A lattice structure design method and system based on shape and load

Abstract

The present invention belongs to the field of aeroengines and relates to lattice structure design technology. It provides a shape- and load-based lattice structure design method and system. The method comprises: generating a single-cell initial model for each lattice design area on a part; topologically optimizing the single-cell initial model using a multi-objective optimization function based on the part's load results to obtain an optimized single-cell model; reconstructing each optimized single-cell model using a surface fitting method to obtain a lattice unit cell geometric model; and optimizing the dimensional parameters of each lattice unit cell geometric model based on the part's design strength to obtain a final unit cell geometric model. The method of the present invention can quickly and accurately provide optimization results for target parts, providing guidance for lattice structure design and application, and can quickly obtain a lattice structure that meets constraint conditions and is manufacturable.

Description

Technical Field

[0001] The present invention belongs to the field of aero-engines, relates to a lattice structure design technology, and in particular to a shape- and load-based lattice structure design method and system. Background Art

[0002] Lattice materials are a type of porous material. Porous media are a widely occurring structural form in nature. Inspired by natural structures, artificial porous materials have made significant progress. With the advancement of additive manufacturing (AM) and material preparation technologies, the fabrication of lattice structures has become relatively easy, and they are widely used in fields such as aerospace and tissue engineering.

[0003] Porous materials can be divided into two categories based on their microstructural geometry: foams and lattice materials. Because lattice materials and structures offer a vastly adjustable design space, variable microstructures and porosities can be engineered to achieve a variety of excellent multifunctional properties. Currently, lattice materials with numerous morphologies have been designed, including three-dimensional truss lattices, three-periodic minimal surface lattices, phase change structure lattices, and negative Poisson's ratio lattices. By designing lattice topologies, numerous properties unattainable with solid materials have been achieved, including integrated multifunctional features such as "insulation-load-bearing" and "load-bearing-stealth," significantly improving material utilization.

[0004] In addition, traditional lattice design methods are usually only used to design simple cubic unit cell models. However, as people's requirements for structural integration and lightweighting are increasing, for structures such as rotationally periodically symmetrical structures, if traditional lattice design methods are used to directly fill them, a large number of "broken lattices" will be generated, thus affecting the overall performance of the structure.

[0005] Therefore, designing a lattice structure design method with greater adaptability and simpler calculation is of great significance to the design and development of lattice structures. Summary of the Invention

[0006] In order to solve the technical problem that the traditional lattice design method affects the overall performance of the structure, the present invention discloses a lattice structure design method based on shape and load, which includes the following steps:

[0007] S1. Obtaining a single-cell initial model of a lattice design region on the part based on the structural characteristics of the part and the load results, wherein the lattice design region has at least one;

[0008] S2. Based on the load results, topology optimization is performed on each of the single-cell initial models under multiple working conditions using the established multi-objective optimization function to obtain an optimized single-cell model;

[0009] S3. Reconstruct each optimized unit cell model using a surface fitting method to obtain a lattice unit cell geometric model, optimize the size parameters of each lattice unit cell geometric model according to the design strength of the part, and obtain the final unit cell geometric model.

[0010] Furthermore, in the above step S1, obtaining a single-cell initial model of the lattice design area on the part according to the structural characteristics of the part and the load results includes:

[0011] S11, performing load analysis on the part to obtain load results, obtaining a lattice design area of the part based on the mechanical load and temperature load in the load results, and extracting the load type and load value borne by each lattice design area;

[0012] S12. Performing structural analysis on the part to obtain structural features, and simplifying each of the lattice design regions according to the structural features to obtain a simple geometric structure with a regular shape;

[0013] S13. Divide each of the simple geometric structures according to the load type to obtain an initial unit cell model of each lattice design area.

