A laser structure design method based on topology optimization

Abstract

The application belongs to the field of laser structure design, and specifically discloses a laser structure design method based on topological optimization, which comprises the following steps: firstly, grid topological optimization is performed; secondly, topological optimization is performed on the laser base by using the relationship between the mechanical properties and the density threshold of the grid after topological optimization; and finally, the grid after topological optimization is filled to realize a variable-density structure and fully exert the performance of variable-density topological optimization; while reducing the weight of the laser, the application ensures that the stiffness of the laser is maximized, and can ensure that the structure of the laser base after reconstruction according to the variable-density distribution after topological optimization by the variable-density method, thereby avoiding the problem of large difference in mechanical properties after optimization and reconstruction, fully exerting the role of variable-density topological optimization, and ensuring that the structure after reconstruction and the structure after topological optimization have considerable mechanical properties.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser structure design, and particularly relates to a laser structure design method based on topology optimization. BACKGROUND

[0002] Laser in the aerospace working environment to face a variety of dynamics, static environment, in space operation structure vibration may cause laser detuning and life decline, serious will lead to the fatigue and damage of the structure, and the large static load of space environment is easy to lead to the fracture of the structure. Nowadays, aerospace equipment is developing towards light weight and miniaturization. Therefore, in the design of the laser structure, the weight and various static and dynamic indicators should be coordinated, and the low-order modal frequency and structural stiffness should be ensured as much as possible when reducing the weight. Kegen Olorwski et al. first used selective laser melting (SLM) printing technology to successfully process a space-grade laser with metal materials, and he combined the topology optimization technology, fully exerted the characteristics of 3D printing that can print any complex structure, and ensured that the first-order modal frequency exceeded 1KHZ on the basis of greatly reducing the weight of the laser.

[0003] In the design requirements of space-grade laser, the weight of the laser is required to be as light as possible, and the stiffness and modal frequency of the laser structure are required to meet the requirements to ensure that the dynamic and static characteristics of the laser are not affected. The existing commonly used topology optimization method adopts the variable density method, which is to find the best distribution of the element density to reduce the weight of the structure as much as possible while ensuring the mechanical properties of the structure. When the optimization is completed, the normalized density is used to represent the importance of each entity, but in fact it is impossible to really change the density of a mean material to fill the optimized grid area according to the relative density value. Major commercial software often uses the density threshold method to directly remove the materials below the appropriate density threshold, and retains the materials above the density threshold. In this way, the relative density above the density threshold is 1, and the density below the threshold is 0. In fact, the materials below the density threshold also need to contribute to the mechanical properties, and the materials above the density threshold do not need such excellent mechanical properties, which will lead to a large difference between the mechanical properties of the reconstructed mechanism after topology optimization and the mechanical properties before topology optimization. SUMMARY

[0004] In order to solve the above technical problems, the present application provides a laser structure design method based on topology optimization.

[0005] In order to achieve the above purpose, the present application is implemented according to the following technical scheme:

[0006] A laser structure design method based on topology optimization, comprising the following steps:

[0007] S100, create a three-dimensional model of the laser using three-dimensional modeling software, and perform finite element meshing on the base of the laser;

[0008] S200, model the grid entity according to the size of the finite element mesh of the base of the laser;

[0009] S300, topological optimization of the grid entity, get the mechanical properties and density threshold of the grid entity;

[0010] S400, in the result of the grid topology optimization, set the equal interval density threshold to obtain the grid structure under the density threshold by sampling and re-modeling the removed material, and restore it to a solid grid structure, which is called the optimized grid entity below;

[0011] S500, assuming that the optimized grid entity is isotropic, and performing finite element analysis on the sample or using a reasonable evaluation function to evaluate the equivalent elastic modulus of the optimized grid entity;

[0012] S600, use polynomial fitting to optimize the relationship between the density threshold and the elastic modulus of the grid entity;

[0013] S700, replace the relationship between the elastic modulus and the density in the form of the penalty function in the Simp model with the polynomial function relationship between the density threshold and the elastic modulus, and perform topology optimization on the base of the laser in Hypermesh; get the density threshold distribution of the laser base grid;

[0014] S800, according to the density threshold distribution of the base structure of the laser, use the density threshold as the material removal condition of the solid grid and reconstruct the grid entity structure to replace the corresponding density threshold grid in the laser base to reconstruct the laser structure;

[0015] S900, after the replacement is completed, the optimization of the entire laser base is completed, and it is handed over to the metal 3D printer for processing and manufacturing.

