Bionic sandwich tube structure based on bamboos

Abstract

The invention relates to the technical field of automobile passive safety protection, in particular to a bamboo-based bionic sandwich tube structure which comprises a double tube and bionic sandwich structures, the double tube is composed of an inner circular tube and an outer circular tube, and the bionic sandwich structures are distributed between the inner circular tube and the outer circular tube in a gradient mode from large to small in the radial direction; the bionic sandwich structure is composed of single-arrow-shaped structures, specifically, the circumference of an inner circular tube is equally divided into eight arcs, and then two adjacent equal division points of the inner circular tube are connected with midpoints of corresponding arc sections of an outer circular tube to form eight single-arrow-shaped structures; and by parity of reasoning, single-arrow-shaped bionic sandwich structures with different orders can be formed, and finally novel bionic sandwich tube structures with different orders are obtained. The bionic sandwich tube structure based on the bamboos is stable in deformation in the compression process, good in energy absorption characteristic and capable of well protecting the safety of passengers.

Description

Technical Field

[0001] The invention relates to the technical field of automobile passive safety protection, in particular to a bamboo-based bionic sandwich tube structure. Background Art

[0002] With the continuous development of the automobile industry, the number of cars on the market has increased rapidly, which has led to an increase in the probability of car collision accidents. In order to reduce the property losses caused by traffic accidents and better protect the personal safety of drivers and passengers, it is very important to design energy-absorbing structures with good crash resistance. During the collision, the energy-absorbing structure absorbs the energy generated by the collision through plastic deformation, thereby reducing the damage to the driver and passengers.

[0003] Existing energy absorption boxes usually adopt a single shape and structure, which cannot cope with the complex collision situations in real accidents. In addition, there is a certain contradiction between lightweight and crash resistance in existing energy absorption structures. Therefore, the crash resistance of energy absorption structures needs to be further improved.

[0004] As a typical structural and functional integrated material, the sandwich structure has excellent impact resistance and energy absorption characteristics, and has good mechanical properties and high load-bearing efficiency in terms of shear resistance. On the other hand, biological structures in nature have good mechanical properties after continuous evolution, and their excellent geometric topology provides a good reference for the design of energy-absorbing structures. The design of energy-absorbing structures by combining sandwich structures and bionic design principles provides new ideas for the design of automotive crash-resistant structures, which has good research significance. Summary of the invention

[0005] In view of the problem that the existing double-tube structure has poor energy absorption performance, the present invention proposes a bionic sandwich tube structure based on bamboo. The present invention combines the bionic design theory and the energy absorption structure design method, and through similarity analysis, selects the microscopic topological structure of the bamboo cross section as the biological prototype for the optimization design of the double-tube structure. According to the similarity between the bamboo cross-sectional structure and the double tube in structure and function, the double tube is combined with the bionic sandwich structure, thereby designing a bionic sandwich tube structure with good crash resistance, enhancing the deformation stability of the double tube structure, and greatly improving the bearing capacity of the double tube structure.

[0006] In order to achieve the above purpose, the technical solutions provided are as follows:

[0007] A bamboo-based bionic sandwich tube structure, characterized in that it comprises a double tube and a bionic sandwich structure, wherein the double tube is composed of an inner circular tube and an outer circular tube, and the bionic sandwich structure is distributed between the inner circular tube and the outer circular tube in a gradient from large to small along the radial direction; the bionic sandwich structure is composed of a single-arrow-shaped structure, specifically, the circumference of the inner circular tube is first divided into 8 arc segments, and then two adjacent equally divided points of the inner circular tube are connected to the midpoint of the corresponding outer circular tube arc segment to form 8 single-arrow-shaped structures; and by analogy, single-arrow-shaped bionic sandwich structures of different orders can be formed, and finally novel bionic sandwich tube structures of different orders are obtained.

[0008] Preferably, the single-arrow-shaped structure is evenly distributed between the inner circular tube and the outer circular tube.

[0009] Preferably, the geometric dimensions of the single-arrow-shaped structure gradually decrease along the radial direction.

[0010] Preferably, the side lengths of the single-arrow-shaped structures of the same order are the same.

[0011] Preferably, the angles of the single-arrow-shaped structures of the same order are the same.

[0012] Preferably, the wall thickness of the single-arrow-shaped structure of the same order is the same as the wall thickness of the inner circular tube and the outer circular tube.

[0013] Preferably, the material of the bamboo-based bionic sandwich tube structure is metal.

[0014] Preferably, the bamboo-based bionic sandwich tube structure can be prepared by wire cutting or 3D printing technology.

[0015] Preferably, the bottom of the bamboo-based bionic sandwich tube structure is fixed to the front longitudinal beam, and the top of the bamboo-based bionic sandