Methods, systems, devices, and storage media for predicting surface stresses of a structural material

Abstract

The application discloses a method, system, device and storage medium for predicting surface stress of structural materials, and belongs to the technical field of new materials.The first principle method is used to predict the surface stress of the structural material, the energy of the bulk and the surface structure of the structural material in the same orientation is obtained through the first principle relaxation calculation, the lattice parameters of the bulk and the surface structure are obtained, the strain tensor is loaded on the bulk and the surface structure only in the x and y directions, the change of the energy of each with the strain tensor is calculated, the quadratic polynomial fitting is used, and the surface stress is predicted.The method is not only simple in calculation model and moderate in calculation amount, but also can quickly and accurately predict the size of the surface stress without complicated experimental steps.Based on the high efficiency and accuracy, the method is expected to be widely applied in various material research fields, and is helpful to in-depth understanding of complex phenomena such as crack tip stress concentration in elastic-plastic mechanics.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology, and specifically relates to a method, system, device and storage medium for predicting surface stress of structural materials. Background Technology

[0002] Truncation of a metallic crystal induces layer relaxation and surface reconstruction, altering the surface structure or parameters. Experimental results show that after layer relaxation, surface atoms in transition metals tend to contract inward, while those in noble metals relax outward. The relaxation of surface atoms typically affects the relaxation of the subsurface layer. Layer relaxation is closely related to the surface stress τ of the metal; that is, the surface stress τ is a quadratic function of the amount of layer relaxation. Surface stress τ is a tensor defined by the reversible work consumed by elastically stretching a unit surface. Surface stress helps in understanding typical cases of stress concentration at crack tips in elastoplastic mechanics.

[0003] Currently, directly measuring surface stress τ is quite challenging. Most obtained τ data comes from reasonable extrapolations of liquid-phase measurements, but this is limited to isotropic crystals and not applicable to specific surface orientations. Therefore, theoretical research on these properties is crucial. Two theoretical methods are frequently used to determine surface stress τ in the prior art: semi-empirical molecular dynamics methods, which, while fast and economical in understanding the trends of surface energy in various materials, have questionable reliability and accuracy; and first-principles methods, which provide reliable data but are computationally expensive. To address the high computational cost of first-principles methods, some existing technologies combine them with other methods to reduce computational costs. For example, patent CN 116230136A proposes a machine learning-based method for predicting the mechanical properties of titanium alloys. This patent first obtains raw data through experiments on the mechanical properties of titanium alloys and first-principles calculations; then, it calculates feature descriptors based on the alloy composition in the raw data to obtain the raw data for training the machine learning model, constructs the machine learning model, and finally uses the trained machine learning model to predict the mechanical properties of titanium alloys. While this method can reduce computational costs, it requires designing multiple mechanical experiments to obtain a large amount of data, making the entire prediction process quite complex. Summary of the Invention

[0004] To address the above problems, in a first aspect, the present invention proposes a method for predicting surface stress of structural materials, comprising the following steps:

[0005] Build a metal structure model of the structural material to obtain the lattice parameters of the bulk structure and the lattice parameters of the corresponding surface structure;

[0006] In the metal structure model, strain tensors are applied to the bulk structure and the corresponding surface structure with the same orientation of the structural material, and atomic relaxation is performed to obtain the first system energy of the bulk structure and the second system energy of the surface structure.

[0007] By fitting the functional relationships between the energy and strain tensor of the first system and the energy and strain tensor of the second system respectively, the linear fitting coefficients of the bulk structure and the linear coefficients of the surface structure are determined.

[0008] The predicted surface stress value of the structural material is determined based on the linear fitting coefficient of the block structure and the linear coefficient of the surface structure.

[0009] Furthermore, the construction of the metal structure model of the structural material includes the following steps:

[0010] Establish the unit cell structure of the metallic structure of structural materials;

[0011] Based on the unit cell structure, a bulk structure of the metal structure is established, a supercell bulk structure is obtained, and the lattice parameters of the bulk structure are obtained.

[0012] Based on the supercellular bulk structure, the vacuum layer thickness is set to construct the surface structure of the metal structure and the lattice parameters of the corresponding surface structure are obtained.