[0016] Further, the step S300 specifically comprises:

[0017] According to the finite element analysis, statistics of various stress forms of the grid in various working conditions, and extract the maximum stress corresponding to various forms of stress, the above stress forms and the corresponding maximum stress are set as one of the various working conditions of the grid and the weighted average is set, the part to be connected with other grids after grid optimization is set as a non-design area, and a certain symmetrical constraint is applied to make the grid entity as isotropic as possible. The topological optimization formula of the grid entity is as follows:

[0018] ;

[0019] Minc(x)= ( ) ;

[0020] St ;

[0021] In the formula: This represents the design variable, namely the relative density of the element, and its value ranges from (0, 1). Indicates the minimum relative density; x A vector representing design variables; N Indicates the number of design variables; c Indicates overall softness; Ee This represents the unit elastic modulus, also known as the cell equivalent elastic modulus. U Represents the total displacement matrix; F Represents the overall force matrix; K Represents the overall stiffness matrix; k e Represents the element stiffness matrix; u e Represents the element displacement matrix; v x , v 0 Represents the solid volume and the total volume of the design domain; f Indicates volume fraction;

[0022] Based on the SIMP method, the relationship between elastic modulus and density is obtained: = ;

[0023] In the formula: E e Indicates the first e The elastic modulus of each unit; Indicates the first e The relative density of each unit; E 0 This represents the initial elastic modulus of the material.

[0024] In step S200, the preparation of the geometric model is as follows: First, the geometric model of the laser base is designed using CAD software such as AutoCAD or SolidWorks.

[0025] Ensure the accuracy of the geometric model, including all dimensions, shapes, holes, and chamfer features;

[0026] Importing the geometric model: Import the designed geometric model into finite element analysis software such as ANSYS or ABAQUS;

[0027] During the import process, ensure that the model's dimensions and units match the actual physical dimensions;

[0028] Determine mesh size: Based on the structural features of the laser base, material properties, and the required analytical accuracy, determine the appropriate mesh size;

[0029] Considering the characteristics of the heat-affected zone in the laser brazing process, the mesh size needs to be finer in the heat-affected zone, and can be appropriately increased in areas away from the heat source;

[0030] Meshing: Use the meshing tool of the finite element software to divide the base into equal-volume-shaped meshes according to the predetermined mesh size;

[0031] Ensure that after meshing, the volume and shape of each mesh element remain consistent, which is crucial for ensuring the accuracy of the analysis results;

[0032] Check and correct the mesh: Check the divided mesh to ensure that there are no mesh quality problems such as excessive distortion, excessive element deformation;

[0033] If the mesh does not meet the requirements, use the software tools to correct it until all meshes meet the analysis requirements;

[0034] Set material properties and boundary conditions: After meshing, set the physical and mechanical properties of the laser base material;

[0035] According to the actual application scenario, set the boundary conditions such as fixed support, load, temperature boundary.

[0036] Load and solve: According to the process parameters of laser brazing, load the heat source and related load;

[0037] Run the finite element solver to calculate and analyze the model;

[0038] Result analysis and verification: Analyze the temperature, stress, strain and other results obtained by calculation to evaluate the thermal deformation of the base during laser brazing;

[0039] Verify the model to ensure the reliability and accuracy of the analysis results.

[0040] In S400, topology optimization result analysis: First, complete the topology optimization analysis to obtain the optimized density distribution results;

[0041] Check the optimized mesh structure to determine the standard for setting the density threshold;

[0042] Determine the density threshold: According to the optimization results and design requirements, select an appropriate equal-interval density threshold, which is used to distinguish the boundary between material retention and removal;

[0043] The equal-spacing density threshold means that in the optimized density distribution, a range of density values ​​will be selected as the condition for retaining the material, and mesh cells below this threshold will be considered invalid or removed;

[0044] Mesh sampling: The optimized mesh structure is sampled, and mesh cells with a density higher than the determined equal-spacing density threshold are retained.

[0045] Mesh cells below a certain threshold are removed; these cells will be removed from the structure.

