A synergistic reinforcement design method for an aircraft lattice structure

Abstract

The application discloses a kind of synergic reinforcement design methods of aircraft dot matrix structure, belong to lightweight dot matrix structure optimization design technical field.The method includes the following steps: establishing cubic model and giving model basic material attribute;Mesh discretization;Establish boundary condition constraint;Finite element analysis;Establish design domain and adopt level set optimization design method to minimize objective function;With flexibility minimization as optimization goal, with different volume fraction as optimization response constraint;Select the best result to carry out geometry reconstruction;Face-centered cubic dot matrix is combined with topological optimization cell space, and a kind of topological-face-centered cubic dot matrix structure is formed.The application guarantees structural stiffness from source, realizes stable failure process by synergic reinforcement design, thereby improves energy absorption capacity, and can be used as the buffer structure of lander in aerospace field.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lightweight lattice structure optimization design, and particularly relates to a collaborative enhancement design method for an aircraft lattice structure. BACKGROUND

[0002] Ultra-light porous materials have great application potential in the field of aerospace. Lattice structure is a typical porous material, which is an ordered topological three-dimensional porous structure composed of one or more repeating units. Due to its unique geometric shape and high porosity, lattice structure can exhibit excellent mechanical properties, such as high strength, high stiffness and excellent energy absorption capacity, while maintaining extremely low density. These characteristics are usually unattainable for solid materials. By adjusting the lattice structure parameters, including the topology and geometry of the unit cell, different mechanical behaviors can be obtained according to the requirements, such as negative Poisson's ratio, negative thermal expansion, etc. In the single-component lattice material system, due to the uniformity of the base material, the mechanical properties of the lattice are completely dependent on the micro-geometry of the unit cell. Therefore, the key to the design of lattice structure with ideal mechanical properties lies in the precise manipulation and innovative design of the microstructure of the unit cell.

[0003] Topology optimization is undoubtedly an effective method for lightweight design of structures by optimizing the distribution of structural materials. The purpose of topology optimization is to maximize the weight reduction of the structure while meeting its performance requirements such as stiffness, strength and stability. Therefore, some novel unit configurations can be achieved through topology optimization methods. In recent years, many topology optimization methods have been proposed for various complex working conditions, such as the solid isotropic material (SIMP) method, the level set method (LSM), etc. However, due to the highly irregular configuration of topology optimization, most of the porous lattices obtained through topology optimization are difficult to produce using traditional manufacturing methods. Therefore, the topology optimization of lattice structures mostly stays at the design level and has the following defects:

[0004] The structure design is single and difficult to meet the high mechanical performance requirements.

[0005] Most of the research on topology optimization for designing lattice structures is related to SIMP, which inevitably has intermediate density elements in the iteration process, as well as the shortcomings of blurred boundaries and not smooth enough boundaries.

[0006] In the BESO method, there are also problems such as checkerboard pattern, gray elements and low computational efficiency. It is difficult to simultaneously consider lightweight and mechanical performance. Failure is accompanied by the expansion of shear bands, and it is difficult to sustain energy absorption. SUMMARY

[0007] The embodiment of the present application aims to provide a synergistic enhancement design method of aircraft lattice structure, which can effectively inhibit the expansion of shear band of the lattice structure, has sustained and stable buffering and energy absorption capacity, ensures the balance of lightweight and high mechanical performance, and is easy to manufacture, thereby solving at least one technical problem involved in the background art.

[0008] To solve the above technical problems, the present application is implemented as follows:

[0009] In a first aspect, the embodiment of the present application provides a synergistic enhancement design method of aircraft lattice structure, comprising the following steps:

[0010] Step S1, establishing a cubic initial model and performing uniform opening, and assigning basic material properties to the model;

[0011] Step S2, discretizing the cubic initial model by using tetrahedral mesh;

[0012] Step S3, applying symmetric displacement constraints to three planes of the cubic, and applying the same pressure to the center area of each plane and the center of the side;

[0013] Step S4, performing finite element analysis, outputting displacement and stress nephogram, and adjusting model parameters according to the analysis results;

[0014] Step S5, excluding the load area and the constraint area, taking the remaining part of the cubic as a design domain, and updating the structure boundary based on the level set optimization method, wherein the boundary is described by an implicit signed distance function;

[0015] Step S6, taking the minimization of structural flexibility as the optimization objective, and taking different volume fractions as response constraints, and performing iterative optimization;

[0016] Step S7, outputting the optimization results and performing geometric reconstruction, and screening the material distribution scheme with the highest stiffness;

[0017] Step S8, performing multiple scanning on the topologically optimized unit cell to generate a smooth connectable curved surface structure;

[0018] Step S9, constructing a face-centered cubic lattice unit cell, embedding it into the geometric space of the topologically optimized unit cell, forming a topological-face-centered cubic composite lattice structure through normalization processing, and performing array arrangement in the xyz three directions.