[0013] Furthermore, the lattice parameters of the bulk structure are the same as the lattice parameters a and b of the corresponding surface structure;

[0014] Where a is the length of the block structure or corresponding surface structure along a specific edge; b is the width of the block structure or surface structure that is in the same plane as a.

[0015] Furthermore, the same orientation means that both the bulk structure and the surface structure are (001) crystal plane, (0001) crystal plane, (111) crystal plane or (110) crystal plane.

[0016] Furthermore, the strain tensor is applied in the x and y directions of the bulk structure and the surface structure;

[0017] The x-direction is the direction of the length a of the block structure or the corresponding surface structure, and the y-direction is the direction of the width b of the block structure or the surface structure.

[0018] Furthermore, the energy of the first system is the result obtained by first-principles relaxation calculation after the lattice parameters of the bulk structure are changed by applying strain tensors in the x and y directions;

[0019] The second system energy is the result obtained by first-principles relaxation calculation after the lattice parameters of the surface structure are changed by applying strain tensors in the x and y directions.

[0020] Furthermore, the functional relationship between the energy and strain tensor of the first system is as follows:

[0021]

[0022] The functional relationship between the energy and strain tensor of the second system is as follows:

[0023]

[0024] Among them, E b (ε) and E s (ε) represent the first system energy of the bulk structure and the second system energy of the surface structure after applying the strain tensor, respectively; ε represents the strain tensor; E b (0) and E s (0) represents the first system energy of the bulk structure without applied strain tensor and the second system energy of the surface structure, respectively; and These represent the linear fitting coefficient and the quadratic term coefficient in the functional relationship obtained by fitting the first system energy and strain tensor of the bulk structure, respectively. and These represent the linear coefficients and quadratic coefficients in the functional relationship obtained by fitting the second system energy and strain tensor of the surface structure, respectively.

[0025] Furthermore, the surface stress of the structural material is determined using the following formula based on the linear fitting coefficient of the block structure and the linear coefficient of the surface structure:

[0026]

[0027] S=a×b×sin(120 / 180)π

[0028] Where τ represents the predicted surface stress of the structural material. The linear coefficients are those in the functional relationship obtained by fitting the second system energy and strain tensor of the surface structure. denoted as the linear fitting coefficient in the functional relationship obtained by fitting the first system energy and strain tensor of the block structure, and S is the surface area of ​​the plane containing the length a and width b of the block structure or the corresponding surface structure.

[0029] Secondly, this invention proposes a system for predicting surface stress of structural materials, comprising the following steps:

[0030] Metal structure model building unit is used to build metal structure models of structural materials and obtain the lattice parameters of the bulk structure and the lattice parameters of the corresponding surface structure.

[0031] The system energy determination unit is used to apply strain tensors and perform atomic relaxation on the bulk structure and corresponding surface structure with the same orientation of the structural material in the metal structure model to obtain the first system energy of the bulk structure and the second system energy of the surface structure.

[0032] A linear relationship fitting unit is used to fit the functional relationships between the energy and strain tensor of the first system and the energy and strain tensor of the second system, respectively, to determine the linear fitting coefficients of the bulk structure and the linear coefficients of the surface structure.

[0033] A surface stress prediction unit is used to determine the predicted surface stress value of the structural material based on the linear fitting coefficient of the block structure and the linear coefficient of the surface structure.

[0034] Thirdly, the present invention proposes an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0035] Memory, which stores computer programs;

[0036] A processor, when executing a program stored in a memory, implements the method for predicting surface stress of structural materials.

[0037] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, which, when run, performs the method for predicting the surface stress of structural materials.

[0038] The beneficial effects of this invention are:

[0039] This invention employs a first-principles method to predict the surface stress of structural materials. Through first-principles relaxation calculations, the energy of the bulk and surface structures of the structural material under the same orientation is obtained, along with their lattice parameters. Strain tensors are applied to the bulk and surface structures only in the x and y directions, and the energy variation with the strain tensor is calculated. A quadratic polynomial is then used for fitting to predict the surface stress. This method not only features a simple computational model and moderate computational cost, but also eliminates the need for cumbersome experimental procedures, enabling rapid and accurate prediction of surface stress magnitude. Based on its efficiency and accuracy, this method is expected to be widely applied in various materials research fields and will contribute to a deeper understanding of complex phenomena such as stress concentration at crack tips in elastoplastic mechanics.

