Multi-cell energy-absorbing thin-walled tube imitating prinsepia utilis veins

Abstract

The invention belongs to the technical field of energy-absorbing structures for protection, and particularly relates to a multi-cell energy-absorbing thin-walled tube imitating a prinsepia utilis vein. The multi-cell energy absorption thin-walled tube comprises a thin-walled tube body, a first bionic element is arranged in the thin-walled tube body in the inner circumferential direction of the thin-walled tube body, the first bionic element comprises a first round tube, small round tubes and oval tubes, the small round tubes and the oval tubes are arranged on the first round tube, and the small round tubes and the oval tubes are arranged on the tube wall of the first round tube in a pairwise continuous mode; a plurality of inner rib plates are evenly distributed in the thin-walled tube body, each inner rib plate extends to the inner wall of the thin-walled tube in the radius direction of the thin-walled tube with the axis of the thin-walled tube as the starting end, the inner rib plates are arranged between every two adjacent oval tubes and between every two adjacent small round tubes, and the two oval tubes located on the two sides of the same inner rib plate are symmetrically arranged. According to the multi-cell energy-absorbing thin-walled tube, the cross section configuration of the multi-cell tube is designed in combination with the cross section of the Wanglian vein, and compared with a traditional structure, the multi-cell energy-absorbing thin-walled tube is higher in specific energy absorption and load stability, more remarkable in energy absorption performance, convenient to manufacture and low in cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy-absorbing structures for protection, and particularly relates to a multi-cell energy-absorbing thin-walled tube imitating the vein of a Victoria leaf. Background Art

[0002] Bionic design has gradually become an important way to improve the performance of structures. Through long-term evolution, biological structures in nature have formed highly adaptable forms and functions. For example, plants such as bamboo, cattail, and horsetail grass effectively withstand harsh environmental loads such as gravity, wind, and snow through hollow tubular structures. Inspired by this, researchers have proposed various bionic structures, such as tower racks, central beams, and robotic arms.

[0003] Thin-walled structures are widely used as protective devices in fields such as automobiles, rail transit, and military industry due to their low cost, excellent mechanical properties, and lightweight characteristics. The main factors affecting the energy absorption performance of thin-walled metal tubes include structural dimensions, loading methods, material properties, and cross-sectional shapes, among which the influence of the cross-sectional shape is particularly significant. In recent years, scholars have conducted in-depth research on the energy absorption characteristics of thin-walled structures from aspects such as theory, experiment, and numerical simulation, covering the performance of different cross-sectional shapes (such as circular, square, triangular, and multi-cell structures), geometric dimensions (length, wall thickness, side length, etc.), and loading conditions (axial loading, oblique loading, transverse bending, etc.). However, with the continuous improvement of the crashworthiness requirements of advanced vehicles, the performance limitations of traditional thin-walled structures have gradually emerged. To address this challenge, researchers have proposed methods such as filling with honeycombs or foams, lattice materials, or pressurized air to enhance the crashworthiness of thin-walled tubes. However, these methods usually require complex material combinations or auxiliary equipment, which limits their practical applications. For example, honeycomb-filled structures generally have complex manufacturing processes and high costs, requiring precision equipment and special materials (such as metal foils or aramid papers), making it difficult to popularize in low-cost fields; they have significant mechanical anisotropy, are sensitive to manufacturing defects (such as delamination and breakage), and local defects will significantly reduce the overall performance; their environmental adaptability is poor, the bonding interface is prone to failure at high temperatures, the material becomes brittle at low temperatures, moisture absorption in a humid environment leads to a decrease in strength, and long-term heat and humidity may cause material aging. These limitations restrict the application of this structure in scenarios with complex loads, extreme environments, or cost-sensitive situations. Therefore, there is an urgent need to propose new thin-walled structure design strategies to improve load stability, reduce the initial peak force, and increase the specific energy absorption performance.