[0046] Remodeling: Reconstruct the mesh structure based on the retained mesh cells;

[0047] Use the reconstruction function in finite element analysis software or CAD tools to convert mesh elements with a density higher than the threshold into a solid model;

[0048] During the remodeling process, it may be necessary to manually adjust or use the software's automated tools to optimize the mesh to ensure that the new solid model meets the design requirements.

[0049] Handling Boundaries and Connections: In the new solid model, address boundary and connection issues arising from mesh cell culling;

[0050] Depending on the needs, transition units may need to be added or smoothing techniques may need to be used to optimize the geometry of the model;

[0051] Validate the new solid model: After completing the remodeling, validate the new solid model to ensure that it meets the design requirements and that the structural characteristics after topology optimization are retained;

[0052] The mechanical and thermodynamic properties of a new structure can be verified through finite element analysis.

[0053] Step S500 in the finite element analysis includes the following steps:

[0054] S21: Model Building: Building a finite element model based on the optimized mesh entity, which includes specifying material properties, boundary conditions, and load conditions;

[0055] S22: Mesh generation: After determining the mesh entity, perform mesh generation. Mesh generation needs to ensure sufficient mesh density in the region of interest to ensure computational accuracy.

[0056] S23: Apply loads and boundary conditions: Define loads and boundary conditions according to the actual situation. These conditions will directly affect the calculated stress and strain distribution.

[0057] S24 Solution: Run the finite element analysis, solve the equations, and obtain the distribution of nodal displacements, stresses, and strains.

[0058] Preferably, in step S600, the following steps are further included:

[0059] S31: Data collection First, enough data points representing the grid entities and their corresponding elastic modulus under different density thresholds need to be collected;

[0060] S32: These data can be obtained through experimental measurement, literature research or finite element simulation;

[0061] S33: Data preprocessing Before fitting, data preprocessing includes: removing outliers: checking and removing abnormal data points caused by experimental errors or input errors;

[0062] Data normalization: if the scale of the data is very different, normalization needs to be performed;

[0063] S34: Selecting the order of the polynomial Selecting an appropriate order of the polynomial;

[0064] S35: Polynomial fitting Using mathematical tools such as least squares, the data is fitted with a polynomial;

[0065] S36: Fitting result evaluation After fitting, the quality of the model needs to be evaluated.

[0066] Compared with the prior art, the grid topology is optimized first, and then the relationship between the mechanical properties after the grid topology optimization and the density threshold is used to perform topology optimization on the laser base, and then the grid after the topology optimization is filled to realize the variable density structure to fully exert the performance of the variable density topology optimization; The present application can reduce the weight of the laser while ensuring the maximum stiffness of the laser, so as to ensure that the structure of the laser base after the reconstruction of the variable density method topology optimization is distributed according to the variable density, avoiding the problem of large difference in mechanical properties after optimization and reconstruction, fully exerting the role of variable density topology optimization, and ensuring that the structure after topology optimization and the structure after topology optimization have considerable mechanical properties. BRIEF DESCRIPTION OF DRAWINGS

[0067] Figure 1 is a flowchart of the present application;

[0068] Figure 2 is a flowchart of the present application;

[0069] Figure 3 is a flowchart of the present application;

[0070] Figure 4 is a flowchart of the present application;

[0071] Figure 5 is a flowchart of the present application. DETAILED DESCRIPTION

[0072] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application is further described in detail below with examples. The specific examples described herein are only used to explain the present application and do not limit the present application.

[0073] As shown in Figures 1-5 , the present embodiment exemplarily shows a laser structure design method based on topology optimization, which is described in detail below.

[0074] S100, first, according to the optical path design of the laser, the geometric constraint requirements of the laser and the installation requirements of the laser, a three-dimensional modeling software such as solidworks is used to create a three-dimensional model of the laser;

[0075] The laser three-dimensional model created in the solidworks in this embodiment; the optical seat of the laser is taken out in the Hypermesh software, and the finite element grid division of the base of the laser is carried out, the grid is in the form of hexahedron, and the grid size is consistent, and the finite element analysis of the laser under various working conditions is carried out;

[0076] S200, after the finite element grid division of the base of the laser, the grid entity modeling of equal volume and equal shape is carried out according to the size of the finite element grid of the base of the laser, and the grid entity modeling is constructed;