[0040] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 A flowchart of a method for predicting surface stress of structural materials proposed in this invention is shown;

[0043] Figure 2 A schematic diagram of the close-packed hexagonal titanium metal structure material in an embodiment of the present invention is shown;

[0044] Figure 3A This diagram illustrates a 10-layer bulk structure formed by expanding a titanium metal single-cell structure in an embodiment of the present invention.

[0045] Figure 3B An embodiment of the present invention is shown. Figure 3A A schematic diagram of the surface structure formed by adding a vacuum layer to a 10-layer block structure;

[0046] Figure 4 A schematic diagram of a system for predicting surface stress of structural materials, as proposed in an embodiment of the present invention, is shown.

[0047] Figure 5 A schematic diagram of an electronic device proposed in an embodiment of the present invention is shown. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] This invention proposes a method for predicting surface stress in structural materials, such as... Figure 1 As shown, it includes the following steps:

[0050] S1: Construct a metal structure model of the structural material and obtain the lattice parameters of the bulk structure and the surface structure in the metal structure model;

[0051] It should be noted that the number of bulk structures and surface structures is not limited in this invention. Generally, complete lattice parameters are described by three lattice constants and three included angles (e.g., These parameters (which can be obtained directly through software) collectively determine the crystal's geometry and symmetry. The lattice constant is typically on the order of a few angstroms (i.e., a few tenths of a nanometer) and can be determined using techniques such as X-ray diffraction and atomic force microscopy.

[0052] Where 'a' represents the length of the bulk structure or corresponding surface structure along a specific edge; 'b' represents the width of the bulk structure or corresponding surface structure in the same plane as 'a'; and 'c' represents the side length of the plane perpendicular to the edges 'a' and 'b' in the bulk structure or corresponding surface structure. Since the surface structure is based on the bulk structure, the lattice parameters 'a' and 'b' of the surface structure are the same as those of the bulk structure. Therefore, when calculating surface stress, the lattice parameters of both structures change synchronously.

[0053] The construction of the metal structure model of the structural material includes the following steps:

[0054] S1.1: Establish the unit cell structure of the metallic structure of the structural material;

[0055] S1.2: Based on the unit cell structure, establish an n-layer bulk structure of the metal structure to obtain a supercell bulk structure and obtain the lattice parameters of the bulk structure;

[0056] S1.3: Based on the supercellular bulk structure, set the vacuum layer thickness to build an n-layer surface structure of the metal structure and determine the corresponding lattice parameters of the surface structure.

[0057] S2: In the metal structure model, strain tensors are applied to the bulk structure and corresponding surface structure with the same orientation of the structural material, and atomic relaxation is performed to obtain the first system energy of the bulk structure and the second system energy of the surface structure.

[0058] Atomic relaxation refers to the process by which an atomic nucleus or atomic system gradually returns to an equilibrium state from a non-equilibrium state in a gradual change physics process.

[0059] Specifically, in this step, the first system energy of the bulk structure and the second system energy of the surface structure are the results obtained by first-principles atomic relaxation calculations after the lattice parameters of the bulk structure and surface structure in the x and y directions have changed. For example, they can be calculated using first-principles relaxation calculation software (such as VASP, LAMMPS, etc.).

[0060] It should be noted that the same orientation means that both the bulk structure and the surface structure are (001) or (0001) or (111) or (110) crystal planes.

[0061] Among them, (001) crystal plane means that the plane formed by the arrangement of atoms in the crystal is on the xy plane, and the z-axis direction is perpendicular to the plane.

[0062] (0001) In a hexagonal or trigonal crystal system, a crystal plane usually represents a plane perpendicular to the c-axis, in which the a-axis and b-axis lie in the plane.

[0063] (111) A crystal plane represents a plane formed by three axes of equal length, which form an equilateral triangle in space.

[0064] (110) The crystal plane represents a plane parallel to the c-axis, and the intercepts of the plane with the x and y axes are equal.

