An Automatic Parametric Modeling Method for Delaminated Composite Material Structures using Finite Element Method

Abstract

This invention relates to an automated parametric finite element modeling method for delaminated composite structures, comprising: drawing the outer contour of the model based on given outer contour dimensions via an ABAQUS interface; calculating the complex geometric and topological features of the delaminated structure using a standardized expression of the given delaminated design configuration; generating delaminated lines layer by layer on the model using ABAQUS drawing functions to complete the drawing of the delaminated structure; assigning material properties and material orientations to corresponding regions via the ABAQUS interface, and setting the analysis steps and boundary conditions; automatically generating the mesh and submitting the calculation; and automatically extracting the load-displacement curves and delamination cracking load values ​​from the ODB file after the calculation is completed. Compared with existing technologies, the method of this invention can realize automated parametric finite element modeling of delaminated designs, greatly improving the efficiency of finite element modeling, and can quickly, automatically, and accurately complete the generation of composite delaminated finite element models, significantly improving the quality and efficiency of composite delaminated design.

Description

Technical Field

[0001] This invention relates to the fields of composite material structure design, finite element simulation modeling and computer-aided engineering analysis, and in particular to an automatic parametric finite element modeling method for fiber-reinforced resin matrix composite delaminated structures. Background Technology

[0002] Fiber-reinforced resin matrix composites possess advantages such as high specific strength, high specific stiffness, good fatigue resistance, and strong designability, and have been widely used in load-bearing structures in aerospace, high-end equipment, rail transportation, and new energy equipment. In the design of composite material structures, to achieve structural weight reduction, thickness transition, and optimization of local load-bearing performance, the layer-dropping design method is often adopted. This involves terminating partial layups layer by layer in specific areas, allowing the structure to gradually transition from thicker to thinner regions.

[0003] However, delaminated regions are often accompanied by significant geometric and material discontinuities. Resin-rich areas tend to form near the ply termination point, leading to localized stress concentrations, interlaminar shear stress concentrations, and normal delamination stress concentrations, which can induce delamination, resin cracking, or ply failure. Therefore, in the design phase of composite delaminated structures, finite element analysis is typically required to evaluate the stress distribution, damage initiation, and delamination propagation behavior of different delaminated configurations.

[0004] Finite element modeling of composite delaminated structures typically relies on manual methods, including steps such as drawing the outer contour, delaminated boundary meshing, resin region construction, assigning material properties, defining material orientations, setting analysis steps, setting boundary conditions, and mesh generation. When there are many delaminated layers, complex delaminated sequences, or when multiple delaminated configurations need to be compared in batches, manual modeling suffers from low efficiency, repetitive operations, difficulty in parameter modification, and challenges in ensuring model consistency. Furthermore, the complex geometric and topological relationships of delaminated regions make manual drawing of delaminated lines and resin region boundaries prone to issues such as boundary misalignment, incomplete region meshing, and incorrect material assignment, thus affecting the accuracy and repeatability of the finite element analysis results.

[0005] Existing technologies also include methods for generating ply drop lines in composite materials using geometric software interfaces. For example, CN120408899A discloses a method for designing and modeling ply drop lines in composite materials. This method obtains the geometric surface and ply information of the ply region of a composite material part through an interface of 3D design software such as CATIA, and generates ply drop lines on the geometric surface. This type of method mainly focuses on the expression of geometric information of composite material ply and the display of ply boundaries, and is suitable for the ply design stage of composite material structures. However, it is not applicable to the finite element analysis of ply drop details and the optimization of ply drop sequence in composite materials.

[0006] Therefore, existing technologies still lack an integrated automatic parametric modeling method that directly addresses the ABAQUS finite element analysis environment and can automatically complete the generation of delaminated geometry, region identification, material assignment, material orientation definition, boundary condition setting, and mesh generation based on the delaminated design configuration. To improve the efficiency of finite element modeling of composite delaminated structures, reduce manual modeling errors, and ensure consistency between models of different delaminated configurations, it is necessary to propose an automatic parametric modeling method for composite delaminated structures. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of complex manual operation, low modeling efficiency, difficulty in parameter modification, poor model consistency, and easy errors in material assignment and orientation definition in the delaminated region during the existing finite element modeling process for composite delaminated structures, and to provide an automatic parametric modeling method for composite delaminated structures.