[0019] Optionally, in step S3, uniform fine holes are used to promote the evolution of the structure boundary, and the mesh is encrypted to improve the calculation efficiency, wherein the number and size of the fine holes are consistent on each surface of the cubic.

[0020] Optionally, in the finite element analysis of step S4, static structural analysis based on force, displacement and thermal load is supported, and the mechanical response of the structure is calculated through the following compliance function:

[0021] ;

[0022] wherein, denotes the total strain vector; denotes the thermal strain vector; denotes the elastic strain vector; denotes the stress vector; denotes the external load; is the reaction force and the specified displacement.

[0023] Optionally, in step S5, the implicit signed distance function satisfies the following conditions:

[0024] ;

[0025] wherein, is the structure entity region; is the boundary of the domain; denotes the level set function; the time partial derivative of the implicit function is obtained as follows:

[0026] ;

[0027] wherein, is the velocity field; t denotes the time domain of the level set iteration; is the vector of the equation; under the action of a specific velocity field, the boundary changes, and this process is realized by the following equation:

[0028] ;

[0029] wherein, is the normal velocity; is the module length;

[0030] and is discretized and solved by the following equation:

[0031] ;

[0032] wherein, denotes the updated gradient; denotes the amount of change of the given velocity field in the boundary; is the discrete point in the domain; is the norm of the gradient.

[0033] Optionally, in step S6, the constraint range of the volume fraction is 10% to 50%, and the iterative process is controlled with a convergence accuracy of 0.1%.

[0034] Optionally, in step S7, the topological cell size after geometric reconstruction is 20mm×20mm×20mm, and its energy absorption capability is verified by a quasi-static compression test, wherein the specific energy absorption... Wm satisfy:

[0035] ;

[0036] In the formula, It is a compressive displacement; It is the total compressive displacement; F ( s ) represents a compressive load. m This represents the total mass of the lattice.

[0037] Optionally, in S9, the geometric center of the face-centered cubic lattice cell coincides with that of the topology-optimized cell, and the diameter of the connecting rod is 1.5 mm, with an array arrangement of 3×3×3.

[0038] In a second aspect, embodiments of the present invention provide an electronic device, comprising:

[0039] At least one processor;

[0040] At least one memory for storing at least one program;

[0041] When the at least one program is executed by the at least one processor, the at least one processor performs the steps of the method described in the first aspect.

[0042] Thirdly, embodiments of the present invention provide a readable storage medium on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect.

[0043] Fourthly, embodiments of the present invention provide a chip, the chip including a processor and a communication interface, the communication interface being coupled to the processor, the processor being used to run programs or instructions to implement the method as described in the first aspect.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0045] 1. This invention significantly improves the energy absorption efficiency and load-bearing capacity of a structure through the synergistic design of level set topology optimization and face-centered cubic lattice. Experiments show that the optimized topology-face-centered cubic lattice has a specific energy absorption 2.4 times that of the traditional face-centered cubic structure, and the peak load and average load reach 1320.77N and 654.67N respectively, which are 2 times and 2.7 times that of the traditional structure, effectively meeting the needs of the aerospace field for high-performance buffer structures.

[0046] 2、The present application realizes the optimal configuration of material distribution by iterative optimization (convergence accuracy > 0.1%) under the constraint of volume fraction, and still maintains high stiffness when the relative density is as low as 10%. Combined with the regular geometric characteristics of face-centered cubic lattice, the overall stiffness and deformation resistance of the structure are considered on the basis of lightweight, solving the problem that lightweight and mechanical properties are difficult to balance in traditional methods.

[0047] 3、The present application adopts the level set optimization method, eliminates the gray area and boundary blur defects in the traditional SIMP method, and obtains an explicit and clear topological boundary. The optimized structure can be directly used for 3D printing or additive manufacturing, without complex post-processing, greatly reducing the manufacturing difficulty and cost.

