A laser deposition manufacturing method for large wing frame beams combined with topology optimization

Abstract

The present invention discloses a laser deposition manufacturing method for a large wing frame beam combined with topology optimization, which belongs to the field of laser additive manufacturing. The method comprises the following steps: based on the aerodynamic load and fatigue life characteristics of the wing frame beam, the wing frame beam is topologically optimized to obtain an output frame structure; the output frame structure is divided into parts to obtain a main body and a sub-body; the main body and the sub-body are scanned based on a variety of scanning methods to obtain a manufactured main body and sub-body; the manufactured main body and the sub-body are connected by laser additive according to the positional relationship to obtain an integral wing frame beam. The present invention solves the problems of heavy wing frame beams and complex structures, has the effects of structural optimization, lightweight and integration, and improves product quality and production efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser additive manufacturing, and in particular relates to a laser deposition manufacturing method for a large wing frame beam combined with topology optimization. Background Art

[0002] Large wing frame beam structures are important core components of various types of aircraft. They are widely used in the aerospace field and play an important role in supporting the overall fuselage structure and bearing alternating loads. Topological optimization composite laser additive manufacturing is a key manufacturing technology for achieving lightweight and integrated parts such as wing frame beam structures.

[0003] Topological optimization of structures is an advanced design concept, and topological optimization composite laser additive technology is an advanced processing method. Under certain loads, constraints and design goals, the optimal distribution of materials in the design domain is found to obtain a new structure that meets the use requirements. After topological optimization, the wing frame beam structure is lightweight, which increases the aircraft's flight time and carrying capacity. Laser additive manufacturing has solved the production defects of traditional processing methods to a certain extent, such as size restrictions and shape design. Lightweight structures, multi-scale assemblies, and integrated design and manufacturing are achieved. At the same time, the accessibility of traditional tool processing is alleviated, and the manufacturing space of complex structures is expanded. Therefore, the present invention proposes a laser deposition manufacturing method for large wing frame beams combined with topological optimization. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a laser deposition manufacturing method for a large wing frame beam combined with topology optimization to solve the problems existing in the above prior art.

[0005] To achieve the above object, the present invention provides a laser deposition manufacturing method for a large wing frame beam combined with topology optimization, comprising:

[0006] Based on the aerodynamic load and fatigue life characteristics of the wing frame beam, the wing frame beam is topologically optimized to obtain the output frame structure;

[0007] Dividing the output frame structure into parts to obtain a main body and sub-bodies;

[0008] Scanning the main body and the sub-body based on a plurality of scanning modes to obtain the manufactured main body and the sub-body;

[0009] The manufactured main body and sub-body are connected by laser additive manufacturing according to the positional relationship to obtain an integral wing frame beam.

[0010] Optionally, based on the aerodynamic load and fatigue life characteristics of the wing frame beam, the process of topologically optimizing the wing frame beam to obtain an output frame structure includes:

[0011] The aerodynamic loads on the wing frame beam are calculated based on the incompressible steady three-dimensional continuity equation and the kinetic energy equation;

[0012] Based on the aerodynamic loads on the wing frame beam, the fatigue life characteristics of the key structure are obtained by finite element analysis;

[0013] Based on the fatigue life characteristics of the key structure, topology optimization is performed with minimum volume as the optimization target to obtain the output frame structure.

[0014] Optionally, based on the aerodynamic loads on the wing frame beam, the process of obtaining the fatigue life characteristics of the key structure by finite element analysis includes:

[0015] Obtaining a maximum aerodynamic lift-drag resultant force based on the aerodynamic loads on the wing frame beam;

[0016] Based on the maximum aerodynamic lift-drag combined force, a finite element static analysis is performed to obtain the stress and strain response of the wing frame under the extreme working condition load;

[0017] Fe-safe fatigue analysis software is used to calculate the stress and strain response of the wing frame under the extreme working load to obtain the fatigue life characteristics of the key structure.

