Aluminum-based energy-absorbing lattice metamaterial based on bionic design and preparation method thereof

Abstract

The application provides an aluminum-based energy-absorbing lattice metamaterial based on bionic design, which comprises a lattice structure, the lattice structure comprises lattice unit cells arranged periodically and connected to each other in three-dimensional space, the lattice unit cell comprises a central part and a plurality of connecting parts, each face of the central part is connected with one connecting part, each connecting part comprises a plurality of arc surfaces, the arc surfaces are arranged around the bottom surface of the connecting part, and the side edges of each two adjacent arc surfaces are connected to form the side edges of the connecting part; the bottom edges of the arc surfaces are connected with the edges of the central part; the same edge of the central part is connected with the arc surfaces of two adjacent connecting parts, the distance between the two arc surfaces changes along a preset rule in the direction away from the central part, and the preset rule is gradually increasing, gradually decreasing or gradually increasing and then gradually decreasing. The aluminum-based energy-absorbing lattice metamaterial based on bionic design provided by the application solves the problems of reduced bearing capacity of the existing SC lattice structure, increased complexity and cost of 3D printing.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy technology, and in particular to an aluminum-based energy-absorbing lattice metamaterial based on biomimetic design and its preparation method. Background Technology

[0002] Aluminum alloy lattice mechanical metamaterials are a new type of material with unique microstructure and macroscopic properties. They are usually composed of regularly arranged lattice structures and have characteristics such as corrosion resistance, high strength, lightweight, and strong energy absorption, making them an ideal choice for aerospace and automotive manufacturing.

[0003] The specific performance of aluminum alloy lattice structures mainly depends on their structure. Existing aluminum alloy lattice structures, such as those using... Figure 1 The simple cubic (SC) lattice structure shown is Figure 2 This is a schematic diagram of the exploded structure of SC.

[0004] Figure 1 The simple cubic (SC) lattice structure shown still has the following problems: First, stress concentration is prone to occur at the central node of the SC lattice structure. This stress concentration will accelerate the failure of the central node, reduce the load-bearing capacity of the entire structure, and further reduce the energy absorption capacity of the structure. Second, since the SC lattice structure has a cantilever beam, in order to successfully achieve 3D printing, it is usually necessary to add support or rotate it at a certain angle, which increases the complexity and cost of 3D printing. Summary of the Invention

[0005] To address the issues of reduced load-bearing capacity and increased complexity and cost of 3D printing in existing simple cubic (SC) lattice structures, this application provides an aluminum-based energy-absorbing lattice metamaterial based on biomimetic design and its preparation method.

[0006] In a first aspect, the present invention provides an aluminum-based energy-absorbing lattice metamaterial based on biomimetic design, comprising a lattice structure, wherein the lattice structure comprises lattice unit cells arranged periodically and interconnected in three-dimensional space, the lattice unit cell comprising a central portion and a plurality of connecting portions, each face of the central portion being connected to one of the connecting portions, each connecting portion comprising a plurality of arc surfaces, the arc surfaces being arranged around the bottom surface of the connecting portion, and the sides of every two adjacent arc surfaces being connected to form the side edge of the connecting portion; the bottom edge of the arc surface is connected to the edge of the central portion;

[0007] The same edge of the central part connects the arc surfaces of two adjacent connecting parts. From the edge of the central part away from the central part, the distance between the two arc surfaces changes according to a preset rule, which is to gradually increase, gradually decrease, or first gradually increase and then gradually decrease.

[0008] Preferably, the bottom surface of the connecting part is connected to the center part, the top surface of the connecting part is away from the center part, and the area of ​​the top surface of the connecting part is smaller than the area of ​​the bottom surface of the connecting part.

[0009] Preferably, the central part has a cubic structure, the bottom surface of the connecting part has a square structure, and the bottom surface of the connecting part coincides with one of the side surfaces of the central part.

[0010] Preferably, the central portion includes multiple side surfaces and multiple first holes, the first holes being disposed at the center of the side surfaces and extending from the side surfaces of the central portion toward the body center of the central portion.

[0011] Preferably, the connecting portion includes a second hole, which is disposed on the bottom surface of the connecting portion and extends from the bottom surface of the connecting portion to the top surface of the connecting portion, and penetrates the top surface of the connecting portion.

