Lightweight energy-absorbing lattice-filled multi-cell thin-wall structure and preparation method thereof

Abstract

The invention discloses a lightweight energy-absorbing lattice filled multi-cell thin-wall structure and a preparation method thereof.The lightweight energy-absorbing lattice filled multi-cell thin-wall structure comprises an internal filled lattice structure and a multi-cell outer wall with a square section, and the internal filled lattice structure is composed of bcc unit cell structures or grid unit cell structures which are periodically arranged in a three-dimensional mode; the multi-cell outer wall and the internal filling lattice structure are integrally formed through 3D printing; according to the scheme, lattice configuration is optimized through a bcc unit cell structure or a grid unit cell structure, the energy absorption capacity and energy absorption efficiency are remarkably improved, specific energy absorption in a quasi-static state is remarkably improved, platform stress is more stable, and the method is suitable for a high-impact environment; a light high-strength composite material and a 3D printing technology are adopted, so that the mechanical property is guaranteed, and meanwhile, light weight and integration of the structure are achieved; the lattice structure filled inside interacts with the multi-cell outer wall to generate a synergistic effect, so that the overall mechanical property is enhanced, and the material is suitable for energy absorption parts in the fields of aerospace, transportation and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of lightweight energy-absorbing structures, and in particular to a lightweight energy-absorbing lattice-filled multi-cellular thin-wall structure and a preparation method thereof. Background Art

[0002] In a range of engineering fields such as aerospace, transportation, nuclear reactors and civil engineering, the demand for lightweight structures with high energy absorption capacity is increasing; therefore, the availability of lightweight structures with excellent energy absorption capacity is crucial for many engineering applications; in recent years, domestic scholars have also conducted a lot of research on the crashworthiness of structures; in current thin-walled tube structures, metals and composite materials are mainly used; domestic and foreign researchers have conducted in-depth research on thin-walled structures. After a collision, metal components will produce collision force due to large plastic deformation and then absorb collision energy. The energy absorption mode of composite thin-walled parts is more complex; lightweight porous materials that have attracted much attention in recent years, such as metal foams, polymer foams and other materials, have good energy absorption properties, and are combined with thin-walled structures to form various types of filled composite structures; especially polymer foam plastics, which are easy to process and shape, are the first choice of many researchers.

[0003] However, although metal and composite thin-walled tube structures can absorb energy through plastic deformation, they have problems such as large mass and low energy absorption efficiency; although lightweight porous materials (such as metal foam and polymer foam) have improved energy absorption performance, they still have disadvantages such as single structural design and insufficient synergistic effect; multi-cellular structures have better crash resistance than single-cell structures in the field of energy absorption and have more promising development prospects; therefore, a new type of lightweight multi-cellular thin-walled structure is urgently needed to improve energy absorption efficiency and mechanical properties. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a lightweight energy-absorbing lattice-filled multi-cellular thin-wall structure and a preparation method thereof, which solves the technical problems mentioned in the above-mentioned technology.

[0005] To achieve the above object, the technical solution adopted by the present invention is: A lightweight energy-absorbing lattice-filled multicellular thin-wall structure is provided, which includes an internal filling lattice structure and a multicellular outer wall with a square cross-section. The internal filling lattice structure is composed of a three-dimensionally periodically arranged BCC unit cell structure or a gyrid unit cell structure, and the multicellular outer wall and the internal filling lattice structure are integrally formed.

[0006] Furthermore, the BCC unit cell structure includes a plurality of lattice rods, one end of which is fixedly connected, and the connection end is located at the geometric center of the other end of the plurality of lattice rods. The lattice size of the BCC unit cell structure is 5-20 mm, the diameter of the lattice rod is 1.0-1.8 mm, and the lattice size of the gyrid unit cell structure is 8-25 mm.

[0007] Furthermore, the relative density of the internal filling lattice structure is 15%-30%.

[0008] Furthermore, the aspect ratio of the multicellular outer wall is 2-5:1, the wall thickness of the multicellular outer wall is 0.5-2 mm, and the surface of the multicellular outer wall is provided with reinforcing ribs.

[0009] Furthermore, the specific energy absorption of the thin-walled structure is 20-50 kJ / kg.

[0010] Furthermore, the plateau stress of the thin-walled structure under quasi-static compression is 5-30 MPa.

[0011] Furthermore, the outer wall of the multi-cell and the internal filling lattice structure are made of lightweight and high-strength composite materials, and the lightweight and high-strength composite materials include PLA, ABS or carbon fiber reinforced polymer.