[0004] Patent Application 2020110024915 discloses a thin-walled energy-absorbing device imitating the vein distribution of jade lotus leaves, which includes an energy-absorbing core. The energy-absorbing core includes an outer thin-walled circular tube, an inner thin-walled circular tube, main vein ribs and branch vein ribs. The energy-absorbing core can undergo orderly progressive plastic deformation during a collision, and the energy-absorbing impact force is stable throughout the compression energy-absorbing process. On the premise of keeping the total mass of the thin-walled energy-absorbing device unchanged, the thickness of the main vein ribs is 1.2 to 1.4 times that of the branch vein ribs. The energy-absorbing core is made by 3D printing or wire cutting, so it is difficult to obtain the energy-absorbing core with this irregular structure by ordinary processing methods.

[0005] Patent Application 202411415455X discloses a novel thin-walled energy-absorbing tube based on multiple bionics. The thin-walled layer is a cylindrical structure, and the tube wall adopts a corrugated structure. A plurality of thin-walled layers are coaxially sleeved outside the central columnar structure in sequence from inside to outside, and a plurality of thin-walled ribs are connected between the plurality of thin-walled layers and the central columnar structure; a hollow column is arranged at the connection position of the thin-walled layer and the thin-walled rib; the central columnar structure includes a plurality of spiral tubes, and the plurality of spiral tubes are coaxially spirally arranged and arranged in layers from outside to inside; the spiral tubes of each layer are connected in sequence, and the spiral tubes of adjacent layers are connected in sequence. Its bionic design structure is complex, and the difficulty of large-scale production and manufacturing is increased due to the manufacturing process requirements, and its application is limited.

[0006] Patent Application 2023107929234 discloses a thin-walled compression energy-absorbing device imitating the vein structure of Victoria amazonica leaves and its installation method. It includes more than one multi-level tree-like branch sub-structure, a cable, an outer thin-walled cylinder, and a central axis; mainly bionics the vein distribution morphology on the back of the Victoria amazonica leaf surface, improving the structural load-bearing capacity and stability.

[0007] The multi-cell energy-absorbing thin-walled tube imitating the vein of Victoria amazonica leaf proposed in this study is simpler to manufacture compared with the aforementioned patent application "A Thin-walled Energy-absorbing Device Imitating the Vein Distribution of Victoria cruziana Leaf". Moreover, based on different structural configurations, its energy-absorbing effect and bionic thin-walled structure are more superior. Compared with the patent application "A Novel Thin-walled Energy-absorbing Tube Based on Multiple Bionics", the multi-cell energy-absorbing thin-walled tube in this study has a higher specific energy absorption. And the optimal configuration is obtained through parameter analysis and optimization of the cross-section. While for the technology of the novel thin-walled energy-absorbing tube based on multiple bionics, it is necessary to adjust mechanical properties such as the Young's modulus, yield strength, and energy-absorbing capacity of the energy-absorbing tube to meet the application requirements, and the process is relatively complex. In addition, its bionic design structure is relatively complex and is manufactured using different 3D printing processes, which is not conducive to large-scale production and cannot be applied in practice. In addition, although both are based on the bionics of Victoria amazonica, compared with the aforementioned "A Thin-walled Compressive Energy-absorbing Device Imitating the Vein Structure of Victoria amazonica Leaf" and the existing bionic thin-walled devices of Victoria amazonica leaf mainly imitating the morphological distribution of the veins on the back of the leaf surface, the focus of this study is on the air chamber structure inside the cross-section of the Victoria amazonica leaf vein. And there are differences in the specific applications between the existing thin-walled compressive energy-absorbing devices imitating the vein structure of Victoria amazonica leaf and this study. Whether it is applicable to the plastic deformation requirements of thin-walled tubes in traffic collisions is not predictable. Especially, the aforementioned thin-walled compressive energy-absorbing devices imitating the vein structure of Victoria amazonica leaf mainly rely on the unique deformation of other devices in the structure, such as flexible cables, to resist local damage, and these are significantly different from the overall structure design, deformation situation, and performance of this study. Summary of the Invention

[0008] The present invention provides a multi-cell energy-absorbing thin-walled tube imitating the vein of Victoria amazonica leaf. By combining the cross-section design of the Victoria amazonica leaf vein to design the cross-section configuration of the multi-cell tube, compared with the traditional structure, this structure has a higher specific energy absorption, load stability, more significant energy-absorbing performance, excellent crashworthiness, is convenient to manufacture, and has a low cost, thus solving the problems existing in the prior art.

