A simulation method for wear of sharp corner forming die of automobile fender

Abstract

The application discloses a kind of automobile fender sharp edge forming die wear simulation method, comprising the following steps: S1, construct fender sharp edge forming finite element model;S2, die and sheet are meshed;S3, set forming simulation condition, start simulation;S4, calculate and record wear amount;S5, whether grid degradation is carried out according to wear result and setting, update forming simulation condition after degradation;S6, cycle S2-S5, until reach wear setting condition end simulation.The application analyzes workpiece forming process by AutoForm forming tool, obtains the position of each node and the contact pressure and speed required for calculating wear in each forming step, compares and analyzes the maximum wear amount calculated using Archard wear calculation formula with the failure evaluation index of fender die wear edge line clarity, when cumulative wear amount reaches failure evaluation index, it is die life value, to realize the prediction of die life.

Description

Technical Field

[0001] This invention relates to a simulation method, specifically a simulation method for the wear of a mold forming a sharp edge of an automobile fender. Background Technology

[0002] With the rapid and vigorous development of my country's new energy vehicle industry, various emerging car manufacturers have sprung up, and traditional automakers have also turned to the electric vehicle market, leading to increasingly fierce competition in the automotive industry. To gain a foothold in the market, continuously improving product quality and reducing production costs are among the most important tasks for automotive companies today. For passenger vehicles, production costs mainly consist of R&D costs, equipment and tooling costs, parts procurement costs, and labor costs, with equipment and tooling costs and parts procurement costs accounting for the largest proportion. A complete vehicle often consists of tens of thousands of parts, more than 80% of which are thin metal sheets. Their production and processing methods are mainly stamping, requiring the use of stamping dies. According to company statistics, a newly developed model can require thousands of stamping dies for producing thin metal sheets, with design, manufacturing, installation, and debugging costs estimated at 200-300 million yuan.

[0003] In recent years, the electrification process in the automotive industry has accelerated, with more and more automakers adopting architecture-based design to gradually replace traditional platform and modular designs. This has led to a surge in shared components, especially sheet metal parts, among different models derived from the same architecture. Generally, stamping dies used to produce sheet metal parts have a stable service life limit of 500,000 to 600,000 strokes. However, because shared components need to simultaneously meet the production requirements of multiple models, stamping dies may need to produce millions of strokes throughout the model's lifecycle, far exceeding their normal operating life. Traditionally, the solution to this extended service life of stamping dies has been to replicate them before they reach their end-of-life, resulting in high vehicle development and manufacturing costs. Therefore, while increasing shared architecture components, continuously improving the service life limit and operating quality of stamping dies to extend their lifespan is a crucial approach to reducing automotive development and manufacturing costs.

[0004] The quality of stamping dies mainly includes three aspects: structural strength, machining accuracy, and fatigue life. The first two aspects are primarily determined by the die structure design, machine tool machining accuracy, machining process, and fitting and adjustment methods. As for fatigue life, it is determined by many factors, including not only the selection of die material, die structure layout, die load mode, and stress distribution, but also the die surface treatment method, lubrication conditions, frequency of regular maintenance, and the strength of the materials used to produce the parts.

[0005] In actual production, plastic deformation of the working parts of the stamping die, deterioration of the die surface roughness and lubrication conditions, and excessive wear during the stamping process will directly reduce the quality and service life of the stamping die, and may even cause it to fail. Among these factors, wear has the greatest impact on the service life of the stamping die. For exterior body panels with sharp side lines, the sharp-edged forming dies experience greater contact stress, resulting in more severe wear. Localized wear of the sharp-edged forming dies not only prevents the reproduction of sharp feature lines but also causes scratches on the surface of the stamped parts, thus failing to meet the quality requirements of automobile production. Based on R&D and manufacturing experience, the design, processing, installation, and debugging of sharp-edged forming dies often require significant time and financial investment. With the maturity of finite element simulation technology, performing finite element simulation analysis on the die before design and manufacturing to predict the forming of the sheet metal and the wear state of the die is of great significance for reducing the manufacturing cost of sharp-edged forming dies and shortening the die design and manufacturing cycle. Currently, industry research on sharp-edge forming dies mainly focuses on steel plates, while research on the wear of sharp-edge forming dies for aluminum automotive body panels with double sharp-edge designs is relatively limited.

