Method for modeling large-scale three-dimensional truss lattice based on reduced-order model, storage medium and equipment

Abstract

This invention discloses a method, storage medium, and device for large-scale three-dimensional truss lattice modeling based on a reduced-order model. The modeling method includes: determining the lattice configuration, coordinates of the center point of each lattice unit cell, and unit cell size of the truss lattice structure; reducing the order of each truss unit in the truss lattice to a central axis skeleton line using a skeleton line extraction method based on the lattice configuration; determining the coordinates of the end nodes of each central axis skeleton line in each unit cell using a coordinate extraction method based on the coordinates of the unit cell center point and unit cell size; determining the connection relationship of the end nodes based on the coordinates of the end nodes of each central axis skeleton line in each unit cell; using two end nodes with a connection relationship as the two endpoints of a beam element to establish a reduced-order simplified unit cell node matrix based on beam elements; determining the array number in the X, Y, and Z directions; linearly assigning values ​​to the reduced-order simplified unit cell node matrix to obtain a large-scale three-dimensional truss lattice model. The method of this invention generates a model with less data and significantly reduces modeling and storage time.

Description

Technical Field

[0001] This invention belongs to the field of computational geometry modeling and lightweight characterization of 3D lattice structures. Specifically, it relates to a method, storage medium, and device for large-scale 3D truss lattice modeling based on a reduced-order model. Background Technology

[0002] Truss lattice structures possess many excellent mechanical properties, such as high specific strength, high specific stiffness, high energy absorption, and lightweight, and are widely used in aerospace, weaponry, biomedicine, vehicle engineering, and sports equipment. The development of additive manufacturing technology has provided even greater design flexibility for truss lattices.

[0003] However, at present, there are the following difficulties when using truss lattice for structural optimization design: First, the massive data processing is difficult and the modeling time is long and costly when modeling large-scale lattice, resulting in low modeling efficiency and excessive storage space requirements; Second, the scale of lattice modeling is limited, making it difficult to achieve efficient modeling of large-scale / ultra-large-scale lattices. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a large-scale three-dimensional truss lattice modeling method, storage medium, and device based on a reduced-order model. This large-scale three-dimensional truss lattice modeling method can effectively solve the problems of traditional modeling methods, such as difficulty in processing massive amounts of data, long modeling time and high cost, and severe limitation on modeling scale when constructing large-scale truss lattices.

[0005] To achieve the above technical objectives, the technical solution adopted by this invention is as follows: a method for large-scale three-dimensional truss lattice modeling based on a reduced-order model, specifically including the following steps:

[0006] Step S1: Determine the lattice configuration, coordinates of the center point of the lattice unit cell, and the unit cell size of the truss lattice structure;

[0007] Step S2: Based on the lattice configuration, the skeleton line extraction method is used to reduce the order of each truss unit in the truss lattice to a central axis skeleton line. Based on the coordinates of the unit cell center point and the unit cell size, the coordinates of the end nodes of the central axis skeleton line in each unit cell are determined by the coordinate extraction method.

[0008] Step S3: Based on the coordinates of the end nodes of the central axis skeleton line in each unit cell, determine the connection relationship of the end nodes, take the two end nodes with the connection relationship as the two endpoints of the beam element, and establish the reduced-order simplified unit cell node matrix based on the beam element.

[0009] Step S4: Determine the number of arrays in the X, Y, and Z directions, and perform linear assignment on the reduced-order simplified unit cell node matrix to obtain a large-scale three-dimensional truss lattice model.

[0010] Furthermore, the lattice configuration in step S1 includes: lattice type T and the number of unit cell truss elements n of the lattice.

[0011] Furthermore, step S3 includes the following sub-steps:

[0012] Step S3.1: Compare the end nodes of each central axis skeleton line in the unit cell pairwise. If two end nodes belong to the same central axis skeleton line, it means that the two end nodes have a connection relationship. Take the two end nodes as the two endpoints of the beam element and store the coordinates of the two endpoints of the beam element in the same row of the reduced-order simplified unit cell node matrix.

[0013] Step S3.2: Repeat step S3.1 until the connection relationship judgment of all the end nodes of the central axis skeleton line is completed, and the reduced-order simplified unit cell node matrix based on beam element is obtained.