[0009] The present invention provides one of the following technical solutions:

[0010] A multi-cell energy-absorbing thin-walled tube imitating the vein of Victoria amazonica leaf, including a thin-walled tube body. A first bionic element is arranged circumferentially inside the thin-walled tube body. The first bionic element includes a first circular tube, small circular tubes, and elliptical tubes arranged on the first circular tube. The small circular tubes and elliptical tubes are continuously arranged in pairs on the tube wall of the first circular tube. A number of internal rib plates are evenly distributed inside the thin-walled tube body. Each internal rib plate extends from the axis of the thin-walled tube as the starting end to the inner wall of the thin-walled tube along the radial direction of the thin-walled tube. The internal rib plates are arranged between two adjacent elliptical tubes and between two adjacent small circular tubes, and the two elliptical tubes on both sides of the same internal rib plate are symmetrically arranged.

[0011] Furthermore, the centers of the elliptical tubes and small circular tubes are all located on the tube wall of the first circular tube.

[0012] Further, the elliptical tube is inclined, and the inclination angle is 20°-30°.

[0013] Further, let the minor axis length, major axis length, and inclination angle of the elliptical tube be represented by a, b, and θ respectively, then a = 5 mm, b = 6 mm, and θ = 30°.

[0014] Further, let the thickness of the multi-cell energy-absorbing thin-walled tube be represented by t, then t is 0.8 mm - 1.0 mm.

[0015] Further, at least 6 inner rib plates are provided.

[0016] The present invention provides the following second technical solution:

[0017] For the multi-cell energy-absorbing thin-walled tube imitating the vein of the Victoria leaf as described above, a second bionic element is further provided inside the thin-walled tube body. The second bionic element includes an inner thin-walled circular tube coaxially arranged with the thin-walled tube body, and the inner rib plates are arranged inside the thin-walled tube body on the outer side of the inner thin-walled circular tube.

[0018] Further, a plurality of second circular tubes are evenly distributed along the circumferential direction of the inner thin-walled circular tube on its tube wall.

[0019] Further, the axis centers of the second circular tubes are arranged on the tube wall of the inner thin-walled circular tube.

[0020] Further, the number or size of the second circular tubes arranged on the inner thin-walled circular tube should not interfere with the arrangement of the first bionic element, that is, ensure that the adjacent second circular tubes do not contact or overlap, and ensure that the second circular tubes do not contact or overlap with the small circular tubes or elliptical tubes. All the arrangement forms of the second bionic element under the premise of avoiding this requirement are within the setting structure of the multi-cell energy-absorbing thin-walled tube of the present invention.

[0021] Further, there are no less than 3 second circular tubes; preferably, there are 3 - 5 second circular tubes, and 6, 8, or 10 inner rib plates are arranged.

[0022] Further, one end of the adjacent inner rib plates close to the inner thin-walled circular tube is fixedly connected to the tube wall of the inner thin-walled circular tube and the tube wall of the second circular tubes arranged thereon respectively; the other ends of the inner rib plates are fixedly connected to the inner tube wall of the thin-walled tube body.

[0023] Further, the thickness of the multi-cell energy-absorbing thin-walled tube means that the thicknesses of the thin-walled tube body, inner thin-walled circular tube, first circular tube, second circular tube, small circular tube, elliptical tube, and inner rib plates are all t.

[0024] Further, the multi-cell energy-absorbing thin-walled tube is made by wire cutting or rolling.

[0025] The present invention also provides an application of the above multi-cell energy-absorbing thin-walled tube, especially used as a protective component in scenarios such as automotive bumper energy-absorbing boxes, energy-absorbing components of rail transit train bumpers, or aerospace landings that require overall plastic deformation and energy absorption.

