Structure optimization method and system of glasses frame special slice for 3D printing

Abstract

This application provides a structural optimization method and system for slicing materials specifically designed for 3D-printed eyeglass frames. The method includes: performing finite element stress analysis and extracting continuous stress field data and principal stress directions; calculating dimensionless stress parameters using the continuous stress field data to divide the model's interior into different stress zones and match them with different unit cell types; adjusting the rotation angle and aspect ratio of the unit cells in real time based on the principal stress directions and stress ratios to generate a stress-adaptive internal lattice structure; performing differential geometry analysis on the surface of the 3D eyeglass frame model to construct a comprehensive curvature threshold function and generate a support structure; searching for optimal structural parameters through Pareto front analysis; and integrating the internal lattice structure, support structure, and structural parameters to generate slicing data and plan the printing path. This application optimizes the load-bearing efficiency of the eyeglass frame structure and improves the specific strength of the material.

Description

Technical Field

[0001] This application relates to the field of 3D printing technology, and more specifically, to a method and system for structural optimization of slabs specifically for 3D printed eyeglass frames. Background Technology

[0002] With the popularization of additive manufacturing technology, personalized custom eyeglasses have become an important application area in the field of 3D printing. They provide users with eyewear products that fit facial features through high-precision molding technology. In the current technical implementation, 3D printed eyeglass frames mostly adopt simple infill patterns or solid structure designs, and are supplemented by standard support generation algorithms for model slicing. These conventional solutions usually do not consider the differences in mechanical distribution inside the model, and the support generation for complex curved surfaces is often based on a single angle threshold judgment.

[0003] However, these solutions have significant drawbacks in practical applications. For example, simple solid or uniformly filled structures lead to excessive material consumption, resulting in heavier frames that fail to meet the lightweight requirements for comfortable wear. Furthermore, the lack of targeted support generation algorithms results in redundant supports at complex curved surfaces, increasing material consumption, making post-processing extremely difficult, and easily damaging the surface quality of the frame. In addition, because existing frames are not optimized for specific conditions such as lateral tension and pressure during wear, they often struggle to achieve an optimal balance between structural strength and wearing comfort.

[0004] Therefore, this application provides a method and system for structural optimization of slabs specifically for 3D printed eyeglass frames, in order to solve one of the aforementioned technical problems. Summary of the Invention

[0005] The purpose of this application is to provide a method and system for structural optimization of slices specifically designed for 3D-printed eyeglass frames, which can solve at least one of the aforementioned technical problems. The specific solution is as follows: According to a specific embodiment of this application, in a first aspect, this application provides a method for structural optimization of a special slice for 3D printed eyeglass frames, comprising: Finite element stress analysis was performed on the 3D model of the eyeglass frame to be processed, extracting continuous stress field data and principal stress directions at specified spatial locations of the model. Dimensionless stress parameters were calculated using the continuous stress field data, and the model's interior was divided into high-stress, medium-stress, and low-stress regions based on these parameters, and matched with body-centered cubic (BCC), face-centered cubic (FCC), and Gyroid unit cells, respectively. Based on the principal stress directions and stress ratios, the rotation angle and aspect ratio of the unit cells were adjusted in real time to generate a stress-adaptive internal lattice structure. This process was then applied to the eyeglass frame. Differential geometry analysis is performed on the surface of the 3D model of the eyeglass frame to determine the principal curvature, Gaussian curvature, and mean curvature, in order to construct a comprehensive curvature threshold function. This function is then used to identify overhanging regions and generate supporting structures. A set of objective functions, including lightweighting, structural strength, stiffness, manufacturing efficiency, and comfort, is established. Through Pareto front analysis, weight vectors are assigned to specific stress conditions in the 3D model of the eyeglass frame to search for optimal structural parameters. Finally, the internal lattice structure, the supporting structure, and the structural parameters are integrated to generate slice data and plan the printing path.

[0006] In one embodiment, calculating the dimensionless stress parameters using the continuous stress field data includes: determining the magnitude of the difference between the von Mises stress and the mean stress at a specified model spatial location, and normalizing the difference between the maximum principal stress and the minimum principal stress in the stress field to obtain the dimensionless stress parameters; wherein, the model internal partitioning is based on the dimensionless stress parameters and adopts the following rules: when When, it is divided into a high-stress region and matched with BCC unit cells; when When, it is divided into a medium stress region and matched with FCC unit cells; when At that time, it was divided into low-stress regions and matched with Gyroid unit cells; among which, Represents dimensionless stress parameters. This represents the threshold value of the first stress parameter. This represents the threshold value for the second stress parameter.

[0007] In one embodiment, during the generation of the internal lattice structure, the method further includes: using an S-shaped logic function with stress gradient modulus and stress gradient threshold as independent variables as a smooth transition function to perform continuous transitions between different cell types; wherein the smooth transition function is provided with a steepness parameter to adjust the continuous switching rate of the cell type.

[0008] In one embodiment, the stress ratio is obtained based on the ratio of the local maximum principal stress to the local minimum principal stress; the aspect ratio of the unit cell is linearly adjusted according to the stress ratio; the rotation angle of the unit cell is calculated based on the components of the stress tensor using an arctangent function, so that the unit cell direction is aligned with the principal stress direction.

[0009] In one embodiment, the comprehensive curvature threshold function is expressed by the following formula: ;in, For the mean curvature, For Gaussian curvature, The gradient of the mean curvature, Let be the gradient of the Gaussian curvature; where, For different weight coefficients, the sum of the weights is 1.

[0010] In one embodiment, identifying the overhanging region includes: extracting the normal vector of the surface of the 3D model of the eyeglass frame; determining the angle between the local surface and the printed horizontal plane based on the normal vector; and identifying the region where the angle exceeds a preset angle as the overhanging region.

[0011] In one embodiment, generating the support structure includes: applying cosine compensation to the comprehensive curvature threshold based on the local printing direction to obtain an effective curvature threshold characterizing the surface forming difficulty; constructing a composite decision function, and determining the overhanging region whose function value exceeds the decision threshold as the support region by coupling the geometric angle features of the overhanging region, the effective curvature threshold, and the estimated local surface roughness; extracting local feature scales within the support region, and calculating the support thickness data at each sampling point within the support region through linear mapping in conjunction with the comprehensive curvature threshold; calculating the gradient distribution of the comprehensive curvature threshold within the support region, and calculating the support spacing data of each region within the support region using an exponential decay function; and associating the support thickness data, the support spacing data, and the geometric boundaries of the support region to generate a support structure containing thickness attributes, density attributes, and spatial topological relationships.

