CN107908917B - High-strength plate stamping forming springback prediction method - Google Patents

High-strength plate stamping forming springback prediction method Download PDF

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CN107908917B
CN107908917B CN201711479583.0A CN201711479583A CN107908917B CN 107908917 B CN107908917 B CN 107908917B CN 201711479583 A CN201711479583 A CN 201711479583A CN 107908917 B CN107908917 B CN 107908917B
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stamping
constitutive model
strength plate
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CN107908917A (en
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王立平
张志刚
邵珠峰
马嵩华
罗仁平
贺亮
邓豪
张兆坤
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Tsinghua University
Shandong University
SAIC General Motors Corp Ltd
Jier Machine Tool Group Co Ltd
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Shandong University
SAIC General Motors Corp Ltd
Jier Machine Tool Group Co Ltd
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Abstract

A high-strength plate stamping forming springback prediction method comprises the following steps: establishing a stress-strain curve family of the high-strength plate through a plurality of groups of material experiments, and fitting an initial constitutive model of the material; importing the initial material constitutive model into finite element software to perform U-shaped groove stamping forming simulation analysis, and comparing the simulation analysis with an actual U-shaped groove stamping experiment; if the error between the simulation data of the material constitutive model and the actual stamping experiment exceeds a threshold value, correcting the current material constitutive model parameters, and repeating the steps; carrying out stamping simulation on the high-strength plate complex stamping part by using the corrected material constitutive model; the method can obtain a high-precision stamping simulation result.

Description

High-strength plate stamping forming springback prediction method
Technical Field
The invention relates to the technical field of plate forming springback prediction, in particular to a high-strength plate stamping springback prediction method.
Background
At present, along with the rapid development of the automobile industry, the size of a stamping part is gradually increased, the shape is gradually complicated, and the precision requirement is continuously improved. The automobile covering parts are made of thin materials, have complex shapes, high requirements on shape and dimension accuracy, good rigidity and the like, and have the problem that the fracture defect is often generated due to poor process control in the stamping forming process, so that digital simulation is required to be carried out before actual stamping. As a three-dimensional curved surface with a complex shape and a large size, the automobile covering part has more concave-convex characteristics, and the plate materials are often subjected to tension and compression loads simultaneously or continuously in the stamping process. The traditional method for carrying out numerical simulation on the forming of the covering part by only relying on finite element simulation software cannot obtain an accurate rebound result, and is difficult to guide process control and mold structure parameter optimization design in actual production. In particular, the wide application of the high-strength plate on the automobile covering part has the resilience prediction precision become an important factor influencing the design and manufacturing quality of a die, the control of process parameters in the stamping process, the production period and the cost.
The actual resilience of the plate is comprehensively influenced by a plurality of factors such as actual performance parameters (including anisotropic behavior, elastoplastic constitutive relation, work hardening mode, Bauschinger effect and the like), a stamping mode, process conditions, loading history, geometric shapes of stamping parts, prediction theory and method and the like of the material. Wherein the error caused by the material property parameters has a decisive influence on the accuracy of the springback prediction. Due to the non-linearity between the material property parameters and the punch rebound result, methods and techniques for purposefully adjusting the material property parameters for the rebound result are lacking.
In summary, an effective solution is not yet available for accurately predicting the springback of the high-strength plate during stamping in the prior art.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide a method for predicting the stamping forming springback of a high-strength plate, which can obtain a high-precision stamping simulation result.