[0012] Secondly, a method for preparing a lightweight energy-absorbing lattice-filled multi-cellular thin-walled structure is provided, which includes integrating the multi-cellular outer wall and the internal filling lattice structure through FDM3D printing, and the printing layer thickness is 0.05-0.2mm, and the 3D printing filling density is 80%-100%.

[0013] The beneficial effects of the present invention are: This solution optimizes the lattice configuration through the bcc unit cell structure or the gyrid unit cell structure, significantly improving the energy absorption capacity and energy absorption efficiency. The specific energy absorption under quasi-static conditions is significantly improved, the platform stress is more stable, and it is suitable for high-impact environments. The use of lightweight and high-strength composite materials achieves lightweight structure while ensuring mechanical properties. The composite materials are recyclable, reducing production costs and complying with the concept of green manufacturing. The integrated molding of the structure is achieved through 3D printing technology, and the process parameters are precisely controllable, which is suitable for the rapid preparation and mass production of complex structures. The internal filling lattice structure interacts with the multi-cellular outer wall and produces a synergistic effect, enhancing the overall mechanical properties, and is suitable for energy absorption components in aerospace, transportation and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the structure of the multicellular outer wall.

[0015] Figure 2 Schematic diagram of the bcc unit cell structure and the gyrid unit cell structure.

[0016] Figure 3 Schematic diagram of the internal filling lattice structure composed of bcc unit cell structure and gyrid unit cell structure.

[0017] Figure 4 The stress-strain curve of the lattice-filled multi-cell thin-walled structure composed of two single-cell structures.

[0018] Figure 5 These are the stress-strain curves of a single lattice, an empty tube, the sum of the empty tube and the lattice, and the overall filling of the bcc unit cell structure.

[0019] Figure 6 These are the stress-strain curves of a single lattice, an empty tube, the sum of the empty tube and the lattice, and the overall filling of the gyrid unit cell structure. DETAILED DESCRIPTION

[0020] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0021] like Figures 1 to 3 As shown, the lightweight energy-absorbing lattice-filled multicellular thin-walled structure of this scheme includes an internal filling lattice structure and a multicellular outer wall with a square cross-section. The internal filling lattice structure is composed of a three-dimensional periodically arranged bcc unit cell structure or a gyrid unit cell structure, and the multicellular outer wall and the internal filling lattice structure are formed as one piece.

[0022] As an optional embodiment, the relative density of the internal filling lattice structure is 15%-30%, wherein the bcc unit cell structure includes a plurality of lattice rods, one end of the plurality of lattice rods is fixedly connected, and the connection end is located at the geometric center of the other end of the plurality of lattice rods, the lattice size of the bcc unit cell structure is 5-20 mm, the diameter of the lattice rods is 1.0-1.8 mm, and the lattice size of the gyrid unit cell structure is 8-25 mm; the aspect ratio of the multi-cellular outer wall is 2-5:1, the wall thickness of the multi-cellular outer wall is 0.5-2 mm, and the surface of the multi-cellular outer wall is provided with reinforcing ribs; so that the specific energy absorption of the thin-walled structure can reach 20-50 kJ / kg, and the platform stress of the thin-walled structure under quasi-static compression can reach 5-30 MPa.

[0023] As an optional implementation, the multi-cellular outer wall and the internal filling lattice structure are made of lightweight, high-strength composite materials, including PLA, ABS or carbon fiber reinforced polymers; while ensuring mechanical properties, the structure is lightweight, and the composite materials are recyclable, reducing production costs, which is in line with the concept of green manufacturing.

[0024] This solution also provides a method for preparing a lightweight energy-absorbing lattice-filled multicellular thin-walled structure, which includes integrating the multicellular outer wall and the internal filling lattice structure through FDM 3D printing, with a printing layer thickness of 0.05-0.2mm and a 3D printing filling density of 80%-100%. The integrated molding of the structure is achieved through 3D printing technology, and the process parameters are precisely controllable, such as the regulation of parameters such as layer thickness and filling density, which is suitable for the rapid preparation and mass production of complex structures.

[0025] The following is a quasi-static analysis of multi-cell thin-walled filling structures with different lattice configurations and composite lattice configurations: Quasi-static compression tests were carried out on multi-cell thin-walled filling structures with different lattice configurations and composite lattice configurations using a universal testing machine. The strain rate was selected as 10 -3 , obtain the stress-strain curve under quasi-static conditions; study the compressive mechanical behavior under quasi-static conditions. Since different structures have different shapes, while ensuring the consistency of the relative density of the filling structure, these different configurations affect the synergistic reinforcement effect of the internal lattice filling and the thin-walled tube, thereby changing the mechanical behavior and energy absorption performance of the overall structure.