[0026] Advantages of the present invention:

[0027] 1. Compared with triangular, square and other tubular structures, the multi-cell energy-absorbing thin-walled tube of the present invention has a higher average crushing force, higher load stability and energy absorption characteristics. It is especially suitable for scenarios such as automobiles and rail transit trains that require overall plastic deformation and energy absorption, and has excellent crashworthiness.

[0028] 2. The multi-cell energy-absorbing thin-walled tube of the present invention introduces bionic elements in combination with the internal air chamber structure of the cross-section of the water lily leaf vein. In particular, the first bionic element provided with small round tubes and elliptical tubes is introduced, which can make the structure deform stably and progressively in the platform stage, enabling the structure to have a continuous and stable energy absorption effect, and significantly improving the crashworthiness.

[0029] 3. By analyzing and optimizing the structural parameters of the multi-cell energy-absorbing thin-walled tube, such as the short and long axis dimensions and inclination angles of the elliptical tube in the first bionic element, the specific energy absorption of the structure is significantly enhanced. The second bionic element is set according to the cross-section structure of the water lily leaf vein and is combined with the first bionic element for the thin-walled tube, obtaining a multi-cell energy-absorbing thin-walled tube with excellent deformation, energy absorption and crashworthiness.

[0030] 4. The structure of the multi-cell energy-absorbing thin-walled tube of the present invention is simple to manufacture, without longitudinal variables and without the need for complex processes, easy to manufacture, low in cost, and can be realized by traditional methods such as wire cutting and rolling. It has strong practicability and is more easily promoted. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0032] Figure 1 shows the design concept of the multi-cell energy-absorbing thin-walled tube imitating the water lily leaf vein of the present invention;

[0033] Figure 2 is Figure 1 the schematic diagram of the multi-cell energy-absorbing thin-walled tube structure shown by the first shape in (b) of ;

[0034] Figure 3 is Figure 1 the schematic diagram of the multi-cell energy-absorbing thin-walled tube structure shown by the second shape in (b) of ;

[0035] Figure 4 is Figure 1 the schematic diagram of the multi-cell energy-absorbing thin-walled tube structure shown in (c) of ;

[0036] Figure 5 For Figure 4 the deformation nephogram under the compression test of the multi-cell energy-absorbing thin-walled tube shown;

[0037] Figure 6 the loading schematic diagram of the compression test of the present invention;

[0038] Figure 7 the deformation comparison diagram under the compression test of thin-walled tubes with different internal structure forms;

[0039] Figure 8 For Figure 7 the energy absorption indexes of the thin-walled tubes with different internal structures in [[ ]];

[0040] Figure 9 the multi-cell energy-absorbing thin-walled tube obtained by controlling the design of different dimensions of the major and minor axes of the elliptical tube;

[0041] Figure 10 For Figure 9 the crashworthiness performance results of the multi-cell energy-absorbing thin-walled tube in [[ ]];

[0042] Figure 11 the multi-cell energy-absorbing thin-walled tube obtained by controlling the inclination angle of the elliptical tube;

[0043] Figure 12 For Figure 11 the crashworthiness performance results of the multi-cell energy-absorbing thin-walled tube in [[ ]];

[0044] Figure 13 the influence results of the thickness of the multi-cell energy-absorbing thin-walled tube on the crashworthiness performance.

[0045] Among them, Figure 1 in (a) are the design elements used for the multi-cell energy-absorbing thin-walled tube of the present invention, and all the design elements are gradually added into the circular tube to form the multi-cell energy-absorbing thin-walled tube; (b) is the combination process of the design elements in (a); (c) is the three-dimensional schematic diagram of a structural form of the formed multi-cell energy-absorbing thin-walled tube of the present invention; (d) is the cross-sectional schematic diagram of the multi-cell energy-absorbing thin-walled tube in (c) (WL4-2-2) and the cross-sectional schematic diagrams of the other two structural forms obtained by changing the number of internal rib plates in the tube (WL3-2-2, WL5-2-2);