[0014] Furthermore, step S4 includes the following sub-steps:

[0015] Step S4.1: Based on the array numbers nx, ny, nz in the X, Y, and Z directions and the unit cell size, form nx, ny, and nz empty cubes with side lengths equal to the unit cell size in the X, Y, and Z directions, respectively.

[0016] Step S4.2: Based on the established reduced-order simplified unit cell node matrix based on beam elements, coordinates are assigned to the empty cube using a linear assignment method to obtain a large-scale three-dimensional truss lattice model with a scale of nx×ny×nz.

[0017] Furthermore, the present invention also provides a computer-readable storage medium storing a computer program that enables a computer to execute the large-scale three-dimensional truss lattice modeling method based on a reduced-order model.

[0018] Furthermore, the present invention also provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the large-scale three-dimensional truss lattice modeling method based on the reduced-order model.

[0019] Compared with existing technologies, the present invention has the following beneficial effects: Based on the rules of lattice unit cell composition, the present invention establishes a method for generating unit cell node coordinates by using the idea of ​​model reduction and simplification, and employing methods such as skeleton line extraction and coordinate extraction; based on the established unit cell node coordinates, a reduced-order simplified unit cell based on beam elements is established according to the connection relationship of the nodes; for the established reduced-order simplified unit cell, a large-scale lattice is quickly arrayed and output by linearly assigning values ​​to the node coordinate matrix, thus obtaining a lightweight lattice representation data structure and forming a general method for efficient modeling of large-scale lattices. The model data volume established by this method is smaller, the storage space is greatly reduced, and the modeling and storage time is greatly reduced. Attached Figure Description

[0020] Figure 1 The flowchart shows the large-scale three-dimensional truss lattice modeling method based on the reduced-order model of the present invention.

[0021] Figure 2 This is a flowchart of step S2 in the present invention;

[0022] Figure 3 A schematic diagram of a common lattice order reduction simplified model;

[0023] Figure 4 Schematic diagrams of simplified models for reducing the order of lattices of different sizes are shown, where, Figure 4 In the model (a), the reduced-order model has 125 units. Figure 4 (b) in the model is a reduced-order simplified model with 1000 units. Figure 4 In the model, (c) represents a reduced-order simplified model with 15625 unit cells. Figure 4 In the model, (d) represents a reduced-order simplified model with 125,000 unit cells;

[0024] Figure 5 A schematic diagram of a simplified model for a million-scale lattice. Detailed Implementation

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] like Figure 1 This is a flowchart of the large-scale three-dimensional truss lattice modeling method based on a reduced-order model according to the present invention. The large-scale three-dimensional truss lattice modeling method specifically includes the following steps:

[0027] Step S1: Determine the lattice configuration, coordinates of the center point of the lattice unit cell, and the unit cell size of the truss lattice structure; In this invention, the lattice configuration includes: lattice type T and the number of truss unit cells n of the lattice.

[0028] Step S2, as follows Figure 2 Based on the lattice configuration, the skeleton line extraction method is used to reduce the order of each truss unit in the truss lattice to a central axis skeleton line. Based on the coordinates of the center point of the unit cell and the unit cell size, the coordinates of the end nodes of the central axis skeleton line in each unit cell are determined by the coordinate extraction method. This removes a lot of complex information in traditional modeling and replaces it with coordinate information, thereby improving modeling efficiency and reducing model size.

[0029] Step S3: Based on the coordinates of the end nodes of the central axis skeleton line in each unit cell, determine the connection relationship of the end nodes. Take the two end nodes with the connection relationship as the two endpoints of the beam element, and establish a reduced-order simplified unit cell node matrix based on the beam element. Each row in the reduced-order simplified unit cell node matrix represents a beam element, which is convenient to store and has high retrieval efficiency. Specifically, it includes the following sub-steps:

[0030] Step S3.1: Compare the end nodes of each central axis skeleton line in the unit cell pairwise. If two end nodes belong to the same central axis skeleton line, it means that the two end nodes have a connection relationship. Take the two end nodes as the two endpoints of the beam element and store the coordinates of the two endpoints of the beam element in the same row of the reduced-order simplified unit cell node matrix.

[0031] Step S3.2: Repeat step S3.1 until the connection relationship judgment of all the end nodes of the central axis skeleton line is completed, and the reduced-order simplified unit cell node matrix based on beam element is obtained.