[0012] In one embodiment, the specific stress conditions include at least one of the following: temple lateral tension condition, frame compression condition, combined stress condition, and wearing comfort priority condition; the weight vectors of each specific stress condition are allocated using the following strategy: the weight vector of the temple lateral tension condition is allocated as follows: The weight vector allocation for the comprehensive stress condition is as follows: The weight vector allocation for the frame under pressure conditions is as follows: The weight vector allocation for the wearing comfort priority condition is as follows: .

[0013] In one embodiment, the method further includes: calculating the Euler eigenvalues ​​of the lattice structure to perform a topological consistency check before generating the slice data; and verifying the tangent vector continuity and curvature continuity of the common boundary between adjacent unit cells.

[0014] According to a specific embodiment of this application, in a second aspect, this application provides a structural optimization system for 3D-printed eyeglass frame slices, comprising: an information extraction module for performing finite element stress analysis on the 3D model of the eyeglass frame to be processed, extracting continuous stress field data and principal stress directions at a specified spatial location of the model; a cell allocation module for calculating dimensionless stress parameters using the continuous stress field data, and dividing the interior of the model into high-stress, medium-stress, and low-stress regions based on the dimensionless stress parameters, and matching body-centered cubic (BCC), face-centered cubic (FCC), and Gyroid cells respectively; and a lattice structure generation module for adjusting the rotation angle and longitudinal direction of the cells in real time based on the principal stress directions and stress ratios. The system employs several modules: a horizontal scaling module to generate a stress-adaptive internal lattice structure; a support structure generation module to perform differential geometric analysis on the surface of the 3D model of the eyeglass frame, determining the principal curvature, Gaussian curvature, and mean curvature to construct a comprehensive curvature threshold function, which is then used to identify overhanging regions and generate support structures; a structural parameter search module to establish a set of objective functions including lightweighting, structural strength, stiffness, manufacturing efficiency, and comfort, and to assign weight vectors to specific stress conditions in the 3D model of the eyeglass frame through Pareto front analysis, thereby searching for the optimal structural parameters; and a slice data generation module to integrate the internal lattice structure, the support structure, and the structural parameters to generate slice data and plan the printing path.

[0015] Compared with the prior art, the above-described solutions of this application have at least the following beneficial effects: This application provides a structural optimization method for slices specifically designed for 3D-printed eyeglass frames. It extracts the stress field and principal stress directions through finite element analysis, providing a precise mechanical basis for the crystal lattice layout. Based on dimensionless stress parameters, the application scientifically divides the model into high, medium, and low stress zones and matches them with BCC, FCC, and Gyroid unit cells respectively. This ensures the highest stress zone receives the strongest support and the lowest stress zone is extremely lightweight, significantly reducing weight while maintaining strength. The application adjusts the unit cell rotation angle and aspect ratio in real time according to the principal stress directions, aligning the principal directions of the crystal lattice with the load path, significantly improving stiffness and material utilization. Furthermore, by constructing a comprehensive curvature threshold function through surface differential geometry analysis, this application accurately identifies overhanging regions and intelligently generates supports, reducing the amount of support material required. The post-processing difficulty is significantly reduced. Furthermore, this application establishes a multi-objective function covering lightweighting, strength, stiffness, manufacturing efficiency, and comfort. Combined with Pareto front analysis, weight vectors are assigned for different stress conditions, systematically balancing conflicting performance indicators. Finally, this application integrates lattice, support, and structural parameters to generate slices and printing paths, achieving closed-loop optimization from mechanical analysis to physical forming, resulting in synergistic improvements in lightweighting, structural reliability, manufacturing economy, and wearing comfort. Attached Figure Description

[0016] Figure 1 A flowchart is shown for a structural optimization method for a special slice for 3D printed eyeglass frames; Figure 2 A unit block diagram of a structural optimization system for a 3D-printed eyeglass frame-specific slice according to an embodiment of this application is shown. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The singular forms “a,” “said,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0019] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0020] It should be understood that although the terms first, second, third, etc., may be used in the embodiments of this application, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, first may also be referred to as second without departing from the scope of the embodiments of this application, and similarly, second may also be referred to as first.

[0021] Depending on the context, the words “if” or “suppose” as used here can be interpreted as “when” or “in response to determination” or “in response to detection.” Similarly, depending on the context, the phrases “if determination” or “if detection (of the stated condition or event)” can be interpreted as “when determination” or “in response to determination” or “when detection (of the stated condition or event)” or “in response to detection (of the stated condition or event).”

[0022] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes said element.

[0023] It should be noted that any symbols and / or numbers present in the specification that are not marked in the accompanying drawings are not reference numerals.

[0024] The optional embodiments of this application are described in detail below with reference to the accompanying drawings.

[0025] The embodiments provided in this application are embodiments of a method for structural optimization of slabs specifically for 3D printed eyeglass frames.

[0026] The following is combined with Figure 1 The embodiments of this application will be described in detail.

[0027] Figure 1 A flowchart illustrating a method for structural optimization of slabs specifically designed for 3D-printed eyeglass frames is shown, such as... Figure 1 As shown, the procedure includes steps S101 to S106.

[0028] Step S101: Perform finite element stress analysis on the 3D model of the eyeglass frame to be processed, and extract the continuous stress field data and principal stress directions at the specified spatial location of the model.

[0029] For example, after obtaining the 3D model of the eyeglass frame to be processed, it is imported into the finite element analysis environment. Material properties are set (e.g., nylon 12), and load conditions such as lateral tension of the temples or compression of the frame are applied. The solver then calculates the model in the specified spatial location. Stress tensor at Furthermore, eigenvalue decomposition is performed on the stress tensor to extract eigenvectors as principal stress directions.

[0030] Step S102: Calculate dimensionless stress parameters using continuous stress field data, and divide the model interior into high stress region, medium stress region and low stress region based on the dimensionless stress parameters, and match them with body-centered cubic (BCC) unit cells, face-centered cubic (FCC) unit cells and Gyroid unit cells respectively.