[0014] Furthermore, in the above step S2, according to the load results, the established multi-objective optimization function is used to perform topology optimization on each of the single-cell initial models under multiple working conditions to obtain an optimized single-cell model, including:

[0015] S21. Using the artificial pseudo-density of the material in the single-cell initial model as a design variable, deformation, stress, and design domain volume ratio as constraints, and compliance and thermal compliance as design goals, construct a multi-objective optimization function for the part under multiple working conditions;

[0016] S22, obtaining the number of single cell initial models in each of the lattice design areas, and extracting the load type and corresponding load value of the lattice design area;

[0017] S23. Allocate the load value corresponding to the load type to the single-cell initial model according to the number of models, and perform topology optimization on the single-cell initial model using the multi-objective optimization function to obtain an optimized single-cell model.

[0018] Furthermore, in the above step S21, the expression of the multi-objective optimization function is:

[0019] ;

[0020] ;

[0021] in, q is the number of design conditions, kis the number of design targets under a certain working condition, represents the weight of the i-th design objective under the m-th working condition, C mi represents the i-th design goal under the m-th working condition, is the design domain volume ratio, is the upper limit of the body ratio, p is an artificial pseudo-density, R It represents the unbalanced force generated during the iterative analysis of the structural geometric nonlinear finite element, u is the structural displacement, u0 is the initial displacement, σ is the structural stress, σ0 is the initial stress of the structure; Minimize is to find the minimum value of the function, st is a constraint condition.

[0022] Furthermore, in the above step S23, allocating the load value corresponding to the load type to the single cell initial model according to the number of models includes:

[0023] S231, determining the load type, and when the load type includes a mechanical load, uniformly distributing a load value corresponding to the mechanical load to the single cell initial model;

[0024] S231. When the load type includes a temperature load, assign a load value corresponding to the temperature load to the single-cell initial model.

[0025] In an improved embodiment of the above-mentioned shape-and-load-based lattice structure design method, the method further includes:

[0026] S4. Evaluate each of the single-cell models.

[0027] Furthermore, in the above step S4, each of the single cell models is evaluated, including:

[0028] S41. Under various working conditions, performing a performance evaluation on the single cell model using a finite element method;

[0029] S42. Evaluating the feasibility of additive manufacturing of the single-cell model;

[0030] S43. When both the performance evaluation result and the feasibility evaluation result meet the design requirements, the lattice structure design is completed; when either the performance evaluation result or the feasibility evaluation result does not meet the design requirements, the single-cell initial model is topologically optimized again according to the multi-objective optimization function.

[0031] An embodiment of the present invention further provides a shape and load-based lattice structure design system, which includes a single-cell initial model design module, a topology optimization module, and a model parameter optimization module.

[0032] The single-cell initial model design module is used to obtain a single-cell initial model of a lattice design area on the part according to the structural characteristics and load results of the part, and the lattice design area is at least one;

[0033] The topology optimization module is used to perform topology optimization on each of the single-cell initial models under multiple working conditions using an established multi-objective optimization function according to the load results to obtain an optimized single-cell model;

[0034] The model parameter optimization module is used to reconstruct each optimized unit cell model using a surface fitting method to obtain a lattice unit cell geometric model, and optimize the size parameters of each lattice unit cell geometric model according to the part design strength to obtain the final unit cell geometric model.

[0035] Furthermore, the system also includes a performance evaluation module, a feasibility evaluation module and a judgment module.

[0036] The performance evaluation module is used to evaluate the performance of the single cell model using the finite element method under various working conditions;

[0037] The feasibility assessment module is used to perform additive manufacturing feasibility assessment on the single-cell model;

[0038] The judgment module is used to complete the lattice structure design when the performance evaluation results and the feasibility evaluation simultaneously meet the design requirements; when any one of the performance evaluation results and the feasibility evaluation does not meet the design requirements, the single-cell initial model is re-topologically optimized according to the multi-objective optimization function.

[0039] Compared with the prior art, the at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects:

[0040] 1. The lattice structure design method of the present invention can simplify and split complex configuration parts into parts composed of simple geometric configurations, greatly simplifying the complexity of the model during calculation.