[0008] This invention reads the standardized expression of the outer contour dimension parameters and the layer-drop design configuration through the ABAQUS interface, automatically calculates the geometric topological features of the layer-drop structure, and completes the model outer contour drawing, layer boundary division, layer-drop resin region boundary generation, material property assignment, material direction definition, analysis step setting, boundary condition setting, element type setting, and mesh generation in ABAQUS, thereby forming a parametric model of composite layer-drop structure that can be directly used for finite element analysis.

[0009] This invention provides an automated parametric modeling method for finite element methods of composite delaminated structures, comprising the following steps: S1: Read the outer contour dimension parameters of the composite material layered structure through the ABAQUS interface, and draw the outer contour of the composite material layered structure model according to the outer contour dimension parameters; S2: Calculate the geometric topological features of the composite material layer-drop structure through the standardized expression of the layer-drop design configuration; based on the geometric topological features and the model outer contour obtained in step S1, use the sketching and segmentation functions of ABAQUS to divide the layup boundaries and layer-drop resin region boundaries layer by layer within the model outer contour to complete the geometric modeling of the composite material layer-drop structure and form the geometric model of the composite material layer-drop structure. S3: Based on the composite material delaminated structure geometric model formed in step S2, identify the layup region and the delaminated resin region through the ABAQUS interface, and assign composite material properties and composite material orientation to the layup region, and assign resin material properties to the delaminated resin region. S4: Through the ABAQUS interface, establish the analysis step according to the finite element analysis type, and set the boundary conditions and load conditions; S5: Using the ABAQUS interface, based on the analysis steps, boundary conditions and load conditions set in step S4, mesh the geometric model of the composite material delaminated structure after executing step S3, and set the element type and mesh size to obtain the finite element parametric model of the composite material delaminated structure. The composite material is a fiber-reinforced resin-based composite material.

[0010] Furthermore, in step S1, the outer contour dimension parameters include the total length of the structural component, the width of the structural component, the thickness of the left side, the thickness of the right side, the length of the left platform, the length of the right platform, and the length of the layer-dropping transition zone.

[0011] Furthermore, in step S1, the outer contour dimension parameters are stored in a parameter file or a region list in XML or JSON format.

[0012] Furthermore, in step S2, the standardized expression of the layer-dropping design configuration includes the total number of plies, the thickness of a single ply, the sequence of layer-dropping ply numbers, and the length of the layer-dropping transition zone.

[0013] Furthermore, the missing layer ply number sequence is used to characterize the ply location where the missing layer occurred and the arrangement order of each missing layer within the missing layer transition zone. For example, the missing layer ply number sequence can be expressed as a string "20-2-18-4-16-6-14-8-12-10", where each number represents the ply number corresponding to the missing layer, and the order of the numbers indicates the order in which the missing layers are arranged within the missing layer transition zone.

[0014] Further, in step S2, the geometric topological features include the ply boundary location, the number of delaminated resin regions, the length of a single delaminated resin region, the thickness of a single delaminated resin region, and the relative position of each delaminated resin region within the delaminated transition zone.

[0015] Further, in step S3, the specific process of assigning composite material properties and composite material orientation to the ply region includes: establishing a set of ply regions based on the ply boundaries formed in step S2; assigning fiber-reinforced resin matrix composite material properties to each ply region; determining a local material coordinate system based on the geometric boundaries of each ply region, so that the first direction of the local coordinate system of the composite material is arranged along the single-layer ply direction, thereby making the main ply direction consistent with the fiber direction.

[0016] Furthermore, the properties of the fiber-reinforced resin matrix composite material include density, longitudinal elastic modulus, transverse elastic modulus, in-plane shear modulus, interlaminar shear modulus, and Poisson's ratio.

[0017] Furthermore, the resin material properties include density, elastic modulus, and Poisson's ratio.

[0018] Furthermore, in step S4, the analysis step is either a static analysis step or an explicit dynamic analysis step.

[0019] Furthermore, in step S4, the boundary conditions include: applying a displacement load on one side of the model and applying a fixed support constraint or a displacement constraint on the other side of the model.

