Method for constructing database on deformation and stress of material

Abstract

One embodiment of the present invention provides a method for constructing a database on deformation and stress of a material, the method comprising: a step of generating a probability-based model in which the irregular distribution of elements is reflected; a structure optimization step of optimizing the structure of the model; a deformation calculation step of creating a series of strained models by deforming the optimized model, and calculating physical properties in the desired direction; and a data analysis step of extracting a tensile test result by using the calculated data. Therefore, a prediction about the physical properties of a material to be developed is provided so that experiments can be efficiently planned and empirical trials and errors can be reduced.

Description

Method for building a database on material deformation and stress

[0001] The present invention relates to a method for constructing a database on deformation and stress of a material, and more particularly, to a method for constructing a database on deformation and stress of a material, which enables efficient planning of experiments and reduction of empirical trial and error through prediction of the properties of a material to be developed.

[0002] Ceramic materials are relatively hard and light, yet exhibit high resistance to corrosive conditions such as acids and bases, and have been used and applied in various fields such as tiles, pottery, high-temperature insulation, and electronic materials since ancient times.

[0003] Before such a wide range of applications can be realized, the physical properties of new materials, such as deformation and stress, must be precisely identified to ensure their usability in diverse environments. Accordingly, research into the physical properties of materials with novel compositions is ongoing.

[0004] When attempting to perform tensile tests on new compositions, the challenge lies in manufacturing ceramic specimens, either through direct experimental tensile testing or through virtual tensile testing using parameters derived from various other tests. Therefore, there is a need for computational simulation techniques that can reduce direct costs and time, predicting theoretical changes in material properties due to tensile changes, and suggesting directions for material development.

[0005] (Patent Document 1) JP 2023-062527

[0006] The technical task to be achieved by the present invention is to provide a method for constructing a database on deformation and stress of a material that can predict theoretical changes in material properties according to tensile changes and suggest directions for material development through computer simulation techniques, thereby reducing direct costs and time consumption required for property change experiments and material development tests.

[0007] The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0008] In order to achieve the above technical task, one embodiment of the present invention provides a method for constructing a database on deformation and stress of a material, including: a step of generating a probability-based model reflecting an irregular distribution of elements; a structural optimization step of optimizing the structure of the model; a deformation calculation step of creating a series of strained models by applying deformation to the optimized model and calculating material properties in a desired direction; and a data analysis step of extracting tensile test results using the calculated data.

[0009] In an embodiment of the present invention, the step of generating the probability-based model may be characterized by performing the step of selecting a model capable of first-principle calculation by setting a decision orientation.

[0010] In an embodiment of the present invention, in the step of generating the probability-based model, the prototype of the model may be characterized by having a cubic or hexagonal structure.

[0011] In an embodiment of the present invention, the deformation calculation step may be characterized by setting a maximum deformation rate and generating a plurality of models for each deformation to perform the calculation.

[0012] In an embodiment of the present invention, the deformation calculation step may be characterized by performing structural optimization of the remaining axes excluding the deformed direction in order to predict accurate stress according to the size of the deformation.

[0013] In an embodiment of the present invention, the data interpretation step may be characterized by measuring stress according to the size and direction of deformation, and extracting and organizing data together with pre-input strain.

[0014] In an embodiment of the present invention, it may be characterized in that when there is an error in the data in the data interpretation step, the structure of the model is optimized again and deformation calculation is performed.

[0015] According to an embodiment of the present invention, by providing a prediction of the properties of a material to be developed, experiments can be efficiently planned and empirical trial and error can be reduced.

[0016] Specifically, the cost of performing tensile tests can be reduced through computer simulation. While actual tensile tests require ceramic specimens of a certain size or larger, equipment, time, and cost, computer simulation can reduce these costs and obtain results faster than performing actual tests.

[0017] In order to perform actual tensile tests, it is necessary to sinter ceramic specimens to a high density, and sintering unverified compositions also requires a high level of technology, so in contrast, the compositions can be efficiently modeled in virtual space.

[0018] This provides the advantage of simulating conditions that are difficult in real experiments, as the design can be optimized and experimental conditions can be controlled more precisely.

[0019] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the composition of the invention described in the claims.

[0020] Figure 1 is a flowchart of a method for constructing a database on deformation and stress of a material of the present invention.

[0021] Figures 2a to 2c are graphs showing the steps of establishing structural optimization conditions of an initial model for virtually conducting a tensile test.

[0022] Figure 3 is an image showing the prototype of the model.

[0023] Figure 4 is an image showing the deformation calculation step that calculates the material properties by applying deformation to the model.

[0024] Figures 5a to 5d are tensile stress-strain curves for the X-axis in the data interpretation stage.

