Strain-driven elastic-plastic damage prediction method with damage cross-border control factor

Abstract

The invention discloses a strain-driven elastic-plastic damage prediction method with a damage cross-border control factor, which relates to the field of elastic-plastic damage prediction, and comprises the following steps: establishing a plastic yield criterion, a non-associated flow rule and a hardening rule; carrying out incremental updating on the plastic internal variable by adopting a return mapping algorithm of a Newton iteration format containing a self-adaptive factor; judging the initial damage state of the material by adopting a parabolic failure criterion, and deducing equivalent strain conjugated with equivalent stress; introducing a damage border-crossing control factor, and mapping equivalent stress and equivalent strain which exceed a real threshold value when the damage is started back to a real damage starting state by referring to a plastic mechanics return mapping algorithm; and establishing a linear damage evolution criterion containing equivalent strain, and introducing the unit size and fracture toughness into the linear damage evolution criterion in combination with the crack zone model. According to the method, the problem that an existing elastic-plastic damage model still has remarkable defects in the aspects of driving mechanism self-consistency, damage starting accuracy, grid independence and the like is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of elastic-plastic damage prediction, and in particular to a strain-driven elastic-plastic damage prediction method with damage overrunning control factor. BACKGROUND

[0002] Resin-based composite materials often undergo irreversible damage evolution processes under complex service environments, and accurate description of their elastic-plastic damage behavior is the key to realizing structural performance prediction and life assessment. Most existing elastic-plastic damage models are based on the modeling assumption of coupled evolution of damage and plastic variables, and the evolution of the damage variable is usually driven by the plastic variable. However, there is a consistency defect in the theoretical structure of this type of model: on the one hand, damage and plasticity can be coupled in physics, but their driving mechanisms are not completely consistent; on the other hand, although some models use the separate plasticity assumption, they still use the plastic variable as the driving source of damage evolution, forming an inconsistent implementation path of "structural decoupling-variable coupling", which affects the physical rationality and expandability of the modeling. Therefore, it is urgent to establish a theoretically consistent and numerically decoupled elastic-plastic damage model framework to realize the essential separation of damage evolution and plasticity mechanism.

[0003] The currently widely used effective stress-driven damage model highly depends on the definition of the damage initiation criterion in its evolution process. Since the effective stress is difficult to accurately obtain directly from experiments, and the initiation criterion is complex in form, it often leads to ineffective triggering of damage or difficulty in model implementation, which seriously restricts its engineering applicability. In contrast, the strain-driven damage model directly uses equivalent strain as the driving variable, which is more intuitive and simple in numerical implementation, and has stronger expandability. However, this type of model also faces a key numerical problem: in actual finite element simulation, the damage initiation criterion often cannot strictly satisfy the threshold condition, and the damage variable will exhibit "overrunning evolution" phenomenon, leading to distortion of the damage initiation stress / strain, and further affecting the accuracy of the subsequent evolution process. Therefore, it is urgent to build a damage overrunning control mechanism to modify the initiation parameters through a scale factor to ensure the continuity and accuracy of the damage evolution path.

[0004] In addition, the continuous damage mechanics model generally faces the problem of grid dependence in finite element discretization: the damage propagation path and structural response obtained by simulation under different grid sizes differ significantly, affecting the objectivity and repeatability of the results. To avoid this problem, it is necessary to explicitly introduce a control term related to the size of the element in the damage evolution criterion, thereby realizing the size correction of the grid effect and improving the applicability and robustness of the model in engineering analysis.

[0005] In summary, the current elastic-plastic damage model still has significant deficiencies in the self-consistency of driving mechanism, the accuracy of damage initiation, and the grid independence, and breakthroughs are needed in the aspects of theoretical modeling and numerical implementation to establish a stable, accurate, and easily expandable damage constitutive analysis framework to support the wide engineering application of resin matrix composites in high-performance structure design, multi-scale simulation, and life assessment. SUMMARY

[0006] In view of the above deficiencies in the prior art, the strain-driven elastic-plastic damage prediction method with damage boundary control factor provided by the present application solves the problem of significant deficiencies in the self-consistency of driving mechanism, the accuracy of damage initiation, and the grid independence of the existing elastic-plastic damage model.