[0077] S300, next, the grid entity needs to be topology optimized to obtain the mechanical property and density threshold value relationship of the grid entity; specifically, according to the finite element analysis, the various stress forms of the grid in various working conditions are counted, and the maximum stress corresponding to various forms of stress is extracted, the above stress forms and the corresponding maximum stress are set as one of the various working conditions of the grid and the weighted average is set, the part to be connected with other grids after the grid optimization is set as a non-design area, and a certain symmetrical constraint is applied to make the grid entity as isotropic as possible, and the topology optimization formula of the grid entity is as follows:

[0078] ;

[0079] Minc(x)= ( ) ;

[0080] S.t. ;

[0081] In the formula: represents the design variable, i.e. the relative density of the unit, whose value range is (0, 1); represents the minimum relative density; x represents the vector of the design variable; N represents the number of design variables;c represents the overall compliance; Ee represents the unit elastic modulus, i.e. the unit equivalent elastic modulus; U represents the overall displacement matrix; F represents the overall force matrix; K represents the overall stiffness matrix; k e represents the unit stiffness matrix; u e represents the unit displacement matrix; v x , v 0 represents the overall volume of the solid and the design domain; f represents the volume fraction;

[0082] According to the SIMP method, the relationship between the elastic modulus and the density is obtained: = ;

[0083] In the formula: E e represents the elastic modulus of the e th unit; represents the relative density of the e th unit; E 0 represents the initial elastic modulus of the material.

[0084] S400, then, in the result of the grid topology optimization, an equal-interval density threshold is set to sample the grid structure under the density threshold obtained by removing the material, and the grid structure is remodeled and restored to a solid grid structure, hereinafter referred to as the optimized grid solid;

[0085] S500, assuming that the optimized grid solid is isotropic, the sample thereof is subjected to finite element analysis or is evaluated by using a reasonable evaluation function to obtain the equivalent elastic modulus of the optimized grid solid;

[0086] S600, then, the relationship between the density threshold and the elastic modulus of the optimized grid solid is fitted by using a polynomial;

[0087] S700, then, the relationship between the elastic modulus and the density in the form of the penalty function in the Simp model is replaced by the polynomial function relationship between the density threshold and the elastic modulus, and the base of the laser is subjected to topology optimization in Hypermesh; the density threshold distribution of the laser base grid is obtained;

[0088] S800, according to the density threshold distribution of the base structure of the laser, the density threshold is taken as the material removal condition of the solid grid, and the structure of the grid solid is reconstructed to replace the grid corresponding to the density threshold in the laser base to reconstruct the laser structure;

[0089] S900、Finally, the entire laser base optimization is completed after the replacement is completed, and it is handed over to the metal 3D printer for processing and manufacturing.

[0090] In the S200 step, the preparation of the geometric model: first, use CAD software such as AutoCAD, SolidWorks to design the geometric model of the laser base;

[0091] Ensure the accuracy of the geometric model, including all dimensions, shapes, holes, chamfer features;

[0092] Import the geometric model: import the designed geometric model into the finite element analysis software such as ANSYS, ABAQUS;

[0093] Ensure that the size and unit of the model are consistent with the actual physical size during import;

[0094] Determine the mesh size: according to the structural characteristics of the laser base, material properties and the required analysis accuracy, determine the appropriate mesh size;

[0095] Considering the characteristics of the heat-affected zone in the laser brazing process, the mesh size needs to be finer in the heat-affected zone, and can be appropriately increased in the area away from the heat source;

[0096] Meshing: use the meshing tool of the finite element software to perform equal-volume shape meshing on the base according to the predetermined mesh size;

[0097] Ensure that after meshing, the volume and shape of each mesh element remain consistent, which is crucial for ensuring the accuracy of the analysis results;

[0098] Check and correct the mesh: check the mesh after division to ensure that there are no mesh quality problems such as excessive distortion, excessive element deformation;

[0099] If the mesh does not meet the requirements, use the software tools to correct it until all meshes meet the analysis requirements;

[0100] Set material properties and boundary conditions: after meshing is completed, set the physical and mechanical properties of the laser base material;

[0101] According to the actual application scenario, set the boundary conditions such as fixed support, load force, temperature boundary.

[0102] Load and solve: according to the process parameters of laser brazing, load the heat source and related load;

[0103] Run the finite element solver to perform calculation and analysis on the model;

[0104] Result analysis and verification: Analyze the calculated temperature, stress, strain, etc. results to evaluate the thermal deformation of the base during laser brazing process.