[0046] Figure 5 shows that under different loading distances, Figure 1 the deformation mode of the multi-cell energy-absorbing thin-walled tube in (c) of [[ ]] is the layer-by-layer crushing deformation;

[0047] Figure 7In the left column, middle column, and right column from top to bottom, there are respectively the top view, sectional view (the cutting positions refer to the cutting lines indicated by A, B, C, D, and E in the figure) after the axial loading test of the multi-cell energy-absorbing thin-walled tubes with five different combinations, and the front view;

[0048] Figure 8 In (a), it is the load-displacement relationship diagram, and in (b), it is the crashworthiness performance result;

[0049] Figure 9 In each figure, there are respectively the cross-sectional configurations of the multi-cell energy-absorbing thin-walled tubes containing elliptical tubes with different lengths of major and minor axes;

[0050] Figure 11 In each figure, there are respectively the cross-sectional configurations of the multi-cell energy-absorbing thin-walled tubes containing elliptical tubes with different inclination angles.

[0051] In the attached drawings, 1 is the inner thin-walled circular tube, 2 is the outer thin-walled circular tube, 3 is the inner rib plate, 4 is the first circular tube, 5 is the second circular tube, 6 is the small circular tube, 7 is the elliptical tube, 8 is the upper pressing plate of the testing machine, 9 is the specimen to be tested, and 10 is the lower pressing plate of the testing machine. Specific embodiments

[0052] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present application is not limited to these embodiments.

[0053] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the attached drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0054] See Figure 1 , which shows the design process of the multi-cell energy-absorbing thin-walled tube imitating the leaf vein of the Victoria amazonica. From the perspective of the tube cross-section, Figure 1 In (a), it is respectively a shape composed of a circle and intersecting straight lines, and this graphic is gradually added to the tube as a bionic element to form the cross-sectional structure of the multi-cell energy-absorbing thin-walled tube imitating the Victoria amazonica in this embodiment. The bionic multi-cell thin-walled tube can be obtained through the combination of each element, as shown in Figure 1 (b) in. Figure 1 In (c), it is the three-dimensional schematic diagram of the thin-walled tube. Among them, by changing the number of inner ribs in the thin-walled tube, thin-walled tubes with different cross-sectional shapes as shown in Figure 1 (d) can be produced.

[0055] As an implementation manner, see Figure 2, the structure of the multi-cell energy-absorbing thin-walled tube includes a thin-walled tube body, and the thin-walled tube body refers to the outer thin-walled circular tube 2. A first bionic element is arranged along the inner circumferential direction of the outer thin-walled circular tube. The first bionic element includes a first circular tube 4, small circular tubes 6 and elliptical tubes 7 arranged on the first circular tube. The small circular tubes 6 and the elliptical tubes 7 are continuously arranged in pairs on the tube wall of the first circular tube 4; a plurality of inner rib plates 3 are evenly distributed in the outer thin-walled circular tube 2. Each inner rib plate takes the axis of the outer thin-walled circular tube as the starting end and extends along the radial direction of the outer thin-walled circular tube to the inner wall of the outer thin-walled circular tube. The inner rib plates 3 are arranged between two adjacent elliptical tubes 7 and between two adjacent small circular tubes 6, and the two elliptical tubes 7 on both sides of the same inner rib plate 3 are symmetrically arranged.

[0056] As another implementation, see Figure 3 , on the basis of the thin-walled tube shown above, Figure 2 , a second bionic element is further arranged in the outer thin-walled circular tube 2. The second bionic element includes an inner thin-walled circular tube 1 coaxially arranged with the outer thin-walled circular tube. The inner rib plate 2 is arranged in the outer thin-walled circular tube on the outer side of the inner thin-walled circular tube. The inner thin-walled circular tube is arranged in the annular space between the first bionic element and the axis of the thin-walled tube.

[0057] As yet another implementation, see Figure 4 , on the basis of the thin-walled tube shown above, Figure 2 , Figure 3 , the second bionic element arranged in the outer thin-walled circular tube 2, in addition to including an inner thin-walled circular tube 1 coaxially arranged with the outer thin-walled circular tube, a plurality of second circular tubes 5 are evenly distributed along the circumferential direction of the inner thin-walled circular tube on the inner thin-walled circular tube.

