An undercompensated iterative compensation method and related apparatus for elastic deformation of forging dies
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-09
- Publication Date
- 2026-08-14
AI Technical Summary
然而在真实三维热锻条件下，型面更新将改变接触状态与接触压力分布，导致载荷重分配，使“型面更新—载荷—弹性位移”的映射呈非线性特征，容易出现过补偿、振荡或收敛效率低等问题
本发明锻模弹性变形的欠补偿迭代补偿方法及其相关装置，针对现有技术中锻模补偿易出现过补偿、振荡、收敛效率低及难以形成稳定“几何更新—仿真验证”闭环流程的问题，本发明通过特定技术步骤实现了精准、稳定且可工程化的锻模补偿，其具体原理如下：本发明在终锻终止工况下提取坯料与模具型腔工作面接触区域的载荷分布并施加至弹性模具模型得到弹性位移场后，在型腔关键区域分别从名义型面与弹性变形后型面导出固定评价点集并建立点位一一对应关系，有效避免了点位错配引入的伪偏差，确保锻件轮廓度评价的准确性与可重复性，为后续补偿提供可靠基准；通过点位偏移向量的反向量确定反向补偿更新量，并利用松弛因子对该更新量进行缩放生成欠补偿更新后的离散点云，实现受控欠补偿，避免了现有技术一次性全补偿或近似线性补偿导致的“型面更新—载荷—弹性位移”非线性映射引发的过补偿、迭代振荡问题，显著提升了迭代稳定性；对欠补偿更新后的离散点云进行曲面拟合重构得到连续光顺的更新型面，该更新型面可直接作为锻造成形有限元模型的模具型面进行再仿真，构建了完整的“终锻求解—载荷提取—弹性位移计算—欠补偿更新—曲面重构—再仿真验证”闭环流程，解决了现有技术离散点云无法直接用于CAD设计与再仿真的难题，提升了方法的工程可实施性；同时，基于更新型面进行终锻成形求解并计算轮廓度综合偏差，以预设公差判据控制迭代终止，形成了可量化、标准化的迭代控制链路，无需依赖经验判断即可确保最终锻件轮廓度满足要求，有效解决了现有技术补偿过程缺乏量化依据的问题，相较于现有技术具有显著创新性与技术进步。
Smart Images
Figure CN122572017A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of precision forging, mold design and numerical simulation technology, and specifically relates to an undercompensation iterative compensation method for elastic deformation of forging dies and its related devices. Background Technology
[0002] Complex curved surface parts are subjected to high temperature and high load during the final forging process, and elastic deformation inevitably occurs on the working surface of the die cavity, resulting in deviations in the forging profile. Compensation design is usually required for the cavity area. This involves accurately analyzing the elastic deformation law of the die under actual working conditions using numerical methods such as finite element analysis (FEA), and combining the cooling shrinkage characteristics and load distribution features of the forging. Reverse offset corrections are then applied to key curved surfaces, corners, and areas of concentrated stress in the cavity to pre-compensate deformation errors in the final forging stage. Ultimately, this ensures that the forging profile meets near-net-shape requirements, reducing subsequent machining allowances and production costs.
[0003] Existing technologies often employ a one-time full compensation or approximately linear compensation strategy, which involves updating the nominal profile based on the elastic displacement of the die under forging load. However, under real three-dimensional hot forging conditions, profile updates will alter the contact state and contact pressure distribution, leading to load redistribution. This results in a nonlinear mapping of "profile update—load—elastic displacement," which is prone to problems such as overcompensation, oscillation, or low convergence efficiency.
[0004] In addition, the compensation update results are usually represented as discrete point clouds. If there is a lack of continuous surface reconstruction and re-simulation interface, it is difficult to form a stable "geometric update - simulation verification" closed loop process, which in turn affects the feasibility of the project and the stability of the iteration.
[0005] Therefore, it is necessary to propose an undercompensation iterative compensation method and system that can suppress overcompensation and maintain stable convergence, while facilitating geometric reconstruction and re-simulation closed-loop verification.