[0065] S3: Fit the functional relationships between the energy and strain tensor of the first system and the energy and strain tensor of the second system respectively to determine the linear fitting coefficients of the bulk structure and the linear coefficients of the surface structure;

[0066] The functional relationship between the energy and strain tensor of the first system is as follows:

[0067]

[0068] The functional relationship between the energy and strain tensor of the second system is as follows:

[0069]

[0070] Among them, E b (ε) and E s (ε) represent the first system energy of the bulk structure and the second system energy of the surface structure after applying the strain tensor, respectively; ε represents the strain tensor; E b (0) and E s (0) represents the first system energy of the bulk structure without applied strain tensor and the second system energy of the surface structure, respectively; and These represent the linear fitting coefficient and the quadratic term coefficient in the functional relationship obtained by fitting the first system energy and strain tensor of the bulk structure, respectively. and These represent the linear coefficients and quadratic coefficients in the functional relationship obtained by fitting the second system energy and strain tensor of the surface structure, respectively.

[0071] S4: Determine the predicted surface stress value of the structural material based on the linear fitting coefficient of the block structure and the linear coefficient of the surface structure, using the following formula:

[0072]

[0073] S=a×b×sin(120 / 180)π

[0074] Where τ represents the predicted surface stress of the structural material. and Let S represent the linear coefficients in the functional relationship between the second system energy and strain tensor of the surface structure and the linear fitting coefficients in the functional relationship between the first system energy and strain tensor of the bulk structure, respectively. S is the surface area of ​​the plane containing the length a and width b of the bulk structure or the corresponding surface structure.

[0075] In an exemplary embodiment of the present invention, the surface stress of close-packed hexagonal titanium is predicted using the method for predicting surface stress of structural materials proposed in this invention. In this embodiment, the bulk structure and surface structure are directly constructed, and atomic relaxation is then performed directly. The specific process is as follows:

[0076] S1: Construct a close-packed hexagonal titanium metal structure using Materials Studio software, and obtain the lattice parameters of the bulk structure and the corresponding surface structure in the metal structure model; the specific process is as follows:

[0077] (1.1) In the Materials Studio software, click File-Import-Structures-metals-pure-metals-Ti.msi in sequence to complete the construction of a close-packed hexagonal unit cell structure of titanium.

[0078] (1.2) Click Build-Symmetry-Supercell in sequence, and set A, B, C (A and B represent the expansion multiples of the unit cell structure in three different directions) to 1, 1, n respectively (n is the number of layers of the bulk structure and the corresponding surface structure, which can generally be 6, 7, 8...). Click Create Supercell to complete the construction of an n-layer bulk structure of a close-packed hexagonal supercell of titanium.

[0079] (1.3) For the n-layer block structure of the constructed supercell, click Build-Surfaces-CleaveSurface in sequence. In the Surface Box column, set (hkl) to (0 0 1) and in the Surface Mesh column, set U(1 0 0) and V(0 1 0) (U and V represent the two crystal orientation indices when the block structure is cut). Click Cleave to obtain a surface structure with a (0 01) surface. Then click Build-Crystals-Build Vacuum Slab Crystal in sequence. Set Vacuumthickness to The software will add vacuum layers above and below the cut surface structure to complete the construction of the n-layer surface structure of the close-packed hexagonal supercell of titanium metal, thus completing the construction of the close-packed hexagonal titanium metal structure.

[0080] S2: For the n-layer bulk structure and n-layer surface structure obtained in (1.2) and (1.3) respectively, apply 0.98, 0.99, 1.00, 1.01, and 1.02 in the x and y directions respectively, and use the Vasp program to perform atomic relaxation. The first system energy E is obtained after convergence. b (0.98), E b (0.99), E b (1.00), E b (1.01), E b (1.02) and the energy E of the second system s (0.98), E s (0.99), E s (1.00), E s (1.01), E s (1.02).

[0081] It should be noted that Vasp is a computer program package for atomic-scale materials simulation, and its main function is to solve problems through approximate methods. The equations are used to obtain the electronic states and energies of the system.

