Complex conformal metamaterial part machining method, system and equipment based on inclination angle-minimum machining diameter interlocking, medium and product

Abstract

The invention discloses a complex conformal metamaterial part machining method, system and device based on inclination angle-minimum machining diameter interlocking, a medium and a product, and relates to the field of complex conformal metamaterial part machining, and the method comprises the steps that a geometric model of a complex conformal metamaterial part is constructed; discretizing the geometric model, and calculating a global coordinate of each node of each hexahedron lattice unit; combining the overlapped nodes based on the global coordinates of the nodes, and constructing a lattice topology network; calculating an inclination angle of each inclination rod relative to a design direction in the lattice topology network; calculating the minimum machining diameter of each inclined rod based on the inclination angle; and processing each inclined rod based on the minimum processing diameter to obtain the complex conformal metamaterial part. According to the invention, a complex conformal metamaterial structure can be designed, and high-quality printing is ensured.

Description

Technical Field

[0001] This application relates to the field of processing complex conformal metamaterial parts, and particularly to a method, system, device, medium and product for processing complex conformal metamaterial parts based on the interlocking of tilt angle - minimum machining diameter. Background Art

[0002] Metal 3D printing (such as powder bed laser melting, PBF-LB / M technology) is widely used in the manufacturing of parts with complex structures, especially in the manufacturing of metamaterials. However, there is a significant relationship between the printing accuracy during the metal printing process and the tilt angle of the object. For complex parts with irregular shapes, the filling of their metamaterials requires the aid of conformal design technology, which makes it difficult to predict the tilt angle of the tilted rods of the metamaterials, making it difficult to design the diameter of the tilted rods that depend on the tilt angle of the tilted rods and unable to ensure high-quality uniform printing. Summary of the Invention

[0003] The purpose of this application is to provide a method, system, device, medium and product for processing complex conformal metamaterial parts based on the interlocking of tilt angle - minimum machining diameter, which can determine the diameter of the tilted rods related to the tilt angle, thereby designing complex conformal metamaterial structures and ensuring high-quality printing.

[0004] To achieve the above purpose, this application provides the following solutions:

[0005] In the first aspect, this application provides a method for processing complex conformal metamaterial parts based on the interlocking of tilt angle - minimum machining diameter, including:

[0006] Construct a geometric model of the complex conformal metamaterial part;

[0007] Discretize the geometric model and calculate the global coordinates of each node of each hexahedral lattice unit;

[0008] Merge overlapping nodes based on the global coordinates of each node and construct a lattice topology network;

[0009] Calculate the tilt angle of each tilted rod in the lattice topology network relative to the design direction;

[0010] Calculate the minimum machining diameter of each tilted rod based on the tilt angle;

[0011] Machine each tilted rod based on the minimum machining diameter to obtain a complex conformal metamaterial part.

[0012] In the second aspect, this application provides a system for processing complex conformal metamaterial parts based on the interlocking of tilt angle - minimum machining diameter, including:

[0013] A geometric model construction module for constructing a geometric model of a complex conformal metamaterial part;

[0014] A global coordinate calculation module for discretizing the geometric model and calculating the global coordinates of each node of each hexahedral lattice unit;

[0015] A lattice topology network construction module for merging overlapping nodes based on the global coordinates of each node and constructing a lattice topology network;

[0016] An inclination angle calculation module for calculating the inclination angle of each inclined rod in the lattice topology network relative to the design direction;

[0017] A minimum machining diameter calculation module for calculating the minimum machining diameter of each inclined rod based on the inclination angle;

[0018] A machining module for machining each inclined rod based on the minimum machining diameter to obtain a complex conformal metamaterial part.

[0019] In a third aspect, the present application provides a computer device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the computer program to implement the above-mentioned method for machining a complex conformal metamaterial part based on the interlock of inclination angle - minimum machining diameter.

[0020] In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the above-mentioned method for machining a complex conformal metamaterial part based on the interlock of inclination angle - minimum machining diameter.

[0021] In a fifth aspect, the present application provides a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the above-mentioned method for machining a complex conformal metamaterial part based on the interlock of inclination angle - minimum machining diameter.