[0006] The information disclosed in this background section is only intended to enhance the understanding of the overall background of the present invention and should not be construed as an admission or implication that it constitutes prior art known in the art. Summary of the Invention
[0007] To address the problems existing in the prior art, the present invention aims to provide an undercompensated iterative compensation method and related device for elastic deformation of forging dies. The present invention achieves step-by-step approximation and stable convergence of profile tolerance through a sequential process of final forging load extraction and elastic solution, closed-loop evaluation of fixed evaluation point set, controlled undercompensation update, and surface fitting reconstruction and resimulation process.
[0008] To achieve the above objectives, the present invention adopts the following technical solution: An undercompensation iterative compensation method for elastic deformation of forging dies includes the following steps: Establish a forging forming finite element model and solve for the final forging forming. Extract the load distribution in the contact area between the billet and the working surface of the die cavity in the forging forming finite element model under the forging termination condition. The load distribution is mapped or equivalently applied to the established elastic mold model, and the elastic mold model is elastically solved to obtain the elastic displacement field of the working surface of the mold cavity. In the mold cavity working surface, the key cavity area for evaluating the profile of the forging is determined. In the key cavity area of the nominal surface, the fixed evaluation point set of the nominal surface is derived. In the key cavity area of the elastically deformed surface, the fixed evaluation point set of the elastically deformed surface is derived. A one-to-one correspondence is established between the fixed evaluation point set of the nominal surface and the fixed evaluation point set of the deformed surface. Based on the one-to-one correspondence of the points, the point offset vector of the fixed evaluation point set is calculated, and the inverse vector of the point offset vector is used as the compensation direction to obtain the reverse compensation update amount; the reverse compensation update amount is scaled using a relaxation factor to generate the undercompensated discrete point cloud. The undercompensated updated discrete point cloud is reconstructed by surface fitting to obtain a continuous and smooth updated surface. The final forging process is solved based on the updated profile and the comprehensive deviation of the profile is calculated. The iteration stops when the comprehensive deviation of the profile meets the preset tolerance criterion; otherwise, the updated profile is used as the mold profile of the forging finite element model to re-establish the forging finite element model and perform the final forging process solution.
[0009] Preferably, the forging termination condition is defined by the die closing gap condition; the load distribution is characterized in the form of contact node force or contact pressure, and the load application area and the application direction are kept consistent when the load is mapped or applied equivalently.
[0010] Preferably, the elastic mold model is a linear elastic material model, and the elastic solution output is a three-dimensional displacement component field of the working surface of the cavity.
[0011] Preferably, the key region of the cavity includes the cavity working surface region corresponding to the key forming surface of the forging, and is a non-boundary, non-rounded transition, and non-geometrically abrupt region; the fixed evaluation point set is obtained by deriving the discrete mesh, triangular facet model, or STL model of the working surface of the mold cavity; the fixed evaluation point set is all discrete points covering the key region or discrete points obtained according to a preset sampling strategy; the one-to-one correspondence is established by deriving the same fixed evaluation point set from the nominal surface and the surface after elastic deformation, so that any evaluation point has the same point sequence number in the two sets of data.
[0012] Preferably, the point offset vector as follows:
[0013] in, , The upper side point set is used to partition the evaluation point set. The lower set of points is used to partition the evaluation point set. For the nominal type surface of the first Coordinates of each evaluation point The corresponding first after elastic deformation Coordinates of each evaluation point; The reverse compensation update amount is: Uncompensated update volume as follows:
[0014] This leads to the updated evaluation point coordinates. as follows:
[0015] in, The coordinates of the evaluation points before the update. As a relaxation factor, This represents the number of iterations.
[0016] Preferably, the evaluation point set is divided into an upper point set and a lower point set, and the contour comprehensive deviation e total The sum of the root mean square of the upper point set and the root mean square of the lower point set is used.
[0017] Preferably, a preset tolerance threshold is used. Construct a convergence criterion when If the overall profile deviation meets the preset tolerance criterion, the iteration stops; otherwise, the updated profile is used as the mold profile of the forging forming finite element model to rebuild the forging forming finite element model and perform the final forging forming solution until the overall profile deviation meets the preset tolerance criterion or the preset termination condition is reached.