[0082] S3: Based on the first system energy of the bulk structure and the second system energy of the surface structure obtained in step S2, use a quadratic polynomial equation. Fit the energy E of the first system respectively b The relationship between the strain tensor ε and the energy E of the second system s The functional relationship between the strain tensor ε and the linear fitting coefficients of the bulk structure are used to determine the linear fitting coefficients. and the linear coefficient of surface structure

[0083] S4: Determine the predicted surface stress value of the surface structure material based on the linear fitting coefficients and the linear coefficients of the surface structure obtained in step S3; the formula for calculating surface stress is as follows:

[0084]

[0085] Where τ represents the predicted surface stress of the structural material. and Let S = a × b × sin(120 / 180)π, representing the linear coefficients in the functional relationship between the second system energy and strain tensor of the surface structure and the linear fitting coefficients in the functional relationship between the first system energy and strain tensor of the bulk structure, respectively. Then, the surface stress value of the close-packed hexagonal metal Ti(0001) surface can be obtained.

[0086] The following combinations are as follows Figure 2The close-packed hexagonal titanium metal shown is an example of the above method. In this embodiment, the lattice parameters of the unit cell are first obtained through lattice relaxation, then the bulk structure and surface structure are built, and atomic relaxation is subsequently performed. The specific process is as follows:

[0087] S1: Use Materials Studio software to build a close-packed hexagonal titanium metal structure model. The completed metal structure model includes 10 layers of block structure and 10 layers of surface structure.

[0088] The specific process is as follows:

[0089] (1.1) Constructing a close-packed hexagonal unit cell structure of titanium: In Materials Studio software, click File-Import-Structures-metals-pure-metals-Ti.msi, delete all atoms, then click Build-Add Atoms, select Ti in Element, first set (a,b,c) (representing the fractional coordinates of the atom positions in the x, y, and z directions of the unit cell structure) to (0,0,0), then click add. Next, set (a,b,c) to (0.6667,0.3333,0.5), then click add again. This completes the construction of the close-packed hexagonal unit cell structure of titanium. Figure 2 As shown.

[0090] (1.2) Determine lattice parameters and lattice relaxation: Right-click the mouse and select Lattice Parameters. You can find that the lattice parameters are a = b = 2.9506 and c = 4.6788. Use the Vasp program to perform lattice relaxation and obtain the latest lattice parameters a = b = 2.9413 and c = 4.6394.

[0091] Steps (1.1)-(1.2) perform lattice relaxation on the constructed unit cell structure to obtain the most stable system energy and corresponding lattice parameters. Lattice relaxation refers to the change in lattice position during electron transitions. When the luminescent central ion is excited, the distribution of the electron cloud changes, which in turn alters the surrounding electric field. This change in electric field affects the lattice ions, causing their equilibrium points to shift. When the electron transitions back to the ground state, the lattice position also changes.

[0092] (1.3) Click Build-Symmetry-Supercell in sequence, set A, B, and C to 1, 1, and 5 respectively, and click Create Supercell to complete the construction of a 10-layer block structure of a close-packed hexagonal supercell of titanium. Figure 3A As shown, the latest lattice parameters are a = b = 2.9413 and c = 23.1968.

[0093] (1.4) For Figure 3A To create a supercellular block structure, click Build-Surfaces-Clear Surface. In the Surface Box field, set (hkl) to (0 0 1), and in the Surface Mesh field, set U(1 0 0) and V(0 1 0). Click Clear, then click Build-Crystals-Build Vacuum Slab Crystal. Set Vacuumthickness to... A 10-layer surface structure of close-packed hexagonal supercells of titanium was successfully constructed, such as... Figure 3B As shown, the latest lattice parameters are a = b = 2.9413 and c = 30.8771.

