A method for automatically fitting Arrhenius constitutive and DMM thermal processing diagrams including compensation

Abstract

The present invention discloses a method for automatically fitting an Arrhenius constitutive and DMM thermal processing diagram including compensation, comprising the following steps: 1) marking and removing unreasonable data in experimental data; 2) sorting the data and outputting the initial rheological curve; 3) performing friction compensation on the data; 4) performing temperature compensation on the data; 5) determining the number of times strain compensation is performed according to the minimum compensation strain, maximum compensation strain and compensation spacing defined by the user, and embedding the thermal processing diagram module for cyclic solution output; 6) establishing corresponding polynomials for all constitutive parameters and strains respectively, and obtaining constitutive equation expressions established after compensation; 7) using an iterative algorithm to reversely solve stress values ​​and compare them with experimental values. The present invention can quickly and accurately obtain the constitutive information of the material and the thermal processing diagram under multiple strains, and can also avoid errors and time costs in the actual calculation and drawing process, thus shortening the development cycle.

Description

Technical Field

[0001] The invention relates to the field of material technology, and in particular to a method for automatically fitting an Arrhenius constitutive and DMM thermal processing diagram including compensation. Background Art

[0002] The constitutive model describes the change of material strength with strain, temperature, strain rate and other factors during deformation, and is a mathematical relationship that best reflects the mechanical properties of materials. As long as an accurate constitutive model is established, the response of metal materials can be predicted through the corresponding state parameters, that is, the corresponding rheological stress, which is an indispensable material property for numerical simulation. Thermal processing diagrams can be used for heat treatment analysis and prediction of material deformation under various deformation conditions. By analyzing the "processing safety zone" and "processing unstable zone" of alloys, a theoretical basis is provided for optimizing process parameters.

[0003] However, in order to ensure the accuracy and universality of the constitutive model and thermal processing diagram, it is often necessary to perform multiple compensation calculations of the constitutive equation and draw thermal processing diagrams under multiple stresses. The cumbersome calculation and drawing process greatly affects the efficiency and accuracy of researchers in extracting material information.

[0004] Therefore, it is urgent to develop a method for fitting constitutive and thermal processing diagrams with high calculation accuracy and high efficiency. Summary of the invention

[0005] The object of the present invention is to provide a method for automatically fitting the Arrhenius constitutive model including compensation and the DMM thermal processing diagram to solve the problems existing in the prior art.

[0006] The technical solution adopted to achieve the purpose of the present invention is as follows: a method for automatically fitting the Arrhenius constitutive and DMM thermal processing diagram including compensation, storing an algorithm, and when the algorithm is executed, comprising the following steps:

[0007] 1) Check the rationality of stress-strain data, mark and eliminate unreasonable data in the experimental data;

[0008] 2) sorting the data obtained in step 1) according to the ascending order of strain, and outputting the initial rheological curve;

[0009] 3) performing friction compensation on the data obtained in step 2) according to the initialized friction compensation rules and relevant information actually input by the user;

[0010] 4) performing temperature compensation on the friction compensated data obtained in step 3) according to the initialized temperature compensation rule and the relevant information actually input by the user;

[0011] 5) The compensated data of step 4) is used as the initial data of strain compensation, and the number of times of strain compensation is determined according to the minimum compensation strain, maximum compensation strain and compensation spacing defined by the user, and the thermal processing diagram module is embedded to perform cyclic solution output;

[0012] 6) Establish corresponding polynomials for all constitutive parameters solved in step 5) and strain respectively, and obtain constitutive equation expressions established after compensation;

[0013] 7) Based on the constitutive equation established in step 6), an iterative algorithm is used to reversely solve the stress value and compare it with the experimental value.

[0014] Furthermore, in step 1), the experimental data are read and traversed at different temperatures and strain rates, and the strain under each processing condition is counted. When repeated values ​​are found to interfere with subsequent solutions, the number of repetitions, data locations and specific data values ​​are recorded. When the traversal is completed, an exception and specific information about the exception are thrown.

[0015] Further, step 3) comprises the following sub-steps:

[0016] 3-1) Calculate based on the relevant information actually input by the user:

[0017]

[0018] Where h0 and h are the heights of the specimen before and after deformation, R0 and R M are the maximum radius of the specimen before and after deformation, respectively;

[0019] According to the calculated B, the friction compensation is judged;

[0020] 3-2) Calculate the friction-corrected stress according to the following formula:

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] Among them, σ f is the corrected flow stress, σ is the experimentally measured flow stress, ε is the strain, f is the friction coefficient, r0 is the initial radius of the cylindrical specimen, h0 is the initial height of the cylindrical specimen, b is the drum shape parameter, h is the height after deformation, r is the average radius of the cylinder after deformation, and r TThe top radius of the deformed cylinder, r M is the maximum radius of the cylinder after deformation;

[0027] 3-3) Output the compensated data and image.