[0105] Verify the model to ensure the reliability and accuracy of the analysis results.

[0106] In S400, topology optimization result analysis: First, complete the topology optimization analysis to get the optimized density distribution results;

[0107] Check the optimized mesh structure to determine the criteria for setting the density threshold;

[0108] Determine the density threshold: According to the optimization results and design requirements, select an appropriate equidistant density threshold, which is used to distinguish the boundary between material retention and removal;

[0109] Equidistant density threshold means that in the optimized density distribution, a range of density values will be selected as the condition for retaining materials, and grid elements below this threshold will be considered invalid or removed;

[0110] Grid sampling: Sample the optimized mesh structure according to the determined equidistant density threshold, and retain grid elements with density higher than the threshold;

[0111] Remove grid elements below the threshold, which will be removed from the structure;

[0112] Re-modeling: Rebuild the mesh structure based on the retained grid elements;

[0113] Use the reconstruction function in finite element analysis software or CAD tools to convert grid elements with density higher than the threshold to solid models;

[0114] During the re-modeling process, manual adjustment or automatic tools may be needed to optimize the mesh to ensure that the new solid model meets the design requirements;

[0115] Handle boundaries and connections: In the new solid model, handle the boundary and connection problems caused by the removal of grid elements;

[0116] If necessary, transition elements may need to be added or smoothing techniques used to optimize the geometry of the model;

[0117] Verify the new solid model: After completing the re-modeling, verify the new solid model to ensure it meets the design requirements and the structural characteristics after topology optimization are retained;

[0118] The performance of the new structure in terms of mechanics and thermodynamics can be verified through finite element analysis.

[0119] The step S500 includes the following steps in the finite element analysis:

[0120] S21: Model building: build the finite element model based on the optimized mesh entity, which includes specifying material properties, boundary conditions, and load conditions;

[0121] S22: Meshing: after determining the mesh entity, meshing is performed to ensure sufficient grid density in the area of interest to ensure calculation accuracy;

[0122] S23: Apply load and boundary conditions: define the load and boundary conditions according to the actual situation, which will directly affect the calculated stress and strain distribution;

[0123] S24: Solve: run the finite element analysis, solve the equation, and get the distribution of node displacement, stress, and strain physical quantities.

[0124] In this embodiment, the following steps are also included in step S600:

[0125] S31: Data collection First, sufficient data points need to be collected, which represent the mesh entity and its corresponding elastic modulus at different density thresholds;

[0126] S32: These data can be obtained through experimental measurement, literature research or finite element simulation;

[0127] S33: Data preprocessing Before fitting, data preprocessing includes: removing outliers: check and remove abnormal data points caused by experimental errors or input errors;

[0128] Data normalization: if the scale of the data is very different, normalization needs to be performed;

[0129] S34: Select the order of the polynomial Select an appropriate order of the polynomial;

[0130] S35: Polynomial fitting Use mathematical tools such as least squares to perform polynomial fitting on the data;

[0131] S36: Evaluate the fitting result After fitting, the quality of the model needs to be evaluated.

[0132] Through the above design, while reducing the weight of the laser, the stiffness of the laser is maximized, which can ensure that the structure of the laser base after reconstruction according to the variable density distribution after variable density topology optimization, avoiding the problem of large difference in mechanical properties after optimization and reconstruction, fully playing the role of variable density topology optimization.

[0133] The technical solutions of the present application are not limited to the above specific embodiments, and any technical variations made according to the technical solutions of the present application fall within the protection scope of the present application.