[0007] To achieve the above-mentioned purposes, the technical scheme adopted by the present application is as follows: a strain-driven elastic-plastic damage prediction method with damage boundary control factor, comprising the following steps: S1: According to the theory of plastic mechanics, establish the plastic yield criterion, non-associated flow rule and hardening rule suitable for the target material, and use the return mapping algorithm with adaptive factor of Newton iteration format to incrementally update the plastic internal variable; S2: Based on the separation plasticity assumption, determine that the damage is completely driven by the elastic free energy, use the parabolic failure criterion to judge the initial damage state of the material, and derive the equivalent strain conjugate to the equivalent stress; S3: Introduce the damage boundary control factor, and use the return mapping algorithm of plastic mechanics to map the equivalent stress and equivalent strain exceeding the true threshold at the damage initiation back to the true damage initiation state; S4: Based on the strain-driven assumption, establish a linear damage evolution criterion containing equivalent strain, combine the crack band model, introduce the element size and fracture toughness into the linear damage evolution criterion, obtain the strain-driven elastic-plastic damage prediction model with damage boundary control factor, and apply it to actual scenarios.

[0008] Further, the plastic yield criterion in S1 is a parabolic yield criterion, and the formula is:

[0009] wherein, is the yield function, and is the first stress invariant and the second deviatoric stress invariant, and is the tensile and compressive strength of the material.

[0010] Further, the non-associated flow rule in S1 is:

[0011] where, is the plastic strain increment, is the plastic multiplier increment, is the flow tensor, is the flow rule, is the deviatoric stress tensor, is the second order unit tensor, is the plastic parameter, is the plastic Poisson's ratio, is the stress tensor, is the first stress invariant.

[0012] Further, the hardening rule in S1 is a function of the tensile and compressive strengths, and the hardening depends on the equivalent plastic strain, and the formula is:

[0013]

[0014] where, and are functions of the tensile and compressive strengths, is the equivalent plastic strain, is the plastic strain increment, is an intermediate variable.

[0015] Further, the return mapping algorithm of the Newton iteration format in S1 with adaptive factor, includes the following steps: a1: select the initial approximation of the plastic multiplier increment and the adaptive factor ; a2: update the approximation according to the iteration format, and the formula is:

[0016] where, is the approximation of the th iteration, is the approximation of the th iteration; a3: compare the size of and , specifically: if < : then when , take , and the calculation process is finished; when , take , and return to a2 to continue iteration; if > When then take and , take , the calculation process ends; When and , take , and return a2 to continue iteration; When and , take the adaptive factor , and return a2 to continue iteration; wherein, , , is an adaptive threshold, is a positive number.

[0017] Further, the parabolic failure criterion in S2 is:

[0018] wherein, is a failure criterion, is a first stress invariant, and are the ultimate strengths of compression and tension, is the Von Mises stress;

[0019] wherein, , and are the principal stress components, , and are the shear stress components.

[0020] Further, the parabolic failure criterion is simplified to obtain the equivalent stress:

[0021] wherein, is the equivalent stress; In a multi-axial stress state, the equivalent strain conjugate to the equivalent stress is:

[0022]

[0023] wherein, is the equivalent strain, is a first strain invariant, is the Poisson's ratio of the material, is the Von Mises equivalent strain, , and Principal strain components, , and For shear strain components.

[0024] Furthermore, the damage overrun control factor in S3 for:

[0025] in, This refers to the equivalent out-of-bounds stress during the numerical calculation process. This refers to the equivalent correction stress during the numerical calculation process. For a first-order term of stress or strain, It is a quadratic term of stress or strain.

[0026] Furthermore, in S4, the crack band model is incorporated, and element size and fracture toughness are introduced into the linear damage evolution criterion, as shown in the following formula:

[0027]

[0028] in, For fracture energy, For the element feature size, For the initial equivalent stress of damage, The equivalent elastic strain at the onset of damage. For damage termination equivalent strain, The equivalent strain at the onset of damage.

