Method and device for simulating fretting fatigue crystal plasticity of twinned alloys containing small-angle grain boundaries

Abstract

The present application relates to a method and device for simulating the crystal plasticity of micro-fatigue of a twin-crystal alloy containing small-angle grain boundaries. The method comprises: performing EBSD characterization on a twin-crystal tenon specimen containing small-angle grain boundaries, generating an inp file from the EBSD results using Dream3d, setting parameters such as grain number and crystal orientation for the inp file using Matlab, importing the input file into ABAQUS to obtain an ABAQUS finite element model, and setting the load, boundary conditions, analysis step, friction and contact conditions. The file is then associated with a Fortran program written based on the crystal plasticity constitutive relation, and the stress, strain and cumulative plastic strain results are simulated. Thus, by establishing a finite element model consistent with the crystal microstructure of the actual specimen, applying the crystal plasticity constitutive relation to each grain, and assigning the true crystal orientation of each grain to each grain, the crystal plasticity simulation of the micro-fatigue specimen is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of material simulation, and in particular to a method and device for simulating fretting fatigue crystal plasticity of a twinned alloy containing small-angle grain boundaries. Background Art

[0002] Fretting fatigue refers to the phenomenon in which a pair of contacting fatigue components, under cyclic loading, experience minute relative sliding in the contact area of ​​the two components, leading to material damage. During the damage evolution process, cracks nucleate, initiate, and propagate, ultimately causing structural failure or fracture. The tenon joint between blades and disks in aircraft engine fans, compressors, and turbines is a typical example of fretting fatigue. Statistics show that approximately one-sixth of aircraft engine fatigue failures each year are caused by fretting fatigue. Therefore, modeling, simulating, and analyzing fretting fatigue issues has significant engineering value and can provide strong technical support for fault analysis and failure prediction of aircraft engine turbine blades.

[0003] The primary material for engine turbine blades is a nickel-based single-crystal superalloy, cast using directional solidification technology. However, due to the complex process and harsh conditions of single-crystal directional solidification casting, as well as the complex morphology of single-crystal blades, it is difficult to ensure that single-crystal blades are free of grain boundary defects. For example, small-angle grain boundaries are one of the main causes of defects in single-crystal blades. Small-angle grain boundaries occur when, due to various disturbances during the casting of single-crystal alloys, the orientation of grains that should have grown in the same orientation changes at a certain moment, deviating from their original orientation and forming grain boundaries. This effectively turns the blade material into a twinned material containing small-angle grain boundaries. Therefore, the fretting fatigue modeling and simulation of twinned alloys containing small-angle grain boundaries has important theoretical and engineering application value. Summary of the Invention

[0004] The present application provides a method and device for simulating the crystal plasticity of fretting fatigue of a twinned alloy containing small-angle grain boundaries. The method fully considers the actual microstructure of the small-angle grain boundaries and grains of the actual crystal material, establishes a finite element model consistent with the crystal microstructure of the actual specimen, applies the crystal plasticity constitutive relationship to each grain, and assigns the actual crystal orientation of each grain to each grain, thereby realizing the crystal plasticity simulation of the fretting fatigue specimen.

[0005] A first embodiment of the present application provides a method for simulating fretting fatigue crystal plasticity of a twinned alloy containing low-angle grain boundaries, comprising the following steps:

[0006] Write the crystal plasticity constitutive relation into a Fortran program;

[0007] Performing EBSD (Electron Backscattered Diffraction) characterization on a twin-crystal tenon specimen containing a low-angle grain boundary to obtain EBSD characterization data of the twin-crystal tenon specimen, and saving the EBSD characterization data as a ctf file;

[0008] Import the ctf file into the self-written Dream3d script to generate an inp file;

[0009] Importing the inp file and the ctf file into a preset Matlab script for execution, converting the EBSD characterization data according to the ctf file and the crystal plasticity constitutive relationship, and setting the grain number and crystal orientation parameters for the inp file;

[0010] The inp file of the grain number and the crystal orientation parameter is imported into ABAQUS to obtain an ABAQUS finite element model. After setting the load, boundary conditions, analysis steps, friction and contact conditions for the ABAQUS finite element model, the file is associated with the Fortran program to simulate and obtain stress, strain and cumulative plastic strain results.