[0022] According to the specific embodiments provided by the present application, the present application has the following technical effects:

[0023] The present application provides a method, system, device, medium, and product for machining a complex conformal metamaterial part based on the interlock of inclination angle - minimum machining diameter. By constructing a lattice topology network to calculate the inclination angle of each inclined rod relative to the design direction, the minimum machining diameter of each inclined rod is calculated, so as to guide the design of the conformal complex metamaterial structure and ensure high-quality printing. Description of the Drawings

[0024] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 Schematic flow chart of a processing method for complex conformal metamaterial parts based on the interlock of tilt angle - minimum machining diameter provided by an embodiment of the present application;

[0026] Figure 2 Schematic design diagram of a hierarchical spiral icosahedron;

[0027] Figure 3 Schematic design diagram of a hierarchical octagonal truss;

[0028] Figure 4 Schematic diagram of a complex metamaterial prepared by laser powder bed printing;

[0029] Figure 5 Schematic diagram for manufacturability evaluation through μ - CT lattice characterization;

[0030] Figure 6 Schematic diagram of the relationship between the manufacturability of the inclined rod in the complex conformal metamaterial and the inclination angle θ;

[0031] Figure 7 Schematic structural diagram of a computer device provided by an embodiment of the present application. Detailed implementation manners

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0033] To make the above - mentioned objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the drawings and specific implementation manners.

[0034] In an exemplary embodiment, as Figure 1As shown, a processing method for complex conformal metamaterial parts based on the interlock of tilt angle - minimum machining diameter is provided. This method is executed by a computer device, which can be specifically executed by a computer device such as a terminal or a server alone, or jointly executed by a terminal and a server. In the embodiments of this application, taking the application of this method to a server as an example for illustration, it includes the following steps S1 to S6. Among them:

[0035] S1: Construct a geometric model of the complex conformal metamaterial part.

[0036] Specifically, construct a geometric model of the complex conformal metamaterial part through computer - aided design (CAD) software.

[0037] S2: Discretize the geometric model and calculate the global coordinates of each node of each hexahedral lattice unit. Specifically, it includes:

[0038] S21: Discretize the geometric model to obtain a plurality of hexahedral meshes, and embed a metamaterial unit in each hexahedral mesh to obtain hexahedral lattice units.

[0039] Specifically, use the finite element method (FEA) to divide the geometric model into hexahedral meshes, and optimize the division accuracy of the hexahedral meshes through adaptive mesh refinement to adapt to the complex conformal design space. Then embed a metamaterial unit in each hexahedral element to obtain hexahedral lattice units.

[0040] S22: Calculate the global coordinates of each node of each hexahedral lattice unit through shape functions.

[0041] Specifically, each metamaterial unit does not match the hexahedral mesh nodes. In addition, the hexahedral meshes often deviate from perfect hexahedrons and take distorted shapes to adapt to the complex design space or geometry. Therefore, introduce a natural coordinate system (ξ, η, ζ) in each hexahedral mesh to accurately determine the natural coordinates of each node of each hexahedral lattice unit, and then introduce a shape function N(ξ, η, ζ) to convert the natural coordinates of each node of each hexahedral lattice unit into global coordinates (x, y, z).

[0042]

[0043] Among them, (x j , y j , z j ) are the global coordinates of the j - th node in the hexahedral lattice unit, and (x i , y i , z i ) are the coordinates of the i - th node in the hexahedral mesh.

[0044] To avoid coordinate drift, the global coordinates are optimized by an interpolation method to ensure geometric accuracy.

[0045] S3: Merge the overlapping nodes based on the global coordinates of each node and construct a lattice topology network.

[0046] Through the above steps, the global coordinates of each node of the hexahedron lattice unit can be quickly and accurately determined in the design space (hexahedron mesh). Next, based on the global coordinates of the nodes, the overlapping nodes are merged to reduce the data size, facilitate the connection of the inclined rods, and automatically link thousands of adjacent lines.

[0047] S31: Based on the global coordinates of each node, use the Euclidean distance formula to calculate the distance d between two nodes.

[0048] \S32: Determine the two nodes with a distance equal to zero as overlapping nodes and merge them to obtain the optimized nodes.