[0018] The present invention also provides an undercompensated iterative compensation system for the elastic deformation of forging dies. This system is used to implement the undercompensated iterative compensation method for the elastic deformation of forging dies described above, and includes: Forming solution module: used to establish a forging forming finite element model and perform final forging forming solution, and extract the load distribution in the contact area between the billet and the working surface of the die cavity in the forging forming finite element model under the forging termination condition; Load mapping and elastic solution module: used to map or apply the load distribution to the established elastic mold model, perform elastic solution on the elastic mold model, and obtain the elastic displacement field of the working surface of the mold cavity; Evaluation Domain and Point Set Module: Used to determine the key cavity area for evaluating the profile of forgings on the working surface of the mold cavity, export the fixed evaluation point set of the nominal surface in the key cavity area of the nominal surface, export the fixed evaluation point set of the elastically deformed surface in the key cavity area of the elastically deformed surface, and establish a one-to-one correspondence between the fixed evaluation point set of the nominal surface and the fixed evaluation point set of the deformed surface. Undercompensated update module: used to calculate the point offset vector of the fixed evaluation point set based on the one-to-one correspondence of the points, and use the inverse vector of the point offset vector as the compensation direction to obtain the reverse compensation update amount; use the relaxation factor to scale the reverse compensation update amount to generate the undercompensated updated discrete point cloud. Surface reconstruction module: used to perform surface fitting and reconstruction on the undercompensated updated discrete point cloud to obtain a continuous and smooth updated surface; Iteration control and evaluation module: used to solve the final forging process based on the updated profile and calculate the comprehensive deviation of the profile. When the comprehensive deviation of the profile meets the preset tolerance criterion, the iteration stops. Otherwise, the updated profile is input into the forming solution module, and the forging forming finite element model is established using the updated profile to re-establish the forging forming finite element model and solve the final forging process.
[0019] The present invention also provides an electronic device, comprising: One or more processors; A memory on which one or more programs are stored; When the one or more programs are executed by the one or more processors, the one or more processors implement the undercompensation iterative compensation method for elastic deformation of forging dies as described above.
[0020] The present invention also provides a storage medium storing a computer program thereon, wherein the computer program, when executed by a processor, implements the undercompensation iterative compensation method for elastic deformation of forging dies as described above.
[0021] The present invention has the following beneficial effects: This invention relates to an undercompensated iterative compensation method and related apparatus for elastic deformation of forging dies. Addressing the problems of overcompensation, oscillation, low convergence efficiency, and difficulty in forming a stable "geometric update-simulation verification" closed-loop process in existing forging die compensation technologies, this invention achieves accurate, stable, and engineerable forging die compensation through specific technical steps. The specific principle is as follows: After extracting the load distribution in the contact area between the billet and the working surface of the die cavity under the final forging termination condition and applying it to the elastic die model to obtain the elastic displacement field, a fixed evaluation point set is derived from the nominal surface and the surface after elastic deformation in the key areas of the cavity, establishing a one-to-one correspondence between the points. This effectively avoids pseudo-deviations introduced by point mismatch, ensuring the accuracy and repeatability of the forging profile evaluation and providing a reliable benchmark for subsequent compensation. The reverse compensation update amount is determined by the inverse vector of the point offset vector, and the update amount is scaled using a relaxation factor to generate a discrete point cloud after undercompensation, achieving controlled undercompensation and avoiding the one-time full compensation or... The overcompensation and iterative oscillation problems caused by the nonlinear mapping of "surface update - load - elastic displacement" due to near-linear compensation are significantly improved by this method. A continuous and smooth updated surface is obtained by surface fitting and reconstruction of the discrete point cloud after undercompensation. This updated surface can be directly used as the mold surface of the forging forming finite element model for re-simulation. A complete closed-loop process of "final forging solution - load extraction - elastic displacement calculation - undercompensation update - surface reconstruction - re-simulation verification" is constructed, solving the problem that discrete point clouds in existing technologies cannot be directly used for CAD design and re-simulation, thus improving the engineering feasibility of the method. Simultaneously, the final forging forming solution is performed based on the updated surface, and the comprehensive deviation of the profile is calculated. The iteration termination is controlled by a preset tolerance criterion, forming a quantifiable and standardized iterative control link. This ensures that the profile of the final forging meets the requirements without relying on empirical judgment, effectively solving the problem of the lack of quantitative basis in the compensation process of existing technologies. This method has significant innovation and technological progress compared to existing technologies. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments are briefly described below: Figure 1 This is a flowchart illustrating the undercompensation iterative compensation method for elastic deformation of forging dies in an embodiment of the present invention. Figure 2 This is a schematic diagram of the selection of ROI and fixed evaluation point set for the key area of the cavity in an embodiment of the present invention; Figure 3 The displacement component in the loading direction within the ROI in this embodiment of the invention. Contour map; Figure 4 The relaxation factor in the embodiments of the present invention Schematic diagram of the convergence behavior of the underpayment compensation iteration; Figure 5 This is a schematic diagram of the continuous surface after compensation point cloud and surface fitting reconstruction in an embodiment of the present invention; Figure 6 Comprehensive deviations in the embodiments of the present invention The variation with the number of iterations and the fitted curve. Detailed Implementation
[0023] The present invention will be further described clearly and in detail below with reference to specific embodiments and the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.