[0031] Among them, dimensionless stress parameters The stress ratio is used to quantify the degree of anisotropy of local stress and is defined as the local maximum principal stress. With minimum principal stress The ratio of .

[0032] In the following embodiments, this application linearly adjusts the aspect ratio of the unit cell in the principal stress direction by the ratio, and uses the principal stress direction to determine the rotation angle of the unit cell, so as to ensure that the lattice pillars are distributed along the load path.

[0033] Step S103: Based on the principal stress direction and stress ratio, adjust the rotation angle and aspect ratio of the unit cell in real time to generate a stress-adaptive internal lattice structure.

[0034] Step S104: Perform differential geometry analysis on the surface of the 3D model of the eyeglass frame to determine the principal curvature, Gaussian curvature and mean curvature, so as to construct a comprehensive curvature threshold function, and use the curvature threshold function to identify the overhanging area and generate the support structure.

[0035] For example, this application solves for the principal curvature by computing the first and second fundamental forms of the surface. Gaussian curvature and mean curvature Among them, the comprehensive curvature threshold function It couples the curvature amplitude and its gradient information to determine the forming risk of surface regions.

[0036] In some specific embodiments, this application identifies areas that meet the determination criteria as overhanging areas and determines the geometric shape of the support structure based on local geometric features.

[0037] Step S105: Establish a set of objective functions including lightweighting, structural strength, stiffness, manufacturing efficiency, and comfort. Through Pareto front analysis, assign weight vectors to specific stress conditions in the 3D model of the eyeglass frame and search for the optimal structural parameters.

[0038] Among them, the lightweight objective corresponds to minimizing weight, structural strength corresponds to minimizing maximum von Mises stress, and comfort corresponds to minimizing contact pressure. This application uses a weighted summation method to construct a multi-objective optimization model, dynamically assigning weights according to specific stress conditions (e.g., temple tension or frame compression), and extracting Pareto non-dominated solutions from the solution space.

[0039] Step S106: Integrate the internal lattice structure, support structure and structural parameters, generate slice data and plan the printing path.

[0040] Based on this, the optimized lattice filler and the frame shell are merged into a complete solid model, the supporting structure geometry is embedded, and it is discretized into a series of two-dimensional layers using slicing software. The motion trajectory of the print head is generated according to the contour filling algorithm, and the processing code that can be directly used in 3D printing equipment is output.

[0041] This application provides a structural optimization method for slices specifically designed for 3D-printed eyeglass frames. Finite element analysis is performed on the 3D model of the eyeglass frame to extract continuous stress field data and principal stress directions, thus obtaining precise mechanical distribution information as the basis for subsequent optimization. Based on this stress data, dimensionless stress parameters are calculated, and the model is scientifically divided into high, medium, and low stress zones. BCC, FCC, and Gyroid unit cells with different mechanical properties are then matched to each zone. This ensures that the high-stress zone receives the strongest isotropic support, the medium-stress zone achieves a balance between strength and weight, and the low-stress zone employs an extremely lightweight, minimally curved surface structure, thereby maximizing weight reduction while ensuring overall structural strength.

[0042] Furthermore, this application adjusts the rotation angle and aspect ratio of the unit cell in real time based on the principal stress direction and stress ratio, ensuring that the principal direction of the internal lattice is perfectly aligned with the load transfer path, significantly improving material utilization efficiency and structural stiffness. Simultaneously, differential geometric analysis is performed on the model surface to construct a comprehensive curvature threshold function and accurately identify overhanging regions to generate support structures, fundamentally solving the problem of redundancy in traditional supports and significantly reducing the amount of support material used and the difficulty of post-processing.

[0043] Building upon this foundation, this application establishes a multi-objective function set encompassing lightweighting, structural strength, stiffness, manufacturing efficiency, and comfort, and introduces Pareto front analysis. Weight vectors are assigned for specific stress conditions to search for optimal structural parameters, achieving a systematic trade-off between conflicting performance indicators. Finally, the aforementioned lattice structure, support structure, and structural parameters are integrated to generate slice data and plan the printing path, enabling a closed-loop optimization of the entire 3D printing process from model analysis to physical forming. This significantly improves the lightweighting, structural reliability, manufacturing economy, and wearing comfort of eyeglass frames.

[0044] In some embodiments, the calculation of dimensionless stress parameters using continuous stress field data includes: determining the modulus of the difference between the von Mises stress and the mean stress at a specified model location, and normalizing the difference between the maximum and minimum principal stresses in the stress field to obtain the dimensionless stress parameters. The calculation formula is as follows: ;in, For von Mises stress, For average stress, These are the maximum and minimum principal stresses.

[0045] The von Mises stress is calculated from the deviator of the stress tensor, and the mean stress is the arithmetic mean of the three principal stresses. The ratio obtained by dividing the absolute value of the difference between the two by the difference between the maximum and minimum principal stresses in the entire field is the dimensionless stress parameter. .

[0046] In this application, the dimensionless stress parameter The value ranges between 0 and 1. The larger the value, the more prominent the anisotropy of the stress state at that location.

[0047] In some embodiments, this application achieves precise construction of the internal structure of eyeglass frames through multi-scale unit cell geometry modeling. For example, this application defines three core unit cell types: body-centered cubic (BCC) unit cell, face-centered cubic (FCC) unit cell, and Gyroid unit cell, and dynamically adjusts the unit cell type and parameters according to the local stress distribution.

[0048] As a specific embodiment, for a body-centered cubic (BCC) unit cell matched in a high-stress region, which has extremely high isotropic strength, this application dynamically adjusts its lattice constant using the following formula. : ;in, Indicates the side length of the unit cell. Represents von Mises stress. and This represents the material constants determined by the material properties. Furthermore, the rotation angle of this unit cell is related to the principal stress direction. Maintain alignment to maximize load-bearing efficiency.

[0049] As a specific embodiment, this application focuses on a face-centered cubic (FCC) unit cell with matched medium stress regions, aiming to balance structural strength and weight. The lattice constant is determined using the following formula. : ; in, Indicates the side length of the unit cell. The average stress represents the local average stress state. and This represents the fitting parameters determined by the material properties. The orientation of this unit cell is set based on the principal directions of the local strain tensor.