[0048] 4、The present application cooperatively enhances the design to inhibit the expansion of shear bands in the compression process, so that the structural failure process presents stable and gradual characteristics (as shown in Figure 8 Compared with traditional lattice structures, the force-displacement curve remains stable oscillation in the plastic stage, and the energy absorption duration is longer, which is suitable for scenarios requiring continuous buffering and energy absorption (such as lander impact protection).

[0049] 5、The present application accelerates the finite element analysis and optimization iteration process through the strategies of uniformizing opening, symmetric boundary constraint and grid discretization. While ensuring the calculation accuracy, the iteration number is reduced, and the design efficiency is significantly improved, providing technical support for rapid optimization under complex working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0051] Figure 1 The flow chart of the cooperative enhancement design method of the aircraft lattice structure of the present application;

[0052] Figure 2 The optimization process chart of the topological lattice structure of the present application;

[0053] Figure 3 The topological lattice structure of the present application with five different volume fractions;

[0054] Figure 4 The optimization iteration process chart of the present application with 10% relative density;

[0055] Figure 5 The front isometric view of the lattice unit formed after the topological optimization of the present application;

[0056] Figure 6 This is a diagram illustrating the topological combination design process of the topology-face-centered cubic lattice unit cell of the present invention.

[0057] Figure 7 This is an isometric view of the lattice structure formed by arranging the topological face-centered cubic lattice unit cells of the present invention.

[0058] Figure 8 This is a diagram illustrating the quasi-static compression process of the topology-face-centered cubic lattice of the present invention.

[0059] Figure 9 This is a comparison diagram of the force-displacement curves of the topological face-centered cubic lattice and the face-centered cubic lattice of the present invention;

[0060] Figure 10 This is a comparison diagram of the energy absorption ratios of the topological face-centered cubic lattice and the face-centered cubic lattice of the present invention.

[0061] Figure 11 This is a comparison diagram of peak load and average load between the topology-face-centered cubic lattice and the face-centered cubic lattice of the present invention;

[0062] Figure 12 This is one of the hardware structure diagrams of the electronic device provided in the embodiments of the present invention;

[0063] Figure 13 This is the second schematic diagram of the hardware structure of the electronic device provided in the embodiment of the present invention. Detailed Implementation

[0064] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0065] The terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0066] The method for cooperatively enhancing the lattice structure of an aircraft provided by the embodiments of the present application will be described in detail below with reference to specific examples and application scenarios.

[0067] Please refer to Figure 1 The method for cooperatively enhancing the lattice structure of an aircraft provided by the embodiments of the present application will be described in detail below with reference to specific examples and application scenarios.

[0068] Step S1, establishing a cubic initial model and performing uniform opening, and assigning basic material properties to the model;

[0069] Step S2, discretizing the cubic initial model using a tetrahedral mesh;

[0070] Step S3, applying symmetric displacement constraints to three planes of the cubic, and applying the same pressure at the center region of each face and the center of the side face;

[0071] Step S4, performing finite element analysis, outputting displacement and stress contour maps, and adjusting model parameters according to the analysis results;

[0072] Step S5, excluding the load region and the constraint region, taking the remaining part of the cubic as a design domain, and updating the structure boundary based on a level set optimization method, wherein the boundary is described by an implicit signed distance function;

[0073] Step S6, performing iterative optimization with the minimum structural flexibility as the optimization objective and different volume fractions as response constraints;

[0074] Step S7, outputting the optimization results and performing geometric reconstruction, and selecting the material distribution scheme with the highest stiffness;

[0075] Step S8, performing multiple scans on the topologically optimized unit cell to generate a smooth and connectable curved surface structure;

[0076] Step S9, constructing a face-centered cubic lattice unit cell, embedding it in the geometric space of the topologically optimized unit cell, forming a topological-face-centered cubic composite lattice structure through normalization processing, and performing array arrangement in the xyz three directions.

[0077] In step S1, the cubic initial model is established, and the holes are opened to promote the gradual evolution of the structure boundary. The holes are uniformly opened on each surface of the cubic. The size and number of the holes can be adjusted according to the actual size when using a cubic with through holes as the initial model, but the number and size of the holes on each surface must be constant. The design of the through holes accelerates the calculation speed, reduces the number of iterations, and ensures the accuracy of the results. The materials in the material library, such as PLA, nylon, and alloy, can be selected as the base material of the initial model, and the parameters such as elastic modulus and negative Poisson's ratio are input into the model.