[0024] In view of the problems existing in the prior art, this invention provides an undercompensated iterative compensation method and related device for elastic deformation of forging dies, which is used to reduce the profile deviation of forgings caused by elastic deformation of forging dies during the forging process. This invention achieves step-by-step approximation and stable convergence of the profile tolerance through a process of "sequential process of final forging load extraction and elastic solution + closed-loop evaluation of fixed evaluation point set + controlled undercompensation update + surface fitting reconstruction and re-simulation". Specifically, the core idea of this invention is: to obtain the contact load and obtain the elastic displacement field of the cavity working surface under the final forging termination condition; to derive a fixed evaluation point set in the key area of the cavity and maintain a one-to-one correspondence between the points; and to divide the evaluation point set into an upper point set. with the lower side point set A comprehensive deviation index is constructed based on point-to-point displacement, and the iteration termination is controlled by tolerance criteria. At the same time, the update amount is undercompensated and scaled by relaxation factor, and surface reconstruction is performed after each step to ensure that the updated surface can be used for CAD and re-simulation.
[0025] For details, see Figure 1 The undercompensation iterative compensation method for elastic deformation of forging dies of the present invention includes the following steps: S10. Establish a finite element model for final forging plastic forming and solve for the final forging process. Under the final forging termination condition (limited by the die closing gap condition), extract the load distribution in the contact area between the billet and the working surface of the cavity in the forging forming finite element model. Specifically, the load distribution is characterized in the form of contact node force or contact pressure, and the load application area and direction are kept consistent during load mapping or equivalent application. Contact traction. (That is, the force per unit area on the contact surface when the blank contacts the mold cavity) can be expressed as:
[0026] in, For the contact area, For the surface normal, To contact pressure, It is tangential traction.
[0027] S20. The load distribution is mapped or equivalently applied to the elastic mold model (the elastic mold model is a linear elastic material model, and the elastic solution output is the three-dimensional displacement component field of the cavity working surface), which can be abstracted as a mapping operator. :
[0028] And perform elasticity calculation on the elastic mold model:
[0029] in, Here is the stiffness matrix. Let be the nodal displacement vector. This is the equivalent external load vector. (From...) Obtain the displacement field of the working surface of the cavity .
[0030] S30. Determine the critical area of the blade shape on the working surface of the mold cavity (the critical area of the cavity is the working surface area of the cavity corresponding to the critical forming surface of the forging, and the critical area avoids boundary, fillet transition and geometric change areas to reduce the impact of contact state changes on evaluation and compensation updates) and construct the evaluation domain. Within the evaluation domain, a fixed set of evaluation points is derived (this fixed set of evaluation points is obtained by deriving the discrete mesh, triangular facet model, or STL model of the working surface of the mold cavity; this fixed set of evaluation points consists of all discrete points covering the key area or discrete points obtained according to a preset sampling strategy) and divided into an upper side point set. with the lower side point set Let the nominal point set be represented as:
[0031] The same fixed evaluation point set is derived from both the nominal and elastically deformed surfaces, ensuring that both sets have consistent point sequence numbers. This establishes a one-to-one correspondence between the fixed evaluation point set on the nominal surface and the fixed evaluation point set on the deformed surface. This correspondence is established by deriving the same fixed evaluation point set from both the nominal and elastically deformed surfaces, ensuring that any evaluation point has the same point sequence number in both sets of data. The corresponding points after deformation can be determined by displacement superposition.