[0025] Figures 6a to 6d are tensile stress-strain curves along the Z-axis in the data interpretation stage.

[0026] Figure 7 shows the interpretation and database creation of data in the data interpretation stage.

[0027] Figure 8 shows a specific example manufactured through a method for constructing a database for material deformation and stress.

[0028] Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention can be implemented in various different forms and is therefore not limited to the embodiments described herein. In the drawings, irrelevant parts have been omitted for clarity of description, and similar parts have been designated with similar reference numerals throughout the specification.

[0029] Throughout the specification, when a part is said to be "connected (connected, contacted, or coupled)" to another part, this includes not only cases where it is "directly connected," but also cases where it is "indirectly connected" with another part in between. Furthermore, when a part is said to "include" a component, this does not exclude other components, but rather implies that it may include other components, unless otherwise specifically stated.

[0030] The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0031] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0032]

[0033] As research into the development of new materials with novel compositions for diverse environmental applications continues, research on their physical properties is also steadily progressing. However, conducting actual experiments, such as tensile testing, in this material development process presents challenges in manufacturing specimens. Furthermore, direct costs and significant time consumption are incurred. Therefore, computational simulation techniques are needed to predict theoretical changes in physical properties due to tensile changes and to suggest directions for material development.

[0034] Accordingly, the present invention provides a method for constructing a database on material deformation and stress to solve these problems.

[0035] Figure 1 is a flowchart of a method for constructing a database for deformation and stress of a material according to the present invention. Referring to Figure 1, a method for constructing a database for deformation and stress of a material according to an embodiment of the present invention will be described.

[0036] A method for constructing a database for deformation and stress of a material according to one embodiment of the present invention may include a step of generating a probability-based model reflecting an irregular distribution of elements; a structural optimization step of optimizing the structure of the model; a deformation calculation step of applying deformation to the optimized model to create a series of strained models and calculating material properties in a desired direction; and a data interpretation step of extracting tensile test results using the calculated data.

[0037] A tensile test is a method for determining the mechanical properties of a material. It involves applying force to a material specimen and measuring its response to tensile stress. It is the most fundamental test, determining mechanical properties such as tensile strength, yield point, elongation, and shrinkage of area, as well as physical properties such as elastic limit, proportional limit, Poisson's ratio, and elastic modulus. A tensile test graph is broadly divided into elastic and plastic deformation regions.

[0038] The present invention aims to develop a virtual tensile testing code to identify the characteristics of a plastic deformation region. Specifically, the core feature of the invention is the use of a tensile test to determine the elastic modulus of the plastic deformation region, and for this purpose, the strain-stress technique is introduced. The strain-stress technique predicts stress according to the magnitude of deformation.

[0039] The first step in the method for constructing a database on material deformation and stress according to the present invention is to create a probability-based model. This step involves creating a probability-based model that reflects the irregular distribution of elements.

[0040] A solid solution is a material in which heterogeneous elements are randomly arranged at their lattice points. To conduct a virtual tensile test on the plastic deformation of such a solid solution, a probabilistic model reflecting the irregular distribution of elements is first created.

[0041] The step of generating the above-mentioned probability-based model is performed by setting a decision orientation, generating a model capable of first-principles calculations, and then selecting the model. In other words, the material properties are predicted through first-principles calculations, and this is used to conduct a selection process prior to conducting experiments.

[0042] First-principles calculations, in this context, refer to a fundamental approach to a problem based on firmly established physical laws (electron interactions) without the introduction of any empirical data or experimental data used for fitting. Computationally, this refers to a method of interpreting the properties of a material by calculating the interaction (force) between electrons using the electron density function.

[0043] Figures 2a through 2c are graphs illustrating the initial model's structural optimization conditions for conducting a virtual tensile test. To ensure efficient computational costs, the process begins by finding a stable energy convergence zone for the model with minimal conditions.

[0044] Figure 3 is an image depicting a prototype of a model. Referring to Figure 3, the prototype of the model in the probabilistic model creation step may be cubic or hexagonal, but is not limited to this and can be modified. Depending on the type and amount of elements added to various prototypes, a model capable of automatic first-principles calculations is created.

[0045] The next step is structural optimization, which optimizes the structure of the selected model to obtain structural and energy data.

[0046] The next step is the deformation calculation step, which applies deformation to the above optimized model to create a series of strained models and calculates the material properties in the desired direction.

[0047] The above deformation calculation step sets a maximum strain and performs calculations by generating multiple models for each deformation. To accurately predict stress according to the magnitude of deformation, structural optimization is performed for the remaining axes, excluding the deformed direction.

[0048] For example, the maximum strain can be set to 50% for each embodiment, and calculations can be performed by generating 20 models for each deformation. However, this is only an example, and the maximum strain and number of models can be set arbitrarily.