[0029] The beneficial effects of this invention are: (1) This invention proposes a strain-driven elastoplastic damage model with an out-of-bounds damage control factor. Unlike the damage evolution criterion of the effective stress-based driving model, which depends on the damage initiation criterion, this method separates damage initiation and damage evolution, making it simpler in numerical implementation. Furthermore, it couples the damage model with the plastic model, increasing the applicability of the model. (2) In order to solve the damage overrun problem in finite element numerical analysis, this invention introduces a polynomial damage overrun control factor, which can calculate the actual damage initiation equivalent stress and equivalent strain, and establish the correct initiation conditions for subsequent damage evolution criteria. (3) This invention proposes a damage evolution criterion for separating plasticity, and it can easily regress from an elastoplastic damage model to an elastic damage model. Furthermore, the method established in this invention is not only applicable to material models with nonlinear yielding behavior, but can also be extended to more general elastoplastic constitutive frameworks, and can be further applied to complex material models such as viscoelastic-viscoplastic models, demonstrating good versatility and engineering applicability. This method can provide reliable theoretical support and efficient numerical tools for material constitutive modeling, structural strength assessment, and high-precision finite element simulation, possessing broad prospects for scientific research and engineering applications. Attached Figure Description

[0030] Figure 1 This is a flowchart of the strain-driven elastoplastic damage prediction method with damage overshoot control factor of the present invention.

[0031] Figure 2 This is a schematic diagram illustrating the separation of the plasticity assumption and the coupling of the plasticity assumption in an embodiment of the present invention.

[0032] Figure 3 This is a schematic diagram of the effective stress-driven model and strain-driven model in an embodiment of the present invention.

[0033] Figure 4 This is a schematic diagram illustrating the numerical calculation of damage exceeding the limit and its correction in an embodiment of the present invention.

[0034] Figure 5 This is a diagram showing the verification results of mesh size independence in an embodiment of the present invention.

[0035] Figure 6 The figure shows the calculation results of elastic / elastoplastic damage of the perforated plate sample in the embodiment of the present invention.

[0036] Figure 7 The figure shows the calculation results of elastic / elastoplastic damage of the "dog bone" sample in the embodiment of the present invention. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0038] like Figure 1 As shown, a strain-driven elastoplastic damage prediction method with a damage overshoot control factor includes the following steps: S1: Based on the theory of plasticity mechanics, establish the plastic yield criterion, non-associated flow rule and hardening rule applicable to the target material, and use the return mapping algorithm with Newton iteration format containing adaptive factors to incrementally update the plastic internal variables.

[0039] Based on the fundamental knowledge of plasticity mechanics, parabolic yield criterion, non-associated flow rule, and hardening rule applicable to epoxy resin were derived and established, laying a theoretical foundation for subsequent algorithm modification and numerical implementation.

[0040] The plastic yield criterion in S1 is a parabolic yield criterion, and the formula is as follows:

[0041] in, Let be the yield function. and These are the first stress invariant and the second deviatoric stress invariant. and It refers to the tensile and compressive strength of the material.

[0042] The non-associated flow rule in S1 is as follows:

[0043] in, For the increment of plastic strain, For the plastic multiplier increment, For the flow tensor, For the law of flow, For the deviatoric stress tensor, It is a second-order unit tensor. For plasticity parameters, For plastic Poisson's ratio, For stress tensor, It is the first invariant of stress.

[0044] The hardening law in S1 is a function of tensile and compressive strength, and hardening depends on the equivalent plastic strain, as shown in the formula:

[0045]

[0046] in, and It is a function of tensile and compressive strength. For equivalent plastic strain, For the increment of plastic strain, It is an intermediate variable.

[0047] The return mapping algorithm of the Newton iterative format with adaptive factors in S1 includes the following steps: a1: Select the initial approximation value of the plastic multiplier increment. and adaptive factor ; a2: Update the approximate value according to the iterative format, the formula is:

[0048] in, For the first Approximate value of the next iteration For the first The approximate value of the next iteration; a3: Comparison and The size, specifically: like < hour: Then when At that time, take The calculation process is now complete. when At that time, take Then return to a2 to continue the iteration; like > hour: Then when and At that time, take The calculation process is now complete. when and ,Pick Then return to a2 to continue the iteration; when and Take the adaptive factor Then return to a2 to continue the iteration; in, , , For adaptive threshold, , It is a positive number.

[0049] S2: Based on the assumption of separation plasticity, it is determined that the damage is entirely driven by elastic free energy. The parabolic failure criterion is used to determine the initial damage state of the material, and the equivalent strain conjugate with the equivalent stress is derived.

