Four-way structure optimization design method under self-weight condition

Abstract

The invention belongs to the technical field of high-energy laser equipment, and particularly discloses a four-way structure optimization design method under a self-weight condition, and the method comprises the steps: carrying out the three-dimensional modeling of a to-be-optimized four-way structure through three-dimensional modeling software, carrying out the recognition and elimination of complex features of a small gap part, and obtaining a CAD model of the four-way structure; importing the CAD model into Abaqus software, dividing a finite element grid, constructing a finite element model, and determining a designable domain and a non-designable domain of topological optimization; based on the basic displacement attribute, a preset load and a boundary condition, determining a working condition under the self-weight load; taking the mass of the minimized four-way structure as an optimization target, taking the working condition under the self-weight load as a constraint condition, adopting a variable density method to carry out topological optimization on the finite element model, and obtaining the finite element model after mass optimization and the corresponding lightweight four-way structure. According to the four-way structure, the high-performance light-weight design of the four-way structure under the self-weight load condition is achieved.

Description

Technical Field

[0001] The present application belongs to the technical field of high-energy laser equipment, and more specifically, to a method for optimizing the design of a four-way structure under deadweight conditions. Background Art

[0002] The terminal launch device of laser equipment is one of the important factors affecting its launch accuracy. A good terminal launch device can effectively ensure the launch accuracy of laser equipment in complex and changeable extreme working environments, and can effectively ensure the accurate strike and shooting of lasers on long-distance targets. However, the heavy weight of the launch device structure will cause its internal structure to deform greatly and squeeze each other, resulting in deformation of the optical machine product structure and thus damage the tracking and aiming accuracy. If the launch device structure is designed in a more reasonable way, it can not only improve the performance of the structure but also reduce its own weight.

[0003] Current statistics show that the benefits of lightweight design are very obvious, so lightweight design has received more and more attention. The four-way structure is a key component in the end-launch device of laser equipment that has the function of bearing and driving transmission, and works with other components to achieve precise tracking and measurement. How to carry out high-performance lightweight design for the four-way structure is an urgent problem to be solved. Summary of the invention

[0004] In view of the defects existing in the related technologies, the embodiments of the present application provide a method for optimizing the design of a four-way structure under deadweight conditions, aiming to solve the problem of high-performance and lightweight design of the four-way structure.

[0005] In a first aspect, an embodiment of the present application provides a method for optimizing the design of a cross-connection structure under deadweight conditions, comprising:

[0006] The 3D modeling software is used to perform 3D modeling on the cross-section structure to be optimized, and the complex features of the small gap parts are identified and eliminated to obtain the CAD model of the cross-section structure;

[0007] Import the CAD model into Abaqus software, divide the finite element mesh, build the finite element model and determine the designable and non-designable domains of topology optimization;

[0008] Determine the working conditions under deadweight load based on basic displacement properties, preset loads and boundary conditions;

[0009] Taking minimizing the mass of the four-way structure as the optimization goal and the working conditions under deadweight load as the constraints, the variable density method is used to perform topological optimization on the finite element model to obtain the mass-optimized finite element model and the corresponding lightweight four-way structure.

[0010] In some embodiments, generating a finite element mesh includes:

[0011] Select the mesh type, global mesh size and element type in the Abaqus pre-processing module, automatically divide the finite element mesh and assign the element type;

[0012] Among them, the mesh type selects tetrahedral mesh and the element type selects linear element.

[0013] In some embodiments, generating a finite element mesh includes:

[0014] Export the STEP model file from Abaqus software and import it into Hypermesh software;

[0015] In the Hypermesh software, the average length of the unit is set, and triangular units are used for two-dimensional meshing;

[0016] Check mesh quality and correct unqualified elements based on element length and internal angle of triangle elements;

[0017] Generate a 3D mesh based on the modified 2D mesh.

[0018] In some embodiments, the basic displacement properties include: model density, elastic modulus and Poisson's ratio; the boundary conditions include: fixed boundary conditions, weight boundary conditions and displacement boundary conditions, the weight boundary conditions include gravitational acceleration constraints in three-dimensional directions, and the displacement boundary conditions include the degrees of freedom of axial translation and rotation around the axis of the mounting surface in three-dimensional directions; the load includes: model self-weight.

[0019] In some embodiments, the method further comprises:

[0020] Taking minimizing the flexibility of the four-way structure as the optimization goal, the finite element model after mass optimization is topologically optimized to obtain a high-rigidity lightweight four-way structure.

[0021] In some embodiments, topology optimization is performed on the quality-optimized finite element model, including:

[0022] Determine the designable domain and non-designable domain in the optimized finite element model. The non-designable domain includes the lens mounting surface, bearing and motor mounting surface, light outlet, and additional equipment mounting surface. The designable domain is the area other than the non-designable domain.

[0023] Determine design variables, including element density and minimum size, where the minimum size is based on the average element length of the finite element elements;

[0024] Determine the response, including volume fraction and compliance;

[0025] Taking minimizing the flexibility of the four-way structure as the optimization goal and the volume fraction being less than the preset value as the constraint condition, the OptiStruct solver was used to perform topology optimization on the optimized finite element model.

[0026] In some embodiments, the method further comprises:

[0027] The finite element model after topology optimization is designed with reinforcement ribs and porous filling.

[0028] In some embodiments, the reinforcing rib design includes:

[0029] Determine the rib parameters, including thickness and angle, based on the topology optimization results;

[0030] A reference surface is established in the CAD model of the optimized cross-section structure, and radial plate-type stiffeners are formed by stretching based on the stiffener parameters.

[0031] In some embodiments, the porous filling comprises:

[0032] The bottom of the four-way structure is used as the filling object, and two layers of unit cells of a set size are filled on the surface of the finite element model after topology optimization.

[0033] In some embodiments, the method further comprises:

[0034] Under the condition of deadweight load, the optimized finite element model is checked for deformation, deformation angle and fundamental frequency;

[0035] The structural parameters of the optimized four-way structure are adjusted based on the verification results.

[0036] In a second aspect, the present application also provides a device for optimizing the design of a cross-way structure under deadweight conditions, including:

[0037] A CAD model acquisition module is used to perform three-dimensional modeling on the cross-shaped structure to be optimized using three-dimensional modeling software, and to identify and eliminate complex features of small gaps to obtain a CAD model of the cross-shaped structure;

[0038] The finite element model building module is used to import the CAD model into the Abaqus software, divide the finite element mesh, build the finite element model and determine the designable and non-designable domains of topology optimization;

[0039] A working condition determination module, used to determine working conditions under deadweight load based on basic displacement properties, preset loads and boundary conditions;

[0040] The first topology optimization module is used to minimize the mass of the four-way structure as the optimization goal, take the working conditions under the deadweight load as the constraint conditions, and use the variable density method to perform topology optimization on the finite element model to obtain the finite element model after mass optimization and the corresponding lightweight four-way structure.

[0041] In a third aspect, an embodiment of the present application further provides an electronic device, comprising: at least one memory for storing programs; and at least one processor for executing the programs stored in the memory. When the program stored in the memory is executed, the processor is used to execute the method described in the first aspect or any possible implementation of the first aspect.

[0042] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method described in the first aspect or any possible implementation of the first aspect.

[0043] In a fifth aspect, an embodiment of the present application further provides a computer program product, which, when executed on a processor, enables the processor to execute the method described in the first aspect or any possible implementation of the first aspect.

[0044] The embodiment of the present application provides a method for optimizing the design of a four-way structure under deadweight conditions, which obtains a CAD model of the four-way structure by performing three-dimensional modeling on the four-way structure to be optimized and removing complex features in small gaps; the CAD model is imported into the Abaqus software and converted into a finite element model, and the working conditions under deadweight load are determined. The finite element model is topologically optimized using a variable density method with minimizing the structural mass as the optimization goal and the working conditions as constraints, thereby obtaining an optimized finite element model and a corresponding lightweight four-way structure, thereby achieving a high-performance lightweight design of the four-way structure under deadweight load conditions, and improving the structural performance by reducing the deadweight of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the present application or related technologies, the following is a brief introduction to the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 It is a flow chart of a method for optimizing the design of a cross-connection structure under deadweight conditions provided in an embodiment of the present application;

[0047] Figure 2 is a schematic diagram of a displacement boundary condition provided in an embodiment of the present application;

[0048] Figure 3 It is a schematic diagram of a model of a four-way structure after topology optimization + rib design + porous filling integration provided in an embodiment of the present application;

[0049] Figure 4 It is a structural schematic diagram of a four-way structure optimization design device under deadweight conditions provided in an embodiment of the present application;

[0050] Figure 5 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0052] In the process of optimizing the four-way structure, the following key basic issues are mainly considered: (1) The surface structure is complicated. The four-way structure has a variety of complex geometric features, such as complex circular end faces. For complex curved surface components, establishing an accurate surface structure feature description model and realizing high-precision numerical simulation calculations are important factors that need to be considered in the design of complex curved surface components; (2) The structure is lightweight. A significant reduction in weight can effectively reduce R&D costs; (3) High performance requirements. The complex and harsh operating environment places higher requirements on the performance of the launch device.

[0053] Based on the above analysis, an embodiment of the present application provides a method for optimizing the design of a four-way structure under self-weight conditions. The CAD model of the four-way structure to be optimized is obtained by performing three-dimensional modeling on the four-way structure and removing complex features of small gaps. The CAD model is imported into the Abaqus software and converted into a finite element model, and the working conditions under the self-weight load are determined. The finite element model is topologically optimized using the variable density method with minimizing the structural mass as the optimization goal and the working conditions as constraints, thereby obtaining an optimized finite element model and the corresponding lightweight four-way structure, thereby achieving a high-performance lightweight design of the four-way structure under self-weight load conditions, and improving the structural performance by reducing the self-weight of the structure.

[0054] Figure 1 : is a flow chart of a method for optimizing a cross-connection structure under deadweight conditions provided in an embodiment of the present application, such as Figure 1 As shown, the method at least includes the following steps:

[0055] S101. Use 3D modeling software to perform 3D modeling on the cross-way structure to be optimized, identify and eliminate complex features of small gaps, and obtain a CAD model of the cross-way structure.

[0056] Specifically, the four-way structure is a key component in the terminal launch device of the laser equipment. As a load-bearing component, it ensures the stability and reliability of the equipment, and as a moving component, it realizes fast and accurate tracking and launching. The four-way structure is usually used in conjunction with components such as precision servo turntables. Optionally, the four-way structure is a rotary structure driven by a bearing motor, with square or hexagram-shaped reinforcement ribs around it, and some circular square holes are configured for installation. Optionally, the four-way structure material is Invar.

[0057] CAD model refers to a three-dimensional model of computer-aided design (Computer Aided Design), which can accurately represent the geometric shape and size of an object. Optionally, the CAD model of the four-way structure to be optimized is pre-built. Specifically, according to the functional requirements and connection form of the four-way structure to be optimized, three-dimensional modeling is performed using three-dimensional modeling software (mainly CAD software), and the CAD model of the four-way structure to be optimized is pre-built. Optionally, CAD software such as UG and SolidWorks is used to perform three-dimensional modeling on the four-way structure.

[0058] There are a large number of complex features in the small gaps of the existing four-way structure. These complex features in the small gaps will be judged as inaccurate geometry when the CAD model is subsequently imported into the finite element analysis software, further affecting the division of the finite element mesh and other subsequent steps. Therefore, it is necessary to simplify the complex features of the small gaps in the four-way structure to be optimized to reduce or avoid the impact of the complex features in the small gaps on the subsequent finite element analysis process.

[0059] Optionally, the complex features of the small gap portion of the cross-type structure include one or more of chamfers, fillets, and mounting threaded hole features. The complex features of the small gap portion are identified and eliminated, and then a CAD model of the cross-type structure to be optimized is obtained to construct a subsequent finite element model.

[0060] Taking the installation threaded hole feature as an example, the feature simplification process is as follows:

[0061] Step a-1, identify the target threaded hole position through the perspective state in the CAD software.

[0062] Step a-2: Select the threaded hole and measure the distance from the hole arc to the outer surface of the model.

[0063] Step a-3, using the distance measured in step a-2 as input data, segment the outer surface of the model and the part of the model where the arc is located.

[0064] Step a-4, extract the part of the model where the arc is located, select and delete the arc feature.

[0065] Step a-5: merge the two parts of the model divided in step a-3.

[0066] At this point, the identification and elimination of the installation threaded hole features are completed.

[0067] Complex small feature removal is part of the geometric feature processing in the finite element pre-processing process. In addition to complex small feature removal, geometric feature processing also includes: geometric feature repair, that is, repairing gaps or errors in the imported CAD model through operations such as patching, removal, and merging.

[0068] S102. Import the CAD model into Abaqus software, divide the finite element mesh, construct the finite element model and determine the designable domain and non-designable domain of topology optimization.

[0069] Specifically, the finite element model is a group of units that are connected only at the nodes, transmit forces only at the nodes, and are constrained only at the nodes. It is the result of the discretization of the mechanical model and is a digital model for numerical calculation. By discretizing the continuous geometric structure into a finite number of units and determining a finite number of nodes in each unit, the continuum is regarded as a geometric body of a group of units connected only at the nodes. The finite element model can transform an infinite degree of freedom problem in a continuous domain into a finite degree of freedom problem in a discrete domain, thereby facilitating numerical calculations.

[0070] CAD models usually cannot be used directly for finite element analysis. Therefore, the specialized finite element analysis software Abaqus can be used to import and convert the CAD model into a finite element model, and then construct the finite element model in the Abaqus software.

[0071] Both Abaqus and Hypermesh can be used for finite element pre-processing, and both have powerful meshing capabilities. Abaqus covers all aspects of finite element analysis, including pre-processing, solving, and post-processing, while Hypermesh focuses on finite element pre-processing, and has extremely high efficiency and accuracy in the finite element pre-processing process.

[0072] Finite element meshing refers to discretizing a geometric model into a finite number of small units, such as triangles, quadrilaterals or hexahedrons, etc. These small units are called finite elements, and their collection constitutes the finite element mesh of the entire structure.

[0073] In some embodiments, dividing the finite element mesh in S102 specifically includes:

[0074] In the Abaqus pre-processing module, select the mesh type, global mesh size and element type, automatically divide the finite element mesh and assign the element type.

[0075] Specifically, Abaqus software covers all aspects of finite element analysis, which can be divided into pre-processing module, solver and post-processing module. In the pre-processing module, the finite element mesh is divided and the finite element model is constructed. In this process, it is necessary to select the mesh type, global mesh size and unit type, etc.

[0076] Exemplarily, the meshing process based on Abaqus includes the following steps:

[0077] Step b-1, obtain the CAD model of the cross-section structure. After completing the feature simplification of the complex features of the small gap part, import the CAD model into Abaqus for meshing. After drawing or importing, the model needs to be edited and adjusted to ensure that it meets the requirements of finite element analysis.

[0078] Step b-2, select the mesh type and global mesh size. Optionally, the mesh type is tetrahedral mesh, and the global mesh size is usually 75. The mesh type and global mesh size affect the model accuracy and analysis results. The higher the mesh size, the higher the model accuracy and the corresponding increase in calculation cost.

[0079] Step b-3, mesh division. Use the automatic meshing function to quickly generate meshes and control mesh distribution. To ensure the continuity and rationality of the mesh, manual adjustments are required to avoid mesh overlap or large gaps.

[0080] Step b-4, select the unit type and assign the unit to the model. Optionally, the unit type is selected as a linear unit to ensure that the connection and interaction of the units are correct, thereby ensuring the accuracy and reliability of the analysis results.

[0081] In some embodiments, dividing the finite element mesh in S102 includes:

[0082] Export the STEP model file from Abaqus software and import it into Hypermesh software;

[0083] In the Hypermesh software, the average length of the unit is set, and triangular units are used for two-dimensional meshing;

[0084] Check mesh quality and correct unqualified elements based on element length and internal angle of triangle elements;

[0085] Generate a 3D mesh based on the modified 2D mesh.

[0086] Specifically, Hypermesh software has extremely high efficiency and accuracy in the finite element pre-processing process, so it is considered to use Hypermesh software to realize meshing.

[0087] Exemplarily, for the meshing based on Hypermesh, the following steps are generally included:

[0088] Step c-1, obtain the CAD model of the four-way structure. Optionally, export the product model data exchange standard STEP model file (a CAD file format) from the Abaqus software, and then import it into the Hypermesh software. Optionally, directly import the CAD model of the four-way structure into Hypermesh, simplify the complex features of the small gap part, and obtain the geometric model of the four-way structure.

[0089] Step c-2, set the average unit length and unit type, and divide the two-dimensional grid in Hypermesh. Due to the high complexity of the model, triangular units are used for meshing. Based on the outer surface of the model and the specific parameters of the model itself, the average unit length is set to 6mm, with a total of 2,651,545 nodes and 5,303,082 units.

[0090] Step c-3, check the mesh quality and correct the unqualified units. The quality of the mesh will affect the calculation accuracy. A mesh with too poor quality may even terminate the calculation. Intuitively, the mesh quality is better when the mesh edges or internal angles are not much different, the mesh surface is not overly distorted, and the edge nodes are located near the boundary equalization points.

[0091] Optionally, in the quality check, the unit length is less than 1 / 3 of the average unit length, i.e., 2 mm, and the internal angle of the triangular unit is less than 20° to screen out the poor quality units in the model. The poor quality units are corrected by adjusting the node position, merging nodes, directly deleting units, etc., and good quality units are generated at the same time. After that, the unit quality check is performed again. Repeat step c-3 until the software analysis requirements are met.

[0092] Step c-4: Generate a 3D mesh based on the corrected 2D mesh. Since the unqualified units have been corrected in step c-3, the analysis requirements are met. Therefore, a 3D tetrahedral mesh can be directly generated on the 2D surface of the model without the need for quality inspection. The total number of 3D nodes is 3,580,970 and the number of units is 13,515,981.

[0093] At this point, the finite element mesh division is completed.

[0094] Optionally, after the finite element model is constructed, due to the complex situations such as mass point coupling in the load of the model, it is necessary to determine the designable domain and non-designable domain of topology optimization, and perform topology optimization only on the design domain. Among them, the non-designable domain includes the lens mounting surface, bearing and motor mounting surface, light outlet, and additional equipment mounting surface; the designable domain is the area except the non-designable domain.

[0095] S103. Determine the working condition under deadweight load based on basic displacement properties, preset loads and boundary conditions.

[0096] Specifically, basic displacement properties, loads and boundary conditions are set in Abaqus software to determine the working conditions under deadweight load.

[0097] Optionally, the basic displacement attributes include: model density, elastic modulus and Poisson's ratio. Exemplarily, the model density is set to 8.1e-9, the elastic modulus is set to 141000, and the Poisson's ratio is set to 0.3.

[0098] Optionally, the boundary conditions include: fixed boundary conditions, weight boundary conditions and displacement boundary conditions. Exemplarily, the weight boundary condition is set to (0, -9800, 0), which represents the gravitational acceleration constraint in the three-dimensional direction. By analyzing the fixed boundary conditions, displacement boundary conditions, etc. in the model, the optimization result can be obtained by solving the degree of freedom of the structure. Displacement boundary conditions refer to conditions specified on the surface of an object to limit the displacement of an object, which are used to limit the degree of freedom of movement of a four-way structure. Fixed boundary conditions are used to constrain fully restricted boundaries, and displacement boundary conditions are used to constrain boundaries with partial degrees of freedom. Figure 2 is a schematic diagram of the displacement boundary conditions provided in the embodiment of the present application, such as Figure 2 Parts (a) and (b) are schematic diagrams of the model from the left and right perspectives, respectively. There are circular hole mounting surfaces on the left and right sides of the model. The displacement boundary conditions are the degrees of freedom of axial translation and rotation around the axis of the mounting surface in the three-dimensional direction, which restrict the translation and rotation of the mounting surface in the three-dimensional direction.

[0099] Optionally, the load includes: the self-weight of the model. In the self-weight load condition, the load is set to include only the self-weight of the model.

[0100] S104. Taking minimizing the mass of the four-way structure as the optimization goal and the working conditions under the deadweight load as the constraint conditions, the finite element model is topologically optimized using the variable density method to obtain the mass-optimized finite element model and the corresponding lightweight four-way structure.

[0101] Specifically, in the optimization process of the four-way structure, the optimization goal is to minimize the mass of the four-way structure, the constraint condition is the working condition under the predetermined deadweight load, and the optimization method adopts the variable density method to obtain the finite element model after mass optimization and the corresponding lightweight four-way structure.

[0102] The variable density method divides the optimization object into multiple tiny units, and uses the density parameter of each unit as the optimization design variable; the density parameter variation range of these units is usually determined between 0 and 1; in the optimization process, the density values ​​of these units are adjusted to achieve the optimization goal; finally, units with density values ​​close to 0 are usually discarded, and units with density values ​​of 1 are retained. The variable density method can solve multi-condition topology optimization problems well, and the calculation process is relatively simple and easy to implement.

[0103] The embodiment of the present application provides a method for optimizing the design of a four-way structure under deadweight conditions, which obtains a CAD model of the four-way structure by performing three-dimensional modeling on the four-way structure to be optimized and removing complex features in small gaps; the CAD model is imported into the Abaqus software and converted into a finite element model, and the working conditions under deadweight load are determined. The finite element model is topologically optimized using a variable density method with minimizing the structural mass as the optimization goal and the working conditions as constraints, thereby obtaining an optimized finite element model and a corresponding lightweight four-way structure, thereby achieving a high-performance lightweight design of the four-way structure under deadweight load conditions, and improving the structural performance by reducing the deadweight of the structure.

[0104] In some embodiments, the method for optimizing the design of a cross-connection structure under deadweight conditions further includes:

[0105] Taking minimizing the flexibility of the four-way structure as the optimization goal, the finite element model after mass optimization is topologically optimized to obtain a high-rigidity lightweight four-way structure.

[0106] Specifically, in order to reduce the weight of the structure and improve the structural stiffness at the same time, the optimized finite element model obtained by S105 was further optimized using topology optimization theory, and the optimization goal was to minimize the flexibility of the four-way structure.

[0107] In some embodiments, topology optimization is performed on the quality-optimized finite element model, specifically including:

[0108] Determine the designable domain and non-designable domain in the optimized finite element model. The non-designable domain includes the lens mounting surface, bearing and motor mounting surface, light outlet, and additional equipment mounting surface. The designable domain is the area other than the non-designable domain.

[0109] Determine design variables, including element density and minimum size, where the minimum size is based on the average element length of the finite element elements;

[0110] Determine the response, including volume fraction and compliance;

[0111] Taking minimizing the flexibility of the four-way structure as the optimization goal and the volume fraction being less than the preset value as the constraint condition, the OptiStruct solver was used to perform topology optimization on the optimized finite element model.

[0112] Specifically, in the topology optimization process with minimizing flexibility as the optimization goal, it is necessary to set design variables, responses, response constraints, etc.

[0113] The steps of topology optimization solution based on Hypermesh are as follows:

[0114] Step d-1, determine the optimization area. Due to the complex situations such as mass point coupling in the model's load, it is necessary to set the non-designable domain, which includes the lens mounting surface, bearing and motor mounting surface, light outlet, and additional equipment mounting surface. The design domain is the area outside the non-designable domain. Figure 2 , red is the undesignable area, and yellow is the designable area.

[0115] Step d-2, determine the design variables, including unit density and minimum size, the minimum size is determined based on the average unit length of the finite element unit. Specifically, the unit density is assigned, and the minimum size is set to 1.5-2 times the average unit length.

[0116] Step d-3, determining the response. Optionally, two responses are determined: volume fraction (Volumefrac) and compliance (Compliance).

[0117] Step d-4, determine the response constraint. Optionally, determine a response constraint for the volume fraction, with upper limits of 0.15, 0.25 and 0.4 respectively.

[0118] Step d-5: Determine the optimization target. The optimization target is set to minimum compliance (Min Compliance).

[0119] Step d-6, optimization solution calculation: Use the OptiStruct solver to solve the finite element model after mass optimization.

[0120] Step d-7, display of optimization results. After solver calculation, observe and analyze the optimized results in Hyperview.

[0121] The topology optimization processing steps in Abaqus are the same as above, but in Abaqus, since the solid model of the optimization result cannot be exported, the result is only used to guide the subsequent redesign of the four-way model. In the final optimization result, the number of model grids is about 100,000. Since its optimization process is simple, time-consuming, and the material distribution form of the final optimization result is more reasonable, it is preferred to select the processing results of Abaqus as the guiding basis for the subsequent design of the model.

[0122] In some embodiments, the method for optimizing the design of a cross-connection structure under deadweight conditions further includes:

[0123] The optimized finite element model is designed with reinforcement ribs and porous filling.

[0124] Specifically, during the topology optimization process, the following problems may occur: the optimization results are fragmented, and it is difficult to make supplementary connections between faces, which requires a lot of time for post-processing; due to the existence of some fragments, the final style of the structure is unclear, and only based on design experience, specific parts are bolded or deleted without knowing how to reasonably handle the optimization results; during the post-processing process, most areas are designed as rod connections, which cannot effectively reduce the quality.

[0125] Therefore, the rib design is introduced to improve the model performance while solving the above optimization problems. Based on the topology optimization results, most of the materials are fully optimized to form holes, which is not conducive to the subsequent redesign of the ribs. Therefore, it is necessary to change the boundary conditions during optimization and set the inner layer of units as a non-designable domain (as the skin of the reinforced structure). This operation is not accurate and cannot obtain a plane. It is only performed to obtain the layout of the ribs. Since the rib design cannot be directly performed in the finite element model after topology optimization, the rib distribution is designed based on the CAD model:

[0126] Reference Figure 2 , the specific process of rib design is as follows:

[0127] Step e-1: fill the left and right areas of the model.

[0128] Step e-2: Determine the rib parameters, including thickness and angle, based on the results of topology optimization.

[0129] Step e-3: Establish a reference plane of the CAD model of the currently optimized cross-shaped structure in the CAD software, and stretch it based on the reinforcement rib parameters to form radial plate-type reinforcement ribs.

[0130] According to the optimization results and the rib design principles, the left and right areas of the CAD model were redesigned to add radial baffle-type ribs. The shape and layout of the radial plate-type ribs are similar to the lines or plates radiating from the center point to the surrounding areas. By dispersing and transferring the load, the strength and stiffness of the structure can be significantly improved.

[0131] From the above steps, it can be seen that the distribution of the reinforcing ribs in the upper and lower parts of the CAD model has not changed. Therefore, the topology optimization method can be used to further optimize the model. Considering the position factor of the mounting surface of the added component, after repeated tests, it was decided to combine the topology optimization results. In the bottom design process, the horizontal bar is retained and some vertical bars are deleted; in the top design process, the skin part is retained, and the horizontal and vertical bars in the corresponding area are deleted based on the position of the hole.

[0132] The embodiment of the present application performs reinforcement treatment in different areas, and determines the distribution form and density of the ribs according to the material density distribution of the optimization result to ensure the structural rigidity. Compared with the traditional reinforcement method relying on design experience, it has a short cycle, high directionality, and the obtained reinforced structure has strong process feasibility.

[0133] Furthermore, topology optimization + rib design can effectively reduce mass and improve model performance. In order to further reduce weight, a porous structure (lattice structure) filling method is introduced to adjust the model.

[0134] When the size of a single unit cell is too small, the number of single-layer unit cells filled and the number of filling layers of the same volume will increase, which will increase the complex features of the porous filling area, and the model file will increase exponentially, making it impossible to perform structural performance analysis; when the size is too large, the number of fillings will be too small, the structural porosity will increase, and the solid filling rate will be too low, which will reduce the mechanical properties of the filling area and affect the first-order modal frequency and vibration type of the structure.

[0135] The solution in the embodiment of the present application is to use the bottom of the four-way structure as the filling object, and test multiple groups of unit cell size data such as 70×70×5, 50×50×5, 30×30×5, 70×70×4, 50×50×4, 30×30×4, 70×70×3, 50×50×3, 30×30×3mm to obtain the unit cell size suitable for structural filling. Optionally, 50×50×4mm is selected as the set size of the filling unit cell, and 2 layers of unit cells are filled on the surface of the optimized finite element model.

[0136] In summary, the topology optimization theory and technology are applied in the embodiments of the present application to reduce the mass of the model while improving the structural stiffness, so as to obtain a high-rigidity lightweight four-way structure; next, according to the rib design principle, the distribution of the ribs is redesigned in the local area of ​​the optimized four-way model; porous filling design is performed on some areas to ensure that while minimizing the mass of the model, the performance requirements of the engineering application standards can still be guaranteed.

[0137] Figure 3 : is a schematic diagram of a model of a four-way structure after topology optimization + rib design + porous filling integration provided in an embodiment of the present application, such as Figure 3 As shown in the figure, the model mass of the four-way structure design model under the deadweight load condition is 0.952t.

[0138] In some embodiments, the method for optimizing the design of a cross-connection structure under deadweight conditions further includes:

[0139] Under the condition of deadweight load, the optimized finite element model is checked for deformation, deformation angle and fundamental frequency;

[0140] The structural parameters of the optimized four-way structure are adjusted based on the verification results.

[0141] Specifically, after each optimization of the four-way structure, the structural model should be checked under deadweight load conditions, and the structural parameters of the optimized four-way structure should be further adjusted based on the check results to obtain a high-rigidity lightweight four-way structure.

[0142] Verification of deformation amount and deformation angle includes:

[0143] Under the condition of deadweight load, the deformation data of the optimized structural model is compared with that of the structural model before optimization. For example, the maximum deformation of the optimized model occurs at 30°, with a value of 0.01931mm; the maximum deformation of the model before optimization occurs at 33°, with a value of 0.03044mm.

[0144] Data comparison of deformation amount and deformation angle of primary and secondary mirrors in the models before and after optimization. Exemplarily, at 85°, the maximum deformation amount of the primary mirror in the optimized model is 0.01817mm; at 75°, the maximum deformation amount of the secondary mirror is 0.01206mm; at 85°, the maximum deformation angle of the primary mirror is 0.0023°; at 75°, the maximum deformation angle of the secondary mirror is 0.00042°. Exemplarily, at 85°, the maximum deformation amount of the primary mirror in the model before optimization is 0.01286mm; at 85°, the maximum deformation amount of the secondary mirror is 0.01467mm; at 60°, the maximum deformation angle of the primary mirror is 0.0128°; at 0°, the maximum deformation angle of the secondary mirror is 0.00058°.

[0145] The mass of the optimized model is 0.952t, and the mass of the model before optimization is 1.1t. It can be seen from the above analysis results that the performance of the optimized model is better than that of the model before optimization, based on a mass reduction of about 150kg.