[0011] Optionally, performing EBSD characterization on the twin-crystal tenon specimen containing low-angle grain boundaries to obtain EBSD characterization data of the twin-crystal tenon specimen, and saving the EBSD characterization data as a ctf file, includes:

[0012] The twin-crystal tenon specimen containing a low-angle grain boundary is polished and electron backscatter diffraction (EBSD) observation is performed to obtain crystal orientation data of the twin-crystal tenon specimen, morphology data of each grain of the twin crystal, and low-angle grain boundary position data;

[0013] The crystal orientation data, the morphology data of each grain of the twin crystal and the low-angle grain boundary position data are saved as the ctf format file.

[0014] Optionally, after saving the crystal orientation data, the morphology data of each grain of the twin crystal, and the low-angle grain boundary position data as the ctf format file, the method further includes:

[0015] The ctf format file is visually analyzed by Matlab script to generate an inverse pole figure image of the twin-crystal tenon specimen.

[0016] Optionally, the crystal plasticity constitutive relation comprises a crystallographic description of plastic behavior, wherein the crystallographic description of plastic behavior is:

[0017]

[0018] in, represents the strain rate on the αth slip system, F P represents the plastic part of the deformation gradient, s (α) is the slip direction of the αth slip system, m (α) is the normal direction of the slip direction of the αth slip system, and α is the index of the slip system.

[0019] Optionally, the strain rate on the slip system is obtained by a plastic flow rate equation, which is as follows:

[0020]

[0021] in, is the relative strain rate, g (α) is the current intensity, n is the rate index, τ (α) is the decomposed shear stress on the αth slip system, X (α) For back stress.

[0022] A second embodiment of the present application provides a device for simulating fretting fatigue crystal plasticity of a twinned alloy containing low-angle grain boundaries, comprising:

[0023] Write a module for writing crystal plasticity constitutive relations as Fortran programs;

[0024] A characterization module is used to perform EBSD characterization on a twin-crystal tenon specimen containing a low-angle grain boundary, obtain EBSD characterization data of the twin-crystal tenon specimen, and save the EBSD characterization data as a ctf file;

[0025] A generation module is used to import the ctf file into a self-written Dream3d script to generate an inp file;

[0026] An operation module is used to import the inp file and the ctf file into a preset Matlab script for operation, convert the EBSD characterization data according to the ctf file and the crystal plasticity constitutive relationship, and set the grain number and crystal orientation parameters for the inp file;

[0027] The simulation module is used to import the inp file of the grain number and the crystal orientation parameter into ABAQUS to obtain the ABAQUS finite element model, and after setting the load, boundary conditions, analysis steps, friction and contact conditions for the ABAQUS finite element model, associate the file with the Fortran program to simulate and obtain stress, strain and cumulative plastic strain results.

[0028] Optionally, the characterization module is specifically configured to:

[0029] The twin-crystal tenon specimen containing a low-angle grain boundary is polished and electron backscatter diffraction (EBSD) observation is performed to obtain crystal orientation data of the twin-crystal tenon specimen, morphology data of each grain of the twin crystal, and low-angle grain boundary position data;

[0030] The crystal orientation data, the morphology data of each grain of the twin crystal and the low-angle grain boundary position data are saved as the ctf format file.

[0031] Optionally, after saving the crystal orientation data, the morphology data of each grain of the twin crystal, and the low-angle grain boundary position data as the ctf format file, the characterization module is further configured to:

[0032] The ctf format file is visually analyzed by Matlab script to generate an inverse pole figure image of the twin-crystal tenon specimen.

[0033] Optionally, the crystal plasticity constitutive relation comprises a crystallographic description of plastic behavior, wherein the crystallographic description of plastic behavior is:

[0034]

[0035] in, represents the strain rate on the αth slip system, F P represents the plastic part of the deformation gradient, s (α) is the slip direction of the αth slip system, m (α) is the normal direction of the slip direction of the αth slip system, and α is the index of the slip system.

[0036] Optionally, the strain rate on the slip system is obtained by a plastic flow rate equation, which is as follows:

[0037]

[0038] in, is the relative strain rate, g (α) is the current intensity, n is the rate index, τ (α) is the decomposed shear stress on the αth slip system, X (α) For back stress.

[0039] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the program to implement the method for simulating fretting fatigue crystal plasticity of a twin-crystal alloy containing small-angle grain boundaries as described in the above embodiment.

[0040] The fourth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the above-mentioned method for simulating fretting fatigue crystal plasticity of a twin-crystal alloy containing small-angle grain boundaries.