[0050] Elastic-plastic coupling analysis models are generally based on either the coupled plasticity assumption or the separated plasticity assumption. The differences between the two are as follows: Figure 2 As shown, where, It is the equivalent stress at the onset of damage. It is the stress obtained after damage evolution. These are plastic strain and elastic strain, SPD Where E is the plastic dissipation work and E is the elastic modulus. It is the element feature size. It is the fracture energy, and the slope of the solid red line is... , It is a damage variable. For the segregated plasticity assumption, that is, after damage initiation, SPDIt no longer grows; the damage is entirely driven by the capabilities of the gray area (as can be seen in the figure, the area of ​​the SPD does not change as the damage evolves, while the elastic strain...). As time changes, the decrease in stress is entirely driven by elastic strain energy. For the coupled plasticity assumption, the parameter meanings remain the same as before; after damage initiation, SPD As the damage continues to increase (as can be seen from the figure, the area of ​​the SPD continues to change as the damage evolution time progresses, which is also the most important difference from the previous assumption), the plastic strain also continues to increase. The damage is driven by the plastic strain, and the stress solved after the damage evolution depends on the corresponding evolution criterion.

[0051] The segregated plasticity assumption posits that elasticity and plasticity separate; once damage begins, plasticity ceases to evolve, and the equivalent plastic strain remains constant throughout the damage evolution process. Lemaitre observed in experiments that the elastic properties of materials decrease as damage evolves, and based on this phenomenon, he hypothesized that damage is entirely driven by elastic strain. Therefore, the fracture energy equals the elastic strain energy at complete damage. This invention is based on the segregated plasticity assumption, which states that damage is entirely driven by elastic free energy.

[0052] In most cases, the matrix material can be considered isotropic, but its tensile and compressive strengths often differ, and its failure behavior is more sensitive to tensile stress. This strength asymmetry indicates that the failure of the matrix is ​​not only affected by deviatoric stress invariants (such as von Mises stress), but also closely related to volumetric stress invariants (i.e., the first stress invariant). To simultaneously consider the influence of these two types of stress components on failure, this invention employs an improved von Mises criterion—a parabolic failure criterion—to determine the initial damage state of the matrix.

[0053] The parabolic failure criterion in S2 is as follows:

[0054] in, As a failure criterion, It is the first stress invariant. and The ultimate strength under compression and tension, Von Mises stress;

[0055] in, , and Principal stress components, , and This represents the shear stress component.

[0056] The parabolic failure criterion is simplified to obtain the equivalent stress:

[0057] in, Equivalent stress; Under multiaxial stress, the equivalent stress conjugate becomes:

[0058]

[0059] in, For equivalent change, As the first strain invariant, The Poisson's ratio of the material, For Von Mises equivalents , and Principal strain components, , and For shear strain components.

[0060] Typically, the Murakami-Ohne damage evolution model is used for strain-driven criteria (in this invention, bold text represents second-order tensors; Euclid symbols represent fourth-order tensors; italics represent scalars):

[0061] in, These are the three principal values ​​of the damage tensor; is the principal direction vector of the damage tensor.

[0062]

[0063] To maintain the symmetry of the stress tensor, the effective stress tensor is symmetricized, i.e.

[0064] in, The stress tensor is the undamaged stress tensor; This is the effective stress tensor.

[0065]

[0066] in, , , , , , , , and These are the components of the stress tensor.

[0067] Therefore, the fourth-order damage tensor M(D) can be simplified to a two-dimensional matrix M(D) in Vogit form. Without the preceding symmetry treatment, the Vogit form cannot be applied. Using the Cordebos-Sidoroff energy assumption, the damage variable is introduced into the stiffness matrix, causing the stiffness to gradually weaken as the damage progresses, i.e.:

[0068] Simplified to matrix form:

[0069] in:

[0070] Where C is the damage stiffness matrix, and the superscript... It is a matrix symmetric shape symbol. , , , , , The coefficients related to the damage variable (intermediate variables, without actual names, used to make the formula more compact). , , , , , , , , These are the components of the damage stiffness matrix.

[0071] It is worth noting that the order of the damage variable in the normal strain direction and the damage variable in the shear strain direction are equal, which meets the requirements of classical damage mechanics.

[0072] S3: Introduce a damage overshoot control factor and, drawing on the plasticity mechanics return mapping algorithm, map the equivalent stress and equivalent strain that exceed the true threshold at the start of damage back to the true damage start state.