[0020] Further, in step S5, the unit type is either a plane strain unit or a plane stress unit, and the mesh size is determined based on the single-layer layup thickness, the size of the missing resin region, or user-input parameters.

[0021] Further, in step S2, based on the geometric topological features and the model outer contour obtained in step S1, the process of dividing the layup boundaries and the missing resin region boundaries layer by layer within the model outer contour includes the following steps: S2.1: Based on the total number of plies, the thickness of a single ply, the sequence of ply loss numbers, and the length of the ply loss transition zone, calculate the number of resin loss regions, the length of a single resin loss region, and the thickness of a single resin loss region. S2.2: Let the total number of plies be N. Starting from the first ply, take the current ply number as i, and the initial value of i is 1. S2.3: Determine whether the current layup number i is less than N. If i is less than N, proceed to step S2.4. If i is not less than N, complete the drawing of the layup boundary and the boundary of the missing resin area. S2.4: Determine whether the current ply number i is less than the smallest ply number in the sequence of dropped ply numbers; if yes, draw the horizontal ply boundary line and set i = i + 1, then return to step S2.3; if no, proceed to step S2.5. S2.5: Determine whether the current ply number i is between the minimum and maximum ply numbers in the missing ply number sequence; if yes, execute the single-layer resin region drawing algorithm to generate the ply boundary and missing resin region boundary corresponding to the current ply, and set i = i + 1, then return to step S2.3; if no, execute step S2.6. S2.6: Draw the diagonal ply boundary line and the horizontal ply boundary line corresponding to the current ply, and let i = i + 1, then return to step S2.3.

[0022] Further, in step S2.5, the single-layer resin area drawing algorithm specifically includes the following steps: S2.5.1: Let the total number of resin loss areas be M. Starting from the position of the first resin loss area, take the current position number as j, and the initial value of j is 1. S2.5.2: Determine if the current position number j is greater than M; if j is greater than M, complete the drawing of the single-layer resin area of ​​the current layup; if j is less than or equal to M, proceed to step S2.5.3. S2.5.3: Determine whether there is a resin loss area in the adjacent position below the current position; if so, draw the hypotenuse of the corresponding resin loss area as the boundary of the resin loss area, and set j=j+1, then return to step S2.5.2; if not, proceed to step S2.5.4. S2.5.4: Determine whether there is a resin loss area in the adjacent position above the current position; if so, draw the long side of the corresponding resin loss area as the boundary of the resin loss area, and let j=j+1, then return to step S2.5.2; if not, proceed to step S2.5.5. S2.5.5: Draw the diagonal and vertical sides of the resin loss area corresponding to the current position as the boundary of the resin loss area, and let j=j+1, then return to step S2.5.2.

[0023] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention achieves automated parametric generation of finite element models for composite material delaminated structures. Through the ABAQU interface, it converts information such as outer contour dimensions, total number of plies, single-layer ply thickness, and delaminated ply sequence into finite element modeling parameters. This automatically completes the drawing of the model's outer contour, ply boundary division, and generation of delaminated resin region boundaries, avoiding the tedious repetitive drawing and manual region segmentation required in traditional manual modeling, thus improving the efficiency of finite element modeling for delaminated structures.

[0024] 2. This invention can automatically construct complex drop-layer geometries based on the drop-layer layup sequence. It describes the drop-layer location and arrangement order using a standardized expression for the drop-layer design configuration, and automatically calculates the number of drop-layer resin regions, the size of each individual drop-layer resin region, and their relative positions based on this standardized expression. This method is applicable to configuration modeling with different numbers of drop-layers and different drop-layer arrangements, and is particularly suitable for batch modeling and comparative analysis of multiple drop-layer configuration schemes.

[0025] 3. It can be directly integrated with the finite element analysis process. Unlike methods that only generate layup / dropout lines or geometric display results, this invention is directly designed for the ABAQUS finite element analysis environment. It can not only generate geometric models of dropped structures, but also further complete the assignment of material properties, definition of material orientation, setting of analysis steps, setting of boundary conditions, selection of element types, and mesh generation, thereby forming a parametric model that can be directly used for finite element calculations.