[0049] If d = 0, the two nodes are regarded as the same node, merged and stored, and the hash mapping is used to store the merge result, reducing data redundancy and improving calculation efficiency.

[0050] Step 33: Based on the optimized nodes, use the inclined rods in the finite element network to construct a line-based lattice topology network.

[0051] Use the inclined rods (beam elements) in the finite element network to construct a line-based lattice topology network and generate the INP file of the topological structure to ensure that the calculation model can be used for subsequent simulations.

[0052] Optimize the lattice topology network according to the connection logic to reduce isolated inclined rods.

[0053] S4: Calculate the inclination angle of each inclined rod in the lattice topology network relative to the design direction.

[0054] Calculate the inclination angle θ of the inclined rod relative to the design direction through the formula:

[0055]

[0056] where (x s , y s , z s ) and (x b , y b , z b ) are the direction vector and the reference direction vector of the inclined rod respectively.

[0057] S5: Calculate the minimum machining diameter of each inclined rod based on the inclination angle.

[0058]

[0059] Among them, is the additional continuity index of the inclined rod, with a value of 0.96, d is the minimum machining diameter, h0 is the initial rod height, and ρ TD is the theoretical density, and ρ PBD is the actual density of the powder bed fusion process.

[0060] S6: Machine each inclined rod based on the minimum machining diameter to obtain a complex conformal metamaterial part.

[0061] Next, two custom Ti-6Al-4V complex lattice examples will be used to demonstrate the complex conformal metamaterial part machining method provided by this application, as Figures 2 - 3 shown. As Figure 2 shown, the first example is a hierarchical octagonal truss, and the input geometry or design space is as Figure 2 (a) shown in. The final Ti-6Al-4V complex lattice structure requires a yield strength of 65 MPa (equivalent to the yield strength of the commonly used cast magnesium alloy Mg-9Al-1Zn).

[0062] Therefore, first mesh the input geometry using two-dimensional (2D) quadrilateral elements as Figure 2 (b) shown in. Then, a two-dimensional linear array unit is nested in each two-dimensional quadrilateral element, as Figure 2 (c) shown in. Then, use formula (5) to determine the inclination angle of each inclined rod, and then use formula (6) to calculate the diameter of each inclined rod. Finally, assign the calculated diameter to each inclined rod and confirm that the resulting lattice relative density is about 41%. Finally, the lattice design shown in Figure 2 (c) is formed. In this design, the minimum void size is 0.8 mm, which is 20 times the powder size Dv(90), and it can be manufactured by LPBF without powder clogging.

[0063] Figure 2 (d)-(g) in are the diameter-inclination angle classification of the inclined rods in the design space or lattice CAD model, where, in (d), θ = 90°, and d 0° = 1250 μm; in (e), 0° < θ < 30°, and d 15° = 1240 μm; in (f), 30° ≤ θ < 60°, and d 45° = 839 μm; in (g), 60° ≤ θ < 90°, and d 75° = 324 μm.

[0064] As Figure 3 shown, another example is a complex octagonal truss structure. As Figure 3As shown in (a) of [], the input geometric shape or design space is the diameter of the inclined rod, i.e., d 0° , d 15° , d 45° and d 75° . Similarly, Ti-6Al-4V is selected as the material for the lattice inclined rod, but this design uses a cubic lattice unit with a required relative density of 19%. According to the same procedure as above, the input geometry is meshed using a hexahedral mesh, as shown in (b) of Figure 3 , and the design of LPBF is completed, as shown in (c) of Figure 3 . Figure 3 (d)-(h) of [] show the 3D distribution of each set of wire inclined rods in the CAD model, where θ = 90° in (d), 0° < θ < 30° in (e), 30° ≤ θ < 60° in (f), 60° ≤ θ < 90° in (g), and θ = 0° in (h).

[0065] A complex conformal octagonal truss structure was fabricated by LPBF printing, as shown in Figure 4 . To study the internal structural details, three cross-sections were extracted from the reconstructed μ-CT lattice, as shown in (a)-(c) of Figure 5 . These cross-sections contain inclined rods with inclination angles from 0° to 90°. As observed, all inclined rods show a uniform cross-section. The minimum lattice unit, as shown in (d) of Figure 5 , shows no powder clogging (the cell cavity size is 1.2 mm). Figure 5 (e)-(g) of [] show the lattice units extracted from the μ-CT digital twin to demonstrate the manufacturability in the complex metamaterial structure.

[0066] The diameter of the inclined rod remains consistent during the design and manufacturing process. Comparison of d = 1207.50 μm (design) with d' = 1200 μm (manufacturing) at θ = 5°; comparison of d = 883.80 μm (design) with d' = 900 μm (manufacturing) at θ = 45°. Figure 5 (e)-(g) of [] show more details of the inclined rod diameter and the inclination angle of the inclined rod. The manufactured inclined rod diameter is very close to the designed inclined rod diameter. The comparison results are: (1) at θ = 90°, d' = 0.22 mm and d = 0.2 mm (in (e) of Figure 5 ); (2) at θ = 60°, d' = 0.38 mm and d = 0.362 mm (in (f) of Figure 6 ); (3) at θ = 50°, d' = 0.65 mm and d = 0.8388 mm (in (g) of Figure 5 ); (3) at θ = 45°, d' = 0.74 mm and d = 0.8388 mm (in (g) of Figure 5in (f)-(g)); (4) when θ = 0°, d' = 1.2 mm and d = 1.250 mm ( Figure 5 in (e)).

[0067] Figure 6 And Table 1 further evaluated the printing quality of the model. Table 1 compared the diameters of the inclined rods manufactured at different inclination angles and their CAD models (i.e., the designed diameters). Figure 6 in the left column (i.e., Figure 6 in (a), (d), (g), (j), and (m)) showed representative scanning electron microscope views of each group of inclined rods, from which it can be seen that the cross-sectional height of each inclined rod is consistent, Figure 6 the number of inclined rods in Figure 6 in the middle column (i.e., Figure 6 in (b), (e), (h), (k), and (n)) were the diameters obtained by scanning and characterizing each group of inclined rods. Figure 6 in the right column (i.e., Figure 6 in (c), (f), (i), (l), and (o)) showed the measured diameter distribution of the inclined rods. If the exact inclination angle of each inclined rod or a narrower inclination angle range (such as 5°) is used, the consistency is expected to be further improved.

[0068] Table 1

[0069]

[0070] Based on the same inventive concept, the embodiment of the present application also provides a system for implementing the above-mentioned processing method of complex conformal metamaterial parts based on the interlock of inclination angle - minimum machining diameter. The implementation solutions provided by this system to solve problems are similar to the implementation solutions recorded in the above method. Therefore, the specific limitations in one or more embodiments of the following complex conformal metamaterial part processing system based on the interlock of inclination angle - minimum machining diameter can refer to the limitations on the processing method of complex conformal metamaterial parts based on the interlock of inclination angle - minimum machining diameter in the above text, and will not be elaborated here.

[0071] In an exemplary embodiment, a complex conformal metamaterial part processing system based on the interlock of inclination angle - minimum machining diameter is provided, including:

[0072] A geometric model construction module for constructing a geometric model of a complex conformal metamaterial part.

[0073] A global coordinate calculation module for discretizing the geometric model and calculating the global coordinates of each node of each hexahedral lattice unit.

[0074] The lattice topology network construction module is used to merge overlapping nodes based on the global coordinates of each node and construct a lattice topology network.

[0075] The tilt angle calculation module is used to calculate the tilt angles of the respective inclined rods in the lattice topology network with respect to the design direction.

[0076] The minimum machining diameter calculation module is used to calculate the minimum machining diameters of the respective inclined rods based on the tilt angles.

[0077] The machining module is used to machine the respective inclined rods based on the minimum machining diameters to obtain a complex conformal metamaterial part.

[0078] In an exemplary embodiment, a computer device is provided, which includes a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps in the above method embodiments are implemented. The computer device can be a server or a terminal, and its internal structure diagram can be as Figure 7 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data to be processed. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for machining a complex conformal metamaterial part based on the interlock of tilt angle - minimum machining diameter is implemented.

[0079] Those skilled in the art can understand that Figure 7 the structure shown in

[0080] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, which when executed by a processor, implements the steps in the above method embodiments.

[0081] In an exemplary embodiment, a computer program product is provided, including a computer program, which when executed by a processor, implements the steps in the above method embodiments.