[0078] In step S2, the grid size is divided, the tetrahedral grid is selected to discretize the geometry, and the total number of nodes and cells is obtained. The grid size is as large as possible under the premise of ensuring the calculation accuracy, which makes the optimization and analysis maintain a good balance between accuracy and calculation speed in the optimization and analysis.

[0079] In step S3, the evolution of the structure boundary is promoted by uniformly opening the holes, and the grid is encrypted to improve the calculation efficiency, wherein the number and size of the holes are consistent on each surface of the cube.

[0080] In the finite element analysis of step S4, static structural analysis based on force, displacement and thermal load is supported, and the mechanical response of the structure is calculated by the following compliance function:

[0081] ;

[0082] In the formula, represents the total strain vector; represents the thermal strain vector; represents the elastic strain vector; represents the stress vector; represents the external load; is the reaction force and specified displacement.

[0083] In step S5, the implicit signed distance function satisfies the following conditions:

[0084] ;

[0085] In the formula, is the solid region of the structure; is the boundary of the domain; represents the level set function; the implicit function is time-derivative, and the following equation is obtained:

[0086] ;

[0087] In the formula, is the velocity field; t represents the time domain of the level set iteration; is the vector of the equation; under the action of a specific velocity field, the boundary changes, and this process is realized by the following equation:

[0088] ;

[0089] In the formula, is the normal velocity; is the module length;

[0090] and the following discretization and solution are obtained:

[0091] ;

[0092] In the formula, Indicates the gradient after the update; This represents the change in a given velocity field within the boundary. These are discrete points in the domain; It is the norm of the gradient.

[0093] In step S6, the volume fraction is constrained to a range of 10% to 50%, and the iterative process is controlled with a convergence accuracy of 0.1%. The topology optimization process can be found in [reference needed]. Figure 2 As shown; topology optimization lattices with different volume fractions can be found in [reference needed]. Figure 3 As shown.

[0094] Through continuous iterative calculations, a topological lattice structure with a relative density of 10% was obtained with a convergence accuracy of 0.1%, as shown below. Figure 4 As shown. The convergence accuracy can be adjusted appropriately according to the convergence domain, and the optimized relative density can be selected according to actual needs. The obtained lattice structure removes excess material and is optimized to the minimum volume fraction to meet lightweight requirements.

[0095] In step S7, the topological cell size after geometric reconstruction is 20mm×20mm×20mm, and its energy absorption capability is verified by a quasi-static compression test, wherein the specific energy absorption... Wm satisfy:

[0096] ;

[0097] In the formula, It is a compressive displacement; It is the total compressive displacement; F ( s ) represents the compressive load; m This represents the total mass of the lattice.

[0098] Peak load is the maximum load during compression and represents the load-bearing capacity of the structure. Average force... P mean Defined as another widely used index for evaluating the energy absorption capacity of lattice structures, it can be calculated using the following formula:

[0099] ;

[0100] in, d max It is the maximum displacement value under bending load.

[0101] In step S8, the model is scanned multiple times to form a smooth, connectable surface. Figure 5 This is an isometric view of a lattice unit cell with a preferred volume fraction of 10% after scanning.

[0102] In S9, the geometric centers of the face-centered cubic lattice cells and the topology-optimized cells coincide, and the diameter of the connecting rods is 1.5 mm. The array arrangement is 3×3×3.

[0103] To ensure that the connections of the internal members are located at the geometric center of the structure, face-centered cubic lattice cells are filled into the geometric space of the topological unit cell, and the connections are normalized to form a novel topological-face-centered cubic lattice. For example... Figure 6 As shown, during assembly, it is necessary to ensure that the topological lattice and the face-centered cubic lattice are located at the same geometric center point, and that the face-centered cubic lattice pillars can be effectively embedded into the topological lattice. A 3x3 array is used to arrange the topological-face-centered cubic lattice in the x, y, and z directions, and then they are combined into a single unit, as shown below. Figure 7 The image shown is its isometric view.