[0026] 4. Applicable to rapid design, optimization, and batch simulation of composite delaminated structures. This invention can quickly generate finite element models of different delaminated configurations by modifying the outer contour dimension parameters and the delaminated ply sequence, providing an efficient modeling tool for parametric design, configuration optimization, batch simulation, and structural performance evaluation of composite delaminated structures. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the boundary conditions, mesh division, and different delamination design configurations of the composite material delamination structure in the embodiments of the present invention. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0029] It should be noted that the finite element automatic parametric modeling method for composite material delaminated structures in this invention can be adjusted according to actual needs, and the specific implementation steps and parameter settings may differ.

[0030] This invention provides an automated parametric modeling method for composite material delaminated structures using the finite element method. This method reads the outer contour dimension parameters and the standardized expression of the delaminated design configuration through an ABAQUS interface, automatically calculating the geometric topological features of the composite material delaminated structure. Based on these geometric topological features, it completes the geometric modeling, material assignment, material orientation definition, analysis step settings, boundary condition settings, and mesh generation of the composite material delaminated structure.

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1 This embodiment provides an automatic parametric modeling method for composite material delaminated structures using the finite element method, including the following steps: S1: Read the outer contour dimensions of the composite material delaminated structure via the ABAQUS interface. These dimensions include the total length of the structural component, its width, left-side thickness, right-side thickness, left-side platform length, right-side platform length, and the length of the delaminated transition zone. Based on these dimensions, create a two-dimensional deformable part in ABAQUS and generate the model's outer contour using the sketching function. The model's outer contour includes a thicker left-side region, a thinner right-side region, and a delaminated transition zone between them.

[0033] In this embodiment, the outer contour dimension parameters can be stored in a parameter file in XML or JSON format, or in a region list. By modifying the dimension parameters in the parameter file or region list, composite material layered structure models with different external dimensions can be generated.

[0034] S2: Calculate the geometric topological characteristics of the composite material layer-drop structure using the standardized expression of the layer-drop design configuration. The standardized expression of the layer-drop design configuration includes the total number of plies, the thickness of a single ply, the sequence of layer-drop ply numbers, and the length of the layer-drop transition zone.

[0035] Among them, the total number of plies is used to determine the number of plies in the thickness direction of the model; the thickness of a single ply is used to determine the distance between the boundaries of adjacent plies; the sequence of ply loss numbers is used to determine the location of the ply loss and the order of each ply loss in the ply loss transition zone; and the length of the ply loss transition zone is used to determine the distribution range of the ply loss resin area in the length direction.

[0036] For example, a missing layer ply sequence can be represented as "20-2-18-4-16-6-14-8-12-10". Each number in this sequence represents the ply number where the missing layer occurred, and the order of the numbers indicates the order of the missing layers within the missing layer transition zone. Based on this sequence, the number of missing resin regions, the location of each missing resin region, and the connection method of adjacent ply boundaries can be calculated.

[0037] Specifically, firstly, the number of depleted resin regions is determined based on the depletion layup sequence. Then, the length of each individual depleted resin region is calculated based on the length of the depletion transition zone and the number of depleted resin regions. The thickness of each individual depleted resin region is determined based on the thickness of a single layup. Finally, the relative position of each depleted resin region within the depletion transition zone is determined based on the position of each depleted layer in the sequence.

[0038] Based on the above geometric topological features and the outer contour of the model obtained in step S1, the layup boundaries and the boundaries of the missing resin regions are divided layer by layer within the outer contour of the model using the sketching and segmentation functions of ABAQUS, thereby completing the geometric modeling of the composite material missing structure and forming the geometric model of the composite material missing structure.