[0041] Therefore, the method for simulating fretting fatigue crystal plasticity of a twinned alloy containing low-angle grain boundaries according to the embodiment of the present application has the following advantages:

[0042] (1) Based on the real material microstructure data measured by EBSD, the embodiment of the present application establishes a finite element model of crystal plasticity of a twinned alloy containing small-angle grain boundaries that conforms to the real microstructure. The model contains information such as the position of the small-angle grain boundaries, the geometric morphology of the small-angle grain boundaries, the crystal orientation of each grain, and the geometric morphology of each grain. Therefore, it is possible to explore the influence of various factors on the fretting fatigue behavior of the twinned alloy, especially the influence of small-angle grain boundaries on the fretting fatigue behavior of the material, without being limited to the study of single crystals.

[0043] (2) Based on the crystal plastic constitutive relationship, the UMAT material subroutine was written, and the crystal plastic finite element simulation of the fretting fatigue behavior of the crystal material was realized by calling the UMAT subroutine through ABAQUS, which better simulated the plastic deformation and damage behavior of the material in the actual fretting fatigue process.

[0044] (3) The crystal plasticity simulation method used in the embodiments of the present application can perform simulations on a scale from micrometers to centimeters, which is closer to the size of turbine blade components used in aircraft engines, thereby providing more direct and effective technical support for engineering practice.

[0045] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0047] Figure 1 This is a flow chart of a method for simulating fretting fatigue crystal plasticity of a twinned alloy containing low-angle grain boundaries according to an embodiment of the present application;

[0048] Figure 2 This is an example diagram of an inverse pole figure image of a tenon specimen according to one embodiment of the present application;

[0049] Figure 3 This is an example diagram of a crystal plasticity finite element model of a tenon specimen according to one embodiment of the present application;

[0050] Figure 4This is an example diagram of meshing a crystal plasticity finite element model of a tenon specimen according to one embodiment of the present application;

[0051] Figure 5 is an example diagram of a cumulative plastic strain contour map according to one embodiment of the present application;

[0052] Figure 6 Flowchart of a method for simulating fretting fatigue crystal plasticity of a bi-crystal alloy containing low-angle grain boundaries according to an embodiment of the present application;

[0053] Figure 7 This is an example diagram of a device for simulating fretting fatigue crystal plasticity of a bi-crystal alloy containing low-angle grain boundaries according to an embodiment of the present application;

[0054] Figure 8 is an example diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0055] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0056] The following describes, with reference to the accompanying drawings, a method and apparatus for simulating fretting fatigue crystal plasticity of a twinned alloy containing low-angle grain boundaries according to an embodiment of the present application.

[0057] Before introducing the crystal plasticity simulation method for fretting fatigue of a twin-crystal alloy containing low-angle grain boundaries according to an embodiment of the present application, a brief introduction to the fretting fatigue simulation method for nickel-based single crystal blades in the related art is first given.

[0058] At present, the simulation of fretting fatigue of nickel-based single crystal blades is mainly limited to the simulation of single crystals without small-angle grain boundaries. The main research includes two aspects: (1) Simulation that only considers elastic anisotropy properties. For example, the elastic anisotropy constant of nickel-based single crystals is input into the finite element software to simulate the elastic behavior of fretting fatigue; (2) The elastic-plastic behavior simulation of nickel-based single crystals is carried out by combining the crystal plasticity constitutive relationship with the finite element software. Although it can simulate the damage and slip behavior of single crystals, it cannot consider the small-angle grain boundary factor. How to realize the modeling of small-angle grain boundaries based on the crystal plasticity constitutive relationship and combined with the finite element is still a challenging problem.

[0059] In addition, a "simulation method for shear-coupled grain boundary migration and crack interaction in binary alloys" has been proposed in the relevant technology. A binary alloy twin model is constructed by randomly replacing atoms, and molecular dynamics simulation is used to obtain the results of shear-coupled grain boundary migration and crack interaction in binary alloys.