[0006] The automotive industry is developing rapidly and competition is becoming increasingly fierce. Reducing costs while pursuing high quality remains a constant pursuit for automakers. In the development and manufacturing costs of automobiles, mold costs can account for more than 30% of the development cost, and more than 90% of automotive parts are produced through mold forming. A new car model requires the development of thousands of molds, with design and manufacturing costs generally around 200 million yuan. With the development trend of automotive platforms, more and more companies are considering how to increase the proportion of platform components, increase the number of shared molds for platform components, and extend the lifespan of molds, thereby reducing automotive development costs.

[0007] The quality of a mold mainly includes three aspects: mold precision, structural strength, and fatigue life. The first two aspects are mainly determined by structural design and machining. The service life is determined by many factors, mainly focusing on the mold's material, structure, local stress distribution, surface treatment, operation, and maintenance.

[0008] Automotive stamping dies frequently fail and become unusable due to factors such as plastic deformation, friction and wear, and fatigue fracture. Wear is particularly prominent, and for exterior body panels with sharp side lines, the dies used for forming sharp edges experience even greater contact stress, leading to more severe wear. Localized wear of these dies not only renders the sharp edges unreproducible but also causes surface scratches on the stamped parts, failing to meet automotive production quality requirements. In actual manufacturing, the design and fabrication of sharp-edge forming dies generally require significant time and financial investment. With the maturity of finite element simulation technology, performing finite element simulation analysis on dies before design and manufacturing to predict sheet metal forming and die wear is crucial for reducing manufacturing costs and shortening the design and manufacturing cycle of sharp-edge forming dies.

[0009] Currently, the industry widely uses finite element analysis software to analyze the wear of mold solid elements and predict mold lifespan. However, this method is slow, has poor accuracy, and is costly, making it unsuitable for repeated adjustments to forming parameters and thus preventing optimization of the mold from a process or structural perspective. Furthermore, the Arcard wear model, commonly used in finite element analysis, neglects the impact of the wear process on mold contact stress and relative sliding velocity, resulting in low prediction accuracy.

[0010] Current wear analysis methods for sharp-edge forming dies typically employ experimental testing, combining experimental data with simulation models for predicting and studying wear. However, due to continuous structural changes during wear, the finite element model requires real-time updates and mesh re-division to capture variations in contact pressure during structural analysis. This wear simulation process places extremely high demands on both software and hardware, and the individual analysis cycles are very lengthy, making it unsuitable for the rapid development needs of stamping dies in the automotive industry. Therefore, traditional wear simulation methods for sharp-edge forming dies based on the Archard wear model urgently require improvement. Summary of the Invention

[0011] In view of the problems described in the background art, the purpose of this invention is to provide a simulation method for the wear of automotive fender sharp edge forming molds that can quickly and accurately predict the wear of fender sharp edge forming molds.

[0012] To achieve the above objectives, the present invention provides a method for simulating the wear of automotive fender sharp-edge forming molds, comprising the following steps:

[0013] S1, construct the finite element model of the sharp edge forming of the fender;

[0014] S2, grid division of mold and sheet metal;

[0015] S3, set the forming simulation conditions, and start the simulation;

[0016] S4, calculate and record the wear amount;

[0017] S5, based on the wear results and settings, decide whether to perform mesh degradation and update the simulation conditions for the degraded form;

[0018] S6, repeat S2 to S5 until the wear setting condition is reached and the simulation ends.

[0019] Preferably, in S1, the three-dimensional model of the stamping die is simplified by removing unnecessary structures and retaining only the working parts of the punch, die, and blank holder of the stamping die to obtain a simplified model. Based on the simplified model, a finite element model for fender sharp edge forming is constructed.

[0020] Further preferred methods include simplifying the three-dimensional model of the stamping die, such as simplifying the structure of the sharp-edged test mold and the upper slide of the press, and stitching and smoothing the broken surfaces in the surface contact area.

[0021] Preferably, the Archard wear model is used to simulate and calculate the wear amount.

[0022] Preferably, the wear process is simulated using the finite element method: the continuous wear region is discretized into a set of finite element units connected in a certain way, and mechanical analysis is performed on each unit, and finally, an overall analysis is performed.

[0023] Preferably, the wear amount is evaluated by the wear depth of the mold.

[0024] A further preferred formula for calculating wear depth is:

[0025]

[0026] k is the wear coefficient, which is the probability of wear occurring and is obtained through experiments; p is the normal stress of the contact surface; v is the relative sliding velocity of the contact surface; dt is the sliding time; and H is the hardness of the worn material, i.e., the mold hardness.