[0039] The process of dividing the layup boundaries and the resin loss region boundaries layer by layer includes: S2.1: Based on the total number of plies, the thickness of a single ply, the sequence of ply loss numbers, and the length of the ply loss transition zone, calculate the number of resin loss regions, the length of a single resin loss region, and the thickness of a single resin loss region. S2.2: Let the total number of plies be N. Starting from the first ply, take the current ply number as i, and the initial value of i is 1. S2.3: Determine if the current layup number i is less than N. If i is less than N, continue drawing the boundary of the current layup. If i is not less than N, complete the drawing of the layup boundary and the boundary of the missing resin area. S2.4: Determine whether the current ply number i is less than the smallest ply number in the sequence of dropped ply numbers; if yes, draw the horizontal ply boundary line and set i = i + 1, then return to step S2.3; if no, proceed with the subsequent judgment (proceed with step S2.5). S2.5: Determine whether the current ply number i is between the minimum and maximum ply numbers in the missing ply number sequence; if yes, execute the single-layer resin region drawing algorithm to generate the ply boundary and missing resin region boundary corresponding to the current ply, and set i = i + 1, then return to step S2.3; if no, execute step S2.6. S2.6: Draw the diagonal ply boundary line and the horizontal ply boundary line corresponding to the current ply, and let i = i + 1, then return to step S2.3.

[0040] In step S2.5, the single-layer resin area drawing algorithm includes the following steps: S2.5.1: Let the total number of resin loss areas be M. Starting from the position of the first resin loss area, take the current position number as j, and the initial value of j is 1. S2.5.2: Determine if the current position number j is greater than M; if j is greater than M, complete the drawing of the single-layer resin area of ​​the current layup; if j is less than or equal to M, proceed to step S2.5.3. S2.5.3: Determine whether there is a resin loss area in the adjacent position below the current position; if so, draw the hypotenuse of the corresponding resin loss area as the boundary of the resin loss area, and set j=j+1, then return to step S2.5.2; if not, proceed to step S2.5.4. S2.5.4: Determine whether there is a resin loss area in the adjacent position above the current position; if so, draw the long side of the corresponding resin loss area as the boundary of the resin loss area, and let j=j+1, then return to step S2.5.2; if not, proceed to step S2.5.5. S2.5.5: Draw the diagonal and vertical sides of the resin loss area corresponding to the current position as the boundary of the resin loss area, and let j=j+1, then return to step S2.5.2.

[0041] Through the above steps, the layup boundaries and resin region boundaries under different layup sequence numbers can be automatically generated based on different layup arrangement methods.

[0042] S3: Based on the composite material delaminated structure geometric model formed in step S2, identify the layup region and delaminated resin region through the ABAQUS interface, and establish corresponding region sets respectively.

[0043] For the ply regions, fiber-reinforced resin matrix composite properties are assigned. These properties include density, longitudinal elastic modulus, transverse elastic modulus, in-plane shear modulus, interlaminar shear modulus, and Poisson's ratio.

[0044] For the delaminated resin regions, resin material properties are assigned. These resin material properties include density, elastic modulus, and Poisson's ratio.

[0045] Simultaneously, the local material coordinate system of the composite material is determined based on the geometric boundaries of each ply region. For horizontal ply regions, a global coordinate system or a local coordinate system consistent with the global coordinate system is used; for inclined ply regions passing through the delamination transition zone, the first direction of the local material coordinate system is determined based on the ply boundary line, so that the first direction of the local coordinate system of the composite material is arranged along the single-layer ply direction, thereby making the main ply direction consistent with the fiber direction.

[0046] By using the above method, it can be ensured that the constitutive relationship of composite materials in different ply regions is established under the principal axis of the material, thus avoiding the distortion of finite element calculation results due to incorrect material orientation settings.

[0047] S4: Establish an analysis step based on the finite element analysis type via the ABAQUS interface. The finite element analysis type includes tension, bending, or tension-bending coupling. The analysis step can be a static analysis step or an explicit dynamic analysis step depending on the actual calculation requirements.

[0048] In this embodiment, taking tensile analysis as an example, a displacement load is applied to one side of the model, and a fixed support constraint or displacement constraint is applied to the other side of the model. To avoid computational instability caused by sudden load changes, the displacement load is applied using a smooth loading method.

[0049] Furthermore, a reference point can be set at the loading end of the model, and the loading end boundary can be coupled to the reference point through coupling constraints, so that the displacement load is uniformly transferred to the loading boundary through the reference point. In this way, the consistency of boundary load application can be improved, and the influence of local boundary effects on the stress analysis results of the delamination region can be reduced.