[0041] 2. The lattice structure design method of the present invention can optimize the target component under multiple load conditions (such as mechanical load and temperature load). The load is partitioned and loaded on the segmented unit cell initial model to optimize the structure of the unit cell initial model. After reconstruction, the lattice configuration is obtained by periodic arrangement, which shortens the design cycle of the lattice configuration.

[0042] 3. The lattice structure designed by the present invention can significantly reduce the weight of parts while ensuring strength and rigidity, and can achieve the goal of reducing weight by more than 40% compared with general solid components.

[0043] 4. The lattice structure design method of the present invention greatly reduces the difficulty of lattice filling design for multi-load complex configuration parts, and plays a certain reference and driving role in the design of complex configuration lattice filling. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0045] Figure 1 A flowchart of a shape- and load-based lattice structure design method disclosed in an embodiment of the present invention;

[0046] Figure 2 The operating process of the shape and load-based lattice structure design method disclosed in an embodiment of the present invention;

[0047] Figure 3 This is a flow chart of designing a lattice structure for a cylindrical rotating body structure disclosed in an embodiment of the present invention;

[0048] Figure 4 Schematic diagram of applying boundary conditions (loads) to the lattice initial models of region I and region II respectively according to an embodiment of the present invention;

[0049] Figure 5 A topologically optimized single cell model in region I and region II of the cylindrical rotating body structure disclosed in an embodiment of the present invention;

[0050] Figure 6 The single cell model reconstruction results after topology optimization in regions I and II of the cylindrical rotating body structure disclosed in the embodiment of the present invention are shown;

[0051] Figure 7 This is an architecture diagram of a shape- and load-based lattice structure design system disclosed in an embodiment of the present invention;

[0052] Among them, 701 is a single-cell initial model design module; 702 is a topology optimization module; 703 is a model parameter optimization module; 704 is a performance evaluation module; 705 is a feasibility evaluation module; and 706 is a judgment module. DETAILED DESCRIPTION

[0053] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0054] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the features of the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0055] The embodiment of the present invention discloses a lattice structure design method based on shape and load, see Figure 1 and Figure 2 As shown, the method includes the following steps:

[0056] S1. Obtaining a single-cell initial model of a lattice design region on the part based on the structural characteristics of the part and the load results, wherein the lattice design region has at least one;

[0057] S2. Based on the load results, topology optimization is performed on each of the single-cell initial models under multiple working conditions using the established multi-objective optimization function to obtain an optimized single-cell model;

[0058] S3. Reconstruct each optimized unit cell model using a surface fitting method to obtain a lattice unit cell geometric model, optimize the size parameters of each lattice unit cell geometric model according to the design strength of the part, and obtain the final unit cell geometric model.

[0059] Furthermore, in the above step S1, obtaining a single-cell initial model of the lattice design area on the part according to the structural characteristics of the part and the load results includes:

[0060] S11. Perform a load analysis on the part to obtain load results. Based on the mechanical load and temperature load in the load results, determine the lattice design area of the part, and extract the load type and load value borne by each lattice design area. Specifically, when determining the lattice design area on the part, if a certain area on the part does not bear a load or the load it bears is lower than a set value, it is ignored and no lattice design is performed.

[0061] S12. Structural analysis is performed on the part to obtain structural features. Based on the structural features, each of the lattice design regions is simplified to obtain a simple geometric structure with a regular shape. When simplifying the lattice design region, inconspicuous features in the lattice design region, such as surface reinforcement ribs, flanges, and holes, may be simplified and removed.

[0062] S13. Divide each of the simple geometric structures according to the load type to obtain a unit cell initial model of each of the lattice design areas, where the unit cell initial model is a three-dimensional solid model of a solid structure.