[0058] Specifically, the above-mentioned multi-cell energy-absorbing thin-walled tube includes an inner thin-walled circular tube 1 and an outer thin-walled circular tube 2 arranged coaxially. The first bionic element is arranged in the outer thin-walled circular tube 2. The first bionic element is a first circular tube 4 arranged close to the outer thin-walled circular tube 2, small circular tubes 6 and elliptical tubes 7 arranged on the first circular tube. The small circular tubes and the elliptical tubes are continuously arranged in pairs on the tube wall of the first circular tube; a plurality of the inner rib plates 3 are evenly distributed between the inner thin-walled circular tube 1 and the outer thin-walled circular tube 2. One ends of adjacent inner rib plates close to the inner thin-walled circular tube 1 are respectively fixedly connected to the tube wall of the inner thin-walled circular tube 1 and the tube wall of the second circular tubes 5 arranged thereon; the other ends of each inner rib plate 3 are fixedly connected to the inner tube wall of the outer thin-walled circular tube 2. The inner rib plates 3 are arranged between two adjacent elliptical tubes and between two adjacent small circular tubes, and the two elliptical tubes 7 on both sides of the same inner rib plate 3 are symmetrically arranged.

[0059] In the above-mentioned multi-cell energy-absorbing thin-walled tube, 3 to 5 second circular tubes 5 are evenly spaced on the inner thin-walled circular tube 1.

[0060] Furthermore, at least 6 inner rib plates are provided and are evenly distributed at 60 degrees, 45 degrees, and 36 degrees.

[0061] In the above multi-cell energy-absorbing thin-walled tube, the thicknesses of the inner thin-walled circular tube 1, the outer thin-walled circular tube 2, the first circular tube 4, the second circular tube 5, the small circular tube 6, the elliptical tube 7, and the inner rib plate 3 are all equal.

[0062] Let the short-axis length, long-axis length, and inclination angle of the elliptical tube be represented by a, b, and θ respectively, and let the thickness of the multi-cell energy-absorbing thin-walled tube be uniformly represented by t. The specific energy absorption of the above multi-cell energy-absorbing thin-walled tube first increases and then decreases with the increase of the inclination angle θ and the elliptical major-axis dimension b. The change of t will also affect the crashworthiness of the structure.

[0063] When the following conditions are met: a = 5 mm, b = 6 mm, θ = 30°; and t = 0.8 mm, the multi-cell energy-absorbing thin-walled tube has higher specific energy absorption and deformation stability, and the crashworthiness of the structure is optimal.

[0064] The following will introduce in detail the specific structural form and application effect of the multi-cell energy-absorbing thin-walled tube imitating the vein of the Victoria leaf through specific embodiments.

[0065] Embodiment 1

[0066] See Figure 6 , which shows the schematic diagram of the compression test loading of this embodiment, mainly composed of the upper platen 8 of the testing machine, the test specimen 9 (a specimen with a multi-cell energy-absorbing thin-walled tube structure), and the lower platen 10 of the testing machine. The test adopts a displacement loading mode, and the test specimen is compressed at a speed of 1 mm / min.

[0067] Through the above loading device, the influence of different cross-sectional structures on the energy absorption capacity and load-bearing performance of the multi-cell energy-absorbing thin-walled tube is investigated, and the performance of each multi-cell energy-absorbing thin-walled tube in terms of compression and energy absorption is tested.

[0068] The indicators used to evaluate the crashworthiness characteristics of thin-walled structures usually include total energy absorption (EA), mean crushing force (MCF), specific energy absorption (SEA), peak crushing force (PCF), and crushing force efficiency (CFE). EA is the total absorbed energy during the crushing process and can be expressed as:

[0069]

[0070] where d is the effective deformation displacement, which is set to 90 mm in this study. F(x) is the instantaneous crushing load.

