A material tensile simulation, comparison and optimization analysis system and method

Abstract

The application relates to a material tensile simulation benchmarking optimization analysis system and method, and belongs to the technical field of material simulation analysis systems and methods.The technical scheme of the application is as follows: a secondary development tool is used to perform secondary development programming on the preprocessing and postprocessing processes of finite element simulation software, and a full-flow parameterized numerical analysis system for tensile specimen simulation benchmarking analysis is established.The beneficial effects of the application are as follows: the modeling efficiency and iterative analysis efficiency of the material simulation benchmarking analysis process are greatly improved, and experimental cost is reduced;the application range is wide, and the types of tensile specimens that can be subjected to benchmarking analysis are more;the system operation process is simple, and human error is reduced.

Description

Technical Field

[0001] The present invention relates to a material stretching simulation benchmarking optimization analysis system and method, belonging to the technical field of material simulation analysis systems and methods. Background Art

[0002] Numerical simulation methods are important means to assist in the structural design, processing formability, service performance, fracture failure analysis, etc. of materials. Generally, finite element simulation software needs to input the constitutive relationship of the material, that is, the true stress-true strain curve, for structural analysis calculations. However, traditional tensile tests obtain the engineering stress-strain curve of the material. For ductile materials, necking will occur during stretching. The engineering stress and strain before necking can be converted into true stress and strain using the principle of volume invariance. After necking, due to the reduction in the cross-sectional size of the void nucleation, obtaining the true stress-strain relationship becomes the key. The simulation results of the material constitutive curve obtained by directly fitting the data before necking using the material theory constitutive formula often have large deviations from the experimental results. Therefore, tensile test simulation benchmarking analysis has become one of the important methods to verify the material constitutive model and obtain the true material constitutive curve. When there are many types and quantities of tensile specimens, a lot of time in the tensile test simulation benchmarking analysis process is spent on model pre-processing and iterative process post-processing, which greatly reduces the efficiency of modeling and analysis. Summary of the Invention

[0003] The purpose of the present invention is to provide a material tensile simulation benchmarking optimization analysis system and method. By using Python secondary development tools to perform secondary development programming on the pre-processing and post-processing processes of the finite element simulation software Abaqus, a full-process parametric numerical analysis system for tensile specimen simulation benchmarking analysis is established, which greatly improves the modeling efficiency and iterative analysis efficiency of the material simulation benchmarking analysis process and reduces experimental costs; the application range is wide, and a large number of tensile specimens can be benchmarked and analyzed; the system operation process is simple, and human errors are reduced; it can be widely used in related research such as material mechanical properties, auxiliary material database construction, support forming, fracture failure analysis and other work, and effectively solves the above-mentioned problems existing in the background technology.

[0004] The technical solution of the present invention is: a material tensile simulation benchmarking optimization analysis system, which includes a specimen model definition unit, an iteration definition unit, a graphic window unit and a calculation control unit; the model definition unit includes a specimen name, a specimen type, a specimen size, material parameters, a unit type, a unit size and a loading displacement configuration; the iteration definition unit includes the configuration of an initial constitutive model, a benchmarking curve, the number of iterations and an iterative fitting method; the graphic window unit includes a benchmarking curve graphic interface and an iterative constitutive graphic interface; the calculation control unit includes a calculation file storage setting, an iteration progress window and a program running and stopping setting.

[0005] The model definition unit, wherein the sample type includes a plate-shaped smooth tensile sample, a plate-shaped notched tensile sample and a rod-shaped tensile sample; the sample size includes a sample gauge length, a sample gauge width, a sample thickness, a sample diameter and a notch diameter; the material parameter includes but is not limited to density, elastic modulus, Poisson's ratio and material anisotropy parameter; the unit type includes a shell unit and a solid unit; and the unit size includes a mesh size and a cross-section mesh number.

[0006] The iteration definition unit, wherein the iteration fitting mode includes but is not limited to Swift constitutive fitting, Ludwick constitutive fitting, Double-Voce constitutive fitting, Modified-Hockeh-Sherby constitutive fitting, polynomial fitting and no fitting.