[0032] Step S4: Determine the number of arrays in the X, Y, and Z directions, and perform linear assignment on the reduced-order simplified unit cell node matrix to quickly obtain a large-scale three-dimensional truss lattice model; specifically, this includes the following sub-steps:

[0033] Step S4.1: Based on the array numbers nx, ny, nz in the X, Y, and Z directions and the unit cell size, form nx, ny, and nz empty cubes with side lengths equal to the unit cell size in the X, Y, and Z directions, respectively.

[0034] Step S4.2: Based on the established reduced-order simplified unit cell node matrix based on beam elements, coordinates are assigned to the empty cube using a linear assignment method to obtain a large-scale three-dimensional truss lattice model with a scale of nx×ny×nz.

[0035] In one technical solution of the present invention, a computer-readable storage medium is also provided, storing a computer program that enables a computer to execute the large-scale three-dimensional truss lattice modeling method based on the reduced-order model.

[0036] In one technical solution of the present invention, an electronic device is also provided, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the large-scale three-dimensional truss lattice modeling method based on the reduced-order model.

[0037] Example

[0038] like Figure 3The large-scale three-dimensional truss lattice modeling method of the present invention is applicable to the rapid generation of various typical truss lattice models, such as BCC, SC, FCC, Like-P, Type-Mi, and Pyramid. The technical solution of the present invention is illustrated below using BCC lattice reduction simplification and rapid modeling as an example.

[0039] Step S1: Determine the lattice type of the truss lattice structure as BCC, the number of unit cell truss elements constituting the lattice is 8, establish the coordinates of the center point of the unit cell of the BCC lattice as (0,0,0), and the size of a single package as 10mm.

[0040] Step S2: Based on the lattice configuration, the skeleton line extraction method is used to reduce the order of each truss element in the truss lattice to a central axis skeleton line. Based on the coordinates of the center point of the BCC unit cell and the unit cell size, the coordinates of the end nodes of the central axis skeleton line in each BCC unit cell are determined by the coordinate extraction method, as shown in Table 1:

[0041] Table 1: Coordinates of End Nodes of Each Central Axis Skeleton Line

[0042] 1 (0,0,0) 2 (-5,-5,-5) 3 (-5,-5,5) 4 (-5,5,-5) 5 (-5,5,5) 6 (5,-5,-5) 7 (5,-5,5) 8 (5,5,-5) 9 (5,5,5)

[0043] Step S3: Based on the coordinates of the end nodes of the central axis skeleton line in each BCC unit cell, determine the connection relationship of the end nodes, and take the two end nodes with the connection relationship as the two endpoints of the beam element. Establish the reduced-order simplified BCC unit cell node matrix based on the beam element, as shown in Table 2:

[0044] Table 2: Reduced-order simplified BCC unit cell node matrix based on beam elements

[0045]

[0046]

[0047] Step S4: Determine the number of arrays in the X, Y, and Z directions, and perform linear assignment on the reduced-order simplified unit cell node matrix to obtain a large-scale three-dimensional truss lattice model. In this embodiment, five sets of array numbers in the X, Y, and Z directions are set respectively, and the generated reduced-order simplified BCC lattices are as follows: Figure 4 (a)-(d) and Figure 5 As shown: Figure 4 In (a) of the model, the array numbers in the X, Y, and Z directions are nx = 5, ny = 5, and nz = 5, respectively, and the number of arrayed unit cells is 125. The traditional modeling method takes 3 seconds to complete the modeling, and the model size is 3000KB. The three-dimensional truss lattice modeling method of this invention completes the modeling in 0.012 seconds, with a model size of 148KB, representing a 250-fold increase in modeling speed and a 95.07% reduction in model storage size. Figure 4In (b) of this paper, the array numbers in the X, Y, and Z directions are nx = 10, ny = 10, and nz = 10, respectively, and the number of arrayed unit cells is 1000. The traditional modeling method takes 42 seconds to complete the modeling, and the model size is 23.44 MB. The 3D truss lattice modeling method of this invention completes the modeling in 0.045 seconds, and the model size is 1.15 MB, which is 56,000 times faster and reduces the model storage size by 95.08%. Figure 4 In (c), the array numbers in the X, Y, and Z directions are nx = 25, ny = 25, and nz = 25, respectively, resulting in 15625 arrayed unit cells. Traditional modeling methods take 25 hours to complete the model, with a model size of 366.21 MB. The 3D truss lattice modeling method of this invention completes the model in 0.55 seconds, with a model size of 1.8 MB, representing a 163636-fold increase in modeling speed and a 99.50% reduction in model storage size. Figure 4 In (d), the array numbers in the X, Y, and Z directions are nx = 50, ny = 50, and nz = 50, respectively, resulting in 125,000 arrayed unit cells. Traditional modeling methods are insufficient to construct this structure. The 3D truss lattice modeling method of this invention completes the modeling in 4.33 seconds, with a model size of 144 MB. Figure 5 The number of arrays in the X, Y, and Z directions are nx = 100, ny = 100, and nz = 100, respectively, and the number of arrayed unit cells is 1,000,000. The modeling time using the three-dimensional truss lattice modeling method of this invention is 35.23 seconds, and the model size is 950 MB. The above analysis shows that the modeling time of the three-dimensional truss lattice modeling method of this invention is significantly reduced compared to traditional modeling methods, the storage size of the constructed model is also greatly reduced, and the constructible scale of the truss lattice is greatly increased.