[0028] Further, step 4) comprises the following sub-steps:

[0029] 4-1) Determine the data that needs temperature compensation in the experimental data based on the strain rate;

[0030] 4-2) Using formula (7) for a strain rate of 1s -1 Fit the data:

[0031]

[0032] In the formula, σ is the flow stress, Q is the deformation thermal activation energy, R is the molar gas constant, T is the deformation temperature, is the strain rate, n, A, and n1 are all material parameters;

[0033] 4-3) Use formula (8) for strain rate>1s -1 Fit the data:

[0034]

[0035] In the formula, σ is the flow stress and β is the material parameter;

[0036] 4-4) Output the compensated data and image.

[0037] Further, step 5) comprises the following sub-steps:

[0038] 5-1) Inherit the data after friction and temperature compensation, and perform multiple strain cycle compensation according to the relevant information actually input by the user;

[0039] 5-2) The thermal processing map module is embedded in each strain cycle compensation and calculated according to the following formula:

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046] Where P is the dissipated power, G is the power related to temperature, J is the power related to microstructure, σ is the flow stress, K is a constant, m is the strain rate sensitivity index, η is the dissipation rate factor, ξ is the instability criterion, and the instability zone and the safe zone are divided;

[0047] The thermal processing map is obtained by superimposing the power dissipation map and the instability map;

[0048] 5-3) Output the parameters and images of each compensation process, the solution values ​​of the constitutive parameters, and the thermal processing map data and images under the compensation strain.

[0049] A system for automatically fitting an Arrhenius constitutive model including compensation and a DMM thermal processing diagram, comprising a readable storage medium, a processor, and a thermal compression experiment data acquisition module;

[0050] The readable storage medium stores a computer program, and the computer program implements the above method when executed by the processor; the thermal compression experiment data acquisition module acquires the experiment data.

[0051] The beneficial effects of the present invention are:

[0052] 1. The present invention develops and uses modules such as experimental data detection and sorting, friction compensation, temperature compensation, strain compensation, thermal processing diagram and constitutive verification to more accurately obtain the parameters and images in the process of solving the Arrhenius constitutive and DMM thermal processing diagrams;

[0053] 2. The present invention can quickly and accurately obtain the constitutive information of the material and the thermal processing diagrams under multiple strains, while avoiding errors and time costs in the actual calculation and drawing process, shortening the development cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a flow chart of the method of the present invention;

[0055] Figure 2 The GUI interface used by the method of the present invention;

[0056] Figure 3 This is a comparison chart between friction correction and original data;

[0057] Figure 4 This is a comparison chart between temperature correction and original data;

[0058] Figure 5 To solve the problem at different temperatures Fitting graph;

[0059] Figure 6 To solve the problem at different temperatures Fitting graph;

[0060] Figure 7 is a schematic diagram of the three-dimensional dissipation rate factor η;

[0061] Figure 8 This is a comparison chart between the constitutive inverse solution and the experimental value;

[0062] Fig. 9 The constitutive verification diagram outputted by the present invention;

[0063] Fig.10 It is a comparison diagram between the thermal processing diagram output by the present invention and the existing thermal processing diagram. DETAILED DESCRIPTION

[0064] The present invention is further described below in conjunction with the embodiments, but it should not be understood that the above subject matter of the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various substitutions and changes are made according to the common technical knowledge and customary means in the art, which should all be included in the protection scope of the present invention.

[0065] Embodiment 1:

[0066] This embodiment discloses a method for automatically fitting the Arrhenius constitutive model and DMM thermal processing diagram including compensation, and solves the Arrhenius constitutive model and DMM thermal processing diagram of 6061 aluminum alloy; wherein the Chinese name of Arrhenius is Arrhenius, and DMM is a dynamic material model.

[0067] The method is based on a system for automatically fitting the compensated Arrhenius constitutive and DMM thermal processing diagrams, the system comprising a readable storage medium, a processor and a thermal compression experimental data acquisition module; the readable storage medium stores a computer program, and the computer program implements the above method when executed by the processor, see Figure 2 , fill in the experimental data and related information into the program interactive interface to solve the problem;

[0068] See also Figure 1 , when the program is executed, the specific steps are as follows:

[0069] 1) Check the rationality of stress-strain data, mark and remove obviously unreasonable data such as repeated values ​​in the experimental data; specifically, read and traverse the experimental data at different temperatures and strain rates, and count the strains under each processing condition. When repeated values ​​and other situations that interfere with subsequent solutions are found, record the number of repetitions, data locations and specific data values. When the traversal is completed, throw an exception and specific information about the exception.