[0050] As a specific embodiment, the Gyroid unit cell, which is matched to the low-stress region, exhibits excellent performance in terms of lightweighting as a triple-repeated conjugate minimal surface structure. This application utilizes its isosurface equation... Define its geometric shape: ;in, Represents spatial coordinates, This represents the frequency parameter that controls the cell period, and it is positively correlated with the local stress level. This represents the isosurface constant controlling the volume fraction. By adjusting... and With these values, this application can minimize the amount of material used while ensuring the minimum structural support requirements are met.

[0051] In this application, the internal partitioning of the model is based on dimensionless stress parameters and adopts the following rules: when At that time, it was divided into a high-stress region and matched with BCC unit cells; when At that time, it is divided into a medium stress region and matched with FCC unit cells; when At that time, it was divided into a low-stress region and matched with the Gyroid unit cell.

[0052] in, Represents dimensionless stress parameters. This represents the threshold value of the first stress parameter. This represents the threshold value for the second stress parameter.

[0053] In this application, the first stress parameter threshold and the second stress parameter threshold can be pre-calibrated through material testing or empirical data, with typical values ​​as follows: .

[0054] The determination rules provided in this application enable the three cell types to be precisely deployed in the regions most suitable for them to exert their mechanical advantages, achieving optimal matching between material distribution and stress field at the macroscopic level.

[0055] As a feasible embodiment, in the process of generating the internal lattice structure, the method further includes: using an S-shaped logic function with stress gradient modulus and stress gradient threshold as independent variables as a smooth transition function to perform continuous transition between different cell types.

[0056] Example, smooth transition function The definition is as follows: ; in, For stress gradient modulus, The stress gradient threshold, This is a parameter representing the steepness of the slope.

[0057] The smooth transition function has a range of 0 to 1 and exhibits a smooth S-shaped curve in the transition region. At the cell type boundary, [the function will...] As interpolation coefficients, the geometric features of adjacent unit cells are mixed; for example, the nodal coordinates of BCC and FCC unit cells are mixed according to... Weighted superposition generates a continuously gradational intermediate configuration.

[0058] Among them, steepness parameter Used to adjust the continuous switching rate of unit cell type. The larger the value, the narrower the transition zone and the faster the switching rate; The smaller the value, the wider the transition region and the smoother the cell type transition. This mechanism effectively avoids stress concentration and printing defects caused by abrupt changes in cell type.

[0059] In some embodiments, the stress ratio is obtained based on the ratio of the local maximum principal stress to the local minimum principal stress.

[0060] For example, the formula for linearly adjusting the aspect ratio of a unit cell based on the stress ratio is as follows: ; in, The aspect ratio of the unit cell. Here are the anisotropy coefficients. The maximum and minimum principal stresses are defined. Simultaneously, the cell rotation angle is calculated based on the components of the stress tensor using the arctangent function, aligning the cell orientation with the principal stress directions.

[0061] For example, when the stress ratio is 1, the aspect ratio is 1, and the unit cell is an isotropic cube. As the stress ratio increases, the aspect ratio increases linearly, and the unit cell elongates along the principal stress direction to enhance its load-bearing capacity.

[0062] Among them, rotation angle The calculation is as follows: ; in, For shear stress components, This represents the normal stress component.

[0063] Example, rotation angle This ensures that the local coordinate system of the unit cell is precisely aligned with the principal stress direction, guaranteeing that the lattice framework is oriented along the load transfer path.

[0064] In this application, the combination of aspect ratio adjustment and directional rotation makes the lattice configuration of each micro-region mechanically conjugate with the local principal stress state, which significantly improves the stiffness and strength of the material per unit mass.

[0065] As a specific implementation, the comprehensive curvature threshold function is expressed by the following formula: ;in, For position The average curvature at that point is determined by the principal curvature. , Calculated as ; The curvature is Gaussian, calculated from the principal curvature as follows: , The gradient vector magnitude of the mean curvature reflects the rate of change of curvature. Let be the magnitude of the gradient vector of the Gaussian curvature.

[0066] in, For different weight coefficients, the sum of the weights is 1.

[0067] In the above embodiments, by adjusting the weighting coefficients, different shape features can be judged using the curvature amplitude or curvature change rate. For example, when the frame surface contains a large number of fine ripples, the weighting coefficient can be appropriately increased. , To more sensitively identify local abrupt changes, this function compresses multidimensional curvature information into a single scalar threshold, providing a physically meaningful quantitative benchmark for identifying overhanging regions.

[0068] As a feasible embodiment, identifying the overhanging region includes: extracting the normal vector of the surface of the 3D model of the eyeglass frame, either by the vertex coordinate difference of the triangular facets or by directly reading the normal vector data from the STL file; based on the normal vector, determining the angle between the local surface and the printing horizontal plane, where the angle is defined as the angle between the normal vector and the vertically upward direction (in an example, the normal of the printing platform), with a value range of... to Regions with included angles exceeding a preset angle are identified as overhanging regions. The preset angle is typically set to... to Between, typical value When the included angle is greater than the preset angle, the surface tilts downward and lacks lower support, which is determined to be a suspended area that needs to add a support structure.

[0069] In this embodiment, the inherent geometric properties of the model are used to quickly identify all potentially dangerous areas, providing a set of candidate patches for subsequent refined support generation.

[0070] Furthermore, in subsequent generation steps, this application performs cosine compensation correction on the comprehensive curvature threshold based on the local printing direction to obtain an effective curvature threshold characterizing the difficulty of surface forming.

[0071] Among them, the effective threshold The calculation is as follows: ;in, Indicates position The effective curvature threshold at that point, Indicates position The overall curvature threshold at that point, The parameter represents the control and adjustment intensity. This represents the angle between the local printing direction and the normal vector.

[0072] In this embodiment of the application, based on the above formula correction, the surface with the same curvature value is closer to horizontal and its effective threshold is lower, that is, it is easier to be judged as needing support. This method realizes adaptive correction of the threshold to characterize the molding difficulty under different printing angles.