[0012] Preferably, the projection of the edge of the second hole located on the bottom surface of the connecting portion in the central direction coincides with the edge of the first hole.

[0013] Preferably, the cross-section of the second hole gradually decreases from the bottom surface of the connector to the top surface of the connector.

[0014] Preferably, the cross-sections of the first hole and the second hole are both polygonal, circular, or elliptical.

[0015] Preferably, the cross-section of the connecting portion is polygonal.

[0016] Secondly, this application provides a method for preparing the above-mentioned biomimetic aluminum-based energy-absorbing lattice metamaterial, comprising the following steps: using Al-Mg-Si-Cu-Fe-Cr-Zr alloy as raw material and fabricating it using a laser powder bed melting process;

[0017] In the laser powder bed melting process, the slice layer thickness is 30μm, the laser power is 330W, the scanning speed is 600mm / s, and the scanning interval is 100μm.

[0018] This application provides a biomimetic-designed aluminum-based energy-absorbing lattice metamaterial, comprising a lattice structure. The lattice structure includes lattice unit cells arranged periodically and interconnected in three-dimensional space. Each lattice unit cell includes a central portion and multiple connecting portions. The sides of the connecting portions are formed by multiple arc surfaces. Each face of the central portion is connected to a connecting portion. The same edge of the central portion connects two of the arc surfaces. From the edge of the central portion away from the central portion, the distance between the two arc surfaces varies according to a preset rule, which is to gradually increase, gradually decrease, or first gradually increase and then gradually decrease. The arc surfaces of the connecting portions and the central portion can form an arch-like structure. When the lattice unit cell is under load, the arch structure effectively enhances the compressive strength of the lattice unit cell and makes the stress distribution more uniform. The tilt angle of the connecting portions (also called cantilever beams) in the unit cell is controllable, which improves the printability of the lattice structure, reduces the complexity of 3D printing, and lowers printing costs. By introducing a biomimetic arch design, the mechanical properties of the lattice structure are significantly improved, thereby enhancing the mechanical properties of the biomimetic-designed aluminum-based energy-absorbing lattice metamaterial. The aluminum-based energy-absorbing lattice metamaterial based on biomimetic design provided in this application solves the problems of reduced load-bearing capacity, increased complexity and cost of 3D printing in existing simple cubic (SC) lattice structures. Attached Figure Description

[0019] Figure 1 Schematic diagram of an SC lattice unit cell in the prior art;

[0020] Figure 2 Exploded cell diagrams of SC lattice in existing technology;

[0021] Figure 3 A schematic diagram of a simple cubic (SC) lattice structure block in the prior art;

[0022] Figure 4 This application presents a schematic diagram of a lattice unit cell of an aluminum-based energy-absorbing metamaterial based on biomimetic design.

[0023] Figure 5 This application presents an exploded diagram of a lattice unit cell of an aluminum-based energy-absorbing metamaterial based on biomimetic design.

[0024] Figure 6 This application presents a schematic diagram of a biomimetic aluminum-based energy-absorbing lattice metamaterial—a lattice structure.

[0025] Figure 7 Compressive stress-strain curves along the Z-direction for the lattice structure of Example 1 and Comparative Example 1;

[0026] Figure 8 Comparative Example 1: Cross-sectional view of the compressive Mises stress distribution along the Z-direction in a lattice unit cell;

[0027] Figure 9Example 1: Cross-sectional view of the compressive Mises stress distribution along the Z-direction in a lattice unit cell;

[0028] 1. SC lattice unit cell; 10. End rod; 100. Center node; 101. Upper end rod; 102. Rear end rod; 103. Right end rod; 104. Lower end rod; 105. Front end rod; 106. Left end rod;

[0029] 2. Lattice unit cell; 20. Connector; 200. Central part; 201. Upper connector; 202. Posterior connector; 203. Right connector; 204. Lower connector; 205. Anterior connector; 206. Left connector. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] To illustrate the technical solution of the present invention, specific embodiments are described below.