[0007] A material tensile simulation fitting analysis method, comprising the following steps:

[0008] (1) the user inputs the name of the tensile material in the model definition unit, selects the type of the tensile sample, inputs the tensile sample gauge size, inputs the material parameter, inputs the unit type and size, and inputs the displacement load size;

[0009] (2) the user uploads the initial constitutive curve of the material in the iteration definition unit, uploads the tensile curve, selects the iteration fitting mode, and inputs the iteration number;

[0010] (3) the user selects the calculation file storage location in the calculation control unit, clicks the program running button to start the material tensile simulation fitting calculation, and the system opens the iteration progress window;

[0011] (4) after the iteration progress is executed, the window is closed, the tensile curve result after the iteration fitting is displayed on the graphic window unit fitting curve graphic interface, and the material constitutive curve after the iteration optimization is displayed on the fitting curve graphic interface;

[0012] (5) the file storage address is opened, and the calculation result file and the process file are viewed.

[0013] The calculation result file includes an input parameter file, a material constitutive parameter iteration optimization process file, a tensile curve iteration process file, an iteration optimized finite element model file, a finite element calculation result file and a log file.

[0014] In the step (3), the material tensile simulation fitting calculation comprises the following steps:

[0015] (a) reading the equivalent plastic strain PE_old and Mises_old in the process file, and the force Fsim_old and the gauge displacement Usim_old in the tensile curve iteration process file;

[0016] (b) Read the test force Ftest_0 and test displacement Utest_0 of the tensile curve file, and perform monotonicity test and monotonicity data processing;

[0017] (c) Read the plastic strain Strain_0 and input true stress Stress_0 of the initial constitutive curve of the material;

[0018] (d) Using the equivalent plastic strain PE_old as the interpolation point, interpolate the input plastic strain Strain_0 and the input true stress Stress_0 to obtain the interpolated Stain_1 and Stress_1;

[0019] (e) Using the gauge displacement Usim-old as the interpolation point, interpolate the test displacement Utest_0 and the test force Ftest_0 to obtain the interpolated values ​​Utest_1 and Ftest_1;

[0020] (f) Calculating the optimized input constitutive curve according to an iterative formula not limited to the following, where eps is a minimum value;

[0021] Stress_2(i)=Ftest_1(i) / (Fsim_old(i)+eps)*Stress_1(i)

[0022] Strain_2(i)= Strain_1(i)

[0023] (g) Find the location of the maximum stress value max(Stress_2) after iteration, delete the stress and strain data after this location; perform monotonicity check and processing on (Strain_2, Stress_2) to generate monotonically increasing (Strain_3, Stress_3);

[0024] (h) Perform data fitting on (Strain_3, Stress_3) according to the iterative fitting method to obtain the updated input constitutive curve (Strain_new, Stress_new), and write it into the process file; write the updated material constitutive parameters into the iteratively optimized finite element model file, generate a new finite element calculation result file and a tensile curve iterative process file, and obtain the force Fsim_new and gauge displacement Usim_new; complete one iterative process.

[0025] The beneficial effects of the present invention are as follows: by using Python secondary development tools to perform secondary development programming on the pre-processing and post-processing processes of the finite element simulation software Abaqus, a full-process parametric numerical analysis system for tensile specimen simulation benchmarking analysis is established, which greatly improves the modeling efficiency and iterative analysis efficiency of the material simulation benchmarking analysis process and reduces experimental costs; it has a wide range of applications and can benchmark and analyze a large variety of tensile specimens; the system operation process is simple and reduces human errors; it can be widely used in related research such as material mechanical properties, assists in the construction of material databases, and supports forming, fracture failure analysis and other work. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a diagram illustrating the system user interface of an embodiment of the present invention;

[0027] Figure 2 This is a diagram showing the system operation results of an embodiment of the present invention;

[0028] Figure 3 A model cloud diagram of an odb file of the system calculation result of an embodiment of the present invention;

[0029] Figure 4 This is a flow chart of the stretching benchmarking optimization method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the invention implementation cases clearer, the technical solutions in the invention implementation cases will be clearly and completely described below in conjunction with the drawings in the implementation cases. Obviously, the implementation cases described are only a small part of the implementation cases of the present invention, rather than all the implementation cases. Based on the implementation cases in the present invention, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] A material tensile simulation benchmarking optimization analysis system comprises a specimen model definition unit, an iteration definition unit, a graphics window unit, and a calculation control unit; the model definition unit includes a specimen name, specimen type, specimen size, material parameters, unit type, unit size, and loading displacement configuration; the iteration definition unit includes configurations of an initial constitutive model, a benchmarking curve, the number of iterations, and an iterative fitting method; the graphics window unit includes a benchmarking curve graphical interface and an iterative constitutive graphical interface; and the calculation control unit includes calculation file storage settings, an iteration progress window, and program run and stop settings.

