Method, device, storage medium and product for lightweighting a traction fan

Abstract

The application discloses a kind of lightweight methods, equipment, storage medium and product of traction fan, it is related to the field of structure optimization.The method includes that topological optimization calculation is carried out to base finite element model, according to the optimization result, the base finite element model is lightweight, and the base model after first optimization is obtained;Topological optimization calculation is carried out to the finite element model of wind cylinder, according to the optimization result, the finite element model of wind cylinder is lightweight, and the wind cylinder model after first optimization is obtained;According to the wind cylinder model after first optimization, the section size and the wall thickness of the parts of the base model after first optimization are designed as design variables, the original mode of base, the stiffness of mounting point and the strength under acceleration load are designed as design constraints, and the multi-objective optimization function with minimum mass and maximum flexibility as optimization goal is constructed, multi-objective optimization is carried out, and then the traction fan of power car is determined.The application can improve the effect and efficiency of the lightweight of traction fan of power car.

Description

Technical Field

[0001] This invention belongs to the field of structural optimization technology, and in particular relates to a method, equipment, storage medium and product for lightweighting a power vehicle traction fan. Background Technology

[0002] High-speed rail has experienced rapid development due to its advantages of large capacity, high speed, low energy consumption, and environmental friendliness. Nowadays, people have increasingly higher requirements for the quality, performance, and transportation efficiency of high-speed trains. As a key component of power vehicles, the lightweighting of traction fans is of great research value.

[0003] Lightweighting research on traction fans can effectively reduce overall vehicle weight and extend driving range. Major domestic and international lightweighting research areas include:

[0004] Reference 1 (Wang L, Wang T, Luo Y. Improved non-dominated sorting genetic algorithm (NSGA)-II in multi-objective optimization studies of wind turbine blades[J]. Applied Mathematics and Mechanics, 2011, 32: 739-748.) studies a new multi-objective optimization method for turbine blade structure by improving the non-dominated sorting genetic algorithm. The optimization results with the maximum power coefficient and minimum blade mass as objectives show that the optimization method has good performance in handling multi-objective optimization of wind turbine structure.

[0005] Reference 2 (Chen J, Wang Q, Shen WZ, et al. Structural optimization study of composite wind turbine blade[J]. Materials and Design, 2013, 46: 247-255.) uses a combination of finite element analysis and particle swarm optimization to optimize the design of composite wind turbine blades, effectively reducing the mass of the blades;

[0006] Reference 3 (Grujicic M, Arakere G, Pandurangan B, et al. Multidisciplinary design optimization for glass-fiber epoxy-matrix composite 5MW horizontal-axis wind-turbine blades[J]. Journal of Materials Engineering and Performance, 2010, 19(8): 1116-1127.) uses the structural finite element method and life assessment analysis to optimize the impeller by minimizing its mass and using static strength, fatigue life and stiffness as constraints. This multidisciplinary optimization design meets the requirements of lightweight impeller design.

[0007] Reference 4 (Negm HM, Maalawi K Y. Structural design optimization of windturbine towers[J].Computers and Structures,2000,74(6):649-666.) uses five optimization methods to optimize the wind turbine structure, transforms the optimization problem into a nonlinear programming problem, solves it using the inner penalty function method, and analyzes the optimal optimization scheme with reducing the vibration level as the objective function.

[0008] Reference 5 (Jureczko M, Pawlak M, A. Optimisation of wind turbine blades[J]. Journal of materials processing technology, 2005, 167(2): 463-471.) The composite material blade structure was optimized according to multiple standards.

[0009] Reference 6 (Luo Bin, Ding Shuiting, Li Guo. A CAD / CAE integration method for parametric lightweight turbine disk structure [J]. Journal of Aerospace Power, 2013, 28(09):2083-2089.) addresses the problem of lightweight design of turbine disk structure. It studies a highly efficient structural optimization design method for turbine disk CAD / CAE automatic integration based on unidirectional fluid-structure interaction algorithm by using parametric CAD modeling and establishing correlation with CAE program. Reference 7 (Meng Chunling, Hu Hongliang, Li Guofeng, et al. Strength analysis and optimization design of wind turbine hub based on ANSYS [J]. Computer Simulation, 2012, 29(07):334-338.) In the research on lightweight design of wind turbine hubs, in view of the problem that the traditional variable cross-section design is difficult to produce and does not include fatigue life analysis, a method is studied to reduce the weight of the wind turbine hub by drilling holes in the hub body; Reference 8 (Xie Guilan, Xiao Chunya, He Licai. Three-dimensional topology optimization design of composite materials for large wind turbine blades [J]. Fiberglass / Composite Materials, 2015(6):53-57.) In view of the problem of lightweighting of large wind turbine blades, three-dimensional topology optimization design was carried out on the basis of fiber reinforced composite material wind turbine blades; Reference 9 (Wang Quan, Chen Jin, Wang Jun, et al. Structural optimization design of composite material wind turbine blades under aerodynamic load [J]. Journal of Mechanical Engineering, 201 4,50(09):114-121.) Considering the aerodynamic load, the composite material wind turbine blade structure was optimized; Reference 10 (Feng Xiaobing, Huang Hai, Wang Wei. Optimization design of root strength of large wind turbine composite material blades based on genetic algorithm [J]. Journal of Composite Materials, 2012, 29(05):196-202.) adopted an improved genetic algorithm to optimize the plying design of large wind turbine composite material blades; Reference 11 (Sun Shunan. Optimization design of offshore tripod gantry wind turbine foundation structure based on reliability [D]. Dalian University of Technology, 2013.) considered the coefficients of variation and statistical laws of load, material and stress of offshore wind power, and optimized the design of composite material wind turbine blades based on aerodynamic load. Multi-objective reliability optimization of the wind turbine foundation structure was carried out, and good optimization design results were obtained. Reference 12 (Lu Qijin, Yang Hezhen. Stochastic dynamic optimization design of offshore wind power support structure [J]. Vibration and Shock, 2013, 32(17):46-51.DOI:10.13465 / j.cnki.jvs.2013.17.036.) fully considered the uncertainties of structural size, materials, environmental loads, etc., and adopted a method combining reliability analysis and structural optimization based on orthogonal experiments and Kriging model technology to carry out reliability optimization design of wind power structure, which has important reference value for practical engineering problems.

[0010] However, although the related technologies for the development of traction wind turbines are in the forward development stage, they only consider the structural mechanical performance and do not carry out refined lightweight design, resulting in serious local material redundancy. Lightweight design methods such as topology optimization are widely used in the structural optimization of automobiles and wind turbine blades, but they cannot be simply transferred to the lightweight design of traction wind turbines for power vehicles. Summary of the Invention

[0011] The purpose of this invention is to provide a method, device, storage medium and product for lightweighting traction fans, so as to solve the problem that traditional methods do not perform fine-grained lightweight design of traction fans, resulting in serious local material redundancy and poor lightweighting effect.

[0012] This invention solves the above-mentioned technical problems through the following technical solution: a method for lightweighting a traction fan, wherein the traction fan includes a base, a fan casing, and a duct, and the lightweighting method includes:

[0013] Construct a finite element model of the base;

[0014] Based on symmetric or asymmetric constraints, with the first constraint condition and the maximum bottom compliance as the objective function, topology optimization calculations are performed on the finite element model of the base to obtain the first optimization result.

[0015] Based on the first optimization result, the finite element model of the base is lightened to obtain a base model after one optimization.

[0016] Construct a finite element model of the ventilation duct;

[0017] Based on cyclic symmetric constraints or axial compression constraints, with the second constraint condition and the maximum flexibility of the duct as the objective function, topology optimization calculations are performed on the finite element model of the duct to obtain the second optimization result.

[0018] Based on the second optimization result, the finite element model of the ventilation duct is lightened to obtain the optimized ventilation duct model.

[0019] Based on the first optimized duct model, a multi-objective optimization function is constructed, with the cross-sectional dimensions of the first optimized base model and the wall thickness of all base components as design variables, the original mode of the base, the stiffness of the mounting point, and the strength under acceleration load as design constraints, and the optimization objectives of minimizing mass and maximizing flexibility as optimization goals. Multi-objective optimization is then performed to obtain the second optimized base model.

[0020] The power vehicle traction fan is determined based on the base model after secondary optimization and the wind tunnel model after primary optimization.

[0021] Furthermore, the construction of the finite element model of the base specifically includes:

[0022] Construct a 3D model of the base based on its outline dimensions;

[0023] The three-dimensional model of the base is meshed to obtain a base mesh model; wherein, the base mesh model uses CTETRA solid elements;

[0024] Loads and constraints are applied to the base mesh model to obtain the base finite element model.

[0025] Furthermore, the first constraint condition is that the first-order modal frequency is less than 67.8 Hz and the volume fraction is less than 0.2.

[0026] Furthermore, the finite element model of the base is lightweighted based on the first optimization result, specifically including:

[0027] Based on the first optimization result, vertical reinforcing ribs are designed on the back panel of the base, the side panels of the base are designed as partially hollowed-out structures, horizontal or vertical reinforcing ribs are designed on the front wall panel of the base, the support feet of the base are designed as square steel support feet, and local reinforcing parts are added to connect the square steel support feet with each panel, or the middle of the front support structure is designed as a hollowed-out structure.