[0073] Subsequently, this application constructs a composite decision function, which, by coupling the geometric angular features of the overhanging region, the effective curvature threshold, and the estimated local surface roughness, identifies overhanging regions whose function values ​​exceed the decision threshold as support regions. The decision function... The expression is as follows: ; in, Indicates position The composite decision function value at the location, This represents the weighting coefficient, used to control the contribution of each feature to the decision. Indicates the local overhang angle. This represents the function for determining the hanging angle. Indicates the overall curvature threshold. This represents the surface roughness estimate, which can be obtained from the local curvature change rate or texture analysis. This function is used to comprehensively determine whether a support structure should be generated at the corresponding location.

[0074] Subsequently, this application extracts local feature scales within the support region and, combined with a comprehensive curvature threshold, calculates the support thickness data at each sampling point within the support region through linear mapping. The support thickness... The calculation is as follows: ;in, Indicates position Support thickness at the location, and These represent the minimum support thickness and the maximum support thickness, respectively. Indicates the overall curvature threshold. This represents the maximum combined curvature threshold. Represents the scale of local features. The model, which represents the reference feature scale, ensures that the support size is dynamically adjusted according to local geometric features, providing robust support for large, high-curvature regions.

[0075] This application further calculates the gradient distribution of the comprehensive curvature threshold within the support region, and uses an exponential decay function to calculate the support spacing data for each region within the support region. Support Spacing The calculation is as follows: ;in, Indicates position Support spacing at the location, and These represent the minimum and maximum support spacing, respectively. The parameter representing the rate of change of the control spacing. The modulus representing the overall curvature gradient is used to reflect the degree of curvature change. In areas of drastic curvature change, the support spacing is small and the distribution is dense, while in areas of gentle curvature change, the spacing is large and the distribution is sparse.

[0076] In this embodiment, the formula optimizes the distribution density of the support based on the printed feature size and the rate of change of curvature.

[0077] Based on the above embodiments, this application associates support thickness data, support spacing data and the geometric boundaries of the support area to generate a support structure that includes thickness attributes, density attributes and spatial topological relationships.

[0078] In some further embodiments, the support structure may be tree-shaped, block-shaped, or lattice-shaped, with its roots connected to the printing platform or the cured layer, and its top in contact with the overhanging surface of the model. The contact point shape is optimized to be conical or serrated to reduce the contact area and facilitate removal in post-processing.

[0079] Based on the above multi-level control strategy, the amount of support material used is reduced compared to traditional uniform distribution support. to Furthermore, the impact of support residue on surface quality is significantly reduced.

[0080] In one specific embodiment, by establishing a set of objective functions including lightweighting, structural strength, stiffness, manufacturing efficiency, and comfort, a multi-dimensional quantitative evaluation benchmark is provided for optimizing the structure of eyeglass frames.

[0081] As a specific implementation, the sub-objectives in the objective function set are defined as follows: Example, lightweight goal To achieve weight minimization, it is obtained by integrating the density field over the frame volume domain, and the calculation formula is as follows: ; in, Represent design variables The total weight below This represents the density field at a spatial location. Represents the frame volume domain. Representing a volumetric element, this target-guided algorithm aims to minimize material accumulation while satisfying mechanical performance requirements.

[0082] Example, structural strength target To achieve stress minimization, the maximum von Mises stress across the entire field under the load condition is extracted. The calculation formula is as follows: ;in, Represent design variables The maximum von Mises stress, Indicates von Mises stress, Represents a position vector. This represents the external load vector, which ensures the structural reliability of the frame under stress.

[0083] Example, stiffness target To achieve displacement minimization, it is obtained by calculating the maximum deformation of the frame under load, and the calculation formula is as follows: .in, Represent design variables The maximum displacement below, This represents the displacement vector at the location. This represents the magnitude of the displacement vector. This objective is used to maintain the geometric stability of the eyeglass frame and prevent deformation when worn.

[0084] Example, manufacturing efficiency target To achieve support minimization, it is obtained by calculating the ratio of the support structure volume to the total model volume, using the following formula: .in, Represent design variables The supporting volume ratio below, Indicates the volume of the supporting structure. This represents the total volume. This target is directly related to printing time and post-processing costs.

[0085] Example, comfort goals To minimize contact pressure, it is obtained by integrating the pressure distribution in the contact area between the frame and the face, and the calculation formula is as follows: ;in, Represent design variables

[0086] Total contact pressure below, Indicates the surface that comes into contact with the face. Indicates the contact pressure at the location. This represents a micro-element of area, and this goal ensures optimized pressure sensitivity during prolonged wear.

[0087] During the optimization process, a series of constraints must be met to ensure the feasibility of the design.

[0088] As one possible implementation, the constraints include geometric constraints, material constraints, and manufacturing constraints.

[0089] For example, geometric constraints define the size range of the eyeglass frames. Local thickness range and curvature range .

[0090] in, This indicates the overall size variation of the eyeglass frame. and These represent the preset minimum and maximum size thresholds, used to ensure that the frames meet ergonomic and basic shape requirements. Indicates position Local thickness at that location and These represent the minimum and maximum local thicknesses, respectively, used to prevent the structure from breaking due to being too thin or becoming too heavy due to being too thick. Indicates position Surface curvature at the location; and These represent the minimum and maximum allowable curvature ranges, respectively, used to ensure the flatness of the eyeglass surface and the feasibility of its design.

[0091] For example, material constraints require that the local maximum von Mises stress be less than the ratio of the material's yield strength to the safety factor, i.e. .

[0092] in, Indicates position The local maximum von Mises stress at that point is used to assess the overall stress level experienced by the material at that point. This indicates the yield strength of the selected printing material (e.g., Nylon 12), which is the ultimate stress of the material before it undergoes permanent deformation. The safety factor is a preset constant greater than 1, used to increase the structural safety redundancy in the design. The overall value represents the allowable stress limit permitted by the design scheme.

[0093] For example, manufacturing constraints limit the actual printing angle from exceeding the maximum permissible printing angle. And the support volume ratio must meet the requirements. .

[0094] in, This represents the actual printing angle (or overhang angle) formed between the normal to the model surface and the printing direction. This indicates the highest printing angle (critical angle) that the printing device can achieve without additional support, and is usually set at... to between, This represents the total volume of the supporting structure generated in the model. This represents the total volume of the eyeglass frame model. This indicates the preset upper limit coefficient for the support volume ratio. This inequality is used to limit the proportion of support material used to ensure manufacturing efficiency and reduce post-processing difficulties.