[0060] However, for method (1), this method cannot take plastic behavior into account, and there is a high stress concentration in the micro-fatigue contact area, which causes the contact area to enter plastic deformation. Therefore, the simulation results of this method are limited in accuracy; and this method cannot take into account the small-angle grain boundary factor, and cannot achieve the modeling and simulation of small-angle grain boundaries; for method (2), although it can simulate the damage and slip behavior of single crystals, it only considers single crystal modeling and simulation, and cannot consider the small-angle grain boundary factor, and cannot simulate twin crystals containing small-angle grain boundaries; for the twin crystal simulation of the "shear-coupled grain boundary migration and crack interaction simulation method in binary alloys", due to the limitation of the computational power of the molecular dynamics method, only atomic-level modeling and simulation can be carried out, and the spatial scale is nanometer-scale, while the size of the turbine blade components used in aircraft engines is centimeter-scale. Therefore, this method is still a certain distance away from the size of the real components.

[0061] It is precisely based on the above problems that the present application provides a method for simulating the crystal plasticity of micro-fatigue of twinned alloys containing small-angle grain boundaries. It can create a finite element crystal model containing more crystallographic information based on the real material data of electron backscatter diffraction scanning, and use the material subroutine to embed the crystal plasticity constitutive relationship into ABAQUS software, and assign the real crystal orientation of each grain to each grain in the finite element model, thereby realizing the crystal plasticity simulation of micro-fatigue of twinned alloys containing small-angle grain boundaries that is consistent with the real material, and can explore the influence of factors such as the position of small-angle grain boundaries, the geometric morphology of small-angle grain boundaries, the crystal orientation of each grain, and the geometric morphology of each grain on the micro-fatigue behavior.

[0062] Specifically, Figure 1 A schematic flow chart of a method for simulating fretting fatigue crystal plasticity of a twin-crystal alloy containing low-angle grain boundaries provided in an embodiment of the present application.

[0063] like Figure 1 As shown, the method for simulating fretting fatigue crystal plasticity of a twin-crystal alloy containing low-angle grain boundaries comprises the following steps:

[0064] In step S101 , the crystal plasticity constitutive relation is written as a Fortran program.

[0065] Specifically, crystal plasticity finite element simulation is an effective computational tool for studying the relationship between the microstructure and mechanical properties of crystalline alloys, especially in exploring the damage and slip behavior of crystalline materials, predicting crack initiation and propagation, and fatigue life. Therefore, in the embodiment of the present application, the crystal plasticity constitutive relationship can be written as a Fortran program, and the Fortran program can be embedded in the ABAQUS software as a material subroutine (User-Defined Material, UMAT) for call calculation.

[0066] Among them, the main part of the crystal plastic constitutive relationship is the crystallographic description of the plastic behavior. The crystallographic description of the plastic behavior of the embodiment of the present application is:

[0067]

[0068] in, represents the strain rate on the αth slip system, F P represents the plastic part of the deformation gradient, s (α) is the slip direction of the αth slip system, m (α) is the normal direction of the slip direction of the αth slip system, and α is the index of the slip system.

[0069] Alternatively, in some embodiments, the strain rate on the slip system is obtained by the plastic flow rate equation, which is as follows:

[0070]

[0071] in, is the relative strain rate, g (α) is the current intensity, n is the rate index, τ (α) is the decomposed shear stress on the αth slip system, X (α) For back stress.

[0072] Among them, τ (α) It is given by:

[0073]

[0074] Back stress X (α) It can be obtained from the Chaboche model, which can better simulate the mechanical behavior of materials under cyclic loading than general models:

[0075]

[0076] Among them, (α) and r (α) is a material-related constant. Current strength g (α) It is given by the slip resistance evolution equation:

[0077]

[0078] h αβ (γ) = h(γ)[q+(1-q)δ αβ ];

[0079] Among them, h αβ (γ) is the potential hardening modulus, q represents the potential hardening parameter, and h(γ) is the self-hardening modulus, which can be calculated as follows:

[0080]

[0081] Where h0 is the initial hardening modulus, τ s represents the initial slip resistance, τ0 represents the slip resistance during the saturation period, and γ represents the Taylor cumulative shear strain on all slip systems, which can be calculated by the following formula:

[0082]

[0083] In step S102, EBSD characterization is performed on the twin-crystal tenon specimen containing low-angle grain boundaries to obtain EBSD characterization data of the twin-crystal tenon specimen, and the EBSD characterization data is saved as a ctf file.