[0032] like Figure 4-6 As shown, this application provides an aluminum-based energy-absorbing lattice metamaterial based on biomimetic design, including a lattice structure. The lattice structure includes lattice unit cells 2 that are periodically and regularly arranged and interconnected in three-dimensional space. Each lattice unit cell 2 includes a central portion 200 and a plurality of connecting portions 20. Each face of the central portion 200 is connected to one of the connecting portions 20. Each connecting portion 20 includes a plurality of arc surfaces. The arc surfaces are arranged around the bottom surface of the connecting portion 20. The sides of every two adjacent arc surfaces are connected to form the side edge of the connecting portion 20. The bottom edge of the arc surface is connected to the edge of the central portion 200. The same edge of the central portion 200 connects the arc surfaces of two adjacent connecting portions 20. From the edge of the central portion 200 in a direction away from the central portion 200, the distance between the two arc surfaces follows a preset rule, which is to gradually increase, gradually decrease, or first gradually increase and then gradually decrease.

[0033] Specifically, such as Figure 6 As shown, in the lattice structure, multiple lattice unit cells 2 are arranged in a periodic pattern along the x-axis, and two connected lattice unit cells 2 are connected to each other through the connecting part 20. Multiple lattice unit cells 2 are arranged in a periodic pattern along the y-axis, and two connected lattice unit cells 2 are connected to each other through the connecting part 20. Multiple lattice unit cells 2 are arranged in a periodic pattern along the z-axis, and two connected lattice unit cells 2 are connected to each other through the connecting part 20.

[0034] like Figure 4-5As shown, the lattice unit cell 2 includes a central portion 200 and multiple connecting portions 20. The central portion 200 includes multiple faces, each face being connected to a connecting portion 20. Each connecting portion 20 includes a bottom face, a top face, and a side face. The bottom face of the connecting portion 20 is connected to the central portion 200. The side face of the connecting portion 20 includes multiple arc surfaces, which surround the bottom face of the connecting portion 20. The side edges of every two adjacent arc surfaces are connected to form the side edge of the connecting portion 20. Each face of the central portion 200 includes an edge, and the bottom edge of the arc surface is the edge of the bottom face of the connecting portion 20. The connection between the bottom edge of the arc surface and the edge of the central portion 200 means that the bottom face of the connecting portion 20 is connected to the face of the central portion 200.

[0035] like Figure 4 As shown, the same edge of the central portion 200 connects to the arc surfaces of two adjacent connecting portions 20. The distance between the two arc surfaces gradually changes from the edge of the central portion 200 towards the direction away from the central portion 200, as shown below. Figure 4 As shown, the distance between the two arc surfaces gradually increases, that is, the two arc surfaces extend in a direction away from the center by 200, and the two arc surfaces gradually move away from each other, and the distance between the two arc surfaces gradually increases.

[0036] The distance between the two arc surfaces follows a preset rule, which is to gradually increase, gradually decrease, or first gradually increase and then gradually decrease, such as... Figure 4 The structure shown is an arc surface, where the distance between the two arc surfaces gradually increases; if the arc surface is an arch structure, the distance between the two arc surfaces first gradually increases and then gradually decreases.

[0037] The biomimetic aluminum-based energy-absorbing lattice metamaterial provided in this application includes a lattice structure. The lattice structure comprises a lattice unit cell 2, including a central portion 200 and multiple connecting portions 20. The sides of each connecting portion 20 are formed by multiple curved surfaces. Each surface of the central portion 200 is connected to a connecting portion 20. Two curved surfaces are connected to the same edge of the central portion 200. The distance between the two curved surfaces varies according to a preset rule, which is either gradually increasing, gradually decreasing, or first gradually increasing. The size gradually decreases; the arc surface of the connecting part 20 and the central part 200 can form an arch-like structure. When the lattice unit cell 2 bears the load, the arch structure effectively enhances the compressive strength of the lattice unit cell 2, and the stress distribution is more uniform; the tilt angle of the connecting part 20 (also called a cantilever beam) in the unit cell is controllable, which improves the printability of the lattice structure, reduces the complexity of 3D printing, and lowers the printing cost; by introducing a biomimetic arch design, the mechanical properties of the lattice structure are significantly improved, and the mechanical properties of the biomimetic aluminum-based energy-absorbing lattice metamaterial are enhanced. The biomimetic aluminum-based energy-absorbing lattice metamaterial provided in this application solves the problems of reduced load-bearing capacity, increased complexity and cost of 3D printing in existing simple cubic (SC) lattice structures.