[0050] S5: Using the ABAQUS interface, mesh the geometric model of the composite material delaminated structure based on the analysis steps, boundary conditions, and load conditions set in step S4.

[0051] The mesh size can be determined based on the single-layer layup thickness, the size of the missing resin region, or user-input parameters. The element type can be either a plane strain element or a plane stress element. For cases requiring focused analysis of stress distribution and delamination risk in the missing resin region, a smaller mesh size can be set based on the size of the missing resin region to improve the calculation accuracy of the missing resin region.

[0052] After mesh generation, a finite element parametric model of the composite material delaminated structure is obtained. By modifying the outer contour dimensions, total number of plies, single-layer ply thickness, delaminated ply sequence, mesh size, and boundary condition parameters, finite element models with different delaminated configurations and under different analysis conditions can be quickly generated.

[0053] like Figure 1 As shown in the figure, this embodiment also presents several layer-dropping design schemes generated based on the aforementioned finite element automatic parametric modeling method. By changing the layer-dropping ply sequence, finite element models of composite layer-dropping structures with different layer-dropping arrangements can be quickly generated. Figure 1 Twelve different layer-dropping design schemes are presented to illustrate that the method of the present invention can be applied to parametric modeling requirements with different numbers of layer drops, different layer dropping positions, and different layer dropping sequences.

[0054] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] The embodiments of the method of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made according to the purpose of the invention. Any parameter changes or calculation simplifications made based on the principle of the technical solution of the present invention, as long as they meet the purpose of the invention and do not deviate from the principle and concept of the finite element automatic parametric modeling method for composite material delaminated structures, shall fall within the protection scope of the present invention.

[0056] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A finite element automatic parametric modeling method for composite material delaminated structures, characterized in that, Includes the following steps: S1: Read the outer contour dimension parameters of the composite material layered structure through the ABAQUS interface, and draw the outer contour of the composite material layered structure model according to the outer contour dimension parameters; S2: Calculate the geometric topological features of the composite material layer-drop structure through the standardized expression of the layer-drop design configuration; based on the geometric topological features and the model outer contour obtained in step S1, use the sketching and segmentation functions of ABAQUS to divide the layup boundaries and layer-drop resin region boundaries layer by layer within the model outer contour to complete the geometric modeling of the composite material layer-drop structure and form the geometric model of the composite material layer-drop structure. S3: Based on the composite material delaminated structure geometric model formed in step S2, identify the layup region and the delaminated resin region through the ABAQUS interface, and assign composite material properties and composite material orientation to the layup region, and assign resin material properties to the delaminated resin region. S4: Through the ABAQUS interface, establish the analysis step according to the finite element analysis type, and set the boundary conditions and load conditions; S5: Using the ABAQUS interface, based on the analysis steps, boundary conditions, and load conditions set in step S4, mesh the geometric model of the composite material delaminated structure, and set the element type and mesh size to obtain the finite element parametric model of the composite material delaminated structure. The composite material is a fiber-reinforced resin-based composite material.

2. The finite element automatic parametric modeling method for composite material delaminated structures according to claim 1, characterized in that, In step S1, the outer contour dimension parameters include the total length of the structural component, the width of the structural component, the thickness of the equal thickness zone on the left side of the layer loss, the thickness of the equal thickness zone on the right side of the layer loss, the length of the left side, the length of the right side, and the length of the layer loss transition zone. In step S1, the outer contour dimensions are stored in the region list in XML or JSON format.

3. The finite element automatic parametric modeling method for composite material delaminated structures according to claim 1, characterized in that, In step S2, the standardized expression of the layer-dropping design configuration includes the total number of plies, the thickness of a single ply, the sequence of layer-dropping ply numbers, and the length of the layer-dropping transition zone. The missing layer ply number sequence is used to characterize the ply location where the missing layer occurs and the order of each missing layer in the missing layer transition zone; In step S2, the standardized expression of the layer-dropping design configuration is stored in a region list in XML or JSON format.

4. The finite element automatic parametric modeling method for composite material delaminated structures according to claim 1, characterized in that, In step S2, the geometric topological features include the ply boundary location, the number of delaminated resin regions, the length of a single delaminated resin region, the thickness of a single delaminated resin region, and the relative position of each delaminated resin region within the delaminated transition zone.