[0094] S2: Apply strains of 0.98, 0.99, 1.00, 1.01, and 1.02 in the x and y directions, respectively, to the 10-layer bulk structure and 10-layer surface structure obtained in step S1. Perform atomic relaxation using the Vasp program and obtain the first system energy E upon convergence. b (0.98), E b (0.99), E b (1.00), E b (1.01), E b (1.02) and the energy E of the second system s (0.98), E s (0.99), E s (1.00), E s (1.01), E s (1.02), detailed values ​​are shown in Table 1:

[0095] Table 1 Energy E of the First System b (ε) and the energy of the second system E s (ε) The change of strain tensor ε with loading

[0096] 0.98 0.99 1.00 1.01 1.02 <![CDATA[E b (e)]]> -79.291279 -79.378404 -79.405819 -79.376951 -79.296131 <![CDATA[E s (e)]]> -77.506132 -77.559006 -77.56819 -77.534814 -77.459921

[0097] S3: According to the first system energy E in Table 1 b (ε) and the energy of the second system E s (ε) The variation of the strain tensor ε under loading is expressed using a quadratic polynomial equation. Fitted total energy E s / b The functional relationship between (ε) and the strain tensor ε is given by the following functional relationship:

[0098] E b (ε)=E b (0)-0.08251ε+280.12357ε2

[0099] E s (ε)=E s (0)+1.16614ε+212.92429ε 2

[0100] At this point, the linear fitting coefficient of the block structure linear coefficient of surface structure

[0101] S4: Calculate the surface stress based on the linear fitting coefficients of the block structure and the linear coefficients of the surface structure obtained in step S3. The calculation formula is as follows:

[0102]

[0103] in, The result is τ = 0.66 J / m. 2 The surface stress of the close-packed hexagonal Ti(0001) metal facet is 0.66 J / m. 2 .

[0104] Based on the same inventive concept, this invention proposes a system for predicting surface stress of structural materials, such as... Figure 4 As shown, it includes:

[0105] Metal structure model building unit is used to build metal structure models of structural materials and obtain the lattice parameters of the bulk structure and the lattice parameters of the corresponding surface structure.

[0106] The system energy determination unit is used to apply strain tensors and perform atomic relaxation on the bulk structure and corresponding surface structure with the same orientation of the structural material in the metal structure model to obtain the first system energy of the bulk structure and the second system energy of the surface structure.

[0107] A linear relationship fitting unit is used to fit the functional relationships between the energy and strain tensor of the first system and the energy and strain tensor of the second system, respectively, to determine the linear fitting coefficients of the bulk structure and the linear coefficients of the surface structure.

[0108] A surface stress prediction unit is used to determine the predicted surface stress value of the structural material based on the linear fitting coefficient of the block structure and the linear coefficient of the surface structure.

[0109] The execution steps of the metal structure model building unit, system energy determination unit, linear relationship fitting unit, and surface stress prediction unit are similar to those described above, and will not be explained in detail here.

[0110] Another exemplary embodiment of the present invention provides an electronic device. For example... Figure 5As shown, the electronic device includes at least one processor 501, at least one communication interface 502, at least one memory 503, and at least one communication bus 504; wherein the processor 501, communication interface 502, and memory 503 communicate with each other through the communication bus 504.

[0111] Memory 503 stores computer programs;

[0112] The processor 501 is used to execute the program stored in the memory 503 to implement the method for predicting the surface stress of structural materials.

[0113] Optionally, the communication interface can be an interface of a communication module, such as the interface of a GSM module; the processor may be a CPU, an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The memory may include high-speed RAM and may also include non-volatile memory, such as at least one disk storage device. The memory stores a program, and the processor calls the program stored in the memory to execute some or all of the above-described method embodiments.

[0114] Based on the same inventive concept, embodiments of this application also provide a computer-readable storage medium storing a computer program, which, when executed, implements some or all of the above-described method embodiments. Optionally, the storage medium may be a non-transitory computer-readable storage medium, such as a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0115] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for predicting surface stress of structural materials, characterized in that, Includes the following steps: Build a metal structure model of the structural material to obtain the lattice parameters of the bulk structure and the lattice parameters of the corresponding surface structure; In the metal structure model, strain tensors are applied to the bulk structure and the corresponding surface structure with the same orientation of the structural material, and atomic relaxation is performed to obtain the first system energy of the bulk structure and the second system energy of the surface structure. By fitting the functional relationships between the energy and strain tensor of the first system and the energy and strain tensor of the second system respectively, the linear fitting coefficients of the bulk structure and the linear coefficients of the surface structure are determined. The predicted surface stress value of the structural material is determined based on the linear fitting coefficient of the block structure and the linear coefficient of the surface structure.