[0073] Under complex loading conditions, the equivalent stress and equivalent displacement at the initial damage initiation are often difficult to obtain accurately in advance through experiments and must be dynamically determined during numerical simulation. However, in actual calculations, when the initial damage is identified, the damage criterion value may be slightly greater than 1, causing the extracted equivalent stress and equivalent displacement at this time to be different from the true initial values. Therefore, the corresponding equivalent stress and equivalent strain at this point are actually... Figure 3 The "probing" in the above diagram. By adopting the separation plasticity assumption, Figure 3 In the left-hand image, by adopting Figure 2Separation plasticity assumption, parameter meaning and Figure 2 The separation plasticity assumption remains completely consistent, therefore the SPD (Separation Plasticity) will not change after damage initiation. Damage is driven by the red curve (effective stress curve). When damage occurs, the stress drops to the intersection of the red dashed line and the gray curve by subtracting from the red curve. Figure 3 In the image on the right, These are the equivalent elastic strain at the onset of damage, the equivalent strain at the onset of damage, the equivalent strain at the current increment, and the equivalent strain at the end of damage.

[0074] Drawing inspiration from the "return mapping algorithm" in plasticity mechanics, a scaling factor is used here. Pull it back to the correct equivalent stress / strain to accurately obtain the reference parameters at the onset of damage:

[0075] in, For equivalent change, This is the equivalent stress.

[0076] After simplification, we get:

[0077] Damage criteria typically include the first quadratic term of stress or strain. Therefore, it is necessary to establish a unified polynomial expression. As shown below: The damage overrun control factor in S3 for:

[0078] in, This refers to the equivalent out-of-bounds stress during the numerical calculation process. This refers to the equivalent correction stress during the numerical calculation process. For a first-order term of stress or strain, It is a quadratic term of stress or strain.

[0079] For the parabolic criterion used in this invention, the first-order term includes the hydrostatic pressure term, and the second-order term includes the Mises stress term.

[0080] S4: Based on the strain-driven assumption, a linear damage evolution criterion with equivalent strain is established. Combined with the crack band model, the element size and fracture toughness are introduced into the linear damage evolution criterion to obtain a strain-driven elastoplastic damage prediction model with damage overshoot control factor, and it is applied to real-world scenarios.

[0081] Considering the uniformity of elastoplastic damage, a damage evolution criterion for separating plastic strain was established. For example... Figure 4As shown, in numerical calculations, an incremental superposition method is used, dividing these increments into multiple incremental steps. When calculating the first... n +1 increment strain Calculate the corresponding stress components And then the damage criterion is applied. At this point, the criterion exceeds the limit of 1 (for example, 1.02, 1.03, etc.), but theoretically, the criterion can only go up to 1. Therefore, this strain needs to be... and stress Corrected to theoretical value , The damage variable is entirely determined by the fracture energy. and unit feature size Confirmed, the area of ​​the blue triangle is... Therefore, based on the calculations... , It can be completely determined ,according to These three values ​​can determine the damage variable. d Alright.

[0082] The actual stress after damage initiation is represented by the diagonal line on the right side of the triangle, based on this assumption:

[0083] in, It is the elastic modulus; Therefore, the damage variable can be obtained. d The expression:

[0084] In the formula, It is a constantly changing quantity, and the difference between the two is the equivalent plastic strain at the onset of damage. This also shows that the damage evolution criterion established in this invention separates plasticity and damage, which is very important for deriving the consistent tangent stiffness matrix of implicit finite element analysis.

[0085] To alleviate the mesh dependency of finite element method calculations, a crack band model is introduced, namely... Figure 4 The area of ​​the middle triangle is equal to the fracture toughness divided by the element characteristic length:

[0086] Therefore, we can obtain:

[0087] in, For fracture energy, For the element feature size, For the initial equivalent stress of damage, The equivalent elastic strain at the onset of damage. For damage termination equivalent strain, The equivalent strain at the onset of damage.

[0088] Based on the finite element software ABAQUS, a strain-driven elastoplastic damage model containing damage overflow control factors was implemented by writing a user material subroutine (UMAT). Mesh independence was investigated, and strength analyses were performed on dog bone specimens and perforated plate specimens to verify its stability and computational performance under complex loading conditions. The relevant calculation results are shown below. Figure 5 , Figure 6 and Figure 7 .from Figure 5 It is evident that the method implemented in this invention can effectively reproduce the input parameter—fracture toughness—and effectively alleviate the mesh dependency problem; from Figure 6 , 7 The comparison results show that the solution implemented in this invention can effectively perform elastic / elastoplastic calculations, demonstrating superior engineering application potential.

[0089] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of the invention.