[0146] For the verification of the fundamental frequency, for example, the first-order frequency of the optimized model is 57.555 Hz, which is higher than 55.859 Hz of the model before optimization, which can effectively avoid the resonance phenomenon and improve the optical pointing accuracy and control accuracy during system operation.

[0147] Figure 4 is a schematic diagram of the structure of the cross-way structure optimization design device under the deadweight condition provided in the embodiment of the present application, such as Figure 4 As shown, the device at least includes:

[0148] The CAD model acquisition module 401 is used to perform three-dimensional modeling on the cross-shaped structure to be optimized using three-dimensional modeling software, and to identify and eliminate complex features of small gaps to obtain a CAD model of the cross-shaped structure;

[0149] The finite element model building module 402 is used to import the CAD model into the Abaqus software, divide the finite element mesh, build the finite element model and determine the designable domain and non-designable domain of the topology optimization;

[0150] The working condition determination module 403 is used to determine the working condition under the deadweight load based on the basic displacement properties, the preset load and the boundary conditions;

[0151] The first topology optimization module 404 is used to minimize the mass of the four-way structure as the optimization goal, take the working conditions under the deadweight load as the constraint conditions, use the variable density method to perform topology optimization on the finite element model, and obtain the finite element model after mass optimization and the corresponding lightweight four-way structure.

[0152] In some embodiments, the finite element model building module 402 includes a first building unit for:

[0153] Select the mesh type, global mesh size and element type in the Abaqus pre-processing module, automatically divide the finite element mesh and assign the element type;

[0154] Among them, the mesh type selects tetrahedral mesh and the element type selects linear element.

[0155] In some embodiments, the finite element model building module 402 includes a second building unit for:

[0156] Export the STEP model file from Abaqus software and import it into Hypermesh software;

[0157] In the Hypermesh software, the average length of the unit is set, and triangular units are used for two-dimensional meshing;

[0158] Check mesh quality and correct unqualified elements based on element length and internal angle of triangle elements;

[0159] Generate a 3D mesh based on the modified 2D mesh.

[0160] In some embodiments, basic displacement properties include: model density, elastic modulus and Poisson's ratio; boundary conditions include: fixed boundary conditions, weight boundary conditions and displacement boundary conditions, the weight boundary conditions include gravitational acceleration constraints in three-dimensional directions, and the displacement boundary conditions include the degrees of freedom of axial translation and rotation around the axis of the mounting surface in three-dimensional directions; the load includes: model self-weight.

[0161] In some embodiments, the apparatus further comprises:

[0162] The second topology optimization module is used to perform topology optimization on the finite element model after mass optimization with the goal of minimizing the flexibility of the four-way structure to obtain a high-rigidity lightweight four-way structure.

[0163] In some embodiments, the second topology optimization module is specifically configured to:

[0164] Determine the designable domain and non-designable domain in the optimized finite element model. The non-designable domain includes the lens mounting surface, bearing and motor mounting surface, light outlet, and additional equipment mounting surface. The designable domain is the area other than the non-designable domain.

[0165] Determine design variables, including element density and minimum size, where the minimum size is based on the average element length of the finite element elements;

[0166] Determine the response, including volume fraction and compliance;

[0167] Taking minimizing the flexibility of the four-way structure as the optimization goal and the volume fraction being less than the preset value as the constraint condition, the OptiStruct solver was used to perform topology optimization on the optimized finite element model.

[0168] In some embodiments, the apparatus further comprises:

[0169] The reinforcement module is used to design reinforcement ribs and fill holes in the finite element model after topology optimization.

[0170] In some embodiments, the reinforcing rib design includes:

[0171] Determine the rib parameters, including thickness and angle, based on the topology optimization results;

[0172] A reference surface is established in the CAD model of the optimized cross-section structure, and radial plate-type stiffeners are formed by stretching based on the stiffener parameters.

[0173] In some embodiments, the porous filling comprises:

[0174] The bottom of the four-way structure is used as the filling object, and two layers of unit cells of a set size are filled on the surface of the finite element model after topology optimization.

[0175] In some embodiments, the device further comprises a verification module, configured to:

[0176] Under the condition of deadweight load, the optimized finite element model is checked for deformation, deformation angle and fundamental frequency;

[0177] The structural parameters of the optimized four-way structure are adjusted based on the verification results.

[0178] It can be understood that the detailed functional implementation of each of the above-mentioned units / modules can be found in the introduction of the aforementioned method embodiment, and will not be repeated here.

[0179] It should be understood that the above-mentioned device is used to execute the method in the above-mentioned embodiment. The implementation principle and technical effect of the corresponding program module in the device are similar to those described in the above-mentioned method. The working process of the device can refer to the corresponding process in the above-mentioned method, which will not be repeated here.

[0180] Based on the method in the above embodiment, an embodiment of the present application provides an electronic device. The device may include: at least one memory for storing programs and at least one processor for executing the programs stored in the memory. When the program stored in the memory is executed, the processor is used to execute the method described in the above embodiment.

[0181] Figure 5 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application, such as Figure 5 As shown, the electronic device may include: a processor 501, a communication interface 502, a memory 503 and a communication bus 504, wherein the processor 501, the communication interface 502 and the memory 503 communicate with each other through the communication bus 504. The processor 501 may call the software instructions in the memory 503 to execute the method described in the above embodiment.