[0026] like Figure 4 As shown in the figure, the stress-strain curves of the two lattice-filled multi-cell thin-walled structures, bcc and gyrid single-cell structures, show three stages: linear elastic stage, plastic deformation stage, and densification stage. The gyrid structure has better overall performance. When the sample begins to yield, the load reaches its peak value, and some internal energy begins to be released after plastic folding. Afterwards, as the folding mode stabilizes, the stress fluctuates at a low level, which is the platform stress stage. In the energy absorption device, a moderate stress drop helps to reduce the impact of the peak load on the main structure, and the lower platform stress stage can smoothly absorb more energy.

[0027] like Figure 5 As shown in , it is the stress-strain curve of a single lattice, an empty tube, the sum of the empty tube and the lattice, and the overall filling of the bcc unit cell structure; Figure 6 As shown in the figure, these are the stress-strain curves of a single lattice, an empty tube, the sum of the empty tube and the lattice, and the overall filling of the gyrid unit cell structure; it can be seen that the overall curve increases more than the curve obtained by the addition, which is due to the synergistic enhancement effect between the lattice filling and the outer wall tube, the filling energy absorption capacity and energy absorption efficiency of the structure are enhanced, and the synergistic enhancement effect is also enhanced.

[0028] In summary, this scheme optimizes the lattice configuration through the BCC unit cell structure or the gyrid unit cell structure, significantly improving the energy absorption capacity and efficiency. The specific energy absorption under quasi-static conditions is significantly improved, the platform stress is more stable, and it is suitable for high-impact environments. The internal filling lattice structure interacts with the multi-cell outer wall and produces a synergistic effect, enhancing the overall mechanical properties, making it suitable for energy absorption components in aerospace, transportation and other fields.

Claims

1. A lightweight energy-absorbing lattice-filled multi-cellular thin-walled structure, characterized in that: It comprises an internal filling lattice structure and a multi-cellular outer wall with a square cross-section, wherein the internal filling lattice structure is composed of a three-dimensional periodically arranged bcc unit cell structure or a gyrid unit cell structure; the multi-cellular outer wall and the internal filling lattice structure are integrally formed.

2. The lightweight energy-absorbing lattice-filled multi-cellular thin-walled structure according to claim 1, characterized in that: The BCC unit cell structure includes a plurality of lattice rods, one end of each of the lattice rods is fixedly connected, and the connection end is located at the geometric center of the other end of each of the lattice rods. The lattice size of the BCC unit cell structure is 5-20 mm, the diameter of the lattice rods is 1.0-1.8 mm, and the lattice size of the gyrid unit cell structure is 8-25 mm.

3. The lightweight energy-absorbing lattice-filled multi-cellular thin-walled structure according to claim 1, characterized in that: The relative density of the internal filling lattice structure is 15%-30%.

4. The lightweight energy-absorbing lattice-filled multi-cellular thin-walled structure according to claim 1, characterized in that: The aspect ratio of the multicellular outer wall is 2-5:1, the wall thickness of the multicellular outer wall is 0.5-2 mm, and the surface of the multicellular outer wall is provided with reinforcing ribs.

5. The lightweight energy-absorbing lattice-filled multi-cellular thin-walled structure according to claim 1, characterized in that: The thin-walled structure has a specific energy absorption of 20-50 kJ / kg.

6. The lightweight energy-absorbing lattice-filled multi-cellular thin-walled structure according to claim 1, characterized in that: The platform stress of the thin-walled structure under quasi-static compression is 5-30 MPa.

7. The method for preparing a lightweight energy-absorbing lattice-filled multi-cellular thin-walled structure according to claim 1, characterized in that: The multi-cellular outer wall and the internal filling lattice structure are made of a lightweight and high-strength composite material, and the lightweight and high-strength composite material includes PLA, ABS or carbon fiber reinforced polymer.

8. The method for preparing a lightweight energy-absorbing lattice-filled multi-cellular thin-walled structure according to claims 1-7, characterized in that: It includes the use of FDM 3D printing to integrate the multi-cellular outer wall and the internal filling lattice structure, with a printing layer thickness of 0.05-0.2mm and a 3D printing filling density of 80%-100%.

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