[0095] As a specific implementation, by incorporating the aforementioned objective functions into the Pareto front analysis process, the algorithm can find the optimal balance between conflicting objectives based on the specific needs under different load conditions. For example, it can increase the weight of structural strength in motion scenarios and increase the weight of comfort in everyday wear scenarios, thereby generating optimized structural parameters in a targeted manner.

[0096] In this application, a weight vector is used. To balance the five objectives of lightweighting, strength, stiffness, efficiency, and comfort, a general expression for the weight vector is shown below: ; in, These represent the respective weights of the five objectives of balancing lightweighting, strength, stiffness, efficiency, and comfort.

[0097] In some embodiments, the specific stress conditions include at least one of the following: temple lateral tension condition, frame compression condition, and wearing comfort priority condition.

[0098] Based on this, the weight vectors for each specific stress condition are allocated using the following strategy: The weight vector allocation for the lateral tension condition of the temples is as follows: ; This configuration emphasizes strength and stiffness, ensuring that the temples have sufficient bending and tensile strength when stretched laterally.

[0099] The weight vector allocation for the frame under compression is as follows: ; This allocation significantly increases the weight of lightweighting, achieving substantial weight reduction at the front of the frame while ensuring compressive strength.

[0100] The weight vector allocation for the comprehensive stress condition is as follows:

[0101] The weight vector allocation for the wearing comfort priority condition is as follows:

[0102] The weight of the comfort target was increased to 0.4, so that the optimization process prioritizes reducing the contact pressure between the nose pad and the end of the temple, while also taking into account the level of lightweighting.

[0103] To further verify the technical effectiveness of the method in practical applications and clarify the optimization strategies under different application scenarios, this application compares and verifies multiple weight allocation schemes obtained by Pareto front analysis by combining finite element simulation and 3D printing physical experiments, and on this basis, forms weight optimization suggestions for typical application scenarios.

[0104] In one specific implementation, a standard three-dimensional model of a wearable eyeglass frame was selected as the test object. A set of objective functions was established, encompassing lightweighting, structural strength, stiffness, manufacturing efficiency, and comfort. The lightweighting objective was represented by the total frame volume; the structural strength objective by the maximum von Mises stress; the stiffness objective by the maximum displacement; the manufacturing efficiency objective by the proportion of support volume; and the comfort objective by the integral of the contact pressure between the nose pads and temples. Furthermore, a weighted summation method was used to transform the multi-objective problem into a single-objective optimization problem. Pareto front analysis was used to search for non-dominated solutions in the solution space. Different weight vectors were assigned to the temple lateral tension condition, the frame compression condition, and the comfort-priority condition. The optimal design point under each weight set was then selected for numerical simulation and physical printing.

[0105] The experimental material used was Nylon 12, and the printing equipment was an industrial-grade fused deposition modeling 3D printer. The layer thickness was set to [missing information]. Printing speed Five different weighted frame samples were prepared. Finite element analysis and physical loading tests were performed on each sample. The test results are shown in Table 1 below.

[0106]

[0107] For example, as shown in Table 1, the weight vector corresponding to the lateral tension condition of the temple is: Under this condition, structural strength and stiffness are prioritized, and the maximum stress under lateral tension is... Maximum displacement This achieves a 32.5% weight reduction; the weight vector corresponding to the frame under pressure is... By increasing the weight reduction factor, a weight reduction of 41.8% was achieved, while the maximum stress and displacement were still controlled within [the specified limits]. and Excellent level; balanced weighting is adopted for comprehensive stress conditions. All indicators showed a balanced performance, with a decrease in weight. Support volume ratio Contact pressure The weight vector corresponding to the wearing comfort priority condition is: The weight of comfort targets was significantly increased, and the contact pressure was reduced after optimization. At the same time, the weight loss still reached This fully demonstrates the effectiveness of multi-objective trade-offs.

[0108] Furthermore, the method of this application was compared with existing traditional methods (examples of traditional schemes combining uniform filling and empirical fabric support), and the comparison results are shown in Table 2 below.

[0109]

[0110] As shown in Table 2, the stress-adaptive lattice filling and curvature threshold driven support generation technology of this application can reduce the weight of the eyeglass frame. to Compared to traditional methods to The weight loss rate increased by approximately to The volume ratio of the supporting material is from to Descending to to The improvement rate reached to Printing time shortened to Surface roughness is from Down to The improvement reached While reducing weight, the structural strength is improved compared to the traditional benchmark. to The above data fully demonstrates the synergistic optimization capabilities of this application in terms of lightweighting, manufacturing efficiency, surface quality, and structural reliability.

[0111] In the embodiments of this application, the weight vectors are all obtained by combining Pareto front analysis with multi-condition simulation and physical test calibration, which can quickly guide the optimization algorithm to converge to a satisfactory solution with balanced performance under the corresponding conditions.

[0112] In some further embodiments, this application also provides specific weight optimization suggestions for different practical application scenarios, as follows.

[0113] The weight vector assignment for sports glasses applications is as follows: ; This scenario emphasizes high strength and manufacturing efficiency, with the expected outcome being both high strength and high manufacturing efficiency. The structural strength weight is increased to 0.4 to ensure the frame remains intact under severe impact and lateral tension. Manufacturing efficiency is moderately retained, and the support volume ratio can be controlled within a certain range. It achieves a balance between high strength, moderate weight, and efficient printing.

[0114] The weight vector assignment for everyday glasses wearers is as follows: ; This scenario considers all performance indicators in a balanced way to achieve optimal overall performance and wearing comfort. Under this balanced configuration, the weights of each objective are similar, and the optimization results are shown in Table 1 as a "comprehensive stress" condition, resulting in a weight reduction of approximately [missing information]. Contact pressure approximately It has the most comprehensive performance.

[0115] The weight vector assignment for high-end fashion eyewear is as follows: ; This scenario prioritizes extreme lightweighting and aesthetics, aiming to achieve a balance between weight reduction and comfort. The proposed solution sets the weight reduction weight at 0.4 and the comfort weight at 0.3, sacrificing a small amount of strength for lower weight and better contact pressure distribution. Simulations and experiments show that weight reduction can reach [amount missing]. The contact pressure can be reduced to the above. Furthermore, due to the significant reduction in the support structure, the surface roughness and smoothness of the frames are significantly improved.