[0032] S40. Calculate the point offset vector of the fixed evaluation point set based on the one-to-one correspondence of the points, and obtain the reverse compensation update amount by using the inverse vector of the point offset vector as the compensation direction; introduce a relaxation factor. ω The reverse compensation update amount is scaled to generate an undercompensated discrete point cloud, specifically: The point offset vector is defined as:
[0033] in, , For the nominal type surface of the first Coordinates of each evaluation point The corresponding first after elastic deformation Coordinates of each evaluation point; Point-to-point displacement is defined as:
[0034] Stack the upper and lower point sets into a matrix by rows: ,
[0035]
[0036] The same logic applies to the lower side. .
[0037] Stack the point-to-point displacements into a vector:
[0038] Using point offset vector The reverse direction is used as the compensation direction, and the reverse compensation update amount is... Introducing a relaxation factor Scaling the update amount yields the undercompensated update amount:
[0039] And based on this, the updated evaluation points are obtained:
[0040] in, , As a relaxation factor, This represents the number of iterations.
[0041] When represented as a point cloud matrix, the updates for the upper and lower sides can be written as follows:
[0042] S50. Since the undercompensated update yields a discrete point cloud, to obtain a continuous and smooth surface suitable for CAD modeling and the next round of simulation, surface fitting reconstruction is performed on the updated point cloud to obtain a continuous and smooth updated surface. This updated surface is then used as the mold surface input for the next round of forming solution. The surface fitting reconstruction includes any one of NURBS surface fitting, B-spline surface fitting, or polynomial surface fitting; and error evaluation is performed on the fitted surface, ensuring the fitting residual is no greater than a preset threshold. Specifically, parametric surfaces... The reconstructed surface can be fitted using regularized least squares:
[0043] in To update the point cloud One point, For smooth regularization terms, The preset weights are used. The fitting residuals are:
[0044] The residual index is set to not exceed a preset threshold as a constraint on the fitting quality. After reconstruction, the updated surface is exported as a geometric format that can be recognized by CAD or simulation software for the next round of simulation closure.
[0045] S60. Based on the updated profile, perform final forging and calculate the overall profile deviation e. total Overall deviation of profile The calculation is based on "upper RMS + lower RMS", as detailed below:
[0046] in, and They are respectively and The number of evaluation points in a point set.
[0047] With preset tolerance threshold Convergence criterion:
[0048] The iteration terminates when the criterion is met; otherwise, the process proceeds to the next round of S10 to S60 with an updated surface until the criterion is met or the preset termination condition is reached.
[0049] It can be obtained through multiple iterations The sequence is fitted to represent the convergence law, for example, using a decay model:
[0050] in, The attenuation function is in the preset form. The parameters are to be estimated; the parameters can be determined by least squares, and the goodness-of-fit index can be used to evaluate the reliability of the prediction, thereby helping to estimate the number of iterations required to reach the tolerance criterion or to help select the relaxation factor and reconstruction parameters.
[0051] The following example illustrates the accuracy of the model in this invention.
[0052] Example This embodiment takes the final forging of aero-engine blades as the object, and uses the DEFORM platform to complete the two-step analysis of final forging plastic forming and die elastic deformation. Based on this, under-compensation iterative compensation and surface reconstruction closed-loop verification are implemented. The overall process of the under-compensation iterative compensation method is as follows: Figure 1 As shown in Table 1, the die material is H13 hot work die steel, and the final forging process parameters and boundary conditions for the blades are summarized in Table 1.
[0053] Table 1
[0054] In the final forging termination condition (6 mm between upper and lower dies), the output billet's contact load distribution on the working surface of the cavity is shown. The load can be derived in the form of contact node force or contact pressure, and used as input for subsequent elastic solution.
[0055] The contact loads extracted during the plastic forming stage are mapped to the corresponding positions in the mold model, and mold elasticity analysis is performed to obtain the three-dimensional displacement field of the cavity working surface. .
[0056] In the elasticity analysis, the mold material adopts a linear elastic model; considering the temperature correlation of the hot elastic modulus, the temperature-elastic modulus data (i.e., the parameters of the mold elastic modulus as a function of temperature) are used as shown in Table 2.
[0057] Table 2
[0058] The mesh parameters for the die elasticity analysis (i.e., the relevant parameters for the finite element simulation of the elastic deformation of the final forging die) are shown in Table 3.