[0063] Furthermore, in the above step S2, according to the load results, the established multi-objective optimization function is used to perform topology optimization on each of the single-cell initial models under multiple working conditions to obtain an optimized single-cell model, including:

[0064] S21. Using the artificial pseudo-density of the material in the single-cell initial model as a design variable, deformation, stress, and design domain volume ratio as constraints, and compliance and thermal compliance as design goals, construct a multi-objective optimization function for the part under multiple working conditions;

[0065] S22, obtaining the number of single cell initial models in each of the lattice design areas, and extracting the load type and corresponding load value of the lattice design area;

[0066] S23. Allocate the load value corresponding to the load type to the single-cell initial model according to the number of models, and perform topology optimization on the single-cell initial model using the multi-objective optimization function to obtain an optimized single-cell model.

[0067] Furthermore, in the above step S21, the expression of the multi-objective optimization function is:

[0068] ;

[0069] ;

[0070] in, q is the number of design conditions, k is the number of design targets under a certain working condition, represents the weight of the i-th design objective under the m-th working condition, C mi represents the i-th design goal under the m-th working condition, is the design domain volume ratio, is the upper limit of the body ratio, p is an artificial pseudo-density, R It represents the unbalanced force generated during the iterative analysis of the structural geometric nonlinear finite element, u is the structural displacement, u0 is the initial displacement, σ is the structural stress, σ0 is the initial stress of the structure; Minimize is to find the minimum value of the function, st is a constraint condition.

[0071] Furthermore, in the above step S23, allocating the load value corresponding to the load type to the single cell initial model according to the number of models includes:

[0072] S231, determining the load type, and when the load type includes a mechanical load, uniformly distributing the load value corresponding to the mechanical load (i.e., the total mechanical load magnitude in the lattice design area) to the single cell initial model;

[0073] S231. When the load type includes a temperature load, assign a load value corresponding to the temperature load to the single-cell initial model.

[0074] Furthermore, in the above step S3, a surface fitting method is used to reconstruct each optimized unit cell model to obtain a lattice unit cell geometric model, and the size parameters of each lattice unit cell geometric model are optimized according to the design strength of the part. The specific method is:

[0075] The surface fitting method is used to reconstruct each optimized unit cell model to make the load-bearing skeleton in the unit cell uniform, smooth, and continuous, and obtain the lattice unit cell geometric model. The following formula is used to optimize the size of the lattice unit cell geometric model according to the design strength of the part:

[0076] ;

[0077] ;

[0078] ;

[0079] in, x is the design variable, i.e. the critical size of the unit cell model, To optimize the objective function, k is the number of design targets under a certain working condition, represents the weight of the i-th design goal, C i represents the i-th design goal, x min and x max are the maximum and minimum thresholds of the design variables, R It represents the unbalanced force generated during the iterative finite element analysis of the structural geometric nonlinearity. is the design domain volume ratio, is the upper limit of the volume ratio, u is the structural displacement, u0 is the initial displacement, σ is the structural stress, and σ0 is the initial stress of the structure. By solving the above formula, the final unit cell geometric model can be obtained.

[0080] In an improved embodiment of the above-mentioned shape-and-load-based lattice structure design method, the method further includes:

[0081] S4. Evaluate each of the single-cell models.

[0082] Furthermore, in the above step S4, see Figure 2 As shown, each of the single cell models was evaluated, including:

[0083] S41. Under each working condition, the performance of the single-cell model is evaluated by the finite element method. The performance evaluation method can be: the strength, stiffness, and thermal conductivity of the lattice filling area formed by the single-cell model are evaluated by finite element analysis. If any of the strength reserve, deformation, thermal insulation / heat transfer, etc. under each working condition does not meet the design requirements, the topology optimization design and model reconstruction are re-performed.

[0084] S42. Evaluate the feasibility of additive manufacturing of the single-cell model. The feasibility evaluation method may be: prepare the reconstructed model using an additive manufacturing process. If it cannot be achieved, it is necessary to re-carry out topology optimization design and model reconstruction.