[0038] In some preferred embodiments, one end of the arc surface extends from the edge of the center portion 200 in a direction away from the center portion 200; the same edge of the center portion 200 connects the arc surfaces of two adjacent connecting portions 20, and the distance between the two arc surfaces gradually increases from the edge of the center portion 200 in a direction away from the center portion 200.

[0039] like Figure 4 As shown, in the unit cell, each edge of the central part 200 is connected to two arc surfaces. The distance between the two arc surfaces gradually increases from the edge of the central part 200 away from the central part 200, which helps the arc surface of the connecting part 20 to form an arched structure with the central part 200, effectively enhancing the compressive strength of the lattice unit cell 2, making the stress distribution more uniform, significantly improving the mechanical properties of the lattice structure, and improving the mechanical properties of the aluminum-based energy-absorbing lattice metamaterial based on biomimetic design.

[0040] In some embodiments, the bottom surface of the connecting portion 20 is connected to the central portion 200, the top surface of the connecting portion 20 is away from the central portion 200, and the area of ​​the top surface of the connecting portion 20 is smaller than the area of ​​the bottom surface of the connecting portion 20.

[0041] Specifically, such as Figure 4As shown, each face of the central part 200 is connected to a connecting part 20. The bottom surface of the connecting part 20 is connected to one of the faces of the central part 200. The top surface of the connecting part 20 is far away from the central part 200. The area of ​​the top surface of the connecting part 20 is smaller than the area of ​​the bottom surface of the connecting part 20, which helps the connecting part 20 and the central part 200 to form an arched structure. The stress distribution of the lattice structure is more uniform, which improves the mechanical properties of the lattice structure and enhances the mechanical properties of the aluminum-based energy-absorbing lattice metamaterial based on biomimetic design.

[0042] In some embodiments, the central portion 200 has a cubic structure, the bottom surface of the connecting portion 20 has a square structure, and the bottom surface of the connecting portion 20 coincides with one of the side surfaces of the central portion 200.

[0043] like Figure 4 , 5 As shown, the central part 200 is a cube, and each face of the central part 200 is a square or rectangle. Each face of the central part 200 is connected to a connecting part 20. The bottom surface of the connecting part 20 is connected to the central part 200. Therefore, the bottom surface of the corresponding connecting part 20 should also be the same shape as the side surface of the central part 200. Thus, the bottom surface of the connecting part 20 is a square or rectangle.

[0044] The bottom surface of the connecting part 20 coincides with one of the sides of the central part 200. Specifically, if the central part 200 is a cubic structure with six sides, each side is connected to a connecting part 20. The side connected to the bottom surface of the connecting part 20 is completely covered by the bottom surface of the connecting part 20, and the edge of the bottom surface of the connecting part 20 completely coincides with the edge of the corresponding side of the central part 200.

[0045] The bottom surface of the connecting part 20 coincides with one side of the central part 200. The connecting part 20 and the central part 200 together form a spatial frame, providing a three-dimensional support network for the lattice structure. When subjected to external forces, it can effectively transfer loads and disperse stress in the structure, improve the mechanical properties of the lattice structure, and improve the mechanical properties of the aluminum-based energy-absorbing lattice metamaterial based on biomimetic design.

[0046] It is understood that the lattice type of the aluminum-based energy-absorbing lattice metamaterial based on biomimetic design provided in this application is a simple cube, so the central part 200 is a cube structure. If it is used for other types of lattice, such as rhombohedral lattice, the structure of the central part 200 will also be changed accordingly.

[0047] In some embodiments, the cross-section of the connecting portion 20 is polygonal.

[0048] Specifically, the cross-section of the connecting part 20 is polygonal, ensuring that each edge is connected to two arc surfaces. Regardless of the direction of force on the lattice unit cell 2, the arched structure provides support, enhancing the compressive strength of the lattice unit cell 2 and resulting in a more uniform stress distribution. The polygon is an n-fold deformation, where n is greater than or equal to 3; for example, polygons include quadrilaterals, pentagons, hexagons, octagons, etc.

[0049] More preferably, the cross-section of the connecting portion 20 is quadrilateral.

[0050] like Figure 4 , 5 As shown, the central part 200 has a cubic structure, and the cross-section of the connecting part 20 is a quadrilateral structure. The structure is simple, easy to prepare, and can improve the mechanical properties of the lattice unit cell 2, thereby improving the mechanical properties of the aluminum-based energy-absorbing lattice metamaterial based on biomimetic design.