[0071] The mean crushing force (MCF) represents the average crushing strength of the thin-walled structure, and the calculation formula is:

[0072]

[0073] The specific energy absorbed per unit mass is a key indicator to distinguish the energy absorption capabilities of different materials and weights, and is defined as follows:

[0074]

[0075] Among them, M is the total mass of the structure. Obviously, the higher the SEA, the better the energy absorption capacity.

[0076] The peak crushing force (PCF) represents the maximum instantaneous crushing load in the effective compression displacement. Considering the impact force of the vehicle, a high PCF usually results in a large deceleration and serious injury or even death of the occupants.

[0077] The crushing force efficiency (CFE) can be expressed as:

[0078]

[0079] CFE is an index characterizing the load consistency. The higher the CFE, the better the load consistency.

[0080] Such as Figure 5 , shows Figure 1 the deformation nephograms at different compression distances under the compression test of the multi-cell energy-absorbing thin-walled tube in (c). As the compression amount increases, the multi-cell energy-absorbing thin-walled tube can generate stable deformation folds.

[0081] Such as Figure 7 , which is a multi-cell structure element imitating the Victoria amazonica leaf in (a) of Figure 1 , and studies the different structures generated after combining different internal elements. Among them, WL1 is the combination of the inner rib plate 3 and the single inner thin-walled circular tube 1; WL2 is the combination of the inner rib plate 3, the single inner thin-walled circular tube 1, and the uniformly distributed second circular tube 5; WL3 is the combination of the inner rib plate 3 and the first circular tube 4 element provided with small circular tubes 6 and elliptical tubes 7; WL4 is the combination of WL1 and the first circular tube 4 element provided with small circular tubes 6 and elliptical tubes 7; WL5 is the combination of WL2 and the first circular tube 4 element provided with small circular tubes 6 and elliptical tubes 7 on the basis of WL2. Among them, WL3-5 respectively correspond to the thin-walled tube structures of the three structures mentioned in the foregoing embodiments.

[0082] Figure 7 The compression test results of the multi-cell energy-absorbing thin-walled tubes with different cross-section structures shown in the middle column and the right column show that after adding the outer circular tube 5 element provided with small circular tubes 6 and elliptical tubes 7, the influence on the energy absorption of the thin-walled tube is significant, more and more stable deformation folds will be generated, and the plateau force is greatly increased, and each energy absorption index is greatly increased. It can be seen that adding the outer circular tube 5 element (WL3, WL4, WL5) provided with small circular tubes 6 and elliptical tubes 7 in the thin-walled tube has a more significant improvement in crashworthiness than adding the thin-walled tube structure with a single inner thin-walled circular tube 1 (WL1) and the thin-walled tube structure with a single inner thin-walled circular tube 1 and uniformly distributed second circular tubes on it (WL2). In addition, it is found through experiments that the multi-cell energy-absorbing thin-walled tube adding several of the above elements at the same time (Figure 4 structure), with the most wrinkles, the highest platform force, and the best crashworthiness indicators, such as Figure 8 result.

[0083] Example 2

[0084] Investigate the influence of the structural parameters of the outer tube element with small round tubes and elliptical tubes on the crashworthiness of the multi-cell energy-absorbing thin-walled tube. Specifically, investigate the influence of changes in the short axis, long axis dimensions, and inclination angle of the elliptical tube on the crashworthiness of the energy-absorbing tube.

[0085] See Figure 9 , control and design the geometric parameters of the multi-cell energy-absorbing thin-walled tube in this embodiment - the short axis dimension a and long axis dimension b of the elliptical tube. It is found that the specific energy absorption shows a trend of increasing first and then decreasing as the long axis dimension b of the ellipse increases. The results are as Figure 10 .

[0086] See Figure 11 , control and design the geometric parameter - the inclination angle θ of the elliptical tube of the multi-cell energy-absorbing thin-walled tube in this embodiment. It is found that the specific energy absorption also shows a trend of increasing first and then decreasing as the inclination angle θ increases, as Figure 12 .

[0087] The above results show that when θ = 30°, a = 5 mm, and b = 6 mm, the multi-cell energy-absorbing thin-walled tube will have higher specific energy absorption and deformation stability, and excellent crashworthiness.