[0085] S43. When both the performance evaluation result and the feasibility evaluation result meet the design requirements, the lattice structure design is completed; when either the performance evaluation result or the feasibility evaluation result does not meet the design requirements, the single-cell initial model is topologically optimized again according to the multi-objective optimization function.

[0086] The present invention takes the overall aircraft engine casing assembly of a cylindrical rotating body structure as an example to illustrate the above-mentioned lattice structure design method. The cylindrical rotating body structure has a radius of 590mm, a thickness of 7mm, and a length of 540mm. It is divided into two halves in the axial direction and is designed with multiple mounting seats. Under stamping conditions, the operating temperature of the stamping duct is about 650°C. The main loads that the casing assembly bears during operation are the pressure difference stress caused by the pressure difference between the inner and outer cavities, the tensile stress along the axial direction, and the bending stress. The uniform pressure on the inner surface is 3MPa, the average tensile stress in the axial direction is 2000N, and the average bending stress is 500N·M. The specific process of lattice design is as follows:

[0087] First, before designing the lattice unit cell, refer to Figure 3 As shown in the figure, based on the main geometric features of the cylindrical rotating body structure, ignoring additional features on the surface that have little impact on the function, such as the mounting edge, limiting screw holes and other structures, and only considering the morphology of the lattice material filling area, the simplified geometric structure is a rotating cylinder with a radius of 589.5 mm, a thickness of 6 mm, and a length of 540 mm.

[0088] Secondly, the simplified geometric model is divided into regular sections according to the simplified geometric structure and the load-bearing area, such as Figure 3As shown in the figure, the rotating cylinder is decomposed into Region I and Region II based on the load analysis results. Region I is 260 mm long, and Region II is 280 mm long. Based on the geometric characteristics of the rotating cylinder, the initial unit cell model is set to a sector model with a sweep angle of 3°, a height of 2 mm, and a distance of 2 mm between the front and back faces.

[0089] Thirdly, according to the geometric division of region I and region II, the loads in each region are distributed and applied to the initial model, and boundary conditions are applied to the lattice initial model. Figure 4 As shown in the figure, a uniform tensile force of 2000 N and a bending moment of 500 N·M are applied to the upper surface of the initial unit cell geometry model obtained by dividing region I. A temperature load of 400°C is applied to the inner surface and a temperature load of 650°C is applied to the outer surface. A periodic constraint is applied to the contact surface of the unit cell geometry model. A uniform tensile force of 1000 N is applied to the upper surface of the initial unit cell geometry model obtained by dividing region II. A temperature load of 400°C is applied to the inner surface and a temperature load of 650°C is applied to the outer surface. A uniform pressure load of 3 MPa is applied to the inner surface. A periodic boundary is applied to the surface of the unit cell geometry model.

[0090] Then, the material properties of GH4169 high-temperature alloy are assigned to the unit cell initial model. The material properties mainly include elastic modulus, density, Poisson's ratio, etc. at different temperatures. The objective function of topology optimization is set, and the artificial pseudo-density ρ of the material in the design unit is used as the design variable. When optimizing the design, the flexibility and thermal flexibility are set as the optimization goals. Among them, the flexibility is minimized, that is, minC (ρ); the thermal flexibility (thermal conductivity) is minimized, that is, minK (ρ). Both optimization goals should be assigned corresponding weights (W i ), the weights of compliance and thermal flexibility are given as 0.74 and 0.26 respectively using the analytic hierarchy process.

[0091] Next, the constraints for topology optimization design are imposed, mainly including:

[0092] (1) Considering the influence of different volume percentage constraints on the optimization results, the volume ratio is used as a constraint condition, requiring the volume ratio to be ≤30%; (2) Considering that the maximum composite stress of stress concentration does not exceed the yield strength σ of the material 0.2 , and σ max ≤650MPa. (3) In order to ensure the symmetry and uniformity of the structure, geometric symmetry constraints are set, that is, the structure is symmetrical about its geometric center point along the X, Y, and Z plane axes.