[0116] The above weight allocation strategies have been verified in multiple independent experiments. Designers can directly call the corresponding weight vector according to the specific product positioning, or make fine adjustments based on the Pareto front solution set, thereby significantly shortening the R&D iteration cycle of specialized eyeglass frame products.

[0117] As one specific embodiment, the method further includes: calculating the Euler eigenvalues ​​of the lattice structure to perform a topological consistency check before generating the slice data.

[0118] For a three-dimensional lattice network composed of BCC, FCC, and Gyroid unit cells, the number of vertices is counted. Number of sides Number of faces And the number of connected components, calculate the Euler characteristic number. Calculate Euler characteristic number .

[0119] Example, Euler characteristic number The calculation is as follows: ; in, Euler eigenvalues ​​are used to characterize the topological uniformity of three-dimensional crystal structures. This represents the total number of vertices of all unit cell frameworks and surface grids in the crystal lattice structure. This represents the total number of edges connecting vertices in a crystal lattice structure. This represents the total number of faces enclosed by edges in a crystal lattice structure. This represents the number of connected components in the crystal lattice structure.

[0120] Among them, the Euler eigenvalue is used to characterize the topological consistency of a three-dimensional lattice structure. This application determines the topological consistency of the lattice structure by... Whether it equals 2 is used to identify whether the structure has non-manifold edges, isolated vertices, or hole defects.

[0121] For example, for a closed, undamaged solid structure, It should equal 2. If the calculation result deviates from 2, it indicates that there are non-manifold edges, isolated vertices, or voids in the lattice network. This application will automatically backtrack to the lattice generation step for local repair or refilling.

[0122] In the above formula, the number of connected components is usually 1, which means that the entire lens frame lattice network is a complete connected entity.

[0123] As a specific embodiment, the method further includes: verifying the tangent vector continuity and curvature continuity of the common boundary between adjacent unit cells.

[0124] At the unit cell splicing interface, the first and second derivatives along the boundary of the two curved surfaces are calculated respectively, and it is determined whether their directions are consistent with the modulus within the tolerance range. If the continuity condition is not met, the boundary region is smoothly reconstructed by fifth-order polynomial interpolation to ensure that the unit cell transition achieves first-order geometric continuity. Even second-order geometric continuity This avoids printing step patterns or stress concentration caused by abrupt changes in normal or curvature discontinuity.

[0125] This application also provides system embodiments that follow the above embodiments, for implementing the method steps of the above embodiments. The interpretation of the same names is the same as that of the above embodiments, and they have the same technical effects as those of the above embodiments, so they will not be repeated here.

[0126] like Figure 2 As shown, this application provides a structural optimization system 200 for 3D-printed eyeglass frame slices, comprising: The information extraction module 201 is used to perform finite element stress analysis on the 3D model of the eyeglass frame to be processed, and to extract the continuous stress field data and principal stress directions at the specified spatial location of the model.

[0127] The cell allocation module 202 calculates dimensionless stress parameters using continuous stress field data, and divides the interior of the model into high-stress, medium-stress, and low-stress regions based on the dimensionless stress parameters, matching body-centered cubic (BCC), face-centered cubic (FCC), and Gyroid cells respectively.

[0128] The lattice structure generation module 203 is used to generate a stress-adaptive internal lattice structure by adjusting the rotation angle and aspect ratio of the unit cell in real time based on the principal stress direction and stress ratio.

[0129] The support structure generation module 204 is used to perform differential geometric analysis on the surface of the 3D model of the eyeglass frame to determine the principal curvature, Gaussian curvature and mean curvature, so as to construct a comprehensive curvature threshold function, and use the curvature threshold function to identify the overhanging area and generate the support structure.

[0130] The structural parameter search module 205 is used to establish a set of objective functions including lightweight, structural strength, stiffness, manufacturing efficiency and comfort. Through Pareto front analysis, weight vectors are assigned to specific stress conditions in the 3D model of the eyeglass frame to search for the optimal structural parameters.

[0131] The slice data generation module 206 is used to integrate the internal lattice structure, support structure and structural parameters, generate slice data and plan the printing path.

[0132] Regarding the system in the above embodiments, the specific manner in which each module performs its operations has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0133] Although the operations are described in a specific order in the accompanying drawings, this should not be construed as requiring these operations to be performed in the specific order or serial order shown, or requiring all of the operations shown to obtain the desired result. In certain environments, multitasking and parallel processing may be advantageous.

[0134] The methods and systems of this application can be implemented using standard programming techniques, utilizing rule-based logic or other logic to implement various method steps. It should also be noted that the terms "system" and "module" as used herein and in the claims are intended to include implementations using one or more lines of software code and / or hardware implementations and / or devices for receiving input.

[0135] Any step, operation, or procedure described herein may be performed or implemented using one or more hardware or software modules, either alone or in combination with other devices. In one embodiment, the software module is implemented using a computer program product comprising a computer-readable medium containing computer program code, which is executable by a computer processor to perform any or all of the described steps, operations, or procedures.

[0136] The foregoing description of implementations of this application has been provided for illustrative and descriptive purposes. The foregoing description is not exhaustive and is not intended to limit this application to the exact forms disclosed. Various modifications and variations may exist in accordance with the foregoing teachings, or may arise from practice of this application. These embodiments were chosen and described to illustrate the principles of this application and its practical application, enabling those skilled in the art to utilize this application in various implementations and modifications to suit the specific purpose of the concept.

[0137] Regarding the system in the above embodiments, the specific manner in which each module performs its operations has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0138] It can be further understood that, unless otherwise specified, "connection" includes both direct connections where no other components exist between the two parties and indirect connections where other components exist between them.

[0139] It is further understood that although the operations are described in a specific order in the accompanying drawings in the embodiments of this application, this should not be construed as requiring these operations to be performed in the specific order or serial order shown, or requiring all the operations shown to be performed to obtain the desired result. In certain environments, multitasking and parallel processing may be advantageous.