[0104] The mechanical properties of the topological face-centered cubic lattice structure were tested using quasi-static compression tests. For example... Figure 8 The failure mode process was investigated. Tests revealed that the failure mode of the topological face-centered cubic lattice structure effectively avoided the generation of tangential shear bands, exhibiting stable cooperative failure characteristics.

[0105] Combination Figures 9 to 11 As shown, the force-displacement curve of the topology-face-centered cubic (FCC) lattice structure exhibits a longer elastic stage and stable oscillations in the plastic stage, rapidly climbing upwards after a 20mm displacement to a peak of 1200N. In contrast, the traditional FCC structure shows a peak at initial compression and then continuously declines. Regarding specific energy absorption, the topology-face-centered cubic structure is 2.4 times that of the traditional FCC, demonstrating excellent energy absorption capacity. Similarly, the peak load and average load of the topology-face-centered cubic structure are 2 times and 2.7 times that of the traditional FCC, respectively, reaching 1320.77N and 654.67N. This indicates significant advantages in shear capacity, energy absorption, and fracture resistance, while also being lightweight, highly tough, and structurally sophisticated.

[0106] The following detailed description of a collaborative enhancement design method for an aircraft lattice structure provided by the present invention is based on specific embodiments.

[0107] Example 1

[0108] Example 1 provides a collaborative enhancement design method for aircraft lattice structures, specifically including:

[0109] Step S1: Initial model establishment and homogenization of openings;

[0110] 1. Construct an initial cube model with a side length of 20 mm, using PLA (elastic modulus 3.5 GPa, Poisson's ratio 0.35) as the material.

[0111] 2. Uniformly open holes on each surface of the cube, hole diameter is 1 mm, the number of holes on each surface is 4×4 array, the distance between holes is 4 mm, to promote the gradual evolution of the structure boundary (see Figure 1 ).

[0112] Step S2: Grid discretization;

[0113] 1. Use tetrahedral elements to divide the cube mesh, the element size is 0.5 mm, and ensure that the grid density is increased in the hole area to improve the calculation accuracy.

[0114] 2. After discretization, the total number of model nodes is about 52,000, and the total number of elements is about 128,000.

[0115] Step S3: Boundary conditions and symmetry constraints;

[0116] 1. Apply symmetric displacement constraints to the three orthogonal planes of the cube, limit the translational freedom of the center of the side (X, Y, Z direction displacement is zero).

[0117] 2. Apply uniform pressure load in the center area of each surface, the pressure value is 10 MPa, simulate the compression load under actual working condition.

[0118] Step S4: Finite element analysis;

[0119] 1. Use ANSYS Mechanical for static analysis, output displacement contour and equivalent stress distribution diagram (see Figure 2 ).

[0120] 2. According to the initial stress distribution (the maximum equivalent stress is 42.74 MPa), adjust the hole layout or grid density to ensure that the stress concentration area meets the design requirements.

[0121] Step S5: Level set topology optimization;

[0122] 1. Exclude the load area and constraint area, and the remaining area as the design domain.

[0123] 2. Update the structure boundary using the level set method, the implicit function is defined as:

[0124] ;

[0125] Update the boundary by iterating the discretized equation:

[0126] ;

[0127] Where, time step Δt=0.01Δ t =0.01, the convergence accuracy is set to 0.1%.

[0128] Step S6: optimization target and constraint setting;

[0129] 1. The objective function is to minimize the structural compliance (i.e., maximize the stiffness), and the response constraint is the volume fraction, which starts from 10% and increases by 5% increments, up to 50%.

[0130] 2. During the optimization process, the topological configuration corresponding to the volume fraction is output every iteration (see Figure 3 ).

[0131] Step S7: geometry reconstruction;

[0132] 1. Select the optimization result with a volume fraction of 10% (the compliance is reduced to 15% of the initial value after convergence), perform geometry reconstruction, and generate smooth surfaces (see Figure 4 、 Figure 5 ).

[0133] 2. The size of the reconstructed topological unit cell is 20 mm x 20 mm x 20 mm, and the rod diameter is 1.5 mm.

[0134] Step S8: curved surface structure generation;

[0135] 1. Scan the topologically optimized unit cell multiple times to generate smooth and connectable curved surface structures;

[0136] Step S9: face-centered cubic lattice integration;

[0137] 1. Construct a face-centered cubic lattice unit cell of the same size, with a rod diameter of 1.5 mm, and ensure that the rod connection points are located at the geometric center.

[0138] 2. Embed the face-centered cubic lattice into the topological unit cell space, and perform normalization processing at the connection points to form a composite topological-face-centered cubic lattice (see Figure 6 ).

[0139] 3. Arrange the composite unit cell in a 3x3x3 array to form an overall lattice structure (see Figure 7 ).

[0140] Example 2: mechanical property verification;

[0141] 1. Quasi-static compression test: Perform compression testing on the topological-face-centered cubic lattice, with a displacement rate of 2 mm / min, and record the force-displacement curve (see Figures 8-9 ).

[0142] Peak load: 1320.77 N (traditional face-centered cubic is 660 N).

[0143] Average load: 654.67 N (traditional face-centered cubic is 242.5 N).

[0144] Specific energy absorption: 48.5 J / g for topological-fcc, 2.4 times of that for traditional fcc (20.2 J / g).

[0145] 2. Failure mode analysis: no shear band propagation occurred in the compression process of the topological-fcc lattice, showing uniform plastic deformation and synergistic failure characteristics (see Figure 8 ).

[0146] As shown in Figure 12 , the embodiment of the present application further provides an electronic device 600, which comprises a processor 601, a memory 602, and a program or instruction stored in the memory 602 and executable on the processor 601. When the program or instruction is executed by the processor 601, each process of the synergistic enhancement design method for the aircraft lattice structure is realized, and the same technical effect is achieved. To avoid repetition, details are not described here.

[0147] It should be noted that the first electronic device in the embodiment of the present application includes the mobile electronic device and the non-mobile electronic device described above.

[0148] Figure 13 A hardware structure schematic diagram of an electronic device for implementing the embodiment of the present application.

[0149] The electronic device 700 includes but is not limited to: a radio frequency unit 701, a network module 702, an audio output unit 703, an input unit 704, a sensor 705, a display unit 706, a user input unit 707, an interface unit 708, a memory 709, and a processor 710, etc.

[0150] Those skilled in the art can understand that the electronic device 700 can further include a power supply (such as a battery) for supplying power to each component, and the power supply can be logically connected to the processor 710 through a power management system, so as to realize the functions of power management, such as charging, discharging, and power consumption management, through the power management system. Figure 13 The electronic device structure shown in the figure does not constitute a limitation on the electronic device, and the electronic device can include more or fewer components than the illustrated components, or combine certain components, or different component arrangements, which are not described here.

[0151] It should be understood that in the embodiments of the present application, the input unit 704 can include a graphics processing unit (GPU) 7041 and a microphone 7042, and the graphics processing unit 7041 processes image data of a still image or a video obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode. The display unit 706 can include a display panel 7061, which can be configured in the form of a liquid crystal display, an organic light-emitting diode, etc. The user input unit 707 includes a touch panel 7071 and other input devices 7072. The touch panel 7071 is also called a touch screen. The touch panel 7071 can include two parts of a touch detection device and a touch controller. The other input devices 7072 can include, but are not limited to, a physical keyboard, function keys (such as volume control keys, on-off keys, etc.), trackballs, mice, joysticks, etc., which will not be described here. The memory 709 can be used to store software programs and various data, including but not limited to application programs and operating systems. The processor 710 can integrate an application processor and a modem processor, wherein the application processor mainly processes operating systems, user interfaces and application programs, etc., and the modem processor mainly processes wireless communication. It can be understood that the above-mentioned modem processor can also not be integrated into the processor 710.

[0152] The embodiments of the present application also provide a readable storage medium, which stores programs or instructions, and the programs or instructions are executed by a processor to realize the processes of the above-mentioned aircraft lattice structure cooperative enhancement design method embodiments and achieve the same technical effects. To avoid repetition, details are not described here.

[0153] The processor is the processor in the electronic device described in the above-mentioned embodiments. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0154] The embodiments of the present application further provide a chip, which includes a processor and a communication interface, the communication interface is coupled with the processor, and the processor is used to run programs or instructions to realize the processes of the above-mentioned aircraft lattice structure cooperative enhancement design method embodiments and achieve the same technical effects. To avoid repetition, details are not described here.

[0155] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip, etc.