[0051] In some embodiments, the central portion 200 includes a plurality of side surfaces and a plurality of first holes, the first holes being disposed at the center of the side surfaces and extending from the side surfaces of the central portion 200 toward the body center of the central portion 200.

[0052] Specifically, such as Figure 5 As shown, the structure of the central part 200 is a cube structure, including six sides. Each side is composed of four edges connected end to end. Each side has a first hole that penetrates the side and extends toward the center of the central part 200.

[0053] Existing simple cubes can be solid or frame-shaped. The lattice structure of the aluminum-based energy-absorbing lattice metamaterial based on biomimetic design provided in this application has a central part 200 in the form of a frame without filling material, which can reduce weight and has good heat transfer or electrical transfer performance, and can be used in aerospace, mechanical engineering and other fields.

[0054] In some embodiments, one end of the first hole on each side of the central portion 200 intersects at the center of the central portion 200.

[0055] Specifically, such as Figure 5 The exploded view of lattice unit cell 2 shows a central portion 200 that is a cube with six sides. Each side has a first hole, which is square and extends through the side towards the center of the cube. The first holes on each side intersect at the center of the cube, resulting in a central portion 200 that forms a cube frame. A connecting part 20 is connected to each side of the cube; there are a total of six connecting parts 20 in lattice unit cell 2. Figure 5As shown, an upper connecting part 201 is connected to the upper side of the cube, a front connecting part 205 is connected to the front side of the cube, a right connecting part 203 is connected to the right side of the cube, a left connecting part 206 is connected to the left side of the cube, a lower connecting part 204 is connected to the lower side of the cube, and a rear connecting part 202 is connected to the rear side of the cube.

[0056] In some embodiments, the connecting portion 20 includes a second hole disposed on the bottom surface of the connecting portion 20, and the second hole extends from the bottom surface of the connecting portion 20 to the top surface of the connecting portion 20 and penetrates the top surface of the connecting portion 20.

[0057] Specifically, such as Figure 5 As shown, the bottom surface of the connecting part 20 is connected to one side of the central part 200; a second hole is provided on the bottom surface of the connecting part 20, and the second hole extends from the bottom surface of the connecting part 20 to the top surface of the connecting part 20 and penetrates the top surface of the connecting part 20. The connecting part 20 is also in the form of a frame and has no filling material, which can also reduce the weight and has good heat transfer or electrical transfer performance.

[0058] In some embodiments, the cross-sections of the first hole and the second hole are both polygonal, circular, or elliptical.

[0059] Specifically, a polygon is an n-sided polygon, where n is greater than or equal to 3. For example, a polygon can be a quadrilateral, pentagon, hexagon, etc.

[0060] In some preferred embodiments, the cross-sections of the first hole and the second hole are quadrilaterals. More preferably, the cross-sections of the first hole and the second hole are squares or rectangles.

[0061] In some embodiments, the cross-sectional area of ​​the first hole is S1, the lateral surface area of ​​the central portion 200 is S2, and 1 / 2S2≤S1<S2.

[0062] The larger area of ​​the first hole reduces the weight of the central part by 200.

[0063] In some embodiments, the cross-sectional area of ​​the second hole gradually decreases from the bottom surface of the connecting portion 20 toward the top surface of the connecting portion 20.

[0064] Because the bottom area of ​​the connecting part 20 is larger than the top area of ​​the connecting part 20, the cross-sectional area of ​​the second hole of the connecting part 20 gradually decreases from the bottom of the connecting part 20 to the top of the connecting part 20.

[0065] In some embodiments, the area of ​​the side of the second hole facing the center portion 200 is defined as S3, and the area of ​​the bottom surface of the connecting portion 20 is defined as S4, where 1 / 2S4≤S3<S4.

[0066] In some embodiments, the area of ​​the side of the second hole away from the center portion 200 is defined as S5, and the area of ​​the top surface of the connecting portion 20 is defined as S6, where 1 / 2S6≤S5<S5.

[0067] Similarly, the area of ​​the second hole should be as large as possible to reduce the weight of the connecting part 20.