[0032] The model definition unit, wherein the sample type includes a plate-shaped smooth tensile sample, a plate-shaped notched tensile sample and a rod-shaped tensile sample; the sample size includes a sample gauge length, a sample gauge width, a sample thickness, a sample diameter and a notch diameter; the material parameter includes but is not limited to density, elastic modulus, Poisson's ratio and material anisotropy parameter; the unit type includes a shell unit and a solid unit; and the unit size includes a mesh size and a cross-section mesh number.

[0033] The iteration definition unit, wherein the iteration fitting mode includes but is not limited to Swift constitutive fitting, Ludwick constitutive fitting, Double-Voce constitutive fitting, Modified-Hockeh-Sherby constitutive fitting, polynomial fitting and no fitting.

[0034] A material tensile simulation fitting analysis method, comprising the following steps:

[0035] (1) the user inputs the name of the tensile material in the model definition unit, selects the type of the tensile sample, inputs the tensile sample gauge size, inputs the material parameters, inputs the unit type and size, and inputs the displacement load size;

[0036] (2) the user uploads the initial constitutive curve of the material in the iteration definition unit, uploads the tensile curve, selects the iteration fitting mode, and inputs the iteration number;

[0037] (3) the user selects the calculation file storage location in the calculation control unit, clicks the program running button to start the material tensile simulation fitting calculation, and the system opens the iteration progress window;

[0038] (4) after the iteration progress is executed, the window is closed, the tensile curve result after iteration fitting is displayed on the graphic window unit fitting curve graphic interface, and the material constitutive curve after iteration optimization is displayed on the fitting curve graphic interface;

[0039] (5) the file storage address is opened to view the calculation result file and the process file.

[0040] The calculation result file includes an input parameter file, a material constitutive parameter iteration optimization process file, a tensile curve iteration process file, an iteration optimized finite element model file, a finite element calculation result file and a log file.

[0041] In the step (3), the material tensile simulation fitting calculation comprises the following steps:

[0042] (a) reading the equivalent plastic strain PE_old and Mises_old in the process file, and the force Fsim_old and the gauge displacement Usim_old in the tensile curve iteration process file;

[0043] (b) Read the test force Ftest_0 and test displacement Utest_0 of the tensile curve file, and perform monotonicity test and monotonicity data processing;

[0044] (c) Read the plastic strain Strain_0 and input true stress Stress_0 of the initial constitutive curve of the material;

[0045] (d) Using the equivalent plastic strain PE_old as the interpolation point, interpolate the input plastic strain Strain_0 and the input true stress Stress_0 to obtain the interpolated Stain_1 and Stress_1;

[0046] (e) Using the gauge displacement Usim-old as the interpolation point, interpolate the test displacement Utest_0 and the test force Ftest_0 to obtain the interpolated values ​​Utest_1 and Ftest_1;

[0047] (f) Calculating the optimized input constitutive curve according to an iterative formula not limited to the following, where eps is a minimum value;

[0048] Stress_2(i)=Ftest_1(i) / (Fsim_old(i)+eps)*Stress_1(i)

[0049] Strain_2(i)= Strain_1(i)

[0050] (g) Find the location of the maximum stress value max(Stress_2) after iteration, delete the stress and strain data after this location; perform monotonicity check and processing on (Strain_2, Stress_2) to generate monotonically increasing (Strain_3, Stress_3);

[0051] (h) Perform data fitting on (Strain_3, Stress_3) according to the iterative fitting method to obtain the updated input constitutive curve (Strain_new, Stress_new), and write it into the process file; write the updated material constitutive parameters into the iteratively optimized finite element model file, generate a new finite element calculation result file and a tensile curve iterative process file, and obtain the force Fsim_new and gauge displacement Usim_new; complete one iterative process.