[0093] The finite element software Hypermesh was used to optimize the initial unit cell geometry model and obtain the force transmission path in the topology optimization area. The optimized lattice was reconstructed using UG·NX software, including: summarizing the discrete force transmission paths in the unit cell model and extending them to the model boundary to obtain a regular, manufacturable unit cell model; arranging the unit cell model periodically; and covering the outer surface of the arranged unit cell model with a 0.5 mm skin to obtain the following: Figure 5 The topologically optimized unit cell models of region I and region II are shown in Figure 1. Figure 4 The unit cell model shown in the figure is reconstructed to obtain Figure 6 As shown in the reconstruction results, after completing the dot matrix filling design of the two areas, the two areas are assembled and combined in the software to restore the part features of the outer surface skin and obtain a complete digital model of the engine casing assembly.

[0094] Finally, the lattice unit cells designed according to the shape are filled back into the split receiver model, and the obtained lattice-filled model is subjected to mechanical simulation tests such as tension and torsion for strength verification. After calculation and analysis, the strength reserve of the lattice-filled receiver component under the design point working condition is 1.86, and the strength initially meets the engineering design requirements, and is significantly improved compared to the strength reserve of traditional receiver components. The maximum displacement of the receiver under stamping conditions is 0.26mm, which is smaller than the maximum displacement of the traditional structure, that is, the stiffness of the lattice-filled receiver is relatively higher. At the same time, the additive manufacturing auxiliary design software Materialise Magics was used to conduct a manufacturability analysis of the lattice-filled receiver component after model reconstruction, set a powder cleaning hole with a diameter of 1mm, and determined that the forming direction of additive manufacturing is printing along the axial direction.

[0095] It has been verified that the weight of the GH4169 high-temperature alloy casing component filled with the dot matrix obtained by the present invention is reduced by 40% after additive printing, and the hollow rate of the dot matrix filled area reaches 60%.

[0096] The shape and load-based lattice structure design of the present invention has the following advantages:

[0097] 1. The lattice structure design method of the present invention can simplify and split complex configuration parts into parts composed of simple geometric configurations, greatly simplifying the complexity of the model during calculation.

[0098] 2. The lattice structure design method of the present invention can optimize the target component under multiple load conditions (such as mechanical load and temperature load). The load is partitioned and loaded on the segmented unit cell initial model to optimize the structure of the unit cell initial model. After reconstruction, the lattice configuration is obtained by periodic arrangement, which shortens the design cycle of the lattice configuration.

[0099] 3. The lattice structure designed by the present invention can significantly reduce the weight of parts while ensuring strength and rigidity, and can achieve the goal of reducing weight by more than 40% compared with general solid components.

[0100] 4. The lattice structure design method of the present invention greatly reduces the difficulty of lattice filling design for multi-load complex configuration parts, and plays a certain reference and driving role in the design of complex configuration lattice filling.

[0101] Based on the same inventive concept, a lattice structure design system based on shape and load is also provided in an embodiment of the present invention, as described in the following embodiment. Since the principle of solving the problem by the lattice structure design system based on shape and load is similar to the lattice structure design method based on shape and load disclosed in the above embodiment, the implementation of the lattice structure design system based on shape and load can refer to the implementation of the lattice structure design method based on shape and load, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and conceived.

[0102] Figure 7 This is a structural block diagram of a lattice structure design system based on shape and load disclosed in an embodiment of the present invention, such as Figure 7 As shown, the system includes a single cell initial model design module 701, a topology optimization module 702 and a model parameter optimization module 703, and the structure is described below.

[0103] The single cell initial model design module 701 is used to obtain a single cell initial model of a lattice design area on the part according to the structural characteristics of the part and the load results, and the lattice design area is at least one;

[0104] The topology optimization module 702 is configured to perform topology optimization on each of the single cell initial models under multiple working conditions using an established multi-objective optimization function according to the load results to obtain an optimized single cell model;

[0105] The model parameter optimization module 703 is used to reconstruct each optimized unit cell model using a surface fitting method to obtain a lattice unit cell geometric model, and optimize the size parameters of each lattice unit cell geometric model according to the part design strength to obtain the final unit cell geometric model.