[0084] Optionally, in some embodiments, EBSD characterization is performed on a twin-crystal tenon specimen containing small-angle grain boundaries to obtain EBSD characterization data of the twin-crystal tenon specimen, and the EBSD characterization data is saved as a ctf file, including: polishing the twin-crystal tenon specimen containing small-angle grain boundaries, performing electron backscatter diffraction EBSD observation, obtaining crystal orientation data of the twin-crystal tenon specimen, morphology data of each grain of the twin crystal, and small-angle grain boundary position data; saving the crystal orientation data, morphology data of each grain of the twin crystal, and small-angle grain boundary position data as a ctf format file.

[0085] Optionally, after saving the crystal orientation data, the morphology data of each grain of the twin crystal and the low-angle grain boundary position data as a ctf format file, it also includes: visually analyzing the ctf format file through a Matlab script to generate an inverse pole figure image of the twin crystal tenon specimen.

[0086] Specifically, the embodiment of the present application can finely polish the twinned tenon specimen containing small-angle grain boundaries, carry out EBSD observation, obtain the crystal orientation data (Euler angle) of the specimen, the morphology of each grain of the twinned crystal, the position of the small-angle grain boundary and other data, save them as ctf format files, and use Matlab scripts to visualize and analyze the data to obtain images such as the inverse pole figure of the tenon specimen, such as Figure 2 shown.

[0087] In step S103, the ctf file is imported into the self-written Dream3d script to generate an inp file.

[0088] It should be understood that the embodiment of the present application can import the ctf file containing the material microstructure information into the self-compiled Dream3d script, which can automatically realize the recognition of crystal orientation data (Euler angle), grain morphology and other data based on the ctf information, and generate the calculation input file (inp format) required by the ABAQUS finite element software.

[0089] In step S104, the inp file and the ctf file are imported into a preset Matlab script and run to convert the EBSD characterization data according to the ctf file and the crystal plasticity constitutive relationship, and set the grain number and crystal orientation parameters for the inp file.

[0090] That is to say, the embodiment of the present application can import the generated inp file and ctf file into a self-written Matlab script for execution. The script can convert the Euler angle data at each EBSD scanning point into the crystal orientation parameters required for the constitutive relationship in step S101 according to the ctf file, and write the parameters into the inp file.

[0091] In step S105, the inp file of grain number and crystal orientation parameters is imported into ABAQUS to obtain the ABAQUS finite element model. After setting the load, boundary conditions, analysis steps, friction and contact conditions for the ABAQUS finite element model, the file is associated with the Fortran program to simulate and obtain the stress, strain and cumulative plastic strain results.

[0092] Specifically, the embodiment of the present application can import the inp file into ABAQUS to generate a crystal plasticity finite element model of the tenon specimen. The model is the same as the actual size of the tenon specimen, and the model includes the small-angle grain boundary position, small-angle grain boundary geometry, crystal orientation of each grain, and geometry of each grain (such as Figure 3 Then, mesh the model in ABAQUS, and refine the mesh in the micro-contact area (as shown in the figure). Figure 4 shown).

[0093] Furthermore, the modeling of the mortise and tenon specimen adopts a macro modeling method. A finite element model can be established according to the actual geometric dimensions of the mortise and tenon specimen. The mortise and tenon model is regarded as an isotropic elastic material and given data such as density, Young's modulus, and Poisson's ratio. The tenon and the mortise are assembled, and loads, boundary conditions, analysis steps, friction, and contact conditions are set for the established crystal model. Among them, the mortise and tenon ends are fixed, fatigue loads are applied to the tenon ends, Static / General analysis steps are used, hard contact is adopted at the contact parts of the mortise and tenon, and a suitable friction coefficient is set.

[0094] Furthermore, the embodiment of the present application can associate the ABAQUS finite element model with the Fortran material subroutine (UMAT) established in step 1 to complete the crystal plasticity finite element modeling. Run the calculation to realize the crystal plasticity simulation of the twin alloy containing small-angle grain boundaries, obtain the stress, strain, cumulative plastic strain and other results, and use ABAQUS to visualize the results (cloud diagrams such as cumulative plastic strain are shown in Figure 2). Figure 5The results can reveal critical locations of stress, strain, and cumulative plastic strain, providing an effective basis for fretting fatigue failure analysis and fault prediction. By repeating the above analysis steps on specimens with different low-angle grain boundaries, stress, strain, and cumulative plastic strain results for different low-angle grain boundaries can be obtained. This allows the influence of factors such as low-angle grain boundary location, low-angle grain boundary geometry, crystal orientation of each grain, and geometric morphology of each grain on fretting fatigue behavior to be studied.

[0095] Therefore, the embodiment of the present application creates a finite element crystal model containing more crystallographic information based on the real material data of electron backscatter diffraction scanning, and uses the material subroutine to embed the crystal plasticity constitutive relationship into the ABAQUS software, and assigns the real crystal orientation of each grain (referred to as "crystal orientation") to each grain in the finite element model, thereby realizing the crystal plasticity simulation of the micro-fatigue of the twin alloy containing small-angle grain boundaries that is consistent with the real material, and can explore the influence of factors such as the position of small-angle grain boundaries, the geometric morphology of small-angle grain boundaries, the crystal orientation of each grain, and the geometric morphology of each grain on the micro-fatigue behavior.

[0096] To facilitate those skilled in the art to further understand the method for simulating fretting fatigue crystal plasticity of a twinned alloy containing low-angle grain boundaries in the embodiment of the present application, a detailed description is given below in conjunction with specific embodiments.

[0097] like Figure 6 As shown, the method for simulating fretting fatigue crystal plasticity of a twin-crystal alloy containing low-angle grain boundaries comprises the following steps:

[0098] S601, write a crystal plasticity subroutine.

[0099] S602, EBSD characterization of tenon specimens containing low-angle grain boundaries.

[0100] S603, generate an inp file based on the EBSD results using Dream3d.

[0101] S604, setting parameters such as grain number and crystal orientation for the inp file through Matlab.

[0102] S605, importing the input file into ABAQUS to obtain the ABAQUS finite element model, and after setting the load, boundary conditions, etc. for the ABAQUS finite element model, the file is associated with the Fortran material subroutine, and simulation is performed to obtain the stress, strain, accumulated plastic strain and other results.

[0103] Therefore, the actual microstructure of the small-angle grain boundaries and grains of the actual crystal material is fully considered, a finite element model consistent with the actual crystal microstructure of the specimen is established, and the crystal plasticity constitutive relationship is applied to each grain, and the real crystal orientation of each grain is assigned to each grain, thus realizing the crystal plasticity simulation of the fretting fatigue specimen.

[0104] According to the method for simulating the crystal plasticity of fretting fatigue of a twin alloy containing small-angle grain boundaries proposed in the embodiment of the present application, a finite element crystal model containing more crystallographic information can be created based on the real material data of electron backscatter diffraction scanning, and the crystal plasticity constitutive relationship can be embedded in the ABAQUS software using the material subroutine, and the real crystal orientation of each grain can be assigned to each grain in the finite element model, thereby realizing the crystal plasticity simulation of fretting fatigue of a twin alloy containing small-angle grain boundaries that is consistent with the real material, and the influence of factors such as the position of small-angle grain boundaries, the geometric morphology of small-angle grain boundaries, the crystal orientation of each grain, and the geometric morphology of each grain on the fretting fatigue behavior can be explored.

[0105] Next, a device for simulating fretting fatigue crystal plasticity of a twin-crystal alloy containing small-angle grain boundaries according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0106] Figure 7 It is a block diagram of a device for simulating fretting fatigue crystal plasticity of a twin-crystal alloy containing low-angle grain boundaries according to an embodiment of the present application.

[0107] like Figure 7 As shown, the device 10 for simulating fretting fatigue crystal plasticity of a twinned alloy containing low-angle grain boundaries includes: a writing module 100 , a characterization module 200 , a generation module 300 , an operation module 400 and a simulation module 500 .

[0108] Wherein, the writing module 100 is used to write the crystal plasticity constitutive relation into a Fortran program;

[0109] The characterization module 200 is used to perform EBSD characterization on the twin-crystal tenon specimen containing low-angle grain boundaries, obtain EBSD characterization data of the twin-crystal tenon specimen, and save the EBSD characterization data as a ctf file;

[0110] The generation module 300 is used to import the ctf file into the self-written Dream3d script to generate an inp file;

[0111] The operation module 400 is used to import the inp file and the ctf file into a preset Matlab script to run, so as to convert the EBSD characterization data according to the ctf file and the crystal plasticity constitutive relationship, and set the grain number and crystal orientation parameters for the inp file;

[0112] The simulation module 500 is used to import the inp file of the grain number and the crystal orientation parameters into ABAQUS to obtain the ABAQUS finite element model, and after setting the load, boundary conditions, analysis steps, friction and contact conditions for the ABAQUS finite element model, associate the file with the Fortran program to simulate and obtain the stress, strain and cumulative plastic strain results.