[0027] Furthermore, the information of p and v is discretized using the finite element method to obtain the following discretized expression of the contact surface:

[0028]

[0029] In the formula, i represents the node position, j represents the number of analysis steps; h i,jH represents the wear depth of node i after wear occurs in step j during a single stamping process; k(i,j) represents the wear coefficient value corresponding to the contact pressure and hardness conditions experienced by node i in step j during a single stamping process in the Kd diagram. i,j This represents the surface hardness value of the die at step j in the i-th node region during a single stamping process.

[0030] The beneficial effects of this invention are as follows: The workpiece forming process was analyzed using the AutoForm forming tool to obtain the position of each node and the contact pressure and speed required to calculate wear in each forming step. Using the Archard wear calculation formula, a mold wear calculation subroutine was written in Python to obtain the wear amount of the mold after 50,000, 500,000, and 800,000 stamping cycles. The calculated maximum wear amount was compared and analyzed with the failure evaluation index of the wear edge clarity of the cover mold. When the cumulative wear amount reaches the failure evaluation index, it is the mold life value, thereby realizing the prediction of mold life.

[0031] The method of this invention can quickly and accurately predict the wear of fender sharp-edge forming dies. Based on the wear simulation results, targeted surface strengthening treatment is applied to the sharp-edge forming die, improving its wear resistance. Mass production verification shows that the fender sharp-edge forming die does not experience excessive wear, meeting continuous production requirements and saving over 600,000 RMB per vehicle in costs for sharp-edge forming die edge repair and surface hardening. Continuous mass production using the fender sharp-edge forming die yields qualified parts without significant cracking, wrinkling, or large surface defects. The two sharp edges show good forming quality, with no slippage defects.

[0032] After 800,000 strokes of the fender sharp-edge forming die, the die's punch was scanned to confirm the wear condition of the characteristic edges and surfaces. Comparative analysis of the scanned data revealed that the wear on the edges and surfaces of the fender sharp-edge forming die was relatively small, indicating that targeted surface strengthening based on wear simulation results can improve the die's wear resistance. Attached Figure Description

[0033] Figure 1 This is the finite element model of the sharp edge forming of the fender in this invention;

[0034] Figure 2 This is a simulation pressure cloud diagram of the contact surface during the forming of the sharp-edged fender of this invention;

[0035] Figure 3 This is a simulation tangential sliding velocity cloud diagram of the sharp-edged fender forming process of the present invention;

[0036] Figure 4 It is an invention logic block diagram;

[0037] Figure 5 This is a flowchart of the wear calculation process based on the number of stamping cycles of this invention;

[0038] Figure 6 This refers to the wear amount of the die after 50,000 stamping cycles according to the present invention.

[0039] Figure 7 This refers to the wear amount of the die after 500,000 stamping cycles according to the present invention;

[0040] Figure 8 This refers to the wear of the die after 800,000 stamping cycles according to the present invention.

[0041] In the diagram: punch 1, die 2, pressure ring 3, sheet metal 4. Detailed Implementation

[0042] The technical solutions (including preferred technical solutions) of the present invention will be further described in detail below with reference to the accompanying drawings and by way of listing some optional embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0043] like Figures 1 to 8 As shown, the wear simulation method for automotive fender sharp edge forming mold designed in this invention includes the following steps:

[0044] S1, construct the finite element model of the sharp edge forming of the fender;

[0045] Finite element analysis of automotive body panel stamping requires consideration of multiple factors. Specifically: ① The sheet metal 4 experiences significant loads during stamping, typically between 100 and 1000 kN, leading to substantial plastic deformation and changes in the relative displacement between the material and the die surface. Traditional linear equations are insufficient to accurately characterize this complex change. ② Once plastic deformation occurs, the sheet metal is difficult to return to its initial state, indicating that the sheet metal itself does not change over time. ③ The contact stress between the stamping die and the sheet metal is nonlinear, making its characterization extremely complex.

[0046] Since the stamping analysis software used is Autoform, which does not support 3D modeling and drawing, it is necessary to first use CAD software to draw, import, and finally assemble the punch, die, blank holder, and other non-standard structures and standard parts of the fender sharp-edge forming die. The CAD software used in this invention is CATIA. After completing the 3D structural drawing of the fender sharp-edge forming die using CATIA, it is converted to an IGS format file and imported into the AutoForm R8 finite element simulation platform. After the model is imported, the assembly relationships between the various components of the stamping die remain unchanged, meaning there is no need to adjust the 3D structural model in AutoForm software. The model in this embodiment is a model of the fender die that retains its structural features.