[0070] 2) sorting the data obtained in step 1) according to the ascending order of strain, and outputting the initial rheological curve;

[0071] 3) According to the initialized friction compensation rules and the relevant information actually input by the user, friction compensation is performed on the data obtained in step 2); specifically, this step includes the following sub-steps:

[0072] 3-1) Calculate based on the relevant information actually input by the user:

[0073]

[0074] Where h0 and h are the heights of the specimen before and after deformation, R0 and R M are the maximum radius of the specimen before and after deformation, respectively;

[0075] According to the calculated B, the friction compensation is judged;

[0076] 3-2) Calculate the friction-corrected stress according to the following formula:

[0077]

[0078]

[0079]

[0080]

[0081]

[0082] Among them, σ f is the corrected flow stress, σ is the experimentally measured flow stress, ε is the strain, f is the friction coefficient, r0 is the initial radius of the cylindrical specimen, h0 is the initial height of the cylindrical specimen, b is the drum shape parameter, h is the height after deformation, r is the average radius of the cylinder after deformation, and r T The top radius of the deformed cylinder, r M is the maximum radius of the cylinder after deformation;

[0083] 3-3) Output the compensated data and image. Figure 3 , which is a comparison chart between friction correction and original data.

[0084] 4) Performing temperature compensation on the friction compensated data obtained in step 3) according to the initialized temperature compensation rule and the relevant information actually input by the user; specifically, this step 4) includes the following sub-steps:

[0085] 4-1) Determine the data that needs temperature compensation in the experimental data based on the strain rate;

[0086] 4-2) Using formula (7) for a strain rate of 1s -1 Fit the data:

[0087]

[0088] In the formula, σ is the flow stress, Q is the deformation thermal activation energy, R is the molar gas constant, T is the deformation temperature, is the strain rate, n, A, and n1 are all material parameters;

[0089] 4-3) Use formula (8) for strain rate>1s -1 Fit the data:

[0090]

[0091] In the formula, σ is the flow stress and β is the material parameter; Figure 5 To solve the problem at different temperatures Fitting graph; Figure 6 To solve the problem at different temperatures Fitting graph;

[0092] 4-4) Output the compensated data and image. Figure 4 , which is a comparison chart between temperature correction and original data.

[0093] 5) The compensated data of step 4) is used as the initial data of strain compensation, and then the number of strain compensation is determined according to the minimum compensation strain, maximum compensation strain and compensation spacing defined by the user, and the thermal processing diagram module is embedded to perform cyclic solution output; specifically, the following sub-steps are included:

[0094] 5-1) Inherit the data after friction and temperature compensation, and perform multiple strain cycle compensation according to the relevant information actually input by the user;

[0095] 5-2) The thermal processing map module is embedded in each strain cycle compensation and calculated according to the following formula:

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] Where P is the dissipated power, G is the power related to temperature, J is the power related to microstructure, σ is the flow stress, K is a constant, m is the strain rate sensitivity index, η is the dissipation rate factor, ξ is the instability criterion, and the instability zone and the safe zone are divided; Figure 7 is a schematic diagram of the three-dimensional dissipation rate factor η;

[0103] The thermal processing map is obtained by superimposing the power dissipation map and the instability map;

[0104] 5-3) Output the parameters and images in each compensation process, the solution values ​​of the constitutive parameters, and the thermal processing image data and images under the compensation strain. The thermal processing image output by this embodiment is compared with the existing thermal processing image as shown in the figure Fig.10 As shown, Fig.10 a is the existing thermal processing diagram, Fig.10 b is the thermal processing diagram outputted in this embodiment.

[0105] 6) Establish corresponding polynomials for all constitutive parameters solved in step 5) and strain respectively, and obtain the constitutive equation expression established after compensation. The output constitutive verification diagram is as follows: Fig. 9 As shown;

[0106] 7) Based on the constitutive equation established in step 6), the stress value is reversely solved using an iterative algorithm and compared with the experimental value, such as Figure 8 shown.

[0107] The method described in this embodiment can be used to quickly and accurately obtain the constitutive information of the material and the thermal processing diagrams under multiple strains, while avoiding errors and time costs in the actual calculation and drawing process, shortening the development cycle.