Claims

1. A laser structure design method based on topology optimization, characterized in that, Includes the following steps: S100. Use 3D modeling software to create a 3D model of the laser and perform finite element mesh generation on the laser base; S200. Model a mesh entity of equal volume and shape according to the size of the finite element mesh of the laser base; S300. Perform topology optimization on the mesh entity to obtain the relationship between the mechanical properties of the mesh entity and the density threshold. S400. In the results of mesh topology optimization, set an equal-spacing density threshold to sample the mesh structure obtained under the density threshold after material removal, and remodel it to restore it to a solid mesh structure. S500. Assuming the optimized mesh entity is isotropic, the equivalent elastic modulus of the optimized mesh entity is obtained by performing finite element analysis on its samples or by using a reasonable evaluation function. S600. The relationship between the density threshold and elastic modulus of the mesh entity after optimization by polynomial fitting. S700. Replace the relationship between elastic modulus and density in the penalty function form in the Simp model with a polynomial function relationship between density threshold and elastic modulus, and perform topology optimization on the laser base in Hypermesh; obtain the density threshold distribution of the laser base mesh. S800. Based on the density threshold distribution of the laser base structure, the density threshold is used as the material condition for eliminating solid mesh and the structure of the mesh entity is reconstructed to replace the mesh with the corresponding density threshold in the laser base to reconstruct the laser structure. After the S900 replacement is completed, the entire laser base is optimized and handed over to a metal 3D printer for processing and manufacturing. In S400, topology optimization result analysis: First, complete the topology optimization analysis to obtain the optimized density distribution results; Examine the optimized mesh structure to determine the criteria for setting the density threshold. Determine the density threshold: Based on the optimization results and design requirements, select an appropriate spacing density threshold. This threshold is used to distinguish the boundary between material retention and rejection. The spacing density threshold means that in the optimized density distribution, a range of density values ​​will be selected as the condition for retaining the material, and mesh cells below this threshold will be considered invalid or removed; Mesh sampling: The optimized mesh structure is sampled, and mesh cells with a density higher than the determined spacing density threshold are retained. Mesh cells below a certain threshold are removed; these cells will be removed from the structure. Remodeling: Reconstruct the mesh structure based on the retained mesh cells; In S400, topology optimization result analysis: First, complete the topology optimization analysis to obtain the optimized density distribution results; Examine the optimized mesh structure to determine the criteria for setting the density threshold. Determine the density threshold: Based on the optimization results and design requirements, select an appropriate equidistant density threshold. This threshold is used to distinguish the boundary between material retention and rejection. The equal-spacing density threshold means that in the optimized density distribution, a range of density values ​​will be selected as the condition for retaining the material, and mesh cells below this threshold will be considered invalid or removed; Mesh sampling: The optimized mesh structure is sampled, and mesh cells with a density higher than the determined equal-spacing density threshold are retained. Mesh cells below a certain threshold are removed; these cells will be removed from the structure. Remodeling: Reconstruct the mesh structure based on the retained mesh cells.

2. The laser structure design method based on topology optimization according to claim 1, characterized in that, Step S300 specifically includes: Based on finite element analysis, various stress forms of the mesh under multiple working conditions are statistically analyzed, and the corresponding maximum stresses for each stress form are extracted. These stress forms and corresponding maximum stresses are then used as one of the various working conditions of the mesh, and a weighted average is applied. The parts of the mesh to be connected with other meshes after optimization are set as non-design regions, and certain symmetry constraints are applied to ensure that the mesh entities maintain isotropy as much as possible. The topology optimization formula for the mesh entities is as follows: ； In the formula: This represents the design variable, namely the relative density of the element, and its value ranges from (0, 1). Indicates the minimum relative density; x A vector representing design variables; N Indicates the number of design variables; c Indicates overall softness; E e This represents the unit elastic modulus, also known as the cell equivalent elastic modulus. U Represents the total displacement matrix; F Represents the overall force matrix; K Represents the overall stiffness matrix; k e Represents the element stiffness matrix; u e Represents the element displacement matrix; v x , v 0 Represents the solid volume and the total volume of the design domain; f This indicates the volume fraction.

3. The laser structure design method based on topology optimization according to claim 1, characterized in that, Based on the SIMP method, the relationship between elastic modulus and density is obtained: = ; In the formula: E e Indicates the first e The elastic modulus of each unit; Indicates the first e The relative density of each unit; E 0 This represents the initial elastic modulus of the material.