[0059] Table 3
[0060] Select a blade shape ROI (a rectangular window covering the key forming area of the blade shape, avoiding the blade root and rounded corner transition area) on the working surface of the corresponding cavity of the blade body. Export a fixed set of evaluation points within the ROI and divide it into an upper side point set. with the lower side point set The ROI and point set are illustrated as follows: Figure 2 As shown. In this embodiment, the point set size is 219 points (derived under the same rule).
[0061] To ensure a one-to-one correspondence between points, a method of "exporting the same ROI point set separately" is adopted, exporting the nominal surface point coordinates and the coordinates of the points after elastic deformation separately, so that the point order of the two sets of data is consistent. Since the elastic offset magnitude of the leaf-shaped region is relatively small compared to the geometric scale of the ROI, directly superimposing and displaying the nominal point set and the deformed point set often results in near-identical visual overlap, making it difficult to identify spatial differences; therefore, this embodiment uses a difference field method to highlight minute offsets: reconstructing discrete points into a Δz contour map, such as... Figure 3 This allows for a direct visualization of the surface offset distribution along the loading direction within the blade-shaped ROI.
[0062] Since the update result is a discrete point cloud, NURBS surface fitting and reconstruction are performed to obtain a continuous, smooth surface suitable for CAD. A schematic diagram of point cloud-surface reconstruction is shown below. Figure 5 As shown in Table 4, the surface fitting parameters are set accordingly.
[0063] Table 4
[0064] The fitted surface is exported as an STL file, then imported into DEFORM via CAD for the next round of final forging simulation and elastic analysis, thus forming a closed loop of "update - reconstruction - re-simulation - re-evaluation". like Figure 4 and Figure 6 As shown, in Under these conditions, the deviation results for iterations 1–10 are as follows (unit: mm): 1st iteration: upper deviation 0.2641; lower deviation 0.2575; combined deviation 0.5216; 5th time: Upper deviation 0.1342; Lower deviation 0.1309; Overall deviation 0.2651; 9th time: Upper deviation 0.0689; Lower deviation 0.0672; Overall deviation 0.1361; 10th time: Upper deviation 0.0650; Lower deviation 0.0634; Overall deviation 0.1284.
[0065] Under the same finite element model, material parameters, and boundary conditions, set 0.01, 0.20 (control), first time meeting the requirement The number of iterations are as follows: The first time the target was achieved, it took 17 iterations (with a deviation of 0.1428 mm when the target was met). The first time the standard was achieved, it took 9 iterations (the deviation was 0.1361 mm when the standard was achieved). The first time the standard was achieved, it took 5 iterations (the deviation was 0.1356 mm when the standard was achieved).
[0066] Different relaxation factors ( Under the conditions of 0.01 and 0.20, the average decrease before the statistical target was met. (Unit: mm) 0.0267, 0.0482, and 0.0831 respectively, indicating... Increasing the size can significantly improve the efficiency of achieving the target; To quantitatively characterize the relationship between "bias" and "iteration number", the comprehensive bias sequence is fitted using an exponential decay method:
[0067] in For decay rate, For amplitude terms, The fitting result for the constant term is:
[0068] Coefficient of determination This indicates that the fitting results are highly close to the actual results.
[0069] Furthermore, embodiments of the present invention also provide an undercompensated iterative compensation system for the elastic deformation of forging dies, used to implement the undercompensated iterative compensation method for the elastic deformation of forging dies described above. The system includes: Forming solution module: used to establish a forging forming finite element model and perform final forging forming solution, and extract the load distribution in the contact area between the billet and the working surface of the die cavity in the forging forming finite element model under the forging termination condition; Load mapping and elastic solution module: used to map or apply the load distribution to the established elastic mold model, perform elastic solution on the elastic mold model, and obtain the elastic displacement field of the working surface of the mold cavity; Evaluation Domain and Point Set Module: Used to determine the key cavity area for evaluating the profile of forgings on the working surface of the mold cavity, export the fixed evaluation point set of the nominal surface in the key cavity area of the nominal surface, export the fixed evaluation point set of the elastically deformed surface in the key cavity area of the elastically deformed surface, and establish a one-to-one correspondence between the fixed evaluation point set of the nominal surface and the fixed evaluation point set of the deformed surface. Undercompensated update module: used to calculate the point offset vector of the fixed evaluation point set based on the one-to-one correspondence of the points, and use the inverse vector of the point offset vector as the compensation direction to obtain the reverse compensation update amount; use the relaxation factor to scale the reverse compensation update amount to generate the undercompensated updated discrete point cloud. Surface reconstruction module: used to perform surface fitting and reconstruction on the undercompensated updated discrete point cloud to obtain a continuous and smooth updated surface; Iteration control and evaluation module: used to solve the final forging process based on the updated profile and calculate the comprehensive deviation of the profile. When the comprehensive deviation of the profile meets the preset tolerance criterion, the iteration stops. Otherwise, the updated profile is input into the forming solution module, and the forging forming finite element model is established using the updated profile to re-establish the forging forming finite element model and solve the final forging process.