[0156] It is to be understood that the terminology "including", "comprising", or any other variation thereof, is intended to cover a non-exclusive inclusion such that process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Exclusionary language, such as "only", does not exclude the addition of other elements, unless the context clearly indicates otherwise. Furthermore, it is to be understood that the terminology "first", "second", and / or "third", and / or the like, is used in the description and claims only to distinguish one element from another, and is not otherwise intended to limit either the elements or the number of elements to the specific term so denominated. That is, an "element" or "step" that can be referred to in one or more places as a "first" element or "first" step can thereafter be referred to as a "second" element or "second" step without departing from the scope of the present application. Such terminology used in the description and claims should not be understood to exclude the presence or addition of other elements or steps in various embodiments of the application. In addition, it should be understood that various embodiments of the application can include location, time, or other information that is not expressly recited in the claims. Further, to the extent that any meaning or definition of a term in this document conflicts with the meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

[0157] The embodiments of the present application described above are merely intended to illustrate the present application, but are not intended to limit the present application. The above-described embodiments are merely illustrative, and are not intended to be limiting. Any person skilled in the art can make various modifications without departing from the spirit and scope of the present application, and such modifications are intended to be within the scope of the present application.

Claims

1. A method of synergistically reinforcing a lattice structure of an aircraft, characterized in that, The method comprises the following steps: Step S1, establishing a cubic initial model and performing uniform opening, and assigning basic material properties to the model; Step S2, discretizing the cubic initial model by using a tetrahedral mesh; Step S3, applying symmetric displacement constraints to three planes of the cube, and applying the same pressure at the center region of each face and the center of the side face; Step S4, performing finite element analysis, outputting displacement and stress contour maps, and adjusting model parameters according to the analysis results; in the finite element analysis, static structure analysis based on force, displacement and thermal load is supported, and the mechanical response of the structure is calculated by the following compliance function: ； wherein denotes the total strain vector; denotes the thermal strain vector; denotes the elastic strain vector; denotes the stress vector; denotes the external load; is the reaction force and the prescribed displacement; Step S5, excluding the load area and the constraint area, taking the remaining part of the cube as a design domain, updating the structure boundary based on the level set optimization method, wherein the boundary is described by an implicit signed distance function which satisfies the following conditions: ； where is the region of the structure; is the boundary of the region; is represented as a level set function; for implicit functions taking the time partial derivative of the implicit function ； where is the velocity field; t denotes the time domain of the level set iteration; is the vector of equations; under the action of a certain velocity field, the boundary changes, then this process is realized by the following equation: ； wherein is the normal velocity; is the module length; and is discretized and solved as follows: ； wherein denotes the updated gradient; denotes the amount of change in the given velocity field that occurs in the boundary; are discrete points in the domain; is the norm of the gradient; Step S6, taking the minimization of structural flexibility as the optimization objective, and taking different volume fractions as response constraints, performing iterative optimization; Step S7, outputting the optimization results and performing geometric reconstruction, and screening the material distribution scheme with the highest stiffness; Step S8, performing multiple scans on the topologically optimized unit cell to generate a smooth connectable curved surface structure; Step S9, constructing a face-centered cubic lattice unit cell, embedding it in the geometric space of the topologically optimized unit cell, forming a topological-face-centered cubic composite lattice structure through normalization processing, and performing array arrangement in the xyz three directions.

2. The method of synergistic reinforcement design of aircraft lattice structures of claim 1, wherein, In step S3, uniform fine holes are used to promote the evolution of the structure boundary, and the grid is encrypted to improve the calculation efficiency, wherein the number and size of the fine holes are consistent on each surface of the cube.

3. The synergistic design method of a truss structure of an aircraft according to claim 1, wherein In step S6, the constraint range of the volume fraction is 10% to 50%, and the iterative process is controlled with a convergence accuracy of 0.1%.

4. The method of synergistic reinforcement design of aircraft lattice structures of claim 1, wherein, In step S7, the size of the topological unit cell after geometric reconstruction is 20 mm x 20 mm x 20 mm, and its energy absorption capacity is verified by a quasi-static compression test, wherein the specific energy absorption Wm satisfies: ； In the formula, It is a compressive displacement; It is the total compressive displacement; F ( s ) represents the compressive load; m This represents the total mass of the lattice.

5. The method of synergistic reinforcement design of aircraft lattice structures of claim 1, wherein, In S9, the face-centered cubic lattice unit cell coincides with the geometric center of the topologically optimized unit cell, the rod diameter at the connection is 1.5 mm, and the array arrangement mode is 3x3x3.

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