[0088] The change in the thickness t of the multi-cell energy-absorbing thin-walled tube will also affect the structural crashworthiness. Since the increase in t will lead to an increase in the structural mass, considering the comprehensive mass and energy absorption indicators, when t = 0.8 mm, the structural crashworthiness is optimal. The results are shown in Figure 13 .

[0089] It should be noted that the terms "first", "second", etc. in the description, claims, and above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of this application described here can be implemented in an order other than those illustrated or described here.

[0090] As described above, only the embodiments of this application are concerned. The protection scope of this application is not limited by these specific embodiments, but is determined by the claims of this application. For those skilled in the art, this application can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the technical idea and principle of this application shall be included within the protection scope of this application.

Claims

1. A multi-cellular energy-absorbing thin-walled tube imitating the veins of Victoria amazonica, characterized in that: The invention comprises a thin-walled tube body, in which a first bionic element is arranged along the inner circumference of the tube, wherein the first bionic element comprises a first circular tube and small circular tubes and elliptical tubes arranged on the first circular tube, wherein the small circular tubes and elliptical tubes are arranged continuously in pairs on the tube wall of the first circular tube; a plurality of inner ribs are evenly distributed in the thin-walled tube body, wherein each inner rib takes the axis of the thin-walled tube as a starting end and extends to the inner wall of the thin-walled tube along the radial direction of the thin-walled tube, wherein the inner ribs are arranged between two adjacent elliptical tubes and between two adjacent small circular tubes, and the two elliptical tubes located on both sides of the same inner rib are arranged symmetrically.

2. The multi-cellular energy-absorbing thin-walled tube imitating the leaf veins of Victoria amazonica according to claim 1, characterized in that: The elliptical tube is tilted, and the tilt angle is 20°-30°.

3. The multi-cellular energy-absorbing thin-walled tube imitating the leaf veins of Victoria amazonica according to claim 2, characterized in that: The minor axis length, major axis length and inclination angle of the elliptical tube are represented by a, b and θ respectively, then a=5 mm, b=6 mm, θ=30°.

4. The multi-cellular energy-absorbing thin-walled tube imitating the leaf veins of Victoria amazonica according to claim 1, characterized in that: The thickness of the multi-cell energy-absorbing thin-walled tube is uniformly represented by t, and t is 0.8mm-1.0mm.

5. The multi-cellular energy-absorbing thin-walled tube imitating the leaf veins of Victoria amazonica according to claim 1, characterized in that: At least six inner ribs are provided.

6. The multi-cellular energy-absorbing thin-walled tube imitating the leaf veins of Victoria amazonica according to any one of claims 1 to 5, characterized in that: A second bionic element is also arranged in the thin-walled tube body, and the second bionic element comprises an inner thin-walled circular tube arranged coaxially with the thin-walled tube body, and the inner rib is arranged in the thin-walled tube body outside the inner thin-walled circular tube.

7. The multi-cellular energy-absorbing thin-walled tube imitating the leaf veins of Victoria amazonica according to claim 6, characterized in that: A plurality of second circular tubes are evenly distributed on the inner thin-wall circular tube along the circumferential direction of the tube wall.

8. The multi-cellular energy-absorbing thin-walled tube imitating the leaf veins of Victoria amazonica according to claim 7, characterized in that: The number of the second circular tubes is no less than 3.

9. The multi-cellular energy-absorbing thin-walled tube imitating the leaf veins of Victoria amazonica according to claim 7, characterized in that: One end of the adjacent inner ribs close to the inner thin-walled circular tube is respectively fixedly connected to the tube wall of the inner thin-walled circular tube and the tube wall of the second circular tube arranged thereon; the other end of each inner rib is fixedly connected to the inner tube wall of the thin-walled tube body.

10. The multi-cellular energy-absorbing thin-walled tube imitating the leaf veins of Victoria amazonica according to claim 1, characterized in that: The multi-cellular energy-absorbing thin-wall tube is manufactured by wire cutting or rolling.

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