[0018] Optionally, the fatigue life characteristics of the critical structure include detail location structural reliability and detail fatigue rating;

[0019] The calculation formula of the structural reliability of the detailed parts is:

[0020]

[0021] The fatigue rating is calculated as:

[0022]

[0023] In the formula, represents the structural reliability of the detailed parts, γ is the service life of titanium alloy; W T W is the titanium alloy coefficient; C is the confidence constant; W R is the reliability constant; U is the fatigue rating of the structural component; P is the stress ratio; δ m0 is the characteristic parameter of titanium alloy material; δ max It is the maximum stress parameter when using titanium alloy.

[0024] Optionally, the process of performing topology optimization with minimum volume as the optimization goal includes performing topology optimization analysis based on a SIMP algorithm;

[0025] Wherein, the left rib plate and the right rib plate of the wing frame beam are optimized and analyzed with the optimal structural layout;

[0026] The front beam, middle beam, rear beam and middle rib plate of the wing frame beam are optimized and analyzed based on the force weight ratio.

[0027] Optionally, the process of dividing the output frame structure into parts to obtain a main body and sub-bodies includes:

[0028] Conducting load distribution simulation analysis on the output frame structure to establish a simulation model;

[0029] Meshing the simulation model and applying load to obtain load distribution;

[0030] Based on the use position, processing difficulty, size and load distribution of the parts in the simulation model, the parts are divided into main bodies and sub-bodies.

[0031] Optionally, the process of scanning the main body and the sub-body to obtain the manufactured main body and the sub-body includes:

[0032] The laser was used to perform serpentine reciprocating scanning on the substrate surface. When the sample deposition height was 100 mm, stress annealing was performed to obtain the first scanning component.

[0033] Based on the initial scanning component, laser scanning and fixed-height annealing are cyclically performed until the processing is completed to obtain the manufactured main body and sub-body.

[0034] Optionally, the scanning method includes:

[0035] The main body is scanned at 45° between layers;

[0036] The sub-body includes: a first sub-body, a second sub-body, a third sub-body and a fourth sub-body;

[0037] The first sub-volume and the second sub-volume are subjected to 90° interlayer staggered scanning; the third sub-volume is subjected to single-layer reciprocating scanning; and the fourth sub-volume is subjected to conventional scanning.

[0038] Optionally, the process of laser additively connecting the manufactured main body and sub-body includes a crystallization annealing heat treatment; the conditions of the crystallization annealing heat treatment include: a temperature of 950° C. and a time of 4 hours.

[0039] Compared with the prior art, the present invention has the following advantages and technical effects:

[0040] The present invention performs topological optimization on the wing frame beam based on the aerodynamic load and fatigue life characteristics of the wing frame beam to obtain an output frame structure; divides the output frame structure into parts to obtain a main body and a sub-body; scans the main body and the sub-body based on a variety of scanning methods to obtain a manufactured main body and sub-body; and performs laser additive connection on the manufactured main body and sub-body according to a positional relationship to obtain an integral wing frame beam.

[0041] Compared with the prior art, the present invention adopts a more advanced topology optimization composite laser additive manufacturing technology, which has a wider range of applications. According to the aerodynamic load and fatigue life characteristics of the wing frame beam, the wing frame beam is topologically optimized. During the structural optimization process, the optimization parameters do not require manual intervention, can be adjusted automatically during the iteration process, and the design target value is accurate. The main body and the individual are manufactured in blocks, which better guarantees the forming accuracy of each block. The use of laser scanning substrate to reduce the cooling rate and fixed height for stress relief annealing can refine the structure and reduce crack defects. Using a variety of different scanning methods can improve material utilization, processing efficiency and refine the microstructure. The main body and the individual are connected into a complete part by additive connection, which reduces the processing difficulty and improves the processing efficiency. At the same time, it has high flexibility, is simple and easy to operate, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0043] Figure 1 It is an overall schematic diagram of the original large wing frame beam structure of an embodiment of the present invention;

[0044] Figure 2 It is an overall schematic diagram of a large wing frame beam structure after topology optimization according to an embodiment of the present invention;

[0045] Figure 3 A flow chart of topological optimization of a large wing frame beam structure according to an embodiment of the present invention;

[0046] Figure 4 A schematic diagram of a topology optimization process of a front beam according to an embodiment of the present invention;

[0047] Figure 5 A schematic diagram of a topology optimization process of a center beam according to an embodiment of the present invention;

[0048] Figure 6 A schematic diagram of a rear beam topology optimization process according to an embodiment of the present invention;

[0049] Figure 7 A schematic diagram of a topology optimization process of a middle rib plate according to an embodiment of the present invention;

[0050] Figure 8 It is a block schematic diagram of a large wing frame beam structure after topology optimization according to an embodiment of the present invention;

[0051] Fig. 9 A schematic diagram of laser scanning and fixed-height annealing according to an embodiment of the present invention;

[0052] Fig.10 This is a schematic diagram of the main body of an embodiment of the present invention adopting 45° interlayer staggered scanning;

[0053] Fig.11 This is a schematic diagram of the first sub-body of an embodiment of the present invention adopting 90° interlayer staggered scanning;

[0054] Fig.12 This is a schematic diagram of a third sub-body adopting single-layer reciprocating scanning in an embodiment of the present invention;

[0055] Fig.13 This is a schematic diagram of a conventional scan of the fourth sub-body of an embodiment of the present invention;

[0056] Marking instructions: 1. Left rib plate; 2. Middle rib plate; 3. Right rib plate; 4. Front beam; 5. Middle beam; 6. Rear beam; 7. Main body; 8. First sub-body; 9. Second sub-body; 10. Third sub-body; 11. Fourth sub-body; 12. Laser; 13. Substrate scanning; 14. Substrate; 15. Fixed height annealing sample. DETAILED DESCRIPTION

[0057] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0058] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0059] Embodiment 1

[0060] In view of the above problems, the present invention provides a laser deposition manufacturing method for a large wing frame beam combined with topology optimization, and the wing frame beam is topologically optimized according to the aerodynamic load and fatigue life characteristics of the wing frame beam. In order to ensure that the wing frame beam structure is formed in an integrated manner and meets the use requirements, laser additive manufacturing is used for block processing. The parts are divided into blocks according to the load distribution, use position, processing difficulty and size of the parts. In order to prevent the sample from cracking and failing during the deposition process, a new method of laser scanning and fixed-height annealing is used for deposition. According to the main body and sub-body of different shapes after block division, a variety of different scanning methods are used in the forming process to improve the material utilization, processing efficiency and refine the microstructure. The main body and sub-body are heat treated, and after meeting the use requirements, the main body and sub-body are connected by additive manufacturing to ensure the integrated forming of the lightweight wing frame beam and meet the design and use requirements.

[0061] This embodiment provides a laser deposition manufacturing method for a large wing frame beam combined with topology optimization, such as Figure 1 As shown, the large wing frame beam includes a left rib plate 1, a middle rib plate 2, a right rib plate 3, a front beam 4, a middle beam 5, and a rear beam 6. Figure 2 As shown in the figure, the overall diagram of the large wing frame beam structure after topology optimization. According to the requirements of lightweight and integrated large wing frame beam structure, the topology optimization composite laser additive block manufacturing and connection method is adopted. The topology optimization process of the large wing frame beam structure includes: Figure 3 As shown in the figure, the wing frame beam is topologically optimized: the volume of the wing frame beam is optimized according to the aerodynamic load and fatigue life characteristics of the wing frame beam; the parts are divided into blocks: the parts are divided into main bodies and sub-bodies according to the load distribution, usage position, processing difficulty and size of the parts; laser scanning and fixed-height annealing: in order to prevent the sample from cracking due to heat accumulation during processing. Before deposition, the substrate surface is laser scanned and heated. During the deposition process, the sample reaches a certain height and undergoes stress relief annealing. Laser scanning and fixed-height annealing are repeated in a cycle; additive manufacturing processes each main body and sub-body: according to the different shapes of the main body and sub-body, a variety of different scanning methods are used to improve the material utilization, processing efficiency and refine the microstructure; the main body and sub-body are heat treated; additive connection is performed between the main body and sub-body.

[0062] In this embodiment, a method for manufacturing a large wing frame beam by laser deposition combined with topology optimization is provided, comprising the following steps: based on the aerodynamic load and fatigue life characteristics of the wing frame beam, the wing frame beam is topologically optimized to obtain an output frame structure, wherein the aerodynamic load on the wing frame beam is calculated based on the incompressible steady-state three-dimensional continuity equation and the kinetic energy equation; based on the aerodynamic load on the wing frame beam, the fatigue life characteristics of the key structure are obtained by finite element analysis; based on the fatigue life characteristics of the key structure, the output frame structure is topologically optimized with the minimum volume as the optimization target. The specific implementation process includes steps S1-S4.

[0063] Step S1: Calculate the aerodynamic load on the wing frame beam using the incompressible steady three-dimensional continuity equation and the kinetic energy equation. Aerodynamic drag ρ is the density of the atmosphere, V is the air velocity, Q is the area of ​​the wing frame beam, C A is the aerodynamic lift coefficient, C Z is the aerodynamic drag coefficient. The simulation platform is used to construct the finite element grid of the wing frame beam, the Menter-shear stress transfer model is used, and the calculation grid is an unstructured grid. The aerodynamic resultant force is calculated through simulation and used as the input load for subsequent wing frame beam fatigue analysis and topology optimization.

[0064] Step S2: Use detailed fatigue ratings to perform fatigue analysis on the wing frame beam structure, establish a finite element analysis model, find out the dangerous position based on the output results, and perform fatigue analysis on the position. Structural reliability life analysis: γ is the service life of titanium alloy; W T W is the titanium alloy coefficient, which is 1.7; C is the confidence constant; W R is the reliability constant. The detailed fatigue rating and The relationship is: K is a parameter, W is the slope of the SN curve of titanium alloy material, δ m0 is the characteristic parameter of titanium alloy material, δ max is the maximum stress parameter when titanium alloy is used, P is the stress ratio, and U is the fatigue rating of the structural component. The maximum stress value at the maximum load cycle number is: N0 is the number of cycles to bear the maximum load, which is generally taken as 1.5×10 5 ; N e is the number of cycles of equivalent load, generally taken as 5.5×10 4 . is the fatigue margin value of the maximum stress.

[0065] Step S3: SIMP algorithm is used based on the power law to associate all units in the optimization area with the continuous density function. The unit density is associated with the elastic modulus of the titanium alloy material. A theoretical mathematical model of topology optimization is established with volume constraints as the condition. The sensitivity analysis model of the unit is established using the total volume of the optimization area. Based on the optimal solution rule of Kuhn-Tucker, the topology optimization model with volume constraints as the condition is constructed, and the Lagrangian function is: L = s + n (v i X i -V * )+n1(x min -x)+n(xx max ).i is the volume of the ith infinitesimal element, V * is the maximum deformation of the volume constraint, n, n1 and n2 are the Lagrange multipliers under the constraint conditions, the design variables are transformed, and the solution is used for iteration.

[0066] Step S4: Reasonably simplify the wing frame beam model, use the pre-processing module in the simulation software to discretize the wing frame beam, and use the hexahedron scanning grid to obtain the finite element model. Set the boundary conditions to default to a completely fixed constraint on the wing frame beam. Take a sine wave function with a loading load of 1Hz as the cyclic load to calculate the fatigue life, and use the fatigue life analysis platform to perform fatigue life analysis on the entire domain of the wing frame beam. Meet the use requirements under the limit load. Perform topology optimization analysis according to the SIMP algorithm, such as Figure 7 As shown in the figure, the left rib plate and the right rib plate are optimized with the best structural layout, as shown in the figure. Figure 4-Figure 7 As shown in the figure, the front beam, middle beam, rear beam and middle rib plate are analyzed according to the force weight ratio. The analysis results of the finite element model are used as input data, combined with the Tosca optimization model, strain energy is used as the objective function of this model, and certain volume optimization index data are selected as constraints for optimization iteration.

[0067] According to the aerodynamic characteristics of the wing frame beam, the maximum aerodynamic lift-drag force is obtained, and it is used as input for finite element static analysis to obtain the stress and strain response of the wing frame under the extreme working load. Through the Fe-safe fatigue analysis software, the fatigue analysis results and fatigue durability characteristics of the key structure are calculated with stress and strain response as input variables. The analysis results are input into the Tosca software for topology optimization. The minimum strain and workpiece volume are used as optimization constraints, and the minimum volume is set as the optimization objective function. The optimal design of the wing frame beam is obtained through calculation and analysis.

[0068] like Figure 8 As shown, the output frame structure is divided into parts to obtain a main body and a sub-body, wherein a load distribution simulation analysis is performed on the output frame structure to establish a simulation model; the simulation model is meshed and a load is applied to obtain a load distribution; and the parts are divided into parts based on the use position, processing difficulty, size of the parts and the load distribution in the simulation model to obtain a main body and a sub-body. The specific implementation process includes step S5.

[0069] Step S5: Carry out load distribution simulation analysis on the optimized wing frame beam, establish a simulation model, define the properties of the element material, determine the size of the grid and grid the frame beam, add constraints, apply loads, analyze the axial force, bending moment, shear force, torque and deformation, and obtain the deformation shape and stress distribution. According to the use position of the parts, the difficulty of processing, the size of the parts and the simulated load distribution, select the place with the smallest deformation and the lowest stress distribution to divide the main body and sub-body into blocks.

[0070] The main body and sub-body are scanned based on multiple scanning methods to obtain the manufactured main body and sub-body, wherein the laser is used to perform snake-like reciprocating scanning on the substrate surface, and when the sample deposition height is 100 mm, stress annealing is performed to obtain the initial scanning component; laser scanning and fixed height annealing are performed cyclically based on the initial scanning component until the processing is completed to obtain the manufactured main body and sub-body. The specific implementation process includes steps S6-S7.

[0071] Step S6: Before the sample is deposited, a laser 12 is used to perform substrate scanning 13 (snake-like reciprocating scanning) on ​​the surface of the substrate 14 to increase the initial temperature of the substrate 14. Laser scanning of the substrate can effectively weaken the heat conduction between the substrate 14 and the deposited layer during the deposition process, reduce the cooling rate of the deposited sample, and thereby reduce the residual internal stress of the sample. Ensure good metallurgical bonding between the substrate 14 and the deposited layer. Through layer-by-layer deposition and layer-by-layer residual stress detection, it was found that when the deposition height was 100 mm, the accumulated residual stress of the deposited sample reached a maximum value, and continued deposition would cause the sample to crack and fail. Therefore, the deposited sample was immediately subjected to stress relief annealing to release the residual stress, and a fixed-height annealed sample 15 was obtained, as shown Fig. 9 As shown. After stress relief annealing, the surface of the deposited sample continues to be scanned back and forth in a serpentine manner. When the deposition height accumulates to 100 mm each time, stress relief annealing is immediately performed. Laser scanning and fixed height annealing are repeated repeatedly until the processing is completed.

[0072] Step S7: Figure 10-13 As shown, the main body 7 is processed by 45° interlayer staggered scanning. The first sub-body 8 and the second sub-body 9 are processed by 90° interlayer staggered scanning. The third sub-body 10 is processed by single-layer reciprocating scanning. The fourth sub-body 11 is processed by conventional scanning.

[0073] The manufactured main body and sub-body are connected by laser additive manufacturing according to the positional relationship to obtain an integral wing frame beam. The specific implementation process includes steps S8 and S9.

[0074] Step S8: The processed main body and sub-body are subjected to recrystallization annealing heat treatment (950° C., 4 hours, air cooling) to reduce residual stress and refine the microstructure of the sample, thereby improving the overall performance.

[0075] Step S9: Use a laser additive connection method to connect the main body and the sub-body to ensure that the parts meet the use requirements.

[0076] As a preferred implementation method, this embodiment uses Ti65 titanium alloy to prepare a wing frame beam with a size of 3500mm×1500mm×800mm. According to the aerodynamic load and fatigue life characteristics of the wing frame beam, the wing frame beam is topologically optimized. The parts are divided into main body and sub-body according to the load distribution, use position, processing difficulty and size of the parts. Since the high-temperature titanium alloy has cracked during the deposition process, laser scanning and fixed-height annealing are used to produce defect-free samples. According to the different shapes of the main body and sub-body, a variety of different scanning methods are used to improve the material utilization, processing efficiency and refine the microstructure. The main body and sub-body are subjected to 950℃ / 4h recrystallization annealing treatment to ensure that there are no processing defects, and then the main body and sub-body are connected by additive material.

[0077] According to the aerodynamic characteristics of the wing frame beam, the maximum aerodynamic lift-drag force is obtained, and it is used as input for finite element static analysis to obtain the stress and strain response of the wing frame under the extreme working load. Through the Fe-safe fatigue analysis software, the fatigue analysis results and fatigue durability characteristics of the key structure are calculated with stress and strain response as input variables. The analysis results are input into the Tosca software for topology optimization. The minimum strain and workpiece volume are used as optimization constraints, and the minimum volume is set as the optimization objective function. The optimal design of the wing frame beam is obtained through calculation and analysis.

[0078] The aerodynamic loads on the wing frame beam are calculated using the incompressible steady three-dimensional continuity equation and the kinetic energy (NS) equation. Aerodynamic drag ρ is the density of the atmosphere, V is the air velocity, Q is the area of ​​the wing frame beam, C A is the aerodynamic lift coefficient, C Z is the aerodynamic drag coefficient. The simulation platform is used to construct the finite element grid of the wing frame beam, the Menter-shear stress transfer model is used, and the calculation grid is an unstructured grid. The lift generated by the wing frame beam is 4000N, the aerodynamic drag on the wing frame beam is 410.35N~1000.96N, and the aerodynamic lift of the wing frame beam is 4020.34N~7520.6N. The aerodynamic resultant force is calculated by simulation and used as the input load for subsequent wing frame beam fatigue analysis and topology optimization.

[0079] Use detailed fatigue ratings to perform fatigue analysis on the wing frame beam structure, establish a finite element analysis model, find out the dangerous position based on the output results, and perform fatigue analysis on the position. Structural reliability life analysis: γ is the service life of titanium alloy; W T W is the titanium alloy coefficient, which is 1.7;C is the confidence constant; W R is the reliability constant. The detailed fatigue rating and The relationship is: K is a parameter, W is the slope of the SN curve of titanium alloy material, δ m0 is the characteristic parameter of titanium alloy material, δ max is the maximum stress parameter when titanium alloy is used, P is the stress ratio, and U is the fatigue rating of the structural component. The maximum stress value at the maximum load cycle number is: N0 is the number of cycles to bear the maximum load, which is generally taken as 1.5×10 5 ; N e is the number of cycles of equivalent load, generally taken as 5.5×10 4 .

[0080] is the fatigue margin value of the maximum stress.

[0081] The SIMP algorithm is used based on the power law to associate all units in the optimization area with the continuous density function. The unit density is associated with the elastic modulus of the titanium alloy material. A theoretical mathematical model of topology optimization is established with volume constraints as the condition. The sensitivity analysis model of the unit is established using the total volume of the optimization area. Based on the Kuhn-Tucker optimal solution rule, the topology optimization model with volume constraints as the condition is constructed, and the Lagrangian function is: L = s + n (v i X i -V * )+n1(x min -x)+n(xx max ). i is the volume of the ith infinitesimal element, V * is the maximum deformation of the volume constraint, n, n1 and n2 are the Lagrange multipliers under the constraint conditions, the design variables are transformed, and the solution is used for iteration.

[0082] The wing frame beam model is reasonably simplified, and the wing frame beam is discretized using the pre-processing module in the simulation software, and the finite element model is obtained using a hexahedral scanning grid. The boundary conditions are set to the default wing frame beam completely fixed constraint, and it is found that the maximum limit load stress in the fatigue crack sensitive area is 900.17MPa. A sine wave function with a loading load of 1Hz is used as the cyclic load to calculate the fatigue life. The fatigue life analysis platform is combined to perform fatigue life analysis on the entire domain of the wing frame beam. Under the maximum load force, the relationship between the stress, fatigue life and detailed fatigue rating in the sensitive area is: Under extreme load times, meeting the use requirements. According to the SIMP algorithm, the topology optimization analysis is carried out. The left and right rib plates are optimized with the optimal structural layout. The front beam, middle beam, rear beam and middle rib plate are analyzed according to the force weight ratio. The analysis results of the finite element model are used as input data, combined with the Tosca optimization model, strain energy is used as the objective function of this model, and certain volume optimization index data are selected as constraints. The optimization iteration is 35 steps. The optimized volume ratio of the front beam is 0.91, the optimized volume ratio of the middle beam is 0.87, the optimized volume ratio of the rear beam is 0.91, the optimized volume ratio of the middle rib plate is 0.81, and the total volume ratio is 0.61.

[0083] The optimized wing frame beam is simulated and analyzed for load distribution, a simulation model is established, the properties of the element materials are defined, the size of the grid is determined and the frame beam is meshed, constraints are added, loads are applied, axial force, bending moment, shear force, torque and deformation are analyzed, and the deformation shape and stress distribution are obtained. According to the use position of the parts, the difficulty of processing, the size of the parts and the simulated load distribution, the parts with the smallest deformation and the lowest stress distribution are selected for the main body and sub-body division.

[0084] In order to prevent the sample from cracking due to heat accumulation during processing. Before the sample is deposited, a 3000W laser is used to perform serpentine reciprocating scanning on the substrate surface to increase the initial temperature of the substrate. Laser scanning the substrate can effectively weaken the heat conduction between the substrate and the deposited layer during the deposition process, reduce the cooling rate of the deposited sample, and thus reduce the residual internal stress of the sample. Ensure good metallurgical bonding between the substrate and the deposited layer. Through layer-by-layer deposition and layer-by-layer residual stress detection, it is found that when the deposition height is 100mm, the residual stress accumulation of the deposited sample reaches the maximum value, and continued deposition will cause the sample to crack and fail. Therefore, the deposited sample is immediately subjected to stress relief annealing to release the residual stress. After stress relief annealing, the surface of the deposited sample continues to be laser reciprocatingly scanned, and each time the deposition height accumulates to 100mm, stress relief annealing is immediately performed. Laser scanning and fixed height annealing are repeated until the processing is completed.

[0085] The processing of the main body 7 adopts 45° interlayer staggered scanning, which has the fastest deposition rate, the highest powder utilization rate, and equiaxial grains. The processing of the first sub-body 8 and the second sub-body 9 adopts 90° interlayer staggered scanning, which has a fast deposition rate, high powder utilization rate, and equiaxial grains. The processing of the third sub-body 10 adopts single-layer reciprocating scanning, and the deposition rate is moderate. The processing of the fourth sub-body 11 adopts conventional scanning.

[0086] The main body and the sub-body are connected by the laser additive connection method to ensure that the parts meet the use requirements.

[0087] In this example, after topology optimization, the minimum fatigue margin value of the wing frame beam structure under maximum load is 4.43. After optimization, the volume is reduced by 39%, and the maximum displacement deformation is only increased by 0.011mm, meeting the requirements of lightweight design and use. Laser scanning and fixed-height annealing are used to reduce residual stress and refine the microstructure. Laser additive manufacturing is used to reduce production costs, ensure processing accuracy, and improve work efficiency. The block parts are connected by additive manufacturing to ensure the integrated forming of the parts. This method has strong operability and versatility and a wide range of applications.

[0088] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A laser deposition manufacturing method for a large wing frame beam combined with topology optimization, characterized in that: include: Based on the aerodynamic load and fatigue life characteristics of the wing frame beam, the wing frame beam is topologically optimized to obtain the output frame structure; Dividing the output frame structure into parts to obtain a main body and sub-bodies; Scanning the main body and the sub-body based on a plurality of scanning modes to obtain the manufactured main body and the sub-body; The manufactured main body and sub-body are connected by laser additive according to the positional relationship to obtain an integral wing frame beam; Based on the aerodynamic load and fatigue life characteristics of the wing frame beam, the process of topological optimization of the wing frame beam to obtain the output frame structure includes: The aerodynamic loads on the wing frame beam are calculated based on the incompressible steady three-dimensional continuity equation and the kinetic energy equation; Based on the aerodynamic loads on the wing frame beam, the fatigue life characteristics of the key structure are obtained by finite element analysis; Based on the fatigue life characteristics of the key structure, topology optimization is performed with minimum volume as the optimization target to obtain an output frame structure; Based on the aerodynamic loads on the wing frame beam, the process of using finite element analysis to obtain the fatigue life characteristics of key structures includes: Obtaining a maximum aerodynamic lift-drag resultant force based on the aerodynamic loads on the wing frame beam; Based on the maximum aerodynamic lift-drag combined force, a finite element static analysis is performed to obtain the stress and strain response of the wing frame under the extreme working condition load; Fe-safe fatigue analysis software is used to calculate the stress and strain response of the wing frame under the extreme working condition load to obtain the fatigue life characteristics of the key structure; Fatigue life characteristics of key structures include structural reliability and fatigue ratings of detailed parts; The calculation formula of the structural reliability of the detailed parts is: The fatigue rating is calculated as: In the formula, represents the structural reliability of the detailed parts, γ is the service life of titanium alloy; W T W is the titanium alloy coefficient; C is the confidence constant; W R is the reliability constant; U is the fatigue rating of the structural component; P is the stress ratio; δ m0 is the characteristic parameter of titanium alloy material; δ max It is the maximum stress parameter when using titanium alloy.

2. The laser deposition manufacturing method for large wing frame beams combined with topology optimization according to claim 1 is characterized in that: The process of topology optimization with minimum volume as the optimization goal includes topology optimization analysis based on SIMP algorithm; Wherein, the left rib plate and the right rib plate of the wing frame beam are optimized and analyzed with the optimal structural layout; The front beam, middle beam, rear beam and middle rib plate of the wing frame beam are optimized and analyzed based on the force weight ratio.

3. The laser deposition manufacturing method for large wing frame beams combined with topology optimization according to claim 1 is characterized in that: The process of dividing the output frame structure into parts to obtain a main body and sub-bodies includes: Conducting load distribution simulation analysis on the output frame structure to establish a simulation model; Meshing the simulation model and applying load to obtain load distribution; Based on the use position, processing difficulty, size and load distribution of the parts in the simulation model, the parts are divided into main bodies and sub-bodies.

4. The laser deposition manufacturing method for large wing frame beams combined with topology optimization according to claim 1 is characterized in that: The process of scanning the main body and the sub-body to obtain the manufactured main body and the sub-body includes: The laser was used to perform serpentine reciprocating scanning on the substrate surface. When the sample deposition height was 100 mm, stress annealing was performed to obtain the first scanning component. Based on the initial scanning component, laser scanning and fixed-height annealing are cyclically performed until the processing is completed to obtain the manufactured main body and sub-body.

5. The laser deposition manufacturing method for large wing frame beams combined with topology optimization according to claim 4 is characterized in that: Scanning methods include: The main body is scanned at 45° between layers; The sub-body includes: a first sub-body, a second sub-body, a third sub-body and a fourth sub-body; The first sub-volume and the second sub-volume are subjected to 90° interlayer staggered scanning; the third sub-volume is subjected to single-layer reciprocating scanning; and the fourth sub-volume is subjected to conventional scanning.

6. The laser deposition manufacturing method for large wing frame beams combined with topology optimization according to claim 1 is characterized in that: The process of laser additive joining the manufactured main body and sub-body includes a crystallization annealing heat treatment; The conditions of the crystallization annealing heat treatment include: a temperature of 950° C. and a time of 4 hours.

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