4. The laser structure design method based on topology optimization according to claim 1, characterized in that, The S200 procedure also includes the following steps: S41: Preparation of geometric model: First, use CAD software AutoCAD and SolidWorks to design the geometric model of the laser base; S42: Ensure the accuracy of the geometric model, including all dimensions, shapes, holes, and chamfer features; S43: Import Geometric Model: Import the designed geometric model into the finite element analysis software ANSYS or ABAQUS; S44: During the import process, ensure that the model's dimensions and units are consistent with the actual physical dimensions; S45: Determine the mesh size: Based on the structural characteristics, material properties, and required analytical accuracy of the laser base, determine the appropriate mesh size; S46: Considering the characteristics of the heat-affected zone during laser brazing, the mesh size needs to be finer in the heat-affected zone, while it can be appropriately increased in areas far from the heat source; S47: Perform mesh generation: Use the mesh generation tool of the finite element software to divide the base into equal volume and shape meshes according to the predetermined mesh size; S48: Ensure that the volume and shape of each mesh cell remain consistent after mesh generation, which is crucial for ensuring the accuracy of the analysis results; S49: Check and correct the mesh: Check the generated mesh to ensure that there are no mesh quality problems: excessive distortion, excessive element deformation; S50: If a non-compliant mesh is found, use the tools in the software to correct it until all meshes meet the analysis requirements; S51: Set material properties and boundary conditions: After meshing, set the physical and mechanical properties of the laser base material; S52: Set boundary conditions according to the actual application scenario: fixed support, loading force, and temperature boundary. S53: Loading and Solving: Apply heat sources and related loads according to the laser brazing process parameters; S54: Run the finite element solver to perform calculations and analysis on the model; S55: Results Analysis and Verification: Analyze the calculated temperature, stress, and strain results to evaluate the thermal deformation of the base during laser brazing; S56: Validate the model to ensure the reliability and accuracy of the analysis results.

5. The laser structure design method based on topology optimization according to claim 1, characterized in that, The analysis of topology optimization results in S400 also includes the following steps: S1: First, complete the topology optimization analysis to obtain the optimized density distribution results; S2: Check the optimized mesh structure and determine the criteria for setting the density threshold; S3: Determine the density threshold: Based on the optimization results and design requirements, select an appropriate equidistant density threshold. This threshold is used to distinguish the boundary between material retention and rejection. S4: Equal spacing density threshold means that in the optimized density distribution, a range of density values ​​will be selected as the condition for retaining the material, and mesh cells below this threshold will be considered invalid or removed; S5: Mesh sampling: Sample the optimized mesh structure and retain mesh cells with a density higher than the determined equal-spacing density threshold. S6: Eliminate grid cells below the threshold; these cells will be removed from the structure. S7: Remodeling: Reconstruct the mesh structure based on the retained mesh cells; S8: Use the reconstruction function in finite element analysis software or CAD tools to convert mesh elements with a density higher than the threshold into a solid model; S9: During the remodeling process, it is necessary to manually adjust or use the software's automatic tools to optimize the mesh to ensure that the new solid model meets the design requirements; S10: Handling Boundaries and Connections: In the new solid model, handle boundary and connection issues arising from mesh cell culling; S11: Add transition units or use smoothing techniques to optimize the geometry of the model as needed; S12: Verify the new entity model: After completing the remodeling, verify the new entity model to ensure that it meets the design requirements and that the structural characteristics after topology optimization are retained; S13: Verify the mechanical and thermodynamic properties of the new structure through finite element analysis.

6. The laser structure design method based on topology optimization according to claim 1, characterized in that, Step S500 in the finite element analysis includes the following steps: S21: Model Building: Building a finite element model based on the optimized mesh entity, which includes specifying material properties, boundary conditions, and load conditions; S22: Mesh generation: After determining the mesh entity, perform mesh generation. Mesh generation needs to ensure sufficient mesh density in the region of interest to ensure computational accuracy. S23: Apply loads and boundary conditions: Define loads and boundary conditions according to the actual situation. These conditions will directly affect the calculated stress and strain distribution. S24: Solution: Run the finite element analysis, solve the equations, and obtain the distribution of nodal displacements, stresses, and strains.

7. The laser structure design method based on topology optimization according to claim 1, characterized in that, Step S600 also includes the following steps: S31: Data Collection First, it is necessary to collect enough data points, which represent the mesh entities under different density thresholds and their corresponding elastic moduli; S32: These data can be obtained through experimental measurements, literature reviews, or finite element simulations; S33: Data preprocessing Before fitting, data preprocessing includes: removing outliers: checking and removing outlier data points caused by experimental errors or input errors; Data normalization: If the data varies greatly in size, normalization is required. S34: Select the polynomial order. Choose an appropriate polynomial order. S35: Polynomial fitting uses the least squares mathematical tool to perform polynomial fitting on the data. S36: Evaluation of Fitting Results After the fitting is completed, it is necessary to evaluate the quality of the model.

Images