The invention adopts the following technical scheme:
a high-strength plate stamping forming springback prediction method comprises the following steps:
step (1): carrying out a plurality of groups of material stretching-compressing experiments, wherein a test piece adopted in the experiments is manufactured into a standard test piece according to the specification of the national standard GB/T228.1-2010, and the section of the test piece is rectangular; the method comprises the following steps of carrying out loading control on 10 high-strength plate test pieces, wherein the loading control strain is firstly linearly increased to 50% of the limit of the test pieces along with the change of time, and then is linearly reduced to 50% of the limit of the test pieces, so that a stress-strain curve family of the high-strength plate is formed;
obtaining an initial material constitutive model by fitting a stress-strain curve group of the high-strength plate by a least square method, wherein the specific method is as follows;
describing the plastic anisotropy of the high-strength plate by using a yield equation, and describing the variability of the Young's modulus by using a follow-up hardening material model; the yield equation is:
Figure GDA0002396587240000021
the in-plane stress state φ is described by two principal values φ', φ ":
wherein m is a material coefficient of the isotropic hardening rate,
Figure GDA0002396587240000022
is the effective stress, and phi ', phi' are expressed as two isotropic functions
Figure GDA0002396587240000023
Figure GDA0002396587240000024
Figure GDA0002396587240000025
Figure GDA0002396587240000031
Figure GDA0002396587240000032
Wherein, X'1、X”1And X'2、X”2Are respectively matrix X '═ X'xxX'yyX'xy]TAnd X ═ X "xxX”yyX”xy]TA main value of (c); for anisotropy, the elements of the matrices X' and X "are each obtained by a linear transformation of the Cauchy stress tensor σ:
X'＝L'σ (7)
X"＝L"σ (8)
l 'and L' are linear transformation matrices of X 'and X', respectively, the components of which are obtained by the following equations (9) and (10):
Figure GDA0002396587240000033
Figure GDA0002396587240000034
wherein, α1-α8Is eight anisotropy coefficients;
the relationship between Young's modulus of elasticity and plastic strain is described by using a Yoshida-Uemori follow-up hardening material model, namely
Figure GDA0002396587240000035
In the formula (13), E0Initial young's modulus of elasticity; eaMinimum young's modulus, ξ attenuation coefficient,
Figure GDA0002396587240000036
is an effective plastic strain; the model assumes that in the plastic deformation process, the size and the shape of a yielding surface are kept unchanged, and the whole body is translated in a stress space;
the Yoshida-ueori following hardened material model can also be described by the yield plane F, and its back stress α and the boundary plane F and its back stress β:
f＝φ(σ-α)-Y＝0 (14)
wherein phi is the equivalent stress calculated through the yield function, sigma and α respectively represent Cauchy stress and back stress, and Y is the material parameter of the initial yield stress;
F＝φ(σ-β)-(B+R)＝0 (15)
the boundary surface is based on isotropic hardening and follow-up hardening, β represents the back stress of the boundary surface, B represents the initial size of the boundary surface, and R represents the isotropic hardening amount of the boundary surface;
the relative relationship of the yield surface to the boundary surface is:
α*＝α-β (16)
wherein, α*Is the relative movement amount;
the hardening behaviour during plastic deformation is defined by the evolution process of the yield surface:
Figure GDA0002396587240000041
wherein the content of the first and second substances,
Figure GDA0002396587240000042
denotes the effective plastic strain rate, C denotes the material parameter which denotes the random hardening rate, and a denotes the difference between the yield plane and the boundary plane, i.e. a ═ B + R-Y ═ a0+R；a0Is the initial value of a;
the evolution law of boundary surface equi-directional hardening amount is as follows:
Figure GDA0002396587240000043
wherein m is a material parameter of the isotropic hardening rate, RsatIs the saturation equivalent value of R;
the saturation stress is defined by the evolution of the boundary surface when undergoing large deformations:
Figure GDA0002396587240000044
wherein b is a saturation equivalent value;
in the above formula, the material parameter Y of initial yield stress, the material parameter C of random hardening rate, the saturation equivalent value b, the material coefficient m of isotropic hardening rate and the saturation equivalent value R of boundary surface isotropic hardening rate dsatThe first calculation is obtained by fitting a plurality of groups of stress-strain curves of a stretching-compressing experiment by a least square method, and the process of establishing an initial material constitutive model F (sigma, epsilon) is realized.