[0113] Optionally, the characterization module 200 is specifically configured to:

[0114] The twinned tenon specimens containing low-angle grain boundaries were polished and subjected to electron backscatter diffraction (EBSD) observations to obtain the crystal orientation data of the twinned tenon specimens, the morphology data of each grain of the twinned crystals, and the position data of the low-angle grain boundaries.

[0115] The crystal orientation data, the morphology data of each grain of the twin crystal and the small-angle grain boundary position data are saved as a ctf format file.

[0116] Optionally, after saving the crystal orientation data, the morphology data of each grain of the twin crystal, and the low-angle grain boundary position data as a ctf format file, the characterization module 200 is further configured to:

[0117] The ctf format file is visualized and analyzed using Matlab scripts to generate the inverse pole figure image of the twin-crystal tenon specimen.

[0118] Optionally, the crystal plasticity constitutive relation contains a crystallographic description of the plastic behavior, which is:

[0119]

[0120] in, represents the strain rate on the αth slip system, F P represents the plastic part of the deformation gradient, s (α) is the slip direction of the αth slip system, m (α) is the normal direction of the slip direction of the αth slip system, and α is the index of the slip system.

[0121] Alternatively, the strain rate on the slip system is obtained from the plastic flow rate equation, which is as follows:

[0122]

[0123] in, is the relative strain rate, g (α) is the current intensity, n is the rate index, τ (α) is the decomposed shear stress on the αth slip system, X (α) For back stress.

[0124] It should be noted that the above explanation of the embodiment of the method for simulating fretting fatigue crystal plasticity of a twin-crystal alloy containing small-angle grain boundaries is also applicable to the apparatus for simulating fretting fatigue crystal plasticity of a twin-crystal alloy containing small-angle grain boundaries in this embodiment, and will not be repeated here.

[0125] According to the device for simulating the micro-fatigue crystal plasticity of a twin-crystal alloy containing small-angle grain boundaries proposed in the embodiment of the present application, a finite element crystal model containing more crystallographic information can be created based on the real material data of electron backscatter diffraction scanning, and the crystal plasticity constitutive relationship can be embedded in the ABAQUS software using the material subroutine, and the real crystal orientation of each grain can be assigned to each grain in the finite element model, thereby realizing the micro-fatigue crystal plasticity simulation of the twin-crystal alloy containing small-angle grain boundaries that is consistent with the real material, and the influence of factors such as the position of small-angle grain boundaries, the geometric morphology of small-angle grain boundaries, the crystal orientation of each grain, and the geometric morphology of each grain on the micro-fatigue behavior can be explored.

[0126] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0127] A memory 801 , a processor 802 , and a computer program stored in the memory 801 and executable on the processor 802 .

[0128] When the processor 802 executes the program, the method for simulating fretting fatigue crystal plasticity of a twinned alloy containing low-angle grain boundaries provided in the above embodiment is implemented.

[0129] Furthermore, the electronic device further includes:

[0130] The communication interface 803 is used for communication between the memory 801 and the processor 802 .

[0131] The memory 801 is used to store computer programs that can be run on the processor 802.

[0132] The memory 801 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0133] If the memory 801, processor 802, and communication interface 803 are implemented independently, the communication interface 803, memory 801, and processor 802 can be connected to each other via a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0134] Optionally, in a specific implementation, if the memory 801, the processor 802 and the communication interface 803 are integrated on a chip, the memory 801, the processor 802 and the communication interface 803 can communicate with each other through an internal interface.

[0135] The processor 802 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0136] This embodiment further provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the above-mentioned method for simulating fretting fatigue crystal plasticity of a twinned alloy containing low-angle grain boundaries is implemented.