[0047] The model was simplified by removing unnecessary structures, resulting in a simplified model that retains only the working parts of the stamping die: the punch, die, and blank holder. Specifically, punch 1, die 2, and blank holder 3 each retain a 60mm casting wall thickness. The main support ribs on the outer perimeter of the forming parts and the general internal reinforcing ribs retain a height of 120mm. All other structures were removed, including standard parts such as material locators, guide plates, balance blocks, and nitrogen springs. The guidance between the various parts of the die is represented by friction pairs. The simplification of the 3D model of the stamping die included simplifying the structure of the sharp-edged test mold and the upper slide of the press. For surface contact areas, broken surfaces needed to be stitched together and smoothed.

[0048] The simplified model of the sharp-edged fender drawing die was imported into AutoForm software. The sheet metal forming process was divided into two stages: a closing stage and a forming stage. In both the closing and forming stages, the die was set as the active die. The relative positions of the die, punch, and blank holder were set. In the closing stage, the die movement direction was set to -Z, while the punch and blank holder remained stationary. The friction coefficient between the die and the sheet metal was set to 0.13, and the operating temperature was set to the default ambient temperature. The sheet metal was 6014-T2 aluminum alloy with a thickness of 0.9 mm. The punch, die, and blank holder of the sharp-edged forming die were all made of KSCD800I material. The completed finite element model of the sharp-edged fender forming die is shown below. Figure 1 As shown.

[0049] S2, grid division of mold and sheet metal;

[0050] Finite element mesh generation was performed on the simplified sharp-edge test mold structure and the upper slider of the press.

[0051] S3, set the forming simulation conditions, and start the simulation;

[0052] Setting up the stamping process and simulation parameters:

[0053] Import the simulated mold model into AutoForm software. Divide the sheet metal forming process into two stages: the closing stage and the forming stage. In both the closing and forming stages, set the die as the active die. Set the relative positions of the die, punch, and blank holder. In the closing stage, set the die movement direction to -Z, while the punch and blank holder remain stationary. The die moves until the gap with the blank holder is 0.9mm and then stops. Set the friction coefficient between the die and the sheet metal to 0.13, and set the operating temperature to the default ambient temperature.

[0054] The stamping speed of a die is typically determined by the forming process requirements and press capacity, and is generally set between 300 and 3000 mm / s. Selecting a stamping speed that matches the die's characteristics can effectively extend its service life. Excessive stamping speed can cause significant changes in the load on the die during forming, affecting the sheet metal forming quality and accelerating die surface wear; insufficient stamping speed leads to low production efficiency and increased per-piece stamping production costs. Considering the production workshop's process conditions and forming simulation experience with similar parts, the stamping speed of the fender sharp edge forming die is set to 1500 mm / s in the no-load stage and 500 mm / s in the loaded stage. The die movement direction is set to -Z direction, the blank holder force is set to 1200 kN, the movement direction is +Z direction, and the blank holder stroke is 125 mm.

[0055] The number of steps set in the stamping simulation process directly determines the efficiency of the numerical simulation and the iterative calculation stroke. To improve simulation efficiency, this invention selects a dynamic display calculation method that does not require direct solution of tangent stiffness, does not require balance iteration, and has a fast calculation speed. For the stamping problem of automotive body panels, a simulation method that controls the die stroke is usually adopted, with the iteration step size taking 1 / 3 of the smallest cell size in the finite element model as a reference. When the control method is time increment, the total die stroke needs to be used as the calculation basis to calculate the total time increment. Since the pressure between the sheet metal and the die working surface during the deformation stage is nonlinear and changes continuously throughout the stamping process, the contact relationship between the sheet metal and the die working surface is quite complex, making it impossible to accurately define the boundary relationship of contact and friction in units of time. This indirectly increases the workload of finite element analysis and invisibly increases the complexity of numerical simulation. Therefore, a reasonable definition of the contact relationship and boundary conditions is a prerequisite and key element for ensuring the accuracy of stamping simulation.

[0056] Define contact relationships and boundary conditions:

[0057] The contact relationship between sheet metal and die is complex, mainly because the relationship between sheet metal deformation and die pressure is nonlinear and constantly changes during the stamping process. The boundary relationship of contact and friction cannot be defined in terms of time, which increases the computational workload and complexity of finite element simulation. Therefore, reasonably defining the contact relationship and boundary conditions is one of the key elements to ensure reliable and accurate analysis results in sheet metal stamping.