Step (2): guiding the fitted initial material constitutive model into finite element analysis software to simulate the stamping forming process of the U-shaped groove of the high-strength plate, and carrying out a U-shaped groove stamping experiment; comparing the actual rebound of the U-shaped groove punching experiment with the finite element simulation rebound result;
and (3): when the relative error between the finite element simulation resilience result and the resilience of the actual stamping experiment exceeds a threshold value of 8%, correcting the material constitutive model parameters, and repeating the step (2); namely if the finite element of the U-shaped groove simulates the rebound angle (theta'1、θ'2) The springback angle (theta) of the actual stamping experiment1、θ2) The difference of (a) exceeds a threshold value, a back stress α, a material parameter Y of an initial yield stress, a material parameter C of a random hardening rate, a saturation equivalent value b, a material coefficient m of an isotropic hardening rate and a saturation equivalent value R of a boundary surface isotropic hardening amount d in the initial material constitutive modelsatAnd (3) adjusting: if the simulation rebound result is smaller than the stamping experiment result, the material real constitutive model is indicated to be positioned below the fitted initial material constitutive model, and a stress-strain curve family above the initial material constitutive model is selected to be fitted again to obtain the revised material constitutive model so as to increase the average Young modulus; on the contrary, if the simulation rebound result is larger than the stamping experiment result, the material real constitutive model is indicated to be positioned above the fitting constitutive model so as to reduce the average Young modulus; will be revisedGuiding the material constitutive model into finite element analysis software to simulate the stamping forming process of the U-shaped groove of the high-strength plate, repeating the stamping forming simulation and springback comparison of the high-strength plate in the step (2), and finally enabling the difference between the simulation result and the experimental result to meet a threshold value to perform the step (4);
and (4): and (4) carrying out stamping simulation on the high-strength plate stamping part by using the corrected material constitutive model meeting the simulation precision requirement to obtain an accurate stamping springback result.
Compared with the prior art, the invention has the beneficial effects that:
(1) the invention establishes a variable material constitutive model. Establishing a material parameter Y of initial yield stress of the variable material constitutive model, a material parameter C of random hardening rate, a saturation equivalent value b, a material coefficient m and a saturation equivalent value R of boundary surface equal to hardening amount dsatSo as to obtain an accurate high-strength plate material performance model, and the simulation precision of the stamping and forming springback of the high-strength plate can be fundamentally improved.
(2) According to the invention, the simulation model of the automobile covering part is simplified by using the U-shaped groove, the U-shaped groove can be bent and reversely bent successively when a plate material is stressed to slide through the fillet position of the female die in the stamping process, the tensile load and the compressive load simultaneously stressed in the stamping process of the automobile covering part can be reflected, the effective equivalence of the stamping and rebounding process of the automobile covering part is realized, and the correction is pertinently carried out.
(3) According to the invention, the corrected material constitutive model is utilized to perform stamping simulation on the actual automobile covering part, and an accurate stamping springback prediction result can be obtained, so that the accuracy of optimization and control on the whole stamping influence parameters (such as stamping mode, process conditions, loading history and stamping part geometric shape) is improved.
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The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.
FIG. 1 shows the dimensions of a high-strength plate test piece
Fig. 2 is a loading curve.
Figure 3 is the U-shaped slot size.
Fig. 4 shows the rebound angle position of the U-shaped groove.
FIG. 5 is a flow chart of the present invention.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
As introduced in the background art, the prior art has the defects of low rebound prediction accuracy and low efficiency in the stamping forming of the high-strength plate, and in order to solve the technical problems, the application provides a rebound prediction system and a rebound prediction method for the stamping forming of the high-strength plate.
In a typical embodiment of the present application, as shown in fig. 5, a high-strength plate stamping springback prediction system and a prediction method are provided, based on a high-strength plate for an automobile covering part, the adopted high-strength plate stamping springback prediction system includes a material constitutive modeling module, a parameter checking and adjusting module, and a stamping springback simulation module, and the material constitutive modeling module includes a plastic anisotropy description module and a follow-up hardening material module.
The high-strength plate stamping forming springback prediction method based on the automobile panel comprises the following steps:
firstly, establishing a material constitutive model of the high-strength plate
The high-strength plate with the thickness of 1.2mm and the type of HSLA590 is selected, the material anisotropy is obvious, the yield strength is high, the high-strength plate is beneficial to being used as an automobile outer covering part, and the mechanical properties of the HSLA590 high-strength plate are shown in Table 1.