[0070] The embodiments of the present invention also provide corresponding electronic devices and computer-readable storage media for implementing the solutions provided in the embodiments of the present invention.
[0071] The electronic device includes a memory and one or more processors. The memory stores one or more programs, and the one or more processors execute the programs to enable the electronic device to perform the undercompensation iterative compensation method for elastic deformation of forging dies as described in any embodiment of this application.
[0072] The storage medium stores a computer program, which, when executed by a processor, implements the undercompensation iterative compensation method for elastic deformation of forging dies as described in any embodiment of this application.
[0073] In summary, the present invention has at least the following characteristics: (1) Controlled undercompensation can be implemented through relaxation factors to suppress the risk of overcompensation and improve iteration stability; (2) By deriving a one-to-one correspondence between points through a fixed set of evaluation points, we can avoid the introduction of false biases due to mismatch of points and improve the consistency and repeatability of evaluation. (3) The discrete compensation point cloud is converted into a continuous smooth surface by surface fitting and reconstruction, and exported for CAD and re-simulation, realizing the closed-loop process of "geometric update - numerical verification". (4) By constructing a unified iterative control link through comprehensive deviation index and tolerance criterion, the compensation process can be quantified, compared and facilitated in engineering applications.
[0074] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.
Claims
1. A method for undercompensation iterative compensation of elastic deformation of forging dies, characterized in that, Includes the following steps: Establish a forging forming finite element model and solve for the final forging forming. Extract the load distribution in the contact area between the billet and the working surface of the die cavity in the forging forming finite element model under the forging termination condition. The load distribution is mapped or equivalently applied to the established elastic mold model, and the elastic mold model is elastically solved to obtain the elastic displacement field of the working surface of the mold cavity. In the mold cavity working surface, the key cavity area for evaluating the profile of the forging is determined. In the key cavity area of the nominal surface, the fixed evaluation point set of the nominal surface is derived. In the key cavity area of the elastically deformed surface, the fixed evaluation point set of the elastically deformed surface is derived. A one-to-one correspondence is established between the fixed evaluation point set of the nominal surface and the fixed evaluation point set of the deformed surface. Based on the one-to-one correspondence of the points, the point offset vector of the fixed evaluation point set is calculated, and the inverse vector of the point offset vector is used as the compensation direction to obtain the reverse compensation update amount. The inverse compensation update amount is scaled using a relaxation factor to generate an undercompensated discrete point cloud. The undercompensated updated discrete point cloud is reconstructed by surface fitting to obtain a continuous and smooth updated surface. The final forging process is solved based on the updated profile and the comprehensive deviation of the profile is calculated. The iteration stops when the comprehensive deviation of the profile meets the preset tolerance criterion; otherwise, the updated profile is used as the mold profile of the forging finite element model to re-establish the forging finite element model and perform the final forging process solution.
2. The undercompensation iterative compensation method for elastic deformation of forging dies according to claim 1, characterized in that, The forging termination condition is defined by the die closing gap condition; the load distribution is characterized in the form of contact node force or contact pressure, and the load application area and the application direction are kept consistent when the load is mapped or applied equivalently.
3. The undercompensation iterative compensation method for elastic deformation of forging dies according to claim 1, characterized in that, The elastic mold model is a linear elastic material model, and the elastic solution output is a three-dimensional displacement component field of the working surface of the cavity.