[0058] In the stamping process of automotive body panels, the contact form and stress state between the sheet metal and the die are quite complex. Among the many contact forms, surface-to-surface contact is the most important, while other complex contact forms such as point-to-surface contact and line-to-surface contact also exist. This paper studies a fender sharp-edge forming die, defining five contact surfaces based on the stamping mechanism and the contact relationship between the die movement and the five contact surfaces: the upper surface of the sheet metal, the lower surface of the sheet metal, the outer surface of the punch, the outer surface of the die, and the outer surface of the blank holder. Three sets of contact relationships are set: the contact between the upper surface of the sheet metal and the outer surface of the die, the contact between the lower surface of the sheet metal and the outer surface of the punch, and the contact between the lower surface of the sheet metal and the outer surface of the blank holder. The stamping simulation parameters are set in detail according to the contact forms and conditions of the three contact relationships. The coefficient of friction between the sheet metal and the working surface of the die is set to 0.13. Regarding temperature settings, since the sharp-edged fender is formed using a cold stamping process, temperature changes during stamping have a relatively small impact on process parameters. To improve the efficiency of finite element analysis, the ambient temperature is set to a constant mode, meaning heat transfer between the sheet metal and the die does not need to be considered. Therefore, based on practical engineering experience, the operating temperature during stamping is set to 20℃.

[0059] After setting all parameters, submit the solution calculation to obtain the contact surface pressure contour map and tangential slip velocity contour map of the sharp-edged fender, as shown below. Figure 2 and Figure 3 As shown.

[0060] S4, calculate and record the wear amount;

[0061] Obtaining the wear depth of the contact surface hinges on capturing the stress at that surface. Therefore, the finite element method (FEM) is introduced to simulate the wear process. The continuous solution domain of the research object is discretized into a set of interconnected finite element units, and mechanical analysis is performed on each unit before a comprehensive analysis is conducted. During stamping wear, the surface morphology of the contact surface changes, resulting in varying wear amounts. Therefore, the die mesh needs to be reprocessed using a mesh generation method to determine the stress values ​​at the contact points, which are then used to calculate the wear depth.

[0062] For mold wear research, considering the issues of calculation speed and accuracy, a secondary development using Python was conducted based on AutoForm molding calculation to calculate the wear amount of contact surface nodes.

[0063]

[0064] In the formula, dV is the material wear volume; dP is the normal load; dL is the relative slip length; H is the hardness of the worn material, i.e., the mold hardness. k is the wear coefficient, which is the probability of wear occurring, obtained through experiments, and is generally in the range of 10. -3 ~10 -8 The wear coefficient varies depending on factors such as the contact material, lubrication conditions, and working environment.

[0065] Based on the above formula, three wear laws can be derived: the longer the friction stroke, the greater the wear; the greater the normal load on the contact surface, the greater the wear; and the greater the surface hardness of the material being worn, the smaller the wear.

[0066] In practice, the evaluation of wear depth is more important for the wear of cover part molds. In the above formula, dV can be expressed as follows:

[0067] dV=dh·dA

[0068] In the formula, dh is the wear depth, and dA is the contact surface area. Therefore,

[0069]

[0070] Then, the expressions for dP and dL in the above formula can be transformed as follows:

[0071] dP = p·dA, dL = v·dt

[0072] In the formula, p is the normal stress of the contact surface, v is the relative sliding velocity of the contact surface, and dt is the sliding time. After simplification:

[0073]

[0074] In the formula, the information of p and v is obtained by discretizing the contact surface using the finite element method, and the discretized expression is as follows:

[0075]

[0076] In the formula, i represents the node position, j represents the number of analysis steps; h i,j H represents the wear depth of node i after wear occurs in step j during a single stamping process; k(i,j) represents the wear coefficient value corresponding to the contact pressure and hardness conditions experienced by node i in step j during a single stamping process in the Kd diagram. i,jThis represents the surface hardness value of the die at step j in the i-th node region during a single stamping process.

[0077] The calculation of wear of the fender sharp edge forming die requires the use of Autoform software and Python language to achieve parallel simulation of sheet metal stamping and die wear, process condition setting, material library establishment, wear requirement setting, and wear result reading.