[0052] Example:

[0053] (1) The user enters the name of the tensile material as "DP780-Solid" in the model definition unit, selects the type of tensile specimen as Smooth plate-shaped smooth tensile specimen; enters the tensile specimen gauge length 50mm, specimen gauge width 10mm, and specimen thickness 1.2mm; enters the material parameters, and the density is 7.85e-9t / mm 3 , the elastic modulus is 178979Mpa, the Poisson's ratio is 0.33, the anisotropic parameters R11 is 1, R22 is 1.20952, R33 is 0.958946, R12 is 1.000409, R13 is 1, and R23 is 1; select the unit type as Solid entity unit, input the grid size as 2, and the number of cross-section grids as 3; input the displacement load size and elongation as 11.25mm.

[0054] (2) The user uploads the initial constitutive curve txt file of DP780 material and the tensile force-displacement curve txt file of DP780 material in the iteration definition unit, selects the iterative fitting method as non-fitting, and enters the number of iterations as 6.

[0055] (3) The user selects the calculation file storage location in the calculation control unit, clicks the program run button to start the material stretching simulation benchmark calculation, and the system opens the iteration progress window.

[0056] (4) After the iteration progress is completed, the window is closed, and the tensile curve result after iterative benchmarking is displayed in the graphics window unit benchmarking curve graphic interface, and the constitutive curve of the material after iterative optimization is displayed in the benchmarking curve graphic interface; see the attached Figure 2 .

[0057] (5) Open the file storage address and view the calculation results and process files.

[0058] Furthermore, the calculation result file includes input parameter file, material constitutive parameter iterative optimization process file, tensile curve iterative process file, iteratively optimized finite element model inp file and finite element calculation result odb file, log file. Figure 3 .

[0059] Furthermore, the benchmarking analysis iteration method in step 3 includes the following:

[0060] (a) Read the equivalent plastic strain PE_old and Mises_old in the iterative optimization process file of the material constitutive parameters in the calculation result file, and the force Fsim_old and gauge length displacement Usim_old in the iterative process file of the tensile curve;

[0061] (b) Read the test force Ftest_0 and test displacement Utest_0 of the uploaded tensile curve file of DP780 material, and perform monotonicity test and monotonicity data processing;

[0062] (c) Read the uploaded plastic strain Strain_0 and input true stress Stress_0 of the initial constitutive curve of DP780 material;

[0063] (d) Using the equivalent plastic strain PE_old as the interpolation point, interpolate the input plastic strain Strain_0 and the input true stress Stress_0 to obtain the interpolated Stain_1 and Stress_1;

[0064] (e) Using the gauge displacement Usim_old as the interpolation point, interpolate the test displacement Utest_0 and the test force Ftest_0 to obtain the interpolated values ​​Utest_1 and Ftest_1;

[0065] (f) Calculate the optimized input constitutive curve according to the following iterative formula, where eps is the minimum value;

[0066] Stress_2(i)=Ftest_1(i) / (Fsim_old(i)+eps)*Stress_1(i)

[0067] Strain_2(i)= Strain_1(i)

[0068] (g) Find the location of the maximum stress value max(Stress_2) after iteration, delete the stress and strain data after this location; perform monotonicity check and processing on (Strain_2, Stress_2) to generate monotonically increasing (Strain_3, Stress_3);

[0069] (h) According to the selected fitting method "non-fitting", data fitting is not performed on (Strain_3, Stress_3), that is, the updated input constitutive curve (Strain_new, Stress_new) is obtained and written into the material constitutive parameter iterative optimization process file; the updated material constitutive parameters are written into the iteratively optimized finite element model file, and a new finite element calculation result file and a tensile curve iterative process file are generated to obtain the force Fsim_new and the gauge length displacement Usim_new; and one iteration process is completed.

Claims

1. A material tensile simulation benchmarking optimization analysis method, characterized by: A material tensile simulation benchmarking optimization analysis system is used for analysis. The system includes a specimen model definition unit, an iteration definition unit, a graphics window unit, and a calculation control unit. The model definition unit includes a specimen name, a specimen type, a specimen size, material parameters, a unit type, a unit size, and a loading displacement configuration. The iteration definition unit includes configurations of an initial constitutive model, a benchmarking curve, the number of iterations, and an iterative fitting method. The graphics window unit includes a benchmarking curve graphical interface and an iterative constitutive graphical interface. The calculation control unit includes calculation file storage settings, an iteration progress window, and program run and stop settings. The system includes the following steps: (1) The user enters the name of the tensile material in the model definition unit, selects the type of tensile specimen, enters the gauge length of the tensile specimen, enters the material parameters, enters the unit type and size, and enters the displacement load size; (2) The user uploads the initial constitutive curve of the material and the tensile curve in the iterative definition unit, selects the iterative fitting method, and enters the number of iterations; (3) The user selects the calculation file storage location in the calculation control unit, clicks the program run button to start the material tensile simulation benchmark calculation, and the system opens the iteration progress window; (4) After the iteration progress is completed, the window is closed, and the tensile curve result after iterative benchmarking is displayed in the unit benchmarking curve graphical interface of the graphics window, and the constitutive curve of the material after iterative optimization is displayed in the benchmarking curve graphical interface; (5) Open the file storage address and view the calculation result file and process file; The calculation result file includes an input parameter file, a material constitutive parameter iterative optimization process file, a tensile curve iterative process file, an iteratively optimized finite element model file, a finite element calculation result file, and a log file; in step (3), the material tensile simulation benchmark calculation includes the following steps: (a) Read the equivalent plastic strain PE_old and Mises_old in the process file, and the force Fsim_old and gauge length displacement Usim_old in the tensile curve iteration process file; (b) Read the test force Ftest_0 and test displacement Utest_0 of the tensile curve file, and perform monotonicity test and monotonicity data processing; (c) Read the plastic strain Strain_0 and input true stress Stress_0 of the initial constitutive curve of the material; (d) Using the equivalent plastic strain PE_old as the interpolation point, interpolate the input plastic strain Strain_0 and the input true stress Stress_0 to obtain the interpolated Stain_1 and Stress_1; (e) Using the gauge displacement Usim-old as the interpolation point, interpolate the test displacement Utest_0 and the test force Ftest_0 to obtain the interpolated values ​​Utest_1 and Ftest_1; (f) Calculating the optimized input constitutive curve according to an iterative formula not limited to the following, where eps is a minimum value; Stress_2(i)=Ftest_1(i) / (Fsim_old(i)+eps)*Stress_1(i) Strain_2(i)= Strain_1(i) (g) Find the location of the maximum stress value max(Stress_2) after iteration, delete the stress and strain data after this location; perform monotonicity check and processing on (Strain_2, Stress_2) to generate monotonically increasing (Strain_3, Stress_3); (h) Perform data fitting on (Strain_3, Stress_3) according to the iterative fitting method to obtain the updated input constitutive curve (Strain_new, Stress_new) and write it into the process file; The updated material constitutive parameters are written into the iteratively optimized finite element model file, a new finite element calculation result file and a tensile curve iteration process file are generated, and the force Fsim_new and gauge length displacement Usim_new are obtained; and an iterative process is completed.

2. The material tensile simulation benchmarking optimization analysis method according to claim 1, characterized in that: In the model definition unit, the specimen types include plate-shaped smooth tensile specimens, plate-shaped notched tensile specimens, and rod-shaped tensile specimens; the specimen dimensions include specimen gauge length, specimen gauge width, specimen thickness, specimen diameter, and notch diameter; material parameters include but are not limited to density, elastic modulus, Poisson's ratio, and material anisotropy parameters; unit types include shell units and solid units; and unit dimensions include grid size and cross-section grid number.

3. The material tensile simulation benchmarking optimization analysis method according to claim 1, characterized in that: In the iterative definition unit, iterative fitting methods include but are not limited to Swift constitutive fitting, Ludwick constitutive fitting, Double-Voce constitutive fitting, Modified-Hockeh-Sherby constitutive fitting, polynomial fitting and no fitting.

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