4. The undercompensation iterative compensation method for elastic deformation of forging dies according to claim 1, characterized in that, The key region of the cavity includes the working surface region of the cavity corresponding to the key forming surface of the forging, and is a non-boundary, non-rounded transition, and non-geometrically abrupt region; the fixed evaluation point set is obtained by deriving the discrete mesh, triangular facet model, or STL model of the working surface of the mold cavity; the fixed evaluation point set is all discrete points covering the key region or discrete points obtained according to a preset sampling strategy; the one-to-one correspondence is established by deriving the same fixed evaluation point set from the nominal surface and the surface after elastic deformation, so that any evaluation point has the same point sequence number in the two sets of data.
5. The undercompensation iterative compensation method for elastic deformation of forging dies according to claim 1, characterized in that, The point offset vector as follows: in, , The upper side point set is used to partition the evaluation point set. The lower set of points is used to evaluate the point set partitioning. For the nominal type surface of the first Coordinates of each evaluation point The corresponding first after elastic deformation Coordinates of each evaluation point; The reverse compensation update amount is: Uncompensated update volume as follows: This leads to the updated evaluation point coordinates. as follows: in, The coordinates of the evaluation points before the update. As a relaxation factor, This represents the number of iterations.
6. The undercompensation iterative compensation method for elastic deformation of forging dies according to claim 1, characterized in that, The evaluation point set is divided into an upper point set and a lower point set, and the contour comprehensive deviation e is... total The sum of the root mean square of the upper point set and the root mean square of the lower point set is used.
7. The undercompensation iterative compensation method for elastic deformation of forging dies according to claim 1, characterized in that, With preset tolerance threshold Construct a convergence criterion when If the overall profile deviation meets the preset tolerance criterion, the iteration stops; otherwise, the updated profile is used as the mold profile of the forging forming finite element model to rebuild the forging forming finite element model and perform the final forging forming solution until the overall profile deviation meets the preset tolerance criterion or the preset termination condition is reached.
8. An undercompensated iterative compensation system for the elastic deformation of a forging die, characterized in that, The undercompensation iterative compensation method for elastic deformation of forging dies as described in any one of claims 1-7 includes: Forming solution module: used to establish a forging forming finite element model and perform final forging forming solution, and extract the load distribution in the contact area between the billet and the working surface of the die cavity in the forging forming finite element model under the forging termination condition; Load mapping and elastic solution module: used to map or apply the load distribution to the established elastic mold model, perform elastic solution on the elastic mold model, and obtain the elastic displacement field of the working surface of the mold cavity; Evaluation Domain and Point Set Module: Used to determine the key cavity area for evaluating the profile of forgings on the working surface of the mold cavity, export the fixed evaluation point set of the nominal surface in the key cavity area of the nominal surface, export the fixed evaluation point set of the elastically deformed surface in the key cavity area of the elastically deformed surface, and establish a one-to-one correspondence between the fixed evaluation point set of the nominal surface and the fixed evaluation point set of the deformed surface. Undercompensated update module: used to calculate the point offset vector of the fixed evaluation point set based on the one-to-one correspondence of the points, and use the inverse vector of the point offset vector as the compensation direction to obtain the reverse compensation update amount; use the relaxation factor to scale the reverse compensation update amount to generate the undercompensated updated discrete point cloud. Surface reconstruction module: used to perform surface fitting and reconstruction on the undercompensated updated discrete point cloud to obtain a continuous and smooth updated surface; Iteration control and evaluation module: used to solve the final forging process based on the updated profile and calculate the comprehensive deviation of the profile. When the comprehensive deviation of the profile meets the preset tolerance criterion, the iteration stops. Otherwise, the updated profile is input into the forming solution module, and the forging forming finite element model is established using the updated profile to re-establish the forging forming finite element model and solve the final forging process.
9. An electronic device, characterized in that, include: One or more processors; A memory on which one or more programs are stored; When the one or more programs are executed by the one or more processors, the one or more processors implement the undercompensation iterative compensation method for elastic deformation of forging dies as described in any one of claims 1-7.
10. A storage medium, characterized in that, It stores a computer program, wherein when the computer program is executed by a processor, it implements the undercompensation iterative compensation method for elastic deformation of forging dies as described in any one of claims 1-7.