[0078] S5, based on the wear results and settings, decide whether to perform mesh degradation and update the simulation conditions for the degraded form;

[0079] Since the actual wear amount in a single stamping operation of the cover die is very small, it is impossible to perform mesh degradation and then repeat the stamping and die wear simulations after each wear calculation. To simulate the minute wear during the die stamping process and reduce computation time and cost, the number of mesh degradation operations for die wear is set, with one mesh degradation operation performed each time. In this embodiment, 50,000 operations are used as the default mesh degradation operation span. The wear amount h at each node is then calculated. Considering the computation time cost, the mesh model is degraded every 50,000 operations for ordinary outer cover dies (the degradation setting value can be modified according to the actual part forming state and forming stress state). During the iterative calculation, it is assumed that the wear amount h between every 50,000 operations is linearly related to the number of operations, so the single wear amount h is magnified by 50,000 times as the wear amount h after 50,000 stamping operations. 50000 .

[0080] S6, repeat S2 to S5 until the wear setting condition is reached and the simulation ends.

[0081] The wear amount h after 50,000 stamping cycles 50000 The system automatically performs mesh degradation operations, corresponding to each node number, to obtain the degraded model file. With the mesh model file, material, and working conditions unchanged, the stamping calculation is submitted back to AutoForm to obtain a new round of stamping calculation results. Wear calculations are then performed again, and the hardness value of each node in this cycle is obtained based on the wear values ​​of each node from the first round. Using the same method as the first round of wear calculations, the contact pressure (CPRESS), velocity (V), and time interval (ΔT) of each node in the mold model are obtained. The re-imported wear calculation formula then yields the wear amount of each node.

[0082] Wear cloud maps of the die after 50,000, 500,000, and 800,000 stamping cycles were obtained through calculation, as shown below. Figure 6 , Figure 7 , Figure 8 As shown.

[0083] The main features of this invention are: (1) The die mesh and sheet metal mesh division, forming simulation conditions, and forming simulation calculations are set in AutoForm. (2) The position of each node and the contact pressure and speed required for wear calculation in each forming step are obtained. (3) Based on the wear results and settings, it is determined whether to perform mesh degradation, and at the same time, the forming simulation conditions are set again to perform cyclic forming simulation calculations and wear calculations until the wear setting conditions are met and the results are output.

[0084] In CAD software, the structure of the sharp-edge test mold and the upper slider of the press are simplified. For the surface contact area, the broken surfaces need to be stitched together and smoothed.

[0085] In CAD software, finite element meshing was performed on the simplified sharp-edge test mold structure and the upper slider of the press, and constraints were set for the fixed and guiding areas.

[0086] The processed finite element model is output as an INP format file and imported into CAE software;

[0087] In the CAE software, set the corresponding boundary constraints and loads according to the actual production conditions of the sharp edge test mold; submit the solution calculation in the CAE software to obtain the stress and strain of the sharp edge test mold, and check whether the stress exceeds the allowable fatigue strength or tensile strength of the mold material.

[0088] It will be readily understood by those skilled in the art that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, combinations, substitutions, improvements, etc., made under the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A method for simulating wear of a mold forming a sharp edge on an automobile fender, characterized in that, Includes the following steps: S1, construct the finite element model of the sharp edge forming of the fender; S2, grid division of mold and sheet metal; S3, set the forming simulation conditions, and start the simulation; S4, calculate and record the wear amount; S5, based on the wear results and settings, decide whether to perform mesh degradation and update the post-degradation forming simulation conditions; wherein, the specific steps of deciding whether to perform mesh degradation and updating the post-degradation forming simulation conditions include: using the default set value as the mesh degradation operation span value, amplifying the single wear amount calculated in S4 by the span value multiple to obtain the wear amount after the stamping span value; matching the wear amount after the stamping span value with the corresponding node number one by one, automatically performing mesh degradation operation to obtain the model file after mesh degradation; S6, repeat S2 to S5 until the wear setting condition is reached and the simulation ends.

2. The method for simulating wear of automotive fender sharp-edge forming molds according to claim 1, characterized in that: The simplification of the three-dimensional model of the stamping die includes: simplifying the structure of the sharp-edged test mold and the upper slide of the press; and stitching and smoothing the broken surfaces in the surface contact area.

3. The method for simulating wear of automotive fender sharp edge forming molds according to claim 1, characterized in that: The wear amount was simulated and calculated using the Archard wear model.

4. The method for simulating wear of automotive fender sharp edge forming molds according to claim 1, characterized in that: The wear amount is evaluated by the wear depth of the mold.

5. The method for simulating wear of automotive fender sharp edge forming molds according to claim 1 or 4, characterized in that: The formula for calculating wear depth is: The wear coefficient is the probability of wear occurring, and it is obtained through experiments. For the normal stress of the contact surface, The relative sliding velocity of the contact surfaces. For the slip time, The hardness of the material being worn is the hardness of the mold.

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