5. The finite element automatic parametric modeling method for composite material delaminated structures according to claim 1, characterized in that, In step S3, the specific process of assigning composite material properties and orientation to the ply region includes: Based on the ply boundaries formed in step S2, establish a set of ply regions; assign fiber-reinforced resin matrix composite material properties to each ply region; determine a local material coordinate system based on the geometric boundaries of each ply region, and arrange the first direction of the local coordinate system of the composite material along the single-layer ply direction, so that the main ply direction is consistent with the fiber direction.

6. The finite element automatic parametric modeling method for composite material delaminated structures according to claim 5, characterized in that, The properties of the fiber-reinforced resin matrix composite material include density, longitudinal elastic modulus, transverse elastic modulus, in-plane shear modulus, interlaminar shear modulus, and Poisson's ratio. The properties of the resin material include density, elastic modulus, and Poisson's ratio.

7. The finite element automatic parametric modeling method for composite material delaminated structures according to claim 1, characterized in that, In step S4, the analysis step is either a static analysis step or an explicit dynamic analysis step; The boundary conditions include: applying a displacement load on one side of the model and applying a fixed support constraint or a displacement constraint on the other side of the model.

8. The finite element automatic parametric modeling method for composite material delaminated structures according to claim 1, characterized in that, In step S5, the element type is either a plane strain element or a plane stress element, and the mesh size is determined based on the single-layer layup thickness, the size of the missing resin region, or user-input parameters.

9. The finite element automatic parametric modeling method for composite material delaminated structures according to claim 1, characterized in that, In step S2, based on the geometric topological features and the model outer contour obtained in step S1, the process of dividing the layup boundaries and the missing resin region boundaries layer by layer within the model outer contour includes the following steps: S2.1: Based on the total number of plies, the thickness of a single ply, the sequence of ply loss numbers, and the length of the ply loss transition zone, calculate the number of resin loss regions, the length of a single resin loss region, and the thickness of a single resin loss region. S2.2: Let the total number of plies be N. Starting from the first ply, take the current ply number as i, and the initial value of i is 1. S2.3: Determine if the current ply number i is less than N. If i is less than N, proceed to step S2.

4. If i is not less than N, then the drawing of the layup boundary and the boundary of the lost resin region is completed; S2.4: Determine whether the current ply number i is less than the smallest ply number in the sequence of dropped ply numbers; if yes, draw the horizontal ply boundary line and set i = i + 1, then return to step S2.3; if no, proceed to step S2.

5. S2.5: Determine whether the current ply number i is between the minimum and maximum ply numbers in the missing ply number sequence; if yes, execute the single-layer resin region drawing algorithm to generate the ply boundary and missing resin region boundary corresponding to the current ply, and set i = i + 1, then return to step S2.3; if no, execute step S2.

6. S2.6: Draw the diagonal ply boundary line and the horizontal ply boundary line corresponding to the current ply, and let i = i + 1, then return to step S2.

3.

10. The finite element automatic parametric modeling method for composite material delaminated structures according to claim 9, characterized in that, In step S2.5, the single-layer resin area drawing algorithm includes the following steps: S2.5.1: Let the total number of resin loss areas be M. Starting from the position of the first resin loss area, take the current position number as j, and the initial value of j is 1. S2.5.2: Determine if the current position number j is greater than M; if j is greater than M, complete the drawing of the single-layer resin area of ​​the current layup; if j is less than or equal to M, proceed to step S2.5.

3. S2.5.3: Determine whether there is a resin loss area in the adjacent position below the current position; If it exists, draw the hypotenuse of the corresponding lost resin region as the boundary of the lost resin region, and let j=j+1, then return to step S2.5.2; if it does not exist, then execute step S2.5.

4. S2.5.4: Determine whether there is a resin loss area in the adjacent position above the current position; if so, draw the long side of the corresponding resin loss area as the boundary of the resin loss area, and let j=j+1, then return to step S2.5.2; if not, proceed to step S2.5.

5. S2.5.5: Draw the diagonal and vertical sides of the resin loss area corresponding to the current position as the boundary of the resin loss area, and let j=j+1, then return to step S2.5.2.

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