[0082] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0083] Those of ordinary skill in the art can understand that all or part of the processes in the above method embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above method embodiments. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memories. Non-volatile memories can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memories can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0084] In each of the embodiments provided in this application, the databases involved may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., without limitation. In each of the embodiments provided in this application, the processor may be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without limitation.

[0085] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0086] Specific examples are used in this article to elaborate on the principles and implementation manners of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A method for processing complex conformal metamaterial parts based on tilt angle-minimum processing diameter interlocking, characterized in that: include: Build geometric models of complex conformal metamaterial parts; Discretizing the geometric model and calculating the global coordinates of each node of each hexahedral lattice unit; Merge overlapping nodes based on the global coordinates of each node and construct a lattice topology network; Calculate the tilt angle of each tilted rod in the lattice topology network relative to the design direction; Calculating the minimum processing diameter of each inclined rod based on the inclination angle; Each tilt rod is processed based on the minimum processing diameter to obtain a complex conformal metamaterial part.

2. The complex conformal metamaterial parts processing method based on the inclination angle-minimum processing diameter interlocking according to claim 1 is characterized in that: Discretizing the geometric model and calculating the global coordinates of each node of each hexahedral lattice unit specifically includes: Discretizing the geometric model to obtain a plurality of hexahedral meshes, and embedding a metamaterial unit in each hexahedral mesh to obtain a hexahedral lattice unit; The global coordinates of each node of each hexahedral lattice unit are calculated by shape function.

3. The method for processing complex conformal metamaterial parts based on inclination angle-minimum processing diameter interlocking according to claim 2 is characterized in that: After calculating the global coordinates of each node of each hexahedral lattice unit by the shape function, it also includes: The global coordinates of each node of each hexahedral lattice unit are optimized by interpolation method.

4. The complex conformal metamaterial parts processing method based on the interlocking of the tilt angle and the minimum processing diameter according to claim 1 is characterized in that: Based on the global coordinates of each node, the overlapping nodes are merged and a lattice topology network is constructed, including: Based on the global coordinates of each node, the distance between two nodes is calculated using the Euclidean distance formula; Determine two nodes with a distance equal to zero as overlapping nodes, and merge them to obtain optimized nodes; Based on the optimized nodes, the inclined rods in the finite element network are used to construct a line-based lattice topology network.

5. The method for processing complex conformal metamaterial parts based on tilt angle-minimum processing diameter interlocking according to claim 1, characterized in that: The calculation formula of the inclination angle is: Where θ is the inclination angle of the tilt rod relative to the design direction, (x s ,y s , z s ) and (x b ,y b , z b ) are the direction vector of the tilt rod and the reference direction vector respectively.

6. The method for processing complex conformal metamaterial parts based on tilt angle-minimum processing diameter interlocking according to claim 5, characterized in that: The calculation formula of the minimum processing diameter is: in, is the additional continuity index of the tilted rod, d is the minimum processing diameter, h0 is the initial rod height, ρ TD is the theoretical density, ρ PBD is the actual density of the powder bed fusion process.

7. A complex conformal metamaterial parts processing system based on tilt angle-minimum processing diameter interlocking, characterized in that: include: A geometric model building module for building geometric models of complex conformal metamaterial parts; A global coordinate calculation module, used for discretizing the geometric model and calculating the global coordinates of each node of each hexahedral lattice unit; A lattice topology network construction module is used to merge overlapping nodes based on the global coordinates of each node and construct a lattice topology network; A tilt angle calculation module, used to calculate the tilt angle of each tilt rod in the lattice topology network relative to the design direction; A minimum processing diameter calculation module, used for calculating the minimum processing diameter of each tilting rod based on the tilt angle; A processing module is used to process each tilt rod based on the minimum processing diameter to obtain a complex conformal metamaterial part.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the complex conformal metamaterial part processing method based on the interlocking of the tilt angle and the minimum processing diameter as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for processing complex conformal metamaterial parts based on the interlocking of the tilt angle and the minimum processing diameter according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for processing complex conformal metamaterial parts based on the interlocking of the tilt angle and the minimum processing diameter according to any one of claims 1 to 6 is implemented.

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