TABLE 1 mechanical Properties of HSLA590 high-strength plates
Figure GDA0002396587240000071
The material tensile-compression test was conducted using test piece dimensions as shown in fig. 1, a single tensile-compression test for loading, and a loading curve as shown in fig. 2, where the strain first increased linearly to 50% of its limit and then decreased linearly with time. After 10 groups of tests, a stress-strain curve family of the high-strength plate is formed, and an initial material constitutive model is obtained through least square fitting. The plastic anisotropy of the HSLA590 is described by using a YLD2000-2d yield equation, and the mobility of the Young modulus is described by using a Yoshida-Uemorio follow-up hardening material model, so that the description precision is high.
In the YLD2000-2d yield equation, the plane stress state φ is described by two principal values φ', φ ":
Figure GDA0002396587240000081
wherein m is a material coefficient of the isotropic hardening rate,
Figure GDA0002396587240000082
is the effective stress, and phi ', phi' are expressed as two isotropic functions
Figure GDA0002396587240000083
Figure GDA0002396587240000084
Figure GDA0002396587240000085
Figure GDA0002396587240000086
Figure GDA0002396587240000087
Wherein, X'1、X”1And X'2、X”2Are respectively matrix X '═ X'xxX'yyX'xy]TAnd X ═ X "xxX”yyX”xy]TA main value of (c); for anisotropy, the elements of the matrices X' and X "are each obtained by a linear transformation of the Cauchy stress tensor σ:
X'＝L'σ (7)
X"＝L"σ (8)
l 'and L' are linear transformation matrices of X 'and X', respectively, the components of which are obtained by the following equations (9) and (10):
Figure GDA0002396587240000091
Figure GDA0002396587240000092
wherein, α1-α8Is eight anisotropy coefficients;
the relationship between Young's modulus of elasticity and plastic strain is described by using a Yoshida-Uemori follow-up hardening material model, namely
Figure GDA0002396587240000093
In the formula (13), E0Initial young's modulus of elasticity; eaMinimum young's modulus, ξ attenuation coefficient,
Figure GDA0002396587240000094
is an effective plastic strain; the model assumes that the size and shape of the yield surface remains unchanged, but is integral, during plastic deformationThe body is translated in the stress space;
the Yoshida-ueori following hardened material model can also be described by the yield plane F, and its back stress α and the boundary plane F and its back stress β:
f＝φ(σ-α)-Y＝0 (14)
wherein phi is the equivalent stress calculated through the yield function, sigma and α respectively represent Cauchy stress and back stress, and Y is the material parameter of the initial yield stress;
F＝φ(σ-β)-(B+R)＝0 (15)
the boundary surface is based on isotropic hardening and follow-up hardening, β represents the back stress of the boundary surface, B represents the initial size of the boundary surface, and R represents the isotropic hardening amount of the boundary surface;
the relative relationship of the yield surface to the boundary surface is:
α*＝α-β (16)
wherein, α*Is the relative movement amount;
the hardening behaviour during plastic deformation is defined by the evolution process of the yield surface:
Figure GDA0002396587240000101
wherein the content of the first and second substances,
Figure GDA0002396587240000102
denotes the effective plastic strain rate, C denotes the material parameter which denotes the random hardening rate, and a denotes the difference between the yield plane and the boundary plane, i.e. a ═ B + R-Y ═ a0+R；a0Is the initial value of a;
the evolution law of boundary surface equi-directional hardening amount is as follows:
Figure GDA0002396587240000103
wherein m is a material parameter of the isotropic hardening rate, RsatIs the saturation equivalent value of R;
the saturation stress is defined by the evolution of the boundary surface when undergoing large deformations:
Figure GDA0002396587240000104
wherein b is a saturation equivalent value;
material parameter Y, a in the above formula0C, b, m and RsatThe calculation of (a) was obtained by least squares fitting the stress-strain curve of the tensile-compression experiment.
Establishing a constitutive model of the initial high-strength plate stamping part by means of a least square method through multiple material experiments, namely determining parameter coefficient α in the yield equation of YLd2000-2d1-α8Y, a in a Yoshida-Uemori follow-up hardening material model0C, b, m and RsatThe value of (c).
Secondly, comparing the simulation result of the U-shaped groove of the high-strength plate with the resilience of the actual stamping experiment
Guiding the fitted material constitutive model into finite element analysis software through an interface program to simulate the stamping forming process of a U-shaped groove of the high-strength plate, wherein the size of the U-shaped groove is shown in figure 3, and carrying out a U-shaped groove stamping experiment; and comparing the actual rebound result of the U-shaped groove punching experiment with the finite element simulation rebound result.
