the additional field is solved by numerical analysis methods, including but not limited to finite element method, boundary element method or discrete element method; the elastic field is calculated by elastic mechanics theory, specifically the superposition of all dislocation elastic fields; wherein, It is expressed as:

[0021] ;

[0022] in, Indicates dislocations, N represents the number of dislocations, Indicates The elastic field strain of a dislocation; It is expressed as:

[0023] ;

[0024] in, Indicates The elastic field stress of a dislocation.

[0025] In some possible implementations, The elastic field stress of a dislocation is expressed as:

[0026] ;

[0027] in:

[0028] ;

[0029] ;

[0030] ;

[0031] in, is the shear modulus, is the Burgers vector, is Poisson's ratio, , is the coordinate of the current dislocation in the local coordinate system; The elastic field strain of a dislocation is expressed as:

[0032] ;

[0033] in:

[0034] ;

[0035] ;

[0036] .

[0037] In some possible implementations, the free energy calculation formula is expressed as:

[0038] ;

[0039] According to the stress and strain generated during the actual plastic deformation of the target crystal material, the dislocation structural energy in the target crystal material is derived using the free energy calculation formula, including: the free energy during the plastic deformation process The stored energy associated with the dislocation and elastic storage energy composition, is the dislocation strain energy and dislocation structure energy The sum of the free energy is expressed as:

[0040] ;

[0041] Due to the singularity of the dislocation stress-strain field, the free energy is further determined according to the free energy calculation formula:

[0042] ;

[0043] Among them, the elastic storage energy related to remote loading can be expressed as:

[0044] ;

[0045] in, and are the stress field and strain field when the same external force is applied to a pure elastic body with the same geometric shape; that is, the dislocation structure energy It is expressed as:

[0046] .

[0047] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0048] The present invention provides a method for calculating dislocation structural energy based on discrete dislocation dynamics theory. By constructing a geometric model of a target crystal material and dynamically simulating the evolution process of dislocations in plastic deformation, the dynamic distribution and morphological changes of dislocations are accurately described. The strain and stress generated by plastic deformation inside the crystal are decomposed into an elastic field generated by dislocations in an infinite continuous medium and an additional field used to correct the real boundary conditions. The stress and strain state of the target crystal material under actual plastic deformation conditions can be accurately captured, thereby profoundly reflecting the influence of the real boundary on the plastic deformation process. The discrete dislocation dynamics theory is used to directly consider the dynamic evolution of a large number of discrete dislocation segments to essentially simulate the plastic behavior of the material, directly capture the evolution process of the dislocation substructure, and essentially reproduce the plastic deformation mechanism of the material. Then, the calculation formula of the dislocation structural energy is derived, the calculation accuracy of the dislocation structural energy is improved, and the intrinsic mechanism of different plastic deformation behaviors of the crystal material can be more deeply understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention, the accompanying drawings required for use in the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0050] Figure 1 A schematic flow chart of an embodiment of a method for calculating dislocation structural energy based on discrete dislocation dynamics provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0052] In the relevant description of this embodiment, the terms "including, containing, having" and the like are open terms and are generally understood to include but not be limited to; the term "at least one" is generally understood to mean one or more, where "plurality" refers to two or more; the term "at least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items, for example, "at least one of a, b or c", or "at least one of a, b and c", can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively; the symbol "A / B" is used to describe the selection relationship of associated objects, generally indicating an "or" relationship before and after.

[0053] In the following description of the present embodiment, the terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0054] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0055] Those skilled in the art will appreciate that the numerical ranges in the embodiments of the present application are to be construed as also specifically disclosing each intermediate value between the upper and lower limits of the scope. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded in the scope.

[0056] Unless otherwise specified, the technical / scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which this application belongs. Although this application only describes preferred methods and materials, any methods and materials similar or equivalent to these may also be used in the implementation or testing of this application. All documents mentioned in this specification are incorporated by reference to disclose and describe methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0057] In order to illustrate the technical solution of the present invention, specific embodiments are provided below for illustration.