[0182] In addition, the logic instructions in the above-mentioned memory 503 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the relevant technology or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present application.

[0183] Based on the method in the above embodiment, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method in the above embodiment.

[0184] Based on the method in the above embodiment, an embodiment of the present application provides a computer program product. When the computer program product runs on a processor, the processor executes the method in the above embodiment.

[0185] It is understandable that the processor in the embodiment of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0186] The method steps in the embodiments of the present application can be implemented by hardware, or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory (Random Access Memory, RAM), flash memory, read-only memory (Read-Only Memory, ROM), programmable read-only memory (Programmable ROM, PROM), erasable programmable read-only memory (Erasable PROM, EPROM), electrically erasable programmable read-only memory (Electrically EPROM, EEPROM), registers, hard disks, mobile hard disks, CD-ROMs or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC.

[0187] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions can be transmitted from a website site, a computer, a server or a data center to another website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or a data center that includes one or more available media integration. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.

[0188] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0189] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for optimizing the design of a cross-connection structure under deadweight conditions, characterized in that: include: Using 3D modeling software to perform 3D modeling on the cross-way structure to be optimized, and identifying and eliminating complex features of small gaps to obtain a CAD model of the cross-way structure; Importing the CAD model into Abaqus software, dividing the finite element mesh, constructing a finite element model and determining the designable domain and non-designable domain of topology optimization; Determine the working conditions under deadweight load based on basic displacement properties, preset loads and boundary conditions; Taking minimizing the mass of the four-way structure as the optimization goal and the working conditions under the deadweight load as the constraints, the finite element model is topologically optimized using the variable density method to obtain the mass-optimized finite element model and the corresponding lightweight four-way structure.

2. The method for optimizing the design of a cross-connection structure under deadweight conditions according to claim 1, characterized in that: The dividing of the finite element mesh comprises: Select the mesh type, global mesh size and element type in the Abaqus pre-processing module, automatically divide the finite element mesh and assign the element type; The mesh type is tetrahedral mesh, and the unit type is linear unit.

3. The method for optimizing the design of a cross-connection structure under deadweight conditions according to claim 1, characterized in that: The dividing of the finite element mesh comprises: Exporting a STEP model file from the Abaqus software and importing it into the Hypermesh software; In the Hypermesh software, the average length of the unit is set, and the two-dimensional mesh is divided using triangular units; Check mesh quality and correct unqualified elements based on element length and internal angle of triangle elements; Generate a 3D mesh based on the modified 2D mesh.

4. The method for optimizing the design of a cross-connection structure under deadweight conditions according to claim 1, characterized in that: The basic displacement properties include: model density, elastic modulus and Poisson's ratio; the boundary conditions include: fixed boundary conditions, weight boundary conditions and displacement boundary conditions, the weight boundary conditions include gravitational acceleration constraints in three-dimensional directions, and the displacement boundary conditions include the degrees of freedom of axial translation and rotation around the axis of the mounting surface in three-dimensional directions; the load includes: model self-weight.

5. The method for optimizing the design of a cross-connection structure under deadweight conditions according to claim 1, characterized in that: The method further comprises: With minimizing the flexibility of the four-way structure as the optimization goal, the finite element model after the mass optimization is topologically optimized to obtain a high-rigidity lightweight four-way structure.

6. The method for optimizing the design of a cross-connection structure under deadweight conditions according to claim 5, characterized in that: The topological optimization of the finite element model after the quality optimization comprises: Determine the designable domain and the undesignable domain in the optimized finite element model, wherein the undesignable domain includes the lens mounting surface, the bearing and motor mounting surface, the light outlet, and the additional equipment mounting surface, and the designable domain is the area except the undesignable domain; determining design variables including element density and a minimum size, the minimum size being determined based on an average element length of the finite element elements; Determine the response, including volume fraction and compliance; Taking minimizing the flexibility of the four-way structure as the optimization goal and taking the volume fraction being less than a preset value as the constraint condition, the OptiStruct solver is used to perform topology optimization on the optimized finite element model.

7. The method for optimizing the design of a cross-connection structure under deadweight conditions according to claim 1 or 5, characterized in that: The method further comprises: The finite element model after topology optimization is designed with reinforcement ribs and porous filling.

8. The method for optimizing the design of a cross-connection structure under deadweight conditions according to claim 7, characterized in that: The reinforcing rib design includes: Determine the rib parameters, including thickness and angle, based on the topology optimization results; A reference plane is established in the CAD model of the optimized cross-shaped structure, and the ribs are stretched based on the rib parameters to form radial plate-type ribs.

9. The method for optimizing the design of a cross-connection structure under deadweight conditions according to claim 7, characterized in that: The porous filling comprises: The bottom of the four-way structure is used as the filling object, and two layers of unit cells of a set size are filled on the surface of the finite element model after topology optimization.

10. The method for optimizing the design of a cross-connection structure under deadweight conditions according to claim 1, characterized in that: The method further comprises: Under the condition of deadweight load, the optimized finite element model is checked for deformation, deformation angle and fundamental frequency; The structural parameters of the optimized four-way structure are adjusted based on the verification results.

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