[0028] Furthermore, the construction of the finite element model of the ventilation duct specifically includes...

[0029] Construct a three-dimensional model of the ventilation duct based on its outline dimensions;

[0030] The three-dimensional model of the ventilation duct is meshed to obtain a mesh model of the ventilation duct; wherein, the mesh model of the ventilation duct adopts a CHEXA hexahedral mesh.

[0031] Loads and constraints are applied to the mesh model of the duct to obtain the finite element model of the duct.

[0032] Furthermore, the second constraint is that the first-order modal frequency is greater than 337Hz and the volume fraction is less than 0.3.

[0033] Furthermore, the finite element model of the ventilation duct is lightweighted based on the second optimization result, specifically including:

[0034] Based on the second optimization result obtained from the cyclic symmetry constraint, a grass-shaped reinforcing member is added to the outside of the air duct to reduce the wall thickness of the air duct corresponding to the non-electrical box position.

[0035] Based on the second optimization result obtained from the axial compression constraint, the number of vertical stiffeners is increased and the wall thickness of the wind tunnel is reduced.

[0036] Based on the same concept, the present invention also provides an electronic device, including a memory, a processor, and a computer program / instructions stored in the memory, wherein the processor executes the computer program / instructions to implement the traction wind turbine lightweighting method as described above.

[0037] Based on the same concept, the present invention also provides a computer-readable storage medium having a computer program / instructions stored thereon, which, when executed by a processor, implements the traction fan lightweighting method as described above.

[0038] Based on the same concept, the present invention also provides a computer program product, including a computer program / instructions, which, when executed by a processor, implement the traction fan lightweighting method as described above.

[0039] Beneficial effects

[0040] Compared with the prior art, the advantages of the present invention are as follows:

[0041] This invention, based on the finite element model of the base, performs topology optimization calculations using symmetric or asymmetric constraints, with the first constraint condition and maximizing the base's flexibility as the objective function, to obtain a first optimization result. Similarly, based on the finite element model of the wind tunnel, it performs topology optimization calculations using cyclic symmetric constraints or axial compression constraints, with the second constraint condition and maximizing the wind tunnel's flexibility as the objective function, to obtain a second optimization result. Based on the optimized wind tunnel model, a multi-objective optimization is established, using the cross-sectional dimensions and component wall thickness of the optimized base model as design variables, the original mode of the base, the stiffness of the mounting point, and the strength under acceleration load as design constraints, and minimizing mass and maximizing flexibility as optimization objectives. This invention adopts a reverse engineering approach to optimize the base and wind tunnel, resulting in lightweight base and wind tunnel components. By iterating the objective function, the overall design efficiency is improved. This invention can improve the lightweighting effect and efficiency of traction fans for power vehicles. Attached Figure Description

[0042] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart of the lightweight traction fan method in an embodiment of the present invention;

[0044] Figure 2 This is the finite element model of the base in the embodiment of the present invention;

[0045] Figure 3This is the first optimization result under symmetric constraints and working condition S2 in the embodiments of the present invention;

[0046] Figure 4 This is the first optimization result under asymmetric constraints and operating condition S2 in the embodiments of the present invention;

[0047] Figure 5 This is a schematic diagram of the back panel of the base with vertical reinforcing ribs, obtained from the first optimization result under symmetry constraints in an embodiment of the present invention.

[0048] Figure 6 This is a schematic diagram of the partially hollowed-out side panel of the base obtained from the first optimization result under symmetry constraints in an embodiment of the present invention.

[0049] Figure 7 This is a schematic diagram of the front wall panel of the base with transverse reinforcing ribs, obtained from the first optimization result under symmetry constraints in an embodiment of the present invention.

[0050] Figure 8 This is a schematic diagram of a square steel support leg obtained from the first optimization result under symmetry constraints in an embodiment of the present invention;

[0051] Figure 9 This is a schematic diagram of the base after one optimization obtained based on the first optimization result under symmetry constraints in an embodiment of the present invention;

[0052] Figure 10 This is a schematic diagram of the back panel of the base with vertical reinforcing ribs, obtained from the first optimization result under asymmetric constraints in an embodiment of the present invention.

[0053] Figure 11 This is a schematic diagram of the partially hollowed-out side panel of the base obtained based on the first optimization result under asymmetric constraints in an embodiment of the present invention.

[0054] Figure 12 This is a schematic diagram of a front wall panel with vertical stiffeners, obtained from the first optimization result under asymmetric constraints in an embodiment of the present invention.

[0055] Figure 13 This is a schematic diagram of the hollowed-out front support structure obtained based on the first optimization result under asymmetric constraints in an embodiment of the present invention;

[0056] Figure 14 This is a schematic diagram of a rear sheet metal part with a cavity structure obtained from the first optimization result under asymmetric constraints in an embodiment of the present invention.

[0057] Figure 15 This is a schematic diagram of the base after one optimization obtained based on the first optimization result under asymmetric constraints in an embodiment of the present invention;

[0058] Figure 16 This is the finite element model of the ventilation duct in this embodiment of the invention;

[0059] Figure 17 This is a schematic diagram of the wind tunnel obtained from the second optimization result based on cyclic symmetry constraints in an embodiment of the present invention;

[0060] Figure 18 This is a schematic diagram of the optimized wind tunnel obtained from the second optimization result based on cyclic symmetry constraints in an embodiment of the present invention.

[0061] Figure 19 This is a schematic diagram of the original air duct with 4 vertical reinforcing ribs in an embodiment of the present invention;

[0062] Figure 20 This is a schematic diagram of the wind tunnel obtained from the second optimization result based on axial compression constraint in an embodiment of the present invention;

[0063] Figure 21 This is a schematic diagram of the optimized air duct obtained from the second optimization result based on axial compression constraint in an embodiment of the present invention;

[0064] Figure 22 This is the result of multi-objective optimization of the front support structure of the base in the embodiment of the present invention;

[0065] Figure 23 This is the result of multi-objective optimization of the side panel of the base in this embodiment of the invention;

[0066] Figure 24 This is the optimized traction fan in the embodiments of the present invention;

[0067] Figure 25 This is a stress cloud diagram of the guide vane weld in an embodiment of the present invention;

[0068] Figure 26 This is a stress cloud diagram of the stiffener weld in an embodiment of the present invention.

[0069] Explanation of reference numerals in the attached drawings: 1-base, 11-back panel, 12-front support structure, 13-front wall panel, 14-rear support structure, 15-vehicle mounting plate, 16-front support plate, 2-air duct, 21-duct body, 22-grass-shaped reinforcing member, 23-vertical reinforcing rib, 24-lower flange, 3-air duct. Detailed Implementation

[0070] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] The technical solutions of this application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0072] Example 1

[0073] The power vehicle traction fan includes a base 1, a fan duct 2, and a duct 3 (such as...). Figure 24 As shown in the figure, the air duct includes a motor, impeller, sealing ring, etc., and the components are fixed by bolts, plugs and crimps.

[0074] Figure 1 A flowchart of the lightweight traction fan method provided by the present invention is shown, as follows: Figure 1 As shown, the lightweighting method for the traction fan includes the following steps:

[0075] Step 1: Construct the finite element model of the base.

[0076] In a specific embodiment of the present invention, the specific implementation process for constructing the finite element model of the base includes:

[0077] Step 1.1: Construct a 3D model of the base based on its outline dimensions.

[0078] Step 1.2: Mesh the 3D model of the base to obtain the base mesh model.

[0079] The 3D model of the base was meshed using Hypermesh software. In this embodiment, the base mesh model uses CTETRA solid elements with a mesh size of 2mm. The total number of elements in the base mesh model is approximately 4.187 million, and the number of nodes is approximately 847,000.

[0080] Step 1.3: Apply loads and constraints to the base mesh model to obtain the base finite element model, as shown below. Figure 2 As shown. Figure 2 In this design, the installation location of the air duct on the upper surface of the base is a non-design area, while the remaining area is the design area (i.e., the blue area). The external nodes of the non-design area are coupled to the center of this area, which serves as the load application point for the base. This constrains the 1-6 degrees of freedom (i.e., translation and rotation in the XYZ directions) of the area connecting the base bottom to the floor. The coordinate system used in this embodiment is the vehicle's overall coordinate system (i.e., the global coordinate system). The load conditions of the base are shown in Table 1.

[0081] Table 1 Load conditions of the base

[0082]

[0083] In Table 1, m represents mass and g represents gravitational acceleration.

[0084] Step 2: Based on symmetric or asymmetric constraints, with the first constraint condition and the maximum bottom compliance as the objective function, perform topology optimization calculations on the finite element model of the base to obtain the first optimization result.

[0085] The finite element model of the base was used for topology optimization calculations in the Optistruct module of HyperWorks software. The first optimization result obtained was the load transfer path of the base. In this embodiment, the first constraint conditions were a first-order modal frequency of less than 67.8 Hz and a volume fraction of less than 0.2. By comparison, the first optimization result under condition S2 in Table 1 is more effective, as shown below. Figure 3 and Figure 4 As shown. According to Figure 3 and Figure 4 It can be seen that after adding symmetry constraints, the cloud map of the first optimization result has good symmetry, which has great reference value for the subsequent lightweighting of the base.

[0086] Step 3: Based on the first optimization result, the finite element model of the base is lightened to obtain the base model after one optimization.

[0087] In one specific embodiment of the present invention, the finite element model of the base is lightened based on the first optimization result obtained based on symmetry constraints and working condition S2:

[0088] Based on the first optimization result obtained from symmetry constraints and working condition S2, a rib structure appears on the back panel of the base. Therefore, vertical reinforcing ribs are designed on the back panel of the base, such as... Figure 5 As shown; a hollow structure appears on the side of the base, therefore the side panel of the base is designed with a partial hollow structure, that is, part of the material of the side panel of the base is removed, such as... Figure 6 As shown; a distinct ribbed structure appears on the front wall of the base, therefore, transverse reinforcing ribs are designed on the front wall panel of the base, such as... Figure 7 As shown;

[0089] Based on the first optimization result obtained from symmetry constraints and working condition S2, it can be seen that the main load transmission path is the four front and rear support legs. Therefore, the lightweight design only strengthens this transmission path, designing the four support legs of the base as square steel support legs, and adding local reinforcements to connect the square steel support legs to each panel, such as... Figure 8 As shown. Based on the first optimization result obtained according to the symmetry constraints and working condition S2, the final design scheme of the base is as follows. Figure 9 As shown, the weight of the base has been reduced from 81kg to 51.1kg, a reduction of 29.9kg.

[0090] In another specific embodiment of the present invention, the finite element model of the base is lightened according to the first optimization result obtained based on asymmetric constraints and working condition S2:

[0091] Based on the first optimization result obtained from asymmetric constraints and working condition S2, it can be seen that a rib structure appears on the back panel 11 of the base 1. Therefore, the original one-piece structure is disassembled, and vertical reinforcing ribs are designed on the back panel 11 of the base 1, such as... Figure 10 As shown; the side panel of base 1 is designed with a partially hollowed-out structure, that is, part of the material of the side panel of base 1 is removed, such as... Figure 11 As shown; a cross-ribbed structure appears on the front wall of the base 1, therefore, vertical reinforcing ribs are designed on the front wall panel 13 of the base 1 to improve its vertical load-bearing capacity, such as... Figure 12 As shown;

[0092] Based on the first optimization result obtained from asymmetric constraints and working condition S2, it can be seen that the main load transmission path is through the four front and rear support legs. The front support structure 12 has a hollow center. Therefore, the lightweight design only strengthens this transmission path, making the center of the front support structure 12 a hollow structure. Figure 13 As shown; based on the rear sheet metal structure, front and rear reinforcing members are added, and the rear sheet metal part forms a cavity structure to improve the cross-sectional stiffness, such as... Figure 14 As shown. Based on the first optimization result obtained according to asymmetric constraints and working condition S2, the final design scheme of the base is as follows. Figure 15 As shown, the base weighs 54.5 kg, a reduction of 26.5 kg from the initial weight.

[0093] Step 4: Construct the finite element model of the ventilation duct.

[0094] In a specific embodiment of the present invention, a finite element model of the ventilation duct is constructed, specifically including...

[0095] Step 4.1: Construct a 3D model of the ventilation duct based on its outline dimensions.

[0096] Step 4.2: Mesh the 3D model of the ventilation duct to obtain the mesh model of the ventilation duct.

[0097] The 3D model of the ventilation duct was meshed using Hypermesh software. In this embodiment, the ventilation duct mesh model adopted a CHEXA hexahedral mesh, with approximately 1.553 million elements and 1.731 million nodes in the entire mesh model.

[0098] Step 4.3: Apply loads and constraints to the duct mesh model to obtain the duct finite element model.

[0099] like Figure 16As shown, the interior of the duct and the installation area are designated as the non-design area (i.e., the gray area), while the exterior is designated as the design area (i.e., the yellow area). The bolt holes on the upper surface of the duct are coupled to a central point, which serves as the load application point (applied mass m1) for the upper component of the duct. The blade edges inside the duct are coupled to a central point, which serves as the motor load application point (applied motor mass m2). The bolt mounting holes on the lower surface are constrained for degrees of freedom 1-6 (i.e., translation and rotation in the XYZ directions). The load application conditions for the load application points of the upper component of the duct are shown in Table 1. Two schemes are used: cyclic symmetric constraint (period of 8) and axial compression constraint. In condition S1, the displacement of the load application point of the upper component of the duct is less than 0.0053 mm, and the displacement of the lower coupling point (i.e., the bolt mounting holes on the lower surface coupled to a central point) is less than 0.0368 mm. In condition S2, the displacement of the load application point of the upper component of the duct is less than 0.0186 mm, and the displacement of the lower coupling point is less than 0.0153 mm.

[0100] Step 5: Based on cyclic symmetric constraints or axial compression constraints, and with the second constraint condition and the maximum flexibility of the duct as the objective function, perform topology optimization calculations on the finite element model of the duct to obtain the second optimization result.

[0101] The finite element model of the ventilation duct was used for topology optimization calculations in the Optistruct module of HyperWorks software. The second optimization result obtained was the load transfer path of the ventilation duct. In this embodiment, the second constraint conditions were: first-order modal frequency greater than 337Hz; volume fraction less than 0.3.

[0102] Step 6: Based on the second optimization result, the finite element model of the ventilation duct is lightened to obtain the optimized ventilation duct model.

[0103] In one specific embodiment of the present invention, the finite element model of the ventilation duct is lightened according to the second optimization result obtained based on cyclic symmetry constraints:

[0104] Based on the second optimization result obtained from the cyclic symmetry constraint, three 0.7mm thick reinforcing members 22 are added to the outside of the duct body 21, reducing the wall thickness of the duct body 21 corresponding to the non-electrical enclosure location from 4mm to 3mm (i.e., avoiding the electrical enclosure location, reducing the wall thickness of the duct body 21 from 4mm to 3mm). Figure 17 As shown. Based on the second optimization result obtained based on cyclic symmetry constraints, the final design scheme of the wind tunnel is as follows. Figure 18 As shown, the weight of the ventilation duct was reduced from 20.06 kg to 16.56 kg, a reduction of 3.5 kg.

[0105] In another specific embodiment of the present invention, the finite element model of the ventilation duct is lightened according to the second optimization result obtained based on the axial compression constraint:

[0106] According to the second optimization result based on axial compression constraint, the distribution of the vertical stiffeners is relatively uniform. Therefore, the original four vertical stiffeners 23 (as shown in the image) of the air duct are adjusted. Figure 19 (As shown) Increase to 8 roots, and distribute them evenly according to the topological positions of the second optimization result, such as Figure 20 As shown, the wall thickness of the ventilation duct was reduced from 4mm to 3mm. Based on the second optimization result obtained from the axial compression constraint, the final design scheme of the ventilation duct is as follows. Figure 21 As shown, the weight of the ventilation duct was reduced from 20.06 kg to 17.08 kg, a reduction of 2.26 kg.

[0107] Step 7: Based on the first optimized duct model, construct a multi-objective optimization function with the cross-sectional dimensions of the first optimized base model and the wall thickness of all base components as design variables, the original mode of the base, the stiffness of the mounting point, and the strength under acceleration load as design constraints, and the optimization objectives of minimizing mass and maximizing flexibility as optimization goals, to obtain the second optimized base model.

[0108] like Figure 22 and Figure 23 As shown, the weight of the base model after the second optimization was reduced to 50.44 kg, achieving a weight reduction of 30.56 kg.

[0109] Step 8: Determine the power vehicle traction fan based on the base model after secondary optimization and the wind tunnel model after primary optimization.

[0110] The performance parameters of each component of the power vehicle traction fan obtained by this invention are shown in Table 2.

[0111] Table 2 Performance parameters of various components of the traction fan

[0112]

[0113] Based on the structural requirements of railway applications—track bodies—basic performance analyses, including constrained modal analysis, static strength analysis, and weld fatigue strength analysis, were performed on the traction fan. The traction fan's duct inlet and the connection between the base and the floor were constrained for degrees of freedom 1-6. According to relevant standards, static strength analysis and weld fatigue strength analysis require loading gravitational acceleration in the X, Y, and Z directions. The loading conditions are shown in Tables 3 and 4.

[0114] Table 3 Loading conditions for static strength analysis

[0115] Load conditions X direction Y direction Z direction S1 \ \ -3g S2 \ \ 1g S3 3g \ -1g S4 -3g \ -1g S5 \ 1g -1g S6 \ -1g -1g

[0116] Table 4 Loading conditions for weld fatigue strength analysis

[0117] Load conditions X direction Y direction Z direction D1 +0.15g +0.12g 1.075g D2 +0.15g +0.12g 0.925g D3 +0.15g -0.12g 1.075g D4 +0.1g -0.12g 0.25g D5 -0.15g +0.12g 1.075g D6 -0.15g +0.12g 0.925g D7 -0.15g -0.12g 1.075g D8 -0.15g -0.12g 0.925g D9 / +0.15g 1.15g D10 / +0.15g 0.85g D11 / -0.15g 1.15g D12 / -0.15g 0.85g

[0118] According to the fourth strength theory, the square root shear stress generated on a single element is the main cause of yield failure. Regardless of the stress state, yield failure will occur when the shear stress equals the material's ultimate limit. Plastic deformation or material failure indicates structural failure. Strength represents the traction fan's ability to resist damage under external forces and is a crucial requirement in structural design. To ensure the traction fan operates normally, it is essential to ensure that the maximum stress on all components of the vehicle body is less than the material's allowable stress under every operating condition.

[0119] The condition under which the stress generated by the applied load under various operating conditions cannot cause the traction fan structure to fail is:

[0120]

[0121] Where: σ ε The equivalent stress is [σ], where [σ] is the allowable stress of the material; σ1, σ2, and σ3 are the first, second, and third principal stresses, respectively, and [σ] = σ s / n, σ s This represents the yield strength of the material, and n is the safety factor, which takes the value of 1.15.

[0122] The results of the first six modal calculations of the traction fan are shown in Table 5, and Table 6 shows the static strength analysis results of the fan. Table 6 shows that the safety factors of all components of the traction fan are within the safe range under different operating conditions. The fan welds mainly consist of guide vane welds and stiffener welds. Table 7 shows the calculated results of allowable fatigue values ​​and load ratios for the fan welds. Table 7 shows that the longitudinal and vertical normal stresses and longitudinal shear forces of the guide vane welds and stiffener welds are all qualified, the weld bearing capacity is low, the safety requirement level is medium, and the weld quality level is CPC3.

[0123] Table 5 Calculation results of the first six modes of the traction fan

[0124] order 1 2 3 4 5 6 Frequency (Hz) 45.56 50.54 61.93 66.85 69.64 76.49

[0125] Table 6 Results of Static Strength Analysis of the Fan

[0126]

[0127] Table 7. Calculation results of allowable fatigue values ​​and load ratios for wind turbine welds.

[0128]

[0129]

[0130] Based on the above optimization results, the traction fan was further optimized. The base was lightweighted using a first optimized structure derived from asymmetric constraints, and the duct was lightweighted using a second optimized structure derived from cyclic symmetric constraints. The final optimized model of the traction fan is as follows: Figure 24 As shown, a total weight reduction of 34.06 kg was achieved. The thickness of the optimized traction fan structure changed. To verify the rationality and correctness of the optimization scheme, it is necessary to check the static strength and fatigue strength of the optimized traction fan and perform modal analysis to determine whether the strength and stiffness of the optimized fan structure meet the requirements.

[0131] The traction fan was checked by constraint mode. The first six constraint modes were calculated by constraining the fan duct opening, the base and the connection position of the floor. As shown in Table 5, the natural frequency of the optimized traction fan model was significantly improved, which can effectively avoid the resonance phenomenon caused by external excitation.

[0132] As shown in Table 6, the safety factors of all components of the traction fan are within the safe range, and the safety factors are significantly improved compared with the original model.

[0133] As shown in Table 7, the longitudinal and vertical normal stresses and longitudinal shear forces of the guide vane welds and stiffening plate welds of the traction fan are all qualified. The weld bearing condition is low, the safety requirement level is medium, and the weld quality level is CPC3. Figure 25 and Figure 26 These are stress contour diagrams for the guide vane weld and the stiffening plate weld, respectively. Figure 25 and Figure 26 The numbers on the middle cylinder indicate the corresponding stress values, for example... Figure 25 The number 3.15 on the cylinder in the maximum normal stress cloud diagram in the Y direction indicates the location and specific value of the maximum normal stress in the Y direction.

[0134] Based on the existing traction fan model, topology optimization and multi-objective optimization were performed. An optimized traction fan model was designed and manufactured based on the optimization results. The optimized model achieved a weight reduction of 34.06 kg compared to the original model, a weight reduction ratio of 12.69%, achieving the lightweight design goal. While achieving weight reduction, the optimized traction fan model met the requirements for basic properties such as constrained modal characteristics, static strength, and weld fatigue strength, and showed significant improvements compared to the original model. A traction fan was manufactured based on the optimized model, and relevant performance tests were conducted. The test results all met the design and usage requirements.

[0135] Example 2

[0136] This invention also provides an electronic device, which includes: a memory, a processor, and a computer program / instructions stored in the memory. The processor executes the computer program / instructions to implement the traction fan lightweighting method in this application embodiment.

[0137] Although not shown, the electronic device includes a processor that can perform various appropriate operations and processes based on programs and / or data stored in read-only memory (ROM) or loaded from a storage portion into random access memory (RAM). The processor can be a multi-core processor or may contain multiple processors. In some embodiments, the processor may include a general-purpose main processor and one or more specialized coprocessors, such as a central processing unit, graphics processing unit (GPU), neural network processor (NPU), digital signal processor (DSP), etc. Various programs and data required for device operation are also stored in RAM. The processor, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0138] The processor and memory described above are used together to execute programs / instructions stored in the memory. When the program / instructions are executed by the computer, they can implement the methods, steps, or functions described in the above embodiments.

[0139] Although not shown, embodiments of the present invention also provide a computer-readable storage medium having a computer program / instructions stored thereon, which, when executed by a processor, implements the traction fan lightweighting method of the present application embodiments.

[0140] Readable storage media include both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer 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 technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient media, such as modulated data signals and carrier waves.

[0141] Although not shown, embodiments of the present invention also provide a computer program product, including: a computer program / instructions that, when executed by a processor, implement the traction fan lightweighting method in the embodiments of this application.

[0142] The above description only discloses specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or modifications that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for lightweighting a traction fan, the traction fan comprising a base, a fan casing, and a duct, characterized in that, The lightweighting method includes: Construct a finite element model of the base; Based on symmetric or asymmetric constraints, with the first constraint condition and the maximum bottom compliance as the objective function, topology optimization calculations are performed on the finite element model of the base to obtain the first optimization result. Based on the first optimization result, the finite element model of the base is lightened to obtain a base model after one optimization. Construct a finite element model of the ventilation duct; Based on cyclic symmetric constraints or axial compression constraints, with the second constraint condition and the maximum flexibility of the duct as the objective function, topology optimization calculations are performed on the finite element model of the duct to obtain the second optimization result. Based on the second optimization result, the finite element model of the ventilation duct is lightened to obtain the optimized ventilation duct model. Based on the first optimized duct model, a multi-objective optimization function is constructed, with the cross-sectional dimensions of the first optimized base model and the wall thickness of all base components as design variables, the original mode of the base, the stiffness of the mounting point, and the strength under acceleration load as design constraints, and the optimization objectives of minimizing mass and maximizing flexibility as optimization goals. Multi-objective optimization is then performed to obtain the second optimized base model. The power vehicle traction fan is determined based on the base model after secondary optimization and the wind tunnel model after primary optimization. Specifically, the finite element model of the ventilation duct is lightweighted based on the second optimization result, including: Based on the second optimization result obtained from the cyclic symmetry constraint, a grass-shaped reinforcing member is added to the outside of the air duct to reduce the wall thickness of the air duct corresponding to the non-electrical box position. Based on the second optimization result obtained from the axial compression constraint, the number of vertical stiffeners is increased and the wall thickness of the wind tunnel is reduced.

2. The lightweighting method for traction fans according to claim 1, characterized in that, The construction of the finite element model of the base specifically includes: Construct a 3D model of the base based on its outline dimensions; The three-dimensional model of the base is meshed to obtain a base mesh model; wherein, the base mesh model uses CTETRA solid elements; Loads and constraints are applied to the base mesh model to obtain the base finite element model.

3. The lightweighting method for traction fans according to claim 1, characterized in that, The first constraint is that the first-order modal frequency is less than 67.8 Hz and the volume fraction is less than 0.

2.

4. The lightweighting method for traction fans according to claim 1, characterized in that, The finite element model of the base is lightened based on the first optimization result, specifically including: Based on the first optimization result, vertical reinforcing ribs are designed on the back panel of the base, the side panels of the base are designed as partially hollowed-out structures, horizontal or vertical reinforcing ribs are designed on the front wall panel of the base, the support feet of the base are designed as square steel support feet, and local reinforcing parts are added to connect the square steel support feet with each panel, or the middle of the front support structure is designed as a hollowed-out structure.

5. The lightweighting method for traction fans according to claim 1, characterized in that, The construction of the finite element model of the ventilation duct specifically includes: Construct a three-dimensional model of the ventilation duct based on its outline dimensions; The three-dimensional model of the ventilation duct is meshed to obtain a mesh model of the ventilation duct; wherein, the mesh model of the ventilation duct adopts a CHEXA hexahedral mesh. Loads and constraints are applied to the mesh model of the duct to obtain the finite element model of the duct.

6. The lightweighting method for traction fans according to claim 1, characterized in that, The second constraint is that the first-order modal frequency is greater than 337Hz and the volume fraction is less than 0.

3.

7. An electronic device comprising a memory, a processor, and a computer program / instructions stored in the memory, characterized in that, The processor executes the computer program / instructions to implement the traction fan lightweighting method as described in any one of claims 1 to 6.

8. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that, When the computer program / instruction is executed by the processor, it implements the traction fan lightweighting method as described in any one of claims 1 to 6.

9. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instruction is executed by the processor, it implements the traction fan lightweighting method as described in any one of claims 1 to 6.

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