[0058] Dislocation structure plays a key role in the generation of crystal defects such as twin nucleation, fatigue crack initiation and propagation. The irreversibility of crack propagation stems from the dissipation generated by dislocation motion, and crack propagation is the result of the evolution of dislocation structure near the crack tip. Therefore, it is crucial to quantify the contribution of dislocation structure to plastic deformation and even fatigue failure.

[0059] During the plastic deformation of metals, most of the plastic work is dissipated in the form of heat, sound, etc., and the rest is stored in the material. The stored energy includes recoverable elastic strain energy and undissipated plastic work. In the absence of deformation damage, the undissipated plastic work includes the energy associated with a single isolated dislocation (dislocation line energy) and the dislocation structural energy generated by the interaction between dislocations. The dislocation structural energy is mainly caused by the change in lattice curvature caused by geometrically required dislocations. It is elastically stored inside the material and is the result of the interaction between dislocation stress fields. It is also a supplement to the sum of all dislocation line energies.

[0060] Existing methods for calculating dislocation structural energy are mainly based on the finite element theory of crystal plasticity. The consideration of dislocations is based on the statistical average theory. There is a certain phenomenology in the mathematical description, and it cannot consider the influence of the discreteness and randomness of dislocation motion at the microstructural scale on the plastic deformation of crystal materials.

[0061] The discrete dislocation dynamics theory simulates the plastic behavior of materials by directly considering the dynamic evolution of a large number of discrete dislocation segments. It can directly capture the evolution process of dislocation substructures. Therefore, it has a natural advantage in calculating dislocation structural energy and can provide a deeper understanding of the intrinsic mechanisms of different plastic deformation behaviors of crystalline materials.

[0062] Figure 1 A schematic diagram of an embodiment of a method for calculating dislocation structural energy based on discrete dislocation dynamics provided by an embodiment of the present invention, see Figure 1 As shown, the above method may include:

[0063] S101, obtaining crystallographic information of a target crystal material and constructing a discrete dislocation dynamics geometric model of the target crystal material;

[0064] Among them, the target crystal material is the crystal material to be studied, and the target crystal material can be any material that can produce plastic deformation, such as metals (such as magnesium alloys, zirconium alloys), semiconductors, etc. Determining the crystallographic information of the target crystal material includes determining its specific chemical composition, possible structural type, crystal orientation, etc. For example, the crystallographic information of the target crystal material can be found using crystallographic databases and literature resources, or it can be obtained through actual measurement of detection equipment, such as Electron Backscatter Diffraction (EBSD) technology.

[0065] Discrete Dislocation Dynamics (DDD) is a branch of dislocation dynamics, which uses a discretization method to simulate the behavior of dislocations in crystals. Dislocations are an important defect in crystals, which are caused by the disorder of atomic arrangement and have a significant impact on the physical and mechanical properties of materials.

[0066] According to the crystallographic information of the target crystal material, a geometric model of the target crystal material is constructed using computer simulation software (such as MaterialsStudio, Vesta, etc.). The unit cell structure, atomic arrangement and possible defects (such as vacancies, dislocations, etc.) of the crystal can be represented in the model. In the DDD simulation, the initial conditions of the dislocation need to be set, including the type of dislocation (such as edge dislocation, screw dislocation, etc.), position, direction and quantity. These initial conditions will affect the dynamic evolution of dislocations and the plastic deformation behavior of crystal materials. Use the DDD simulation software to simulate the constructed geometric model.

[0067] S102, according to the geometric model and based on the dislocation evolution mechanism, simulating the dynamic evolution process of dislocations in the target crystal material during plastic deformation; the dynamic evolution process is used to describe the dynamic distribution and morphological changes of dislocations in the target crystal material;

[0068] It should be noted that the dislocation evolution mechanism includes but is not limited to dislocation multiplication, dislocation movement, interaction, annihilation, etc. Depending on the target material, there is a corresponding dislocation evolution mechanism.