[0140] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the field of this application that are not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0141] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

[0142] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for structural optimization of slices specifically for 3D printed eyeglass frames, characterized in that, include: Finite element stress analysis was performed on the 3D model of the eyeglass frame to be processed, and continuous stress field data and principal stress directions were extracted at a specified spatial location of the model. Dimensionless stress parameters are calculated using the continuous stress field data, and the model interior is divided into high-stress, medium-stress, and low-stress regions based on the dimensionless stress parameters, which are matched with body-centered cubic (BCC), face-centered cubic (FCC), and Gyroid cells, respectively. Based on the principal stress direction and stress ratio, the rotation angle and aspect ratio of the unit cell are adjusted in real time to generate a stress-adaptive internal lattice structure. Differential geometry analysis is performed on the surface of the 3D model of the eyeglass frame to determine the principal curvature, Gaussian curvature and mean curvature, so as to construct a comprehensive curvature threshold function. The curvature threshold function is used to identify the overhanging area and generate the support structure. A set of objective functions including lightweighting, structural strength, stiffness, manufacturing efficiency, and comfort is established. Through Pareto front analysis, weight vectors are assigned to specific stress conditions in the 3D model of the eyeglass frame, and the optimal structural parameters are searched for. By integrating the internal lattice structure, the support structure, and the structural parameters, slice data is generated and a printing path is planned.

2. The method according to claim 1, characterized in that, The calculation of dimensionless stress parameters using the continuous stress field data includes: Determine the magnitude of the difference between the von Mises stress and the mean stress at a specified model location, and normalize it using the difference between the maximum principal stress and the minimum principal stress in the stress field to obtain the dimensionless stress parameter. The internal partitioning of the model is based on the dimensionless stress parameters and adopts the following rules: when At that time, it was divided into a high-stress region and matched with BCC unit cells; when At that time, it is divided into a medium stress region and matched with FCC unit cells; when At that time, it was divided into a low-stress region and matched with Gyroid unit cells; in, Represents dimensionless stress parameters. This represents the threshold value of the first stress parameter. This represents the threshold value for the second stress parameter.

3. The method according to claim 1, characterized in that, In the process of generating the internal lattice structure, the method further includes: A sigmoid logic function with stress gradient modulus and stress gradient threshold as independent variables is used as a smooth transition function to achieve continuous transition between different cell types. The smooth transition function is provided with a steepness parameter to adjust the continuous switching rate of the cell type.

4. The method according to claim 1, characterized in that, The stress ratio is obtained based on the ratio of the local maximum principal stress to the local minimum principal stress; The aspect ratio of the unit cell is linearly adjusted according to the stress ratio value; The rotation angle of the unit cell is calculated based on the components of the stress tensor using the arctangent function, so that the unit cell direction is aligned with the principal stress direction.

5. The method according to claim 1, characterized in that, The comprehensive curvature threshold function is expressed by the following formula: ； in, For the mean curvature, For Gaussian curvature, The gradient of the mean curvature, The gradient of the Gaussian curvature; in, For different weight coefficients, the sum of the weights is 1.

6. The method according to claim 5, characterized in that, The identified overhanging area includes: Extract the normal vectors from the surface of the 3D model of the eyeglass frame; Based on the normal vector, determine the angle between the local surface and the printed horizontal plane; The region where the included angle exceeds a preset angle is identified as the hanging region.

7. The method according to claim 6, characterized in that, The generated support structure includes: Based on the local printing direction, the comprehensive curvature threshold is corrected by cosine compensation to obtain an effective curvature threshold that characterizes the difficulty of surface forming. A composite decision function is constructed, which, by coupling the geometric angle features of the overhanging region, the effective curvature threshold, and the estimated local surface roughness, determines the overhanging region whose function value exceeds the decision threshold as the support region. Local feature scales within the support region are extracted and combined with the comprehensive curvature threshold to calculate the support thickness data at each sampling point within the support region through linear mapping. Calculate the gradient distribution of the comprehensive curvature threshold within the support region, and use the exponential decay function to calculate the support spacing data of each region within the support region; The support thickness data, the support spacing data, and the geometric boundaries of the support area are correlated to generate a support structure that includes thickness attributes, density attributes, and spatial topological relationships.

8. The method according to claim 1, characterized in that, The specific stress conditions include at least one of the following: temple lateral tension condition, frame compression condition, comprehensive stress condition, and condition prioritizing wearing comfort. The weight vectors for each specific stress condition are assigned using the following strategy: The weight vector allocation for the temple lateral tension condition is as follows: ; The weight vector allocation for the comprehensive stress condition is as follows: ; The weight vector allocation for the pressure condition of the mirror frame is as follows: ; The weight vector allocation for the wearing comfort priority condition is as follows: .

9. The method according to claim 1, characterized in that, The method further includes: Before generating the slice data, the Euler eigenvalues ​​of the lattice structure are calculated to perform a topological consistency check; The continuity of tangential vectors and curvature at the common boundary of adjacent unit cells is verified.

10. A structural optimization system for slabs specifically designed for 3D-printed eyeglass frames, characterized in that, include: The information extraction module is used to perform finite element stress analysis on the 3D model of the eyeglass frame to be processed, and to extract continuous stress field data and principal stress directions at a specified spatial location of the model. The cell allocation module calculates dimensionless stress parameters using the continuous stress field data, and divides the interior of the model into high-stress, medium-stress, and low-stress regions based on the dimensionless stress parameters, matching body-centered cubic (BCC), face-centered cubic (FCC), and Gyroid cells respectively. The lattice structure generation module is used to adjust the rotation angle and aspect ratio of the unit cell in real time based on the principal stress direction and stress ratio to generate a stress-adaptive internal lattice structure. The support structure generation module is used to perform differential geometric analysis on the surface of the 3D model of the eyeglass frame to determine the principal curvature, Gaussian curvature and mean curvature, so as to construct a comprehensive curvature threshold function, and use the curvature threshold function to identify the overhang area and generate the support structure. The structural parameter search module is used to establish a set of objective functions including lightweighting, structural strength, stiffness, manufacturing efficiency, and comfort. Through Pareto front analysis, weight vectors are assigned to specific stress conditions in the 3D model of the eyeglass frame to search for the optimal structural parameters. The slice data generation module is used to integrate the internal lattice structure, the support structure, and the structural parameters to generate slice data and plan the printing path.

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