Third, revision of material constitutive model
And (5) when the relative error of the finite element simulation data and the resilience of the actual stamping experiment exceeds a threshold value, correcting the material constitutive model parameters, and repeating the step two. As shown in fig. 4, that is, if U-shaped groove finite element stamping simulation rebound angle (theta'1、θ'2) The springback angle (theta) of the actual stamping experiment1、θ2) Exceeds a threshold value of 8%, and a saturation equivalent value R of a back stress α, a material parameter Y of an initial yield stress, a material parameter C of a random hardening rate, a saturation equivalent value b, a material coefficient m and a boundary surface equal hardening amount d in the material constitutive modelsatAnd (3) adjusting: if the simulation rebound result is smaller than the stamping experiment result, the material real constitutive model is indicated to be positioned above the fitting constitutive model, and a stress-strain curve family above the initial constitutive model is selected to be fitted again to obtain a revised material constitutive model so as to increase the average Young modulus; on the contrary, if the simulation is performedThe rebound result is smaller than the punching experiment result, which shows that the real constitutive model of the material should be positioned above the fitting constitutive model to reduce the average Young modulus. And (4) importing the revised material constitutive model into finite element analysis software to simulate the stamping forming process of the U-shaped groove of the high-strength plate, repeating the stamping forming simulation and springback comparison of the high-strength plate in the second step, and finally enabling the relative error between the simulation and the experimental result to meet a threshold value to perform a fourth step.
The material constitutive model established by the method can be used for adjusting parameters according to the U-shaped groove experiment result, and can accurately reflect the material property of the high-strength plate, so that a stamping simulation result with higher precision can be obtained.
Fourthly, stamping simulation is carried out on the automobile covering part by utilizing the corrected material constitutive model
And (3) the corrected high-strength plate material constitutive model is used for importing finite element software to carry out stamping simulation on the actual automobile covering part, so that an accurate stamping springback result can be obtained.
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (1)

1. A high-strength plate stamping forming springback prediction method is characterized by comprising the following steps: the method comprises the following steps:
step (1): carrying out a plurality of groups of material stretching-compressing experiments, wherein a test piece adopted in the experiments is manufactured into a standard test piece according to the specification of the national standard GB/T228.1-2010, and the section of the test piece is rectangular; the method comprises the following steps of carrying out loading control on 10 high-strength plate test pieces, wherein the loading control strain is firstly linearly increased to 50% of the limit of the test pieces along with the change of time, and then is linearly reduced to 50% of the limit of the test pieces, so that a stress-strain curve family of the high-strength plate is formed;
obtaining an initial material constitutive model by fitting a stress-strain curve group of the high-strength plate by a least square method, wherein the specific method is as follows;
describing the plastic anisotropy of the high-strength plate by using a yield equation, and describing the variability of the Young's modulus by using a follow-up hardening material model; the yield equation is:
Figure FDA0002396587230000011
the in-plane stress state φ is described by two principal values φ', φ ":
wherein m is a material coefficient of the isotropic hardening rate,
Figure FDA0002396587230000012
is the effective stress, and phi ', phi' are expressed as two isotropic functions
Figure FDA0002396587230000013
Figure FDA0002396587230000014
Figure FDA0002396587230000015
Figure FDA0002396587230000016
Figure FDA0002396587230000017
Wherein, X'1、X”1And X'2、X”2Are respectively matrix X '═ X'xxX'yyX'xy]TAnd X ═ X "xxX”yyX”xy]TA main value of (c); for anisotropy, the elements of the matrices X' and X "are each obtained by a linear transformation of the Cauchy stress tensor σ:
X'＝L'σ (7)
X"＝L"σ (8)
l 'and L' are linear transformation matrices of X 'and X', respectively, the components of which are obtained by the following equations (9) and (10):
Figure FDA0002396587230000021
Figure FDA0002396587230000022
wherein, α1-α8Is eight anisotropy coefficients;
the relationship between Young's modulus of elasticity and plastic strain is described by using a Yoshida-Uemori follow-up hardening material model, namely
Figure FDA0002396587230000023