[0068] like Figure 6 The diagram shows the arrangement of the lattice structure, with the lattice unit cell size designed to be 6×6×6mm. 3 To avoid the size effect of the lattice unit cell and ensure the mechanical properties of the lattice structure, the number of lattice unit cells 2 arranged along the x, y, and z directions is designed to be 5, resulting in an overall size of 30×30×30mm. 3 A three-dimensional solid dot matrix block. Figure 6 This is just one arrangement of the lattice unit cell 2. It is understood that the lattice unit cell 2 can also be arranged in other ways, and this application does not limit it.

[0069] exist Figure 6 In the middle, two adjacent lattice unit cells 2 are connected to each other through the top of the connecting part 20, thereby connecting the two adjacent lattice unit cells 2.

[0070] In some embodiments, the projection of the edge of the second hole located on the bottom surface of the connecting portion 20 in the direction of the central portion 200 coincides with the edge of the first hole;

[0071] Specifically, such as Figure 5 As shown, the long side and wide side of the second hole located on the bottom surface of the connecting part 20 coincide with the long side and wide side of the first hole on the side surface of the center part 200 connected to the bottom surface of the connecting part 20, which facilitates the production and preparation of the dot matrix structure and reduces the processing difficulty.

[0072] The biomimetic aluminum-based energy-absorbing lattice metamaterial provided in this application effectively enhances the compressive strength of the lattice unit cell 2 under load, disperses stress, and makes the stress distribution more uniform. The cantilever beam tilt angle of the lattice structure is controllable, which improves the printability of the lattice structure. By introducing a biomimetic arch design, the mechanical properties of the biomimetic aluminum-based energy-absorbing lattice metamaterial are significantly improved.

[0073] Thirdly, this application provides a method for preparing an aluminum-based energy-absorbing lattice metamaterial based on biomimetic design, comprising the following steps: using an Al-Mg-Si-Cu-Fe-Cr-Zr alloy as raw material and fabricating it using a laser powder bed melting process;

[0074] In the laser powder bed melting process, the slice layer thickness is 30μm, the laser power is 330W, the scanning speed is 600mm / s, and the scanning interval is 100μm.

[0075] Specifically, using Al-Mg-Si-Cu-Fe-Cr-Zr alloy as raw material, laser powder bed melting technology is used to construct a three-dimensional lattice structure and prepare an aluminum-based energy-absorbing lattice metamaterial based on biomimetic design.

[0076] In the laser powder bed melting process, Al-Mg-Si-Cu-Fe-Cr-Zr alloy powder particles are used as raw materials. The thickness of the slice layer is 30μm. The laser power is 330W, the scanning speed is 600mm / s, and the scanning interval is set to 100μm. The slice layer is scanned according to a predetermined path.

[0077] This application provides a method for preparing an aluminum-based energy-absorbing lattice metamaterial, which is simple and low in cost.

[0078] The present invention will be further illustrated by the following examples.

[0079] Example 1

[0080] This embodiment provides an aluminum-based energy-absorbing lattice metamaterial based on biomimetic design and its preparation method.

[0081] The fabrication method of aluminum-based energy-absorbing lattice metamaterials based on biomimetic design includes the following steps:

[0082] The material selected is an Al-Mg-Si-Cu-Fe-Cr-Zr alloy, and the preparation method is laser powder bed melting (LPBF) technology. The LPBF preparation process parameters are as follows:

[0083] The slice thickness was 30 μm, the laser power was 330 W, the scanning speed was 600 mm / s, and the scanning interval was set to 100 μm.

[0084] The structure of the prepared lattice unit cell 2 is as follows Figure 4-6 As shown. The central part 200 is a cube with six sides. Each side has a first hole, which is square and extends through the side to the center of the cube. The first holes on each side intersect at the center of the cube; the resulting central part 200 forms a cube frame. A connecting part 20 is connected to each side of the cube. In the lattice unit cell 2, there are a total of six connecting parts 20. Figure 5As shown, an upper connecting part 201 is connected to the upper side of the cube, a front connecting part 205 is connected to the front side of the cube, a right connecting part 203 is connected to the right side of the cube, a left connecting part 206 is connected to the left side of the cube, a lower connecting part 204 is connected to the lower side of the cube, and a rear connecting part 202 is connected to the rear side of the cube.