[0137] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0138] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0139] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0140] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or N wires (electronic devices), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and a portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0141] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiment, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0142] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0143] In addition, the functional units in the various embodiments of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into a module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0144] The storage medium mentioned above may be a read-only memory, a magnetic disk, or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application. Persons skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for simulating fretting fatigue crystal plasticity of a twinned alloy containing low-angle grain boundaries, characterized in that: The following steps are involved: Write the crystal plasticity constitutive relation into a Fortran program; Performing EBSD characterization on a twin-crystal tenon specimen containing a low-angle grain boundary to obtain EBSD characterization data of the twin-crystal tenon specimen, and saving the EBSD characterization data as a ctf file; Import the ctf file into the self-written Dream3d script to generate an inp file; Importing the inp file and the ctf file into a preset Matlab script for execution, converting the EBSD characterization data according to the ctf file and the crystal plasticity constitutive relationship, and setting the grain number and crystal orientation parameters for the inp file; Importing the inp file containing the grain number and the crystal orientation parameters into ABAQUS to obtain an ABAQUS finite element model, setting loads, boundary conditions, analysis steps, friction and contact conditions for the ABAQUS finite element model, and then associating the file with the Fortran program to simulate and obtain stress, strain, and cumulative plastic strain results; Among them, the EBSD characterization of the twin-crystal tenon specimen containing small-angle grain boundaries, obtaining the EBSD characterization data of the twin-crystal tenon specimen, and saving the EBSD characterization data as a ctf file includes: polishing the twin-crystal tenon specimen containing small-angle grain boundaries, carrying out electron backscatter diffraction EBSD observation, obtaining the crystal orientation data of the twin-crystal tenon specimen, the morphology data of each grain of the twin crystal, and the small-angle grain boundary position data; saving the crystal orientation data, the morphology data of each grain of the twin crystal, and the small-angle grain boundary position data as the ctf format file.

2. The method according to claim 1, characterized in that After saving the crystal orientation data, the morphology data of each grain of the twin crystal and the low-angle grain boundary position data as the ctf format file, the method further includes: The ctf format file is visually analyzed by Matlab script to generate an inverse pole figure image of the twin-crystal tenon specimen.

3. The method according to claim 1, characterized in that The crystal plasticity constitutive relation includes a crystallographic description of the plastic behavior, which is: in, represents the strain rate on the αth slip system, F P represents the plastic part of the deformation gradient, s (α) is the slip direction of the αth slip system, m (α) is the normal direction of the slip direction of the αth slip system, and α is the index of the slip system.

4. The method according to claim 3, characterized in that The strain rate on the slip system is obtained from the plastic flow rate equation, which is as follows: in, is the relative strain rate, g (α) is the current intensity, n is the rate index, τ (α) is the decomposed shear stress on the αth slip system, X (α) For back stress.

5. A device for simulating fretting fatigue crystal plasticity of a twinned alloy containing low-angle grain boundaries, characterized in that: include: Write a module for writing crystal plasticity constitutive relations as Fortran programs; A characterization module is used to perform EBSD characterization on a twin-crystal tenon specimen containing a low-angle grain boundary, obtain EBSD characterization data of the twin-crystal tenon specimen, and save the EBSD characterization data as a ctf file; A generation module is used to import the ctf file into a self-written Dream3d script to generate an inp file; An operation module is used to import the inp file and the ctf file into a preset Matlab script for operation, convert the EBSD characterization data according to the ctf file and the crystal plasticity constitutive relationship, and set the grain number and crystal orientation parameters for the inp file; A simulation module is used to import the inp file of the grain number and the crystal orientation parameter into ABAQUS to obtain an ABAQUS finite element model, and after setting the load, boundary conditions, analysis step, friction and contact conditions for the ABAQUS finite element model, associate the file with the Fortran program to simulate and obtain stress, strain and cumulative plastic strain results; Among them, the characterization module is specifically used to: polish the twin-crystal tenon specimen containing small-angle grain boundaries, carry out electron backscatter diffraction EBSD observation, obtain the crystal orientation data of the twin-crystal tenon specimen, the morphology data of each grain of the twin crystal and the small-angle grain boundary position data; save the crystal orientation data, the morphology data of each grain of the twin crystal and the small-angle grain boundary position data as the ctf format file.

6. The device according to claim 5, characterized in that After saving the crystal orientation data, the morphology data of each grain of the twin crystal, and the low-angle grain boundary position data as the ctf format file, the characterization module is further configured to: The ctf format file is visually analyzed by Matlab script to generate an inverse pole figure image of the twin-crystal tenon specimen.

7. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for simulating fretting fatigue crystal plasticity of a twin-crystal alloy containing low-angle grain boundaries as claimed in any one of claims 1 to 4.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the method for simulating fretting fatigue crystal plasticity of a bi-crystalline alloy containing low-angle grain boundaries as claimed in any one of claims 1 to 4.

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