[0069] For example, the dislocation multiplication mechanism can include the Frank-Read dislocation source mechanism, where dislocations move inside the crystal under the action of external loads. This movement is affected by many factors, including stress field, temperature, and interaction between dislocations. The movement speed of dislocations can be described by dislocation dynamics equations, which can be based on the principles of continuum mechanics and statistical mechanics. Under the action of the Frank-Read dislocation source mechanism, dislocations can multiply inside the crystal. When the shear stress exceeds a certain threshold, new dislocations will nucleate from the dislocation source and expand along the slip plane. At the same time, dislocations may also interact with each other to cause annihilation (such as dislocation cancellation, dislocation recombination, etc.).

[0070] In some embodiments, the above step S102 may specifically include:

[0071] Determine the initial dislocation configuration of the target crystal material. Specifically, it is necessary to clarify the dislocation distribution of the target crystal material at the beginning of the simulation, including the position, type (such as edge dislocation, screw dislocation), Burgers vector, etc. of the dislocation.

[0072] Applying a preset shear stress to the discrete dislocation dynamics model ; This stress is the main external factor driving dislocation movement. The size of the preset shear stress can be determined based on the physical properties of the target material, experimental data, simulation requirements, and possible theoretical models or empirical judgments to simulate the effect of actual external loads on the internal dislocation movement of the material.

[0073] When the shear stress After the dislocation source intensity exceeds the preset time, the Burgers vector is The edge dislocation nucleates from the dislocation source and continues to slide along the corresponding slip plane. The dislocation nucleation time for:

[0074] ;

[0075] in is a constant related to the dislocation drag coefficient, is the length of the dislocation source. When the attraction between dislocations is equal to the applied shear stress nuc At equilibrium, the diameter of the initial dislocation ring is for:

[0076] ;

[0077] where G is the shear modulus, v is Poisson's ratio, is the dislocation source strength, which is obtained through experimental data. The sliding speed of dislocations between pinning obstacles is for:

[0078] .

[0079] in, is the Boltzmann constant, is the representative distance of cooperative dislocation slip, is the atomic vacancy volume, It is the temperature The vacancy equilibrium concentration under is the vacancy diffusion coefficient.

[0080] It can be understood that the use of the above-mentioned Boltzmann constant, the representative distance of cooperative dislocation slip, the atomic vacancy volume, the vacancy equilibrium concentration at temperature, and the vacancy diffusion coefficient to calculate the sliding speed of dislocations between pinning obstacles has clear physical meaning and a solid theoretical basis (for example, the Boltzmann constant is related to thermodynamics, and the vacancy diffusion coefficient describes the diffusion rate of vacancies in the material. These parameters jointly determine the dynamic behavior of dislocations between pinning obstacles). These parameters are not only directly related to the sliding mechanism of dislocations, but also can be measured or estimated by experimental means (for example, the vacancy diffusion coefficient can be obtained by diffusion experiments, and the vacancy equilibrium concentration can be obtained by thermodynamic calculations. This makes this method feasible in practical applications). As a result, the above-mentioned calculation method has a wider range of applications in practical applications, and it can be applied to various types of materials and conditions. Whether it is metal, ceramic or polymer material, as long as the relevant parameters can be obtained, this method can be used for calculation. In addition, this method is also applicable to the calculation of dislocation sliding speed under different temperature, pressure and stress conditions. Compared with using only macroscopic mechanical property parameters, these fundamental parameters reveal the microscopic mechanism of dislocation sliding more deeply, thus providing more accurate and reliable calculation results.

[0081] It should be noted that in determining the dislocation nucleation time in the above parameters After that, the position of dislocation in the target crystal material can be further determined, and then the initial dislocation ring diameter can be calculated. , we can determine the size of the dislocation, and finally determine the sliding speed of the dislocation between the pinning obstacles. , the direction of movement of the dislocation when it expands along the slip plane can be determined. In this way, by calculating the above parameters, the dynamic evolution of dislocations in the target crystal material can be described, and the dynamic evolution process of dislocations in the material can be simulated and described, including the proliferation, movement, interaction of dislocations and their impact on the macroscopic properties of the material.