[0048] In the embodiments disclosed in this application, a computer storage medium may be a tangible medium that may contain or store programs for use by or in conjunction with an instruction execution system, apparatus, or device. The computer storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of computer storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0049] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this application can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0050] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A reduced-order model based modeling method for large-scale three-dimensional truss lattice, characterized in that, Specifically, the steps include the following: Step S1: Determine the lattice configuration, coordinates of the center point of the lattice unit cell, and the unit cell size of the truss lattice structure; Step S2: Based on the lattice configuration, the skeleton line extraction method is used to reduce the order of each truss unit in the truss lattice to a central axis skeleton line. Based on the coordinates of the unit cell center point and the unit cell size, the coordinates of the end nodes of each central axis skeleton line in the unit cell are determined by the coordinate extraction method. Step S3: Based on the coordinates of the end nodes of each central axis skeleton line in the unit cell, determine the connection relationship of the end nodes, and take the two end nodes with the connection relationship as the two endpoints of the beam element to establish a reduced-order simplified unit cell node matrix based on the beam element; including the following sub-steps: Step S3.1: Compare the end nodes of each central axis skeleton line in the unit cell pairwise. If two end nodes belong to the same central axis skeleton line, it means that the two end nodes have a connection relationship. Take the two end nodes as the two endpoints of the beam element and store the coordinates of the two endpoints of the beam element in the same row of the reduced-order simplified unit cell node matrix. Step S3.2: Repeat step S3.1 until the connection relationship judgment of all central axis skeleton line end nodes is completed, and the reduced-order simplified unit cell node matrix based on beam element is obtained. Step S4: Determine the number of arrays in the X, Y, and Z directions, and perform linear assignment on the reduced-order simplified unit cell node matrix to obtain a large-scale three-dimensional truss lattice model.

2. The method for large-scale three-dimensional truss lattice modeling based on a reduced-order model according to claim 1, characterized in that, The lattice configuration in step S1 includes: lattice type T The number of unit cell truss elements in the lattice n .

3. The method for large-scale three-dimensional truss lattice modeling based on a reduced-order model according to claim 1, characterized in that, Step S4 includes the following sub-steps: Step S4.1: Based on the array numbers in the X, Y, and Z directions nx , ny , nz And the unit cell size, formed in the X, Y, and Z directions respectively. nx , ny , nz An empty cube with a side length equal to the size of a single cell; Step S4.2: Based on the established reduced-order simplified unit cell node matrix based on beam elements, the coordinates of the empty cube are assigned using a linear assignment method to obtain a scale of... nx × ny × nz A large-scale three-dimensional truss lattice model.

4. A computer-readable storage medium storing a computer program, characterized in that, The computer program causes the computer to execute the large-scale three-dimensional truss lattice modeling method based on a reduced-order model as described in any one of claims 1-3.

5. An electronic device, characterized in that, include: The memory, the processor, and the computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the large-scale three-dimensional truss lattice modeling method based on a reduced-order model as described in any one of claims 1-3.

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