[0108] Embodiment 2:

[0109] This embodiment discloses a method for automatically fitting an Arrhenius constitutive model including compensation and a DMM thermal processing diagram, wherein an algorithm is stored and when the algorithm is executed, the following steps are included:

[0110] 1) Check the rationality of stress-strain data, mark and eliminate unreasonable data in the experimental data;

[0111] 2) sorting the data obtained in step 1) according to the ascending order of strain, and outputting the initial rheological curve;

[0112] 3) performing friction compensation on the data obtained in step 2) according to the initialized friction compensation rules and relevant information actually input by the user;

[0113] 4) performing temperature compensation on the friction compensated data obtained in step 3) according to the initialized temperature compensation rule and the relevant information actually input by the user;

[0114] 5) The compensated data of step 4) is used as the initial data of strain compensation, and the number of times of strain compensation is determined according to the minimum compensation strain, maximum compensation strain and compensation spacing defined by the user, and the thermal processing diagram module is embedded to perform cyclic solution output;

[0115] 6) Establish corresponding polynomials for all constitutive parameters solved in step 5) and strain respectively, and obtain constitutive equation expressions established after compensation;

[0116] 7) Based on the constitutive equation established in step 6), an iterative algorithm is used to reversely solve the stress value and compare it with the experimental value.

[0117] Embodiment 3:

[0118] The main steps of this embodiment are the same as those of Embodiment 2. Furthermore, in step 1), the experimental data are read and traversed at different temperatures and strain rates, and the strain under each processing condition is counted. When it is found that repeated values ​​interfere with subsequent solutions, the number of repetitions, data locations and specific data values ​​are recorded. When the traversal is completed, an exception and specific information about the exception are thrown.

[0119] Embodiment 4:

[0120] The main steps of this embodiment are the same as those of Embodiment 2. Further, step 3) includes the following sub-steps:

[0121] 3-1) Calculate based on the relevant information actually input by the user:

[0122]

[0123] Where h0 and h are the heights of the specimen before and after deformation, R0 and R M are the maximum radius of the specimen before and after deformation, respectively;

[0124] According to the calculated B, the friction compensation is judged;

[0125] 3-2) Calculate the friction-corrected stress according to the following formula:

[0126]

[0127]

[0128]

[0129]

[0130]

[0131] Among them, σ fis the corrected flow stress, σ is the experimentally measured flow stress, ε is the strain, f is the friction coefficient, r0 is the initial radius of the cylindrical specimen, h0 is the initial height of the cylindrical specimen, b is the drum shape parameter, h is the height after deformation, r is the average radius of the cylinder after deformation, and r T The top radius of the deformed cylinder, r M is the maximum radius of the cylinder after deformation;

[0132] 3-3) Output the compensated data and image.

[0133] Embodiment 5:

[0134] The main steps of this embodiment are the same as those of Embodiment 2. Further, step 4) includes the following sub-steps:

[0135] 4-1) Determine the data that needs temperature compensation in the experimental data based on the strain rate;

[0136] 4-2) Using formula (7) for a strain rate of 1s -1 Fit the data:

[0137]

[0138] In the formula, σ is the flow stress, Q is the deformation thermal activation energy, R is the molar gas constant, T is the deformation temperature, is the strain rate, n, A, and n1 are all material parameters;

[0139] 4-3) Use formula (8) for strain rate>1s -1 Fit the data:

[0140]

[0141] In the formula, σ is the flow stress and β is the material parameter;

[0142] 4-4) Output the compensated data and image.

[0143] Embodiment 6:

[0144] The main steps of this embodiment are the same as those of Embodiment 2. Further, step 5) includes the following sub-steps:

[0145] 5-1) Inherit the data after friction and temperature compensation, and perform multiple strain cycle compensation according to the relevant information actually input by the user;

[0146] 5-2) The thermal processing map module is embedded in each strain cycle compensation and calculated according to the following formula:

[0147]

[0148]

[0149]

[0150]

[0151]

[0152]

[0153] Where P is the dissipated power, G is the power related to temperature, J is the power related to microstructure, σ is the flow stress, K is a constant, m is the strain rate sensitivity index, η is the dissipation rate factor, ξ is the instability criterion, and the instability zone and the safe zone are divided;

[0154] The thermal processing map is obtained by superimposing the power dissipation map and the instability map;

[0155] 5-3) Output the parameters and images of each compensation process, the solution values ​​of the constitutive parameters, and the thermal processing map data and images under the compensation strain.