[0082] S103, based on discrete dynamics theory, decomposing the stress and strain of the target crystal material caused by plastic deformation into an elastic field generated by dislocations in an infinite continuous medium and an additional field for correcting real boundary conditions, to obtain the stress and strain generated by the actual plastic deformation of the target crystal material;

[0083] Specifically, in some embodiments, the stress and strain generated when the target crystal material is actually plastically deformed are respectively the superposition of the corresponding elastic field and the additional field;

[0084] At this time, the strain generated during the actual plastic deformation is expressed as:

[0085] ;

[0086] in, is the actual strain, is the strain field of the dislocation, is the additional field of strain;

[0087] Similar to strain, the stress generated during actual plastic deformation is expressed as:

[0088] ;

[0089] in, is the actual stress, is the stress field of the dislocation, is the additional field of stress.

[0090] In some embodiments, the additional field may be solved using numerical analysis methods, including but not limited to finite element method, boundary element method or discrete element method;

[0091] In some embodiments, the elastic field is calculated using elastic mechanics theory, specifically the superposition of the elastic fields of all dislocations;

[0092] in, It is expressed as:

[0093] ;

[0094] in, Indicates dislocations, N represents the number of dislocations, Indicates The elastic field strain of a dislocation;

[0095] It is expressed as:

[0096] ;

[0097] in, Indicates The elastic field stress of a dislocation.

[0098] In some embodiments, The elastic field stress of a dislocation is expressed as:

[0099] ;

[0100] in:

[0101] ;

[0102] ;

[0103] ;

[0104] in, is the shear modulus, is the Burgers vector, is Poisson's ratio, , is the coordinate of the current dislocation in the local coordinate system;

[0105] No. The elastic field strain of a dislocation is expressed as:

[0106] ;

[0107] in:

[0108] ;

[0109] ;

[0110] .

[0111] S104, deriving the dislocation structural energy in the target crystal material using a free energy calculation formula according to the obtained stress and strain generated during the actual plastic deformation of the target crystal material.

[0112] In some embodiments, the free energy calculation formula can be expressed as:

[0113] ;

[0114] It can be further deduced as:

[0115] ;

[0116] It should be noted that due to the free energy in the plastic deformation process The stored energy associated with the dislocation is usually and elastic storage energy Composition, and is the dislocation strain energy and dislocation structure energy The sum of , that is, the free energy can also be expressed as:

[0117] .

[0118] Due to the singularity of the dislocation stress-strain field, it is difficult to obtain a finite value for the free energy, so the free energy can be further determined as:

[0119]

[0120] The elastic storage energy associated with remote loading can be expressed as:

[0121] ;

[0122] in, and are the stress field and strain field when the same external force is applied to a pure elastic body with the same geometric shape. is derived as:

[0123]

[0124] In this way, the calculation of dislocation structural energy in the target crystal material based on discrete dislocation dynamics is realized. Compared with the traditional statistical averaging method, the discrete dislocation dynamics model provides higher calculation accuracy. It can directly consider the complex processes such as the interaction between dislocations, the proliferation and annihilation of dislocations, so as to quantitatively analyze their contribution to plastic deformation, and can more deeply understand the intrinsic mechanism of different plastic deformation behaviors of crystal materials, so that the calculated dislocation structural energy is closer to the actual situation. This is of great significance for predicting the mechanical properties of materials, evaluating the reliability of materials and optimizing the design. And through the calculation of dislocation structural energy, we can have a deeper understanding of the behavior of crystal materials under different plastic deformation conditions. For example, we can analyze the influence of different loading paths, temperatures, strain rates and other factors on dislocation structure and energy distribution, so as to reveal how these factors affect the plastic deformation ability and failure mechanism of materials.