[0085] The connecting portion 20 includes a bottom surface, a top surface, and a side surface. The bottom surface of the connecting portion 20 completely overlaps with one of the side surfaces of the central portion 200. The top surface of the connecting portion 20 is away from the central portion 200. The side surface of the connecting portion 20 is disposed between the bottom surface and the top surface. The side surface of the connecting portion 20 is formed by multiple arc surfaces surrounding the bottom surface of the connecting portion 20. The side edges of every two adjacent arc surfaces are connected to form the side edge of the connecting portion 20. The bottom edge of the arc surface is connected to the edge of the central portion 200. The same edge of the central portion 200 connects two adjacent arc surfaces of the connecting portion 20. From the edge of the central portion 200 towards the direction away from the central portion 200, the distance between the two arc surfaces follows a preset rule, which is to gradually increase.

[0086] A second hole is provided on the bottom surface of the connecting part 20, and the second hole extends from the bottom surface of the connecting part 20 to the top surface of the connecting part 20 and penetrates through the top surface of the connecting part 20. The connecting part 20 is also in the form of a frame and has no filling material. The bottom surface area of ​​the connecting part 20 is larger than the top surface area of ​​the connecting part 20, and the projection of the top surface of the connecting part 20 onto the bottom surface of the connecting part 20 is located within the bottom surface of the connecting part 20.

[0087] Among them, the size of the biomimetic arch-shaped lattice unit cell 2 is designed to be 6×6×6mm. 3 To avoid the size effect of the lattice unit cell 2 and ensure the mechanical properties of the lattice structure, the lattice unit cell 2 of the lattice structure is arranged along the following... Figure 6 The x-axis, y-axis, and z-axis arrangements shown are designed with 5 elements, thus forming a pattern as follows: Figure 6 The overall dimensions shown are 30×30×30mm. 3 A three-dimensional solid dot matrix block.

[0088] Comparative Example 1

[0089] Comparative Example 1 shows an existing simple cubic (SC) lattice structure block. For example... Figure 2 The figure shows an exploded view of the existing SC lattice unit cell 1 structure. Each face of the central node 100 is connected to an end rod 10. The end rod 10 is a cylinder. The circular bottom of the cylinder is connected to the side of the central node 100. A third hole is provided in the center of the end rod 10. The third hole penetrates the cylinder and extends towards the body center of the central node 100. The third holes of each face of the central node 100 intersect at the body center of the central node 100.

[0090] like Figure 1 As shown, an upper end rod 101 is connected to the upper side of the center node 100, a front end rod 105 is connected to the front side of the center node 100, a right end rod 103 is connected to the right side of the center node 100, a left end rod 106 is connected to the left side of the center node 100, a lower end rod 104 is connected to the lower side of the center node 100, and a rear end rod 102 is connected to the rear side of the center node 100. Figure 3 It is an isometric view of the upper and lower sections of an existing simple cubic (SC) lattice structure block.

[0091] The simple cubic (SC) lattice structure of Comparative Example 1 was also prepared using laser powder bed fusion (LPBF) technology. The material selected was an Al-Mg-Si-Cu-Fe-Cr-Zr alloy, and the LPBF preparation process parameters were as follows:

[0092] The slice thickness was 30 μm, the laser power was 330 W, the scanning speed was 600 mm / s, and the scanning interval was set to 100 μm.

[0093] The mechanical properties of the aluminum-based energy-absorbing lattice metamaterial based on biomimetic design prepared in Example 1 and the aluminum-based lattice metamaterial with a simple cubic (SC) lattice structure prepared in Comparative Example 1 were tested. The test results are shown in Table 1.

[0094] Figure 7 The figures show the compressive stress-strain curves in the Z direction of the lattice structure of the aluminum-based energy-absorbing lattice metamaterial prepared in Example 1 and the simple cubic (SC) lattice structure prepared in Comparative Example 1.

[0095] Table 1

[0096] Group Compressive strength / MPa Energy absorption / J Example 1 29.4 361.4 Comparative Example 1 23.2 221.1

[0097] As shown in Table 1, the lattice structure of the aluminum-based energy-absorbing lattice metamaterial prepared in Example 1, based on biomimetic design, showed a 26.7% increase in compressive strength and a 63.5% increase in energy absorption compared to the simple cubic (SC) lattice structure in Comparative Example 1. This indicates that the arched structure of the aluminum-based energy-absorbing lattice metamaterial based on biomimetic design provided in this application effectively enhances the compressive strength of the lattice unit cell 2, improves the mechanical properties of the lattice structure, and enhances the mechanical properties of the aluminum-based energy-absorbing lattice metamaterial based on biomimetic design.

[0098] Figure 8 The cross-sectional view of the compressive Mises stress distribution along the Z direction of the SC lattice unit cell 1 in the simple cubic (SC) lattice structure of Comparative Example 1 is shown. Figure 9 Cross-sectional view of the compressive Mises stress distribution along the Z-direction in the lattice unit cell 2 of the lattice structure of the biomimetic aluminum-based energy-absorbing lattice metamaterial prepared in Example 1. Figure 8, 9 The comparison shows that the stress distribution of the lattice unit cell 2 in Example 1 is more uniform, indicating that the arched structure of the lattice unit cell 2 of the aluminum-based energy-absorbing lattice metamaterial based on biomimetic design provided in this application makes the stress distribution of the lattice structure more uniform, which significantly improves the mechanical properties of the aluminum-based energy-absorbing lattice metamaterial based on biomimetic design.

[0099] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A biomimetic aluminum-based energy-absorbing lattice metamaterial, characterized in that, The system includes a lattice structure comprising periodically arranged and interconnected lattice unit cells in three-dimensional space. Each lattice unit cell includes a central portion and multiple connecting portions. Each face of the central portion is connected to one of the connecting portions. Each connecting portion includes multiple arc surfaces surrounding the bottom surface of the connecting portion. The sides of every two adjacent arc surfaces are connected to form the side edge of the connecting portion. The bottom edge of the arc surface is connected to the edge of the central portion. The connecting portion includes a bottom surface and a top surface. The same edge of the central part connects the arc surfaces of two adjacent connecting parts. From the edge of the central part away from the central part, the distance between the two arc surfaces changes according to a preset rule, which is to gradually increase or first gradually increase and then gradually decrease.

2. The aluminum-based energy-absorbing lattice metamaterial based on biomimetic design according to claim 1, characterized in that, The bottom surface of the connecting part is connected to the center part, the top surface of the connecting part is away from the center part, and the area of ​​the top surface of the connecting part is smaller than the area of ​​the bottom surface of the connecting part.

3. The aluminum-based energy-absorbing lattice metamaterial based on biomimetic design according to claim 1, characterized in that, The central part has a cubic structure, the bottom surface of the connecting part has a square structure, and the bottom surface of the connecting part coincides with one of the side surfaces of the central part.

4. The aluminum-based energy-absorbing lattice metamaterial based on biomimetic design according to claim 1 or 3, characterized in that, The central portion includes multiple side surfaces and multiple first holes, the first holes being disposed at the center of the side surfaces and extending from the side surfaces of the central portion toward the body center of the central portion.

5. The aluminum-based energy-absorbing lattice metamaterial based on biomimetic design according to claim 4, characterized in that, The connecting portion includes a second hole, which is disposed on the bottom surface of the connecting portion and extends from the bottom surface of the connecting portion to the top surface of the connecting portion, and penetrates the top surface of the connecting portion.

6. The aluminum-based energy-absorbing lattice metamaterial based on biomimetic design according to claim 5, characterized in that, The projection of the edge of the second hole located on the bottom surface of the connecting part in the direction of the center part coincides with the edge of the first hole.

7. The aluminum-based energy-absorbing lattice metamaterial based on biomimetic design according to claim 5, characterized in that, The cross-section of the second hole gradually decreases from the bottom surface of the connector to the top surface of the connector.

8. The aluminum-based energy-absorbing lattice metamaterial based on biomimetic design according to claim 6 or 7, characterized in that, The cross-sections of the first hole and the second hole are both polygonal, circular, or elliptical.

9. The aluminum-based energy-absorbing lattice metamaterial based on biomimetic design according to claim 1, characterized in that, The cross-section of the connecting part is polygonal.

10. A method for preparing an aluminum-based energy-absorbing lattice metamaterial based on biomimetic design as described in any one of claims 1-9, characterized in that, Includes the following steps: It is made from Al-Mg-Si-Cu-Fe-Cr-Zr alloy using laser powder bed melting process; In the laser powder bed melting process, the slice layer thickness is 30μm, the laser power is 330W, the scanning speed is 600mm / s, and the scanning interval is 100μm.

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