[0049] Figure 4 is an image illustrating the deformation calculation step for calculating material properties by applying deformation to the model. Referring to Figure 4, by setting the deformation (strain) to 0 to 0.5 (0, 0.1, 0.2, 0.3, 0.4, 0.5), structural optimization can be performed on the remaining axes excluding the deformed direction to accurately predict stress according to the magnitude of such deformation.

[0050] The next step is data interpretation, which is the data interpretation step that extracts tensile test results using the calculated data above.

[0051] This step extracts the tensile test results, called the actual tensile stress-stress curve, using the calculated data. At each point, stress is measured according to the magnitude and direction of deformation, and the data is extracted and organized along with the pre-entered strain. If errors are found in the data, the model structure can be optimized again and deformation calculations performed.

[0052] Figures 5a to 5d are tensile stress-strain curves along the X-axis during the data interpretation phase. These graphs illustrate the stress applied to a material as the material's X-axis strain increases. Through the interpretation of these graphs, the brittle and plastic regions of the material can be identified, and various mechanical properties such as Young's modulus, yield strength, and tensile strength can be predicted.

[0053] Figures 6a through 6d are tensile stress-strain curves along the Z-axis during the data interpretation phase. These graphs depict the stress applied to a material as its Z-axis strain increases. Similar to Figure 5, interpretation of these graphs allows for the identification of the material's brittle and plastic properties and the prediction of various mechanical properties.

[0054] Figure 7 illustrates the data interpretation and database creation process during the data interpretation stage. By creating a database of stress values ​​resulting from deformation of various materials, compositions exhibiting desired properties can be selected.

[0055] In conclusion, the method for constructing a database on material deformation and stress according to the present invention provides predictions of the properties of the material being developed, thereby enabling efficient experimental planning and reducing empirical trial and error. Specifically, computational simulation can reduce the costs of conducting tensile tests. While actual tensile tests require ceramic specimens of a certain size, equipment, time, and money, computational simulation can reduce these costs and produce results faster than actual tests.

[0056]

[0057] Manufacturing example: Model manufactured through a method for building a database on material deformation and stress.

[0058] First, the Vienna ab initio simulation package (VASP) was used to investigate the effects of M, A, and X vacancies on the mechanical behavior in the V2AlC max phase model. 2-x AlC, V2Al 1-x C and V2AlC 1-x formed a vacancy model.

[0059] Next, models were formed according to the vacancy contents (x) of 0.0277, 0.0416, 0.0833, and 0.125 of the above models, and structural optimization calculations were performed.

[0060] Next, the stress was calculated by setting the strain of the above models to (0, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30).

[0061] According to Fig. 8, it can be confirmed that the order of UTS is non-public model > carbon public model > aluminum public model > vanadium public model, with values ​​of 33.528 (ε30.513 (ε26.736 (ε18.944 GPa (ε), respectively.

[0062] This confirms that the presence of vanadium vacancies facilitates physical exfoliation.

[0063] Density functional theory (DFT) results show that it is easy to predict the mechanical properties of a material through stress calculations according to deformation of a model with pores and the interpretation of the resulting graph.

[0064] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0065] The scope of the present invention is indicated by the claims described below, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims

1. A step of creating a probability-based model that reflects the irregular distribution of elements; A structural optimization step for optimizing the structure of the above model; A deformation calculation step for creating a series of strained models by applying deformation to the above optimized model and calculating the material properties in the desired direction; and A method for constructing a database for deformation and stress of a material, comprising a data interpretation step of extracting tensile test results using the calculated data above.

2. In paragraph 1, The step of creating the above probability-based model is: A method for constructing a database for deformation and stress of a material, characterized in that it is performed by selecting a model capable of first-principle calculation by setting a decision orientation.

3. In paragraph 1, A method for constructing a database for deformation and stress of a material, characterized in that in the step of creating the above probability-based model, the prototype of the model has a cubic or hexagonal structure.

4. In paragraph 1, The above transformation calculation step is, A method for constructing a database for deformation and stress of a material, characterized in that the maximum strain is set and calculations are performed by creating multiple models for each deformation.

5. In paragraph 1, The above transformation calculation step is, A method for constructing a database for deformation and stress of a material, characterized in that structural optimization is performed on the remaining axes excluding the deformed direction in order to predict accurate stress according to the size of deformation.

6. In paragraph 1, A method for constructing a database on material deformation and stress, characterized by measuring stress according to the size and direction of deformation, and extracting and organizing data together with pre-input strain.

7. In paragraph 1, A method for constructing a database for deformation and stress of a material, characterized in that when there is an error in the data in the above data interpretation step, the structure of the model is optimized again and deformation calculation is performed.

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