[0156] Embodiment 7:

[0157] This embodiment discloses a system for automatically fitting an Arrhenius constitutive model including compensation and a DMM thermal processing diagram, including a readable storage medium, a processor, and a thermal compression experiment data acquisition module;

[0158] The readable storage medium stores a computer program, and when the computer program is executed by the processor, any one of the methods in Examples 1 to 6 is implemented; the thermal compression experiment data acquisition module acquires experimental data, and the thermal compression experiment data acquisition module is a Gleeble thermal simulation test machine.

Claims

1. A method for automatically fitting a compensated Arrhenius constitutive and DMM thermal processing diagram, characterized in that: The following steps are involved: 1) Check the rationality of stress-strain data, mark and eliminate unreasonable data in the experimental data; 2) sorting the data obtained in step 1) according to the ascending order of strain, and outputting the initial rheological curve; 3) performing friction compensation on the data obtained in step 2) according to the initialized friction compensation rules and relevant information actually input by the user; 4) performing temperature compensation on the friction compensated data obtained in step 3) according to the initialized temperature compensation rule and the relevant information actually input by the user; 5) The compensated data of step 4) is used as the initial data of strain compensation, and the number of strain compensation is determined according to the minimum compensation strain, maximum compensation strain and compensation spacing defined by the user, and the thermal processing diagram module is embedded to perform cyclic solution output; step 5) includes the following sub-steps: 5-1) Inherit the data after friction and temperature compensation, and perform multiple strain cycle compensation according to the relevant information actually input by the user; 5-2) The thermal processing map module is embedded in each strain cycle compensation and calculated according to the following formula: Where P is the dissipated power, G is the power related to temperature, J is the power related to microstructure, σ is the flow stress, K is a constant, m is the strain rate sensitivity index, η is the dissipation rate factor, ξ is the instability criterion, and the instability zone and the safe zone are divided; The thermal processing map is obtained by superimposing the power dissipation map and the instability map; 5-3) Output the parameters and images in each compensation process, the solution values ​​of the constitutive parameters, and the thermal processing map data and images under the compensation strain; 6) Establish corresponding polynomials for all constitutive parameters solved in step 5) and strain respectively, and obtain constitutive equation expressions established after compensation; 7) Based on the constitutive equation established in step 6), an iterative algorithm is used to reversely solve the stress value and compare it with the experimental value.

2. The method for automatically fitting the compensated Arrhenius constitutive and DMM thermal processing diagram according to claim 1, characterized in that: In step 1), the experimental data are read and traversed at different temperatures and strain rates, and the strain under each processing condition is counted. When repeated values ​​are found to interfere with subsequent solutions, the number of repetitions, data locations and specific data values ​​are recorded. When the traversal is completed, an exception and specific information about the exception are thrown.

3. A method for automatically fitting the compensated Arrhenius constitutive and DMM thermal processing diagram according to claim 1 or 2, characterized in that: Step 3) includes the following sub-steps: 3-1) Calculate based on the relevant information actually input by the user: Where h0 and h are the heights of the specimen before and after deformation, R0 and R M are the maximum radius of the specimen before and after deformation, respectively; According to the calculated B, the friction compensation is judged; 3-2) Calculate the friction-corrected stress according to the following formula: Among them, σ f is the corrected flow stress, σ is the experimentally measured flow stress, ε is the strain, f is the friction coefficient, r0 is the initial radius of the cylindrical specimen, h0 is the initial height of the cylindrical specimen, b is the drum shape parameter, h is the height after deformation, r is the average radius of the cylinder after deformation, and r T The top radius of the deformed cylinder, r M is the maximum radius of the cylinder after deformation; 3-3) Output the compensated data and image.

4. A method for automatically fitting the compensated Arrhenius constitutive and DMM thermal processing diagram according to claim 1 or 3, characterized in that: Step 4) includes the following sub-steps: 4-1) Determine the data that needs temperature compensation in the experimental data based on the strain rate; 4-2) Using formula (13) for a strain rate of 1s -1 Fit the data: In the formula, σ is the flow stress, Q is the deformation thermal activation energy, R is the molar gas constant, T is the deformation temperature, is the strain rate, n, A, and n1 are all material parameters; 4-3) Use formula (14) for strain rate>1s -1 Fit the data: In the formula, σ is the flow stress and β is the material parameter; 4-4) Output the compensated data and image.

5. A system for automatically fitting compensated Arrhenius constitutive and DMM thermal processing diagrams, characterized in that: It includes a readable storage medium, a processor and a thermal compression experiment data acquisition module; The readable storage medium stores a computer program, and when the computer program is executed by a processor, any one of the methods in claims 1 to 4 is implemented; the thermal compression experiment data acquisition module acquires the experiment data.

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