[0125] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0126] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A method for calculating dislocation structural energy based on discrete dislocation dynamics, characterized in that: include: Acquiring crystallographic information of a target crystal material and constructing a discrete dislocation dynamics geometric model of the target crystal material; According to the geometric model, based on the dislocation evolution mechanism, the dynamic evolution process of dislocations in the target crystal material during plastic deformation is simulated; the dynamic evolution process is used to describe the dynamic distribution and morphological changes of dislocations in the target crystal material; Based on discrete dynamics theory, the stress and strain caused by plastic deformation of the target crystal material are decomposed into an elastic field generated by dislocations in an infinite continuous medium and an additional field for correcting real boundary conditions, so as to obtain the stress and strain generated by the actual plastic deformation of the target crystal material; The dislocation structural energy in the target crystal material is derived using a free energy calculation formula based on the obtained stress and strain generated during the actual plastic deformation of the target crystal material.

2. The method according to claim 1, characterized in that The method of simulating the dynamic evolution of dislocations of the target crystal material during plastic deformation according to the geometric model and based on the dislocation evolution mechanism comprises: Determine the initial dislocation configuration of the target crystal material and apply a preset shear stress to the discrete dislocation dynamics model ; When the shear stress After the dislocation source intensity exceeds the preset time, the Burgers vector is The edge dislocation nucleates from the dislocation source and continues to slide along the corresponding slip plane. The dislocation nucleation time for: ； in is a constant related to the dislocation drag coefficient, is the length of the dislocation source. When the attraction between dislocations is equal to the applied shear stress nuc At equilibrium, the diameter of the initial dislocation ring is for: ； where G is the shear modulus, v is Poisson's ratio, is the dislocation source strength, which is obtained through experimental data. The sliding speed of dislocations between pinning obstacles is for: ； in, is the Boltzmann constant, is the representative distance of cooperative dislocation slip, is the atomic vacancy volume, It is the temperature The vacancy equilibrium concentration under is the vacancy diffusion coefficient.

3. The method according to claim 2, characterized in that The stress and strain generated during the actual plastic deformation of the target crystal material are respectively the superposition of the corresponding elastic field and the additional field; The strain generated during actual plastic deformation is expressed as: ； in, is the actual strain, is the strain field of the dislocation, is the additional field of strain; The stress generated during actual plastic deformation is expressed as: ； in, is the actual stress, is the stress field of the dislocation, is the additional field of stress.

4. The method according to claim 3, characterized in that The additional fields are solved using numerical analysis methods, including but not limited to the finite element method, the boundary element method or the discrete element method; The elastic field is calculated using the elastic mechanics theory, specifically the superposition of all dislocation elastic fields; in, It is expressed as: ； in, Indicates dislocations, N represents the number of dislocations, Indicates The elastic field strain of a dislocation; It is expressed as: ； in, Indicates The elastic field stress of a dislocation.

5. The method according to claim 4, characterized in that: No. The elastic field stress of a dislocation is expressed as: ； in: ； ； ； in, is the shear modulus, is the Burgers vector, is Poisson's ratio, , is the coordinate of the current dislocation in the local coordinate system; No. The elastic field strain of a dislocation is expressed as: ； in: ； ； 。 6. The method according to claim 5, characterized in that: The free energy calculation formula is expressed as: ； The method of deducing the dislocation structural energy in the target crystal material by using a free energy calculation formula based on the obtained stress and strain generated during the actual plastic deformation of the target crystal material comprises: Free energy during plastic deformation The stored energy associated with the dislocation and elastic storage energy composition, is the dislocation strain energy and dislocation structure energy The sum of the free energy is expressed as: ； Due to the singularity of the dislocation stress-strain field, the free energy is further determined according to the free energy calculation formula as: ； Among them, the elastic storage energy related to remote loading can be expressed as: ； in, and are the stress field and strain field when the same external force is applied to a pure elastic body with the same geometric shape; that is, the dislocation structure energy It is expressed as: 。

Images