In the formula (13), E0Initial young's modulus of elasticity; eaMinimum young's modulus, ξ attenuation coefficient,
Figure FDA0002396587230000024
is an effective plastic strain; the model assumes that in the plastic deformation process, the size and the shape of a yielding surface are kept unchanged, and the whole body is translated in a stress space;
the Yoshida-ueori following hardened material model can also be described by the yield plane F, and its back stress α and the boundary plane F and its back stress β:
f＝φ(σ-α)-Y＝0 (14)
wherein phi is the equivalent stress calculated through the yield function, sigma and α respectively represent Cauchy stress and back stress, and Y is the material parameter of the initial yield stress;
F＝φ(σ-β)-(B+R)＝0 (15)
the boundary surface is based on isotropic hardening and follow-up hardening, β represents the back stress of the boundary surface, B represents the initial size of the boundary surface, and R represents the isotropic hardening amount of the boundary surface;
the relative relationship of the yield surface to the boundary surface is:
α*＝α-β (16)
wherein, α*Is the relative movement amount;
the hardening behaviour during plastic deformation is defined by the evolution process of the yield surface:
Figure FDA0002396587230000031
wherein the content of the first and second substances,
Figure FDA0002396587230000032
denotes the effective plastic strain rate, C denotes the material parameter which denotes the random hardening rate, and a denotes the difference between the yield plane and the boundary plane, i.e. a ═ B + R-Y ═ a0+R；a0Is the initial value of a;
the evolution law of boundary surface equi-directional hardening amount is as follows:
Figure FDA0002396587230000033
wherein m is a material parameter of the isotropic hardening rate, RsatIs the saturation equivalent value of R;
the saturation stress is defined by the evolution of the boundary surface when undergoing large deformations:
Figure FDA0002396587230000034
wherein b is a saturation equivalent value;
in the above formula, the material parameter Y of initial yield stress, the material parameter C of random hardening rate, the saturation equivalent value b, the material coefficient m of isotropic hardening rate and the saturation equivalent value R of boundary surface isotropic hardening rate dsatThe first calculation is obtained by fitting a plurality of groups of stress-strain curves of a stretching-compressing experiment by a least square method, and the process of establishing an initial material constitutive model F (sigma, epsilon) is realized.
Step (2): guiding the fitted initial material constitutive model into finite element analysis software to simulate the stamping forming process of the U-shaped groove of the high-strength plate, and carrying out a U-shaped groove stamping experiment; comparing the actual rebound of the U-shaped groove punching experiment with the finite element simulation rebound result;
and (3): when the relative error between the finite element simulation resilience result and the resilience of the actual stamping experiment exceeds a threshold value of 8%, correcting the material constitutive model parameters, and repeating the step (2); namely if the finite element of the U-shaped groove simulates the rebound angle (theta'1、θ'2) The springback angle (theta) of the actual stamping experiment1、θ2) The difference of (a) exceeds a threshold value, a back stress α, a material parameter Y of an initial yield stress, a material parameter C of a random hardening rate, a saturation equivalent value b, a material coefficient m of an isotropic hardening rate and a saturation equivalent value R of a boundary surface isotropic hardening amount d in the initial material constitutive modelsatAnd (3) adjusting: if the simulation rebound result is smaller than the stamping experiment result, the material real constitutive model is indicated to be positioned below the fitted initial material constitutive model, and a stress-strain curve family above the initial material constitutive model is selected to be fitted again to obtain the revised material constitutive model so as to increase the average Young modulus; on the contrary, if the simulation rebound result is larger than the stamping experiment result, the material real constitutive model is indicated to be positioned above the fitting constitutive model so as to reduce the average Young modulus; guiding the revised material constitutive model into finite element analysis software to simulate the stamping forming process of the U-shaped groove of the high-strength plate, repeatedly performing stamping forming simulation and springback comparison of the high-strength plate in the step (2), and finally enabling the difference between simulation and experimental results to meet a threshold value to perform a step (4);
and (4): and (4) carrying out stamping simulation on the high-strength plate stamping part by using the corrected material constitutive model meeting the simulation precision requirement to obtain an accurate stamping springback result.
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