Claims

1. A strain-driven elastoplastic damage prediction method with a damage overshoot control factor, characterized in that, Includes the following steps: S1: Based on the theory of plasticity mechanics, establish the plastic yield criterion, non-associated flow rule and hardening rule applicable to the target material, and use the return mapping algorithm with Newton iteration format containing adaptive factor to incrementally update the plastic internal variables. S2: Based on the assumption of separation plasticity, it is determined that the damage is entirely driven by elastic free energy. The parabolic failure criterion is used to determine the initial damage state of the material, and the equivalent strain conjugate with the equivalent stress is derived. S3: Introduce a damage overshoot control factor and, by drawing on the plasticity return mapping algorithm, map the equivalent stress and equivalent strain that exceed the true threshold at the start of damage back to the true damage start state. S4: Based on the strain-driven assumption, a linear damage evolution criterion with equivalent strain is established. Combined with the crack band model, the element size and fracture toughness are introduced into the linear damage evolution criterion to obtain a strain-driven elastoplastic damage prediction model with damage overshoot control factor, and it is applied to real-world scenarios.

2. The strain-driven elastoplastic damage prediction method with a damage overshoot control factor according to claim 1, characterized in that, The plastic yield criterion in S1 is a parabolic yield criterion, and the formula is as follows: in, Let be the yield function. and These are the first stress invariant and the second deviatoric stress invariant. and It refers to the tensile and compressive strength of the material.

3. The strain-driven elastoplastic damage prediction method with damage overshoot control factor according to claim 2, characterized in that, The non-associated flow rule in S1 is as follows: in, For the increment of plastic strain, For the plastic multiplier increment, For the flow tensor, For the law of flow, For the deviatoric stress tensor, It is a second-order unit tensor. For plasticity parameters, For plastic Poisson's ratio, For stress tensor, It is the first invariant of stress.

4. The strain-driven elastoplastic damage prediction method with a damage overshoot control factor according to claim 2, characterized in that, The hardening law in S1 is a function of tensile and compressive strength, and hardening depends on the equivalent plastic strain, as shown in the formula: in, and It is a function of tensile and compressive strength. For equivalent plastic strain, For the increment of plastic strain, It is an intermediate variable.

5. The strain-driven elastoplastic damage prediction method with a damage overshoot control factor according to claim 4, characterized in that, The return mapping algorithm of the Newton iterative format with adaptive factors in S1 includes the following steps: a1: Select the initial approximation value of the plastic multiplier increment. and adaptive factor ; a2: Update the approximate value according to the iterative format, the formula is: in, For the first Approximate value of the next iteration For the first The approximate value of the next iteration; a3: Comparison and The size, specifically: like < hour: Then when At that time, take The calculation process is now complete. when At that time, take Then return to a2 to continue the iteration; like > hour: Then when and At that time, take The calculation process is now complete. when and ,Pick Then return to a2 to continue the iteration; when and Take the adaptive factor Then return to a2 to continue the iteration; in, , , For adaptive threshold, It is a positive number.

6. The strain-driven elastoplastic damage prediction method with a damage overshoot control factor according to claim 5, characterized in that, The parabolic failure criterion in S2 is as follows: in, As a failure criterion, As the first stress invariant, and The ultimate strength under compression and tension, Von Mises stress; in, , and Principal stress components, , and This represents the shear stress component.

7. The strain-driven elastoplastic damage prediction method with a damage overshoot control factor according to claim 6, characterized in that, The parabolic failure criterion is simplified to obtain the equivalent stress: in, Equivalent stress; Under multiaxial stress, the equivalent stress conjugate becomes: in, For equivalent change, As the first strain invariant, The Poisson's ratio of the material, For Von Mises equivalent changes, , and Principal strain components, , and For shear strain components.

8. The strain-driven elastoplastic damage prediction method with a damage overshoot control factor according to claim 7, characterized in that, The damage overrun control factor in S3 for: in, This refers to the equivalent out-of-bounds stress during the numerical calculation process. This refers to the equivalent correction stress during the numerical calculation process. For a first-order term of stress or strain, It is a quadratic term of stress or strain.

9. The strain-driven elastoplastic damage prediction method with a damage overshoot control factor according to claim 8, characterized in that, In S4, the crack band model is incorporated, and element size and fracture toughness are introduced into the linear damage evolution criterion, as shown in the following formula: in, For fracture energy, For the element feature size, For the initial equivalent stress of damage, The equivalent elastic strain at the onset of damage. For damage termination equivalent strain, The equivalent strain at the onset of damage.

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