[0106] Further, see Figure 7 As shown, the system further includes a performance evaluation module 704 , a feasibility evaluation module 705 and a judgment module 706 .

[0107] The performance evaluation module 704 is used to perform performance evaluation on the single cell model using a finite element method under various working conditions;

[0108] The feasibility assessment module 705 is used to perform additive manufacturing feasibility assessment on the single cell model;

[0109] The judgment module 706 is used to complete the lattice structure design when the performance evaluation results and the feasibility evaluation results simultaneously meet the design requirements; when any one of the performance evaluation results and the feasibility evaluation results does not meet the design requirements, the single-cell initial model is re-topologically optimized according to the multi-objective optimization function.

[0110] In this embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, any of the above-mentioned shape- and load-based lattice structure design methods is implemented to solve the technical problems of traditional lattice design methods that affect the overall performance of the structure.

[0111] Specifically, the computer device may be a computer terminal, a server or a similar computing device.

[0112] In this embodiment, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program for executing any of the above-mentioned shape- and load-based lattice structure design methods.

[0113] Specifically, computer-readable storage media include permanent and non-permanent, removable and non-removable media that can be used to store information by any method or technology. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer-readable storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable storage media does not include transitory media such as modulated data signals and carrier waves.

[0114] Obviously, those skilled in the art should understand that the various modules or steps of the above-mentioned embodiments of the present invention can be implemented using a general-purpose computing device, they can be concentrated on a single computing device, or distributed across a network composed of multiple computing devices. Alternatively, they can be implemented using program code executable by the computing device, so that they can be stored in a storage device and executed by the computing device. In some cases, the steps shown or described can be performed in a different order than herein, or they can be made into separate integrated circuit modules, or multiple modules or steps can be made into a single integrated circuit module for implementation. Thus, the embodiments of the present invention are not limited to any specific combination of hardware and software.

[0115] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A lattice structure design method based on shape and load, characterized in that: include: Obtaining a single-cell initial model of a lattice design region on the part according to structural characteristics of the part and load results, wherein the lattice design region has at least one; According to the load results, topology optimization is performed on each of the single-cell initial models under multiple working conditions using an established multi-objective optimization function to obtain an optimized single-cell model, including: using the artificial pseudo-density of the material in the single-cell initial model as a design variable, deformation, stress and design domain volume ratio as constraints, and compliance and thermal flexibility as design goals to construct a multi-objective optimization function for the part under multiple working conditions; obtaining the number of single-cell initial models in each of the lattice design areas, extracting the load type and corresponding load value of the lattice design area; assigning the load value corresponding to the load type to the single-cell initial model according to the number of models, and topologically optimizing the single-cell initial model using the multi-objective optimization function to obtain an optimized single-cell model; the expression of the multi-objective optimization function is: ； ； in, q is the number of design conditions, k is the number of design targets under a certain working condition, represents the weight of the i-th design objective under the m-th working condition, C mi represents the i-th design goal under the m-th working condition, is the design domain volume ratio, is the upper limit of the body ratio, p is an artificial pseudo-density, R It represents the unbalanced force generated during the iterative analysis of the structural geometric nonlinear finite element, u is the structural displacement, u0 is the initial displacement, σ is the structural stress, σ0 is the initial stress of the structure, Minimize is to find the minimum value of the function, st is a constraint condition; A surface fitting method is used to reconstruct each optimized unit cell model to obtain a lattice unit cell geometric model. The size parameters of each lattice unit cell geometric model are optimized according to the design strength of the part to obtain the final unit cell geometric model.