2. The method for predicting surface stress of structural materials according to claim 1, characterized in that, The construction of the metal structure model of the structural material includes the following steps: Establish the unit cell structure of the metallic structure of structural materials; Based on the unit cell structure, a bulk structure of the metal structure is established, a supercell bulk structure is obtained, and the lattice parameters of the bulk structure are obtained. Based on the supercellular bulk structure, the vacuum layer thickness is set to construct the surface structure of the metal structure and the lattice parameters of the corresponding surface structure are obtained.

3. The method for predicting surface stress of structural materials according to claim 1 or 2, characterized in that, The lattice parameters of the bulk structure are the same as the lattice parameters a and b of the corresponding surface structure; Where a is the length of the block structure or corresponding surface structure along a specific edge; b is the width of the block structure or surface structure that is in the same plane as a.

4. The method for predicting surface stress of structural materials according to claim 1, characterized in that, The same orientation means that both the bulk structure and the surface structure are (001) crystal plane, (0001) crystal plane, (111) crystal plane or (110) crystal plane.

5. The method for predicting surface stress of structural materials according to claim 3, characterized in that, The strain tensor is applied in the x and y directions of the bulk structure and the surface structure; The x-direction is the direction of the length a of the block structure or the corresponding surface structure, and the y-direction is the direction of the width b of the block structure or the surface structure.

6. The method for predicting surface stress of structural materials according to claim 5, characterized in that, The energy of the first system is the result obtained by first-principles relaxation calculation after the lattice parameters of the bulk structure are changed by applying strain tensors in the x and y directions; The second system energy is the result obtained by first-principles relaxation calculation after the lattice parameters of the surface structure are changed by applying strain tensors in the x and y directions.

7. The method for predicting surface stress of structural materials according to claim 1, characterized in that, The functional relationship between the energy and strain tensor of the first system is as follows: The functional relationship between the energy and strain tensor of the second system is as follows: Among them, E b (ε) and E s (ε) represent the first system energy of the bulk structure and the second system energy of the surface structure after applying the strain tensor, respectively; ε represents the strain tensor; E b (0) and E s (0) represents the first system energy of the bulk structure without applied strain tensor and the second system energy of the surface structure, respectively; and These represent the linear fitting coefficient and the quadratic term coefficient in the functional relationship obtained by fitting the first system energy and strain tensor of the bulk structure, respectively. and These represent the linear coefficients and quadratic coefficients in the functional relationship obtained by fitting the second system energy and strain tensor of the surface structure, respectively.

8. The method for predicting surface stress of structural materials according to claim 6, characterized in that, The surface stress of the structural material is determined using the following formula based on the linear fitting coefficient of the block structure and the linear coefficient of the surface structure: S=a×b×sin(120 / 180)π Where τ represents the predicted surface stress of the structural material. The linear coefficients are those in the functional relationship obtained by fitting the second system energy and strain tensor of the surface structure. denoted as the linear fitting coefficient in the functional relationship obtained by fitting the first system energy and strain tensor of the block structure, and S is the surface area of ​​the plane containing the length a and width b of the block structure or the corresponding surface structure.

9. A system for predicting surface stress of structural materials, characterized in that, Includes the following steps: Metal structure model building unit is used to build metal structure models of structural materials and obtain the lattice parameters of the bulk structure and the lattice parameters of the corresponding surface structure. The system energy determination unit is used to apply strain tensors and perform atomic relaxation on the bulk structure and corresponding surface structure with the same orientation of the structural material in the metal structure model to obtain the first system energy of the bulk structure and the second system energy of the surface structure. A linear relationship fitting unit is used to fit the functional relationships between the energy and strain tensor of the first system and the energy and strain tensor of the second system, respectively, to determine the linear fitting coefficients of the bulk structure and the linear coefficients of the surface structure. A surface stress prediction unit is used to determine the predicted surface stress value of the structural material based on the linear fitting coefficient of the block structure and the linear coefficient of the surface structure.

10. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, which stores computer programs; A processor, when executing a program stored in a memory, implements the method for predicting surface stress of a structural material as described in any one of claims 1-8.

11. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is run, it performs the method for predicting surface stress of structural materials as described in any one of claims 1-8.

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