2. The shape and load-based lattice structure design method according to claim 1, characterized in that: According to the structural characteristics of the part and the load results, a single-cell initial model of the lattice design area on the part is obtained, including: Performing load analysis on the part to obtain load results, obtaining a lattice design area of the part based on the mechanical load and temperature load in the load results, and extracting the load type and load value borne by each lattice design area; Performing structural analysis on the part to obtain structural features, and simplifying each of the lattice design areas according to the structural features to obtain a simple geometric structure with a regular shape; Each of the simple geometric structures is divided according to the load type to obtain a unit cell initial model of each of the lattice design areas.

3. The shape and load-based lattice structure design method according to claim 1, characterized in that: Allocating the load value corresponding to the load type to the single cell initial model according to the number of models includes: Determining the load type, when the load type includes a mechanical load, uniformly distributing a load value corresponding to the mechanical load to the single cell initial model; When the load type includes a temperature load, a load value corresponding to the temperature load is assigned to the single-cell initial model.

4. The shape and load-based lattice structure design method according to claim 1, characterized in that: Also includes: Each of the single cell models was evaluated.

5. The shape and load-based lattice structure design method according to claim 4, characterized in that: Each of the single-cell models was evaluated, including: Under various working conditions, the performance of the single cell model is evaluated by the finite element method; Conducting an additive manufacturing feasibility assessment on the single-cell model; When both the performance evaluation results and the feasibility evaluation results meet the design requirements, the lattice structure design is completed; when either the performance evaluation results or the feasibility evaluation results do not meet the design requirements, the single-cell initial model is re-topologically optimized according to the multi-objective optimization function.

6. A lattice structure design system based on shape and load, characterized in that: include: A single-cell initial model design module, wherein the single-cell initial model design module is used to obtain a single-cell initial model of a lattice design area on the part according to the structural characteristics of the part and the load results, wherein the lattice design area has at least one; A topology optimization module is used to perform topology optimization on each of the single-cell initial models under multiple working conditions using an established multi-objective optimization function according to the load results to obtain an optimized single-cell model, including: using the artificial pseudo-density of the material in the single-cell initial model as a design variable, deformation, stress and design domain volume ratio as constraints, and compliance and thermal flexibility as design goals to construct a multi-objective optimization function for the part under multiple working conditions; obtaining the number of single-cell initial models in each of the lattice design areas, extracting the load type and corresponding load value of the lattice design area; assigning the load value corresponding to the load type to the single-cell initial model according to the number of models, and performing topology optimization on the single-cell initial model using the multi-objective optimization function to obtain an optimized single-cell model; the expression of the multi-objective optimization function is: ； ； in, q is the number of design conditions, k is the number of design targets under a certain working condition, represents the weight of the i-th design objective under the m-th working condition, C mi represents the i-th design goal under the m-th working condition, is the design domain volume ratio, is the upper limit of the body ratio, p is an artificial pseudo-density, R It represents the unbalanced force generated during the iterative analysis of the structural geometric nonlinear finite element, u is the structural displacement, u0 is the initial displacement, σ is the structural stress, σ0 is the initial stress of the structure, Minimize is to find the minimum value of the function, st is a constraint condition; The model parameter optimization module is used to reconstruct each optimized unit cell model using a surface fitting method to obtain a lattice unit cell geometric model, and optimize the size parameters of each lattice unit cell geometric model according to the part design strength to obtain the final unit cell geometric model.

7. The shape and load-based lattice structure design system according to claim 6, characterized in that: Also includes: A performance evaluation module, configured to perform performance evaluation on the single cell model using a finite element method under various operating conditions; A feasibility assessment module, configured to perform an additive manufacturing feasibility assessment on the single-cell model; A judgment module is used to complete the lattice structure design when the performance evaluation results and the feasibility evaluation results simultaneously meet the design requirements; when any one of the performance evaluation results and the feasibility evaluation results does not meet the design requirements, re-topology optimization of the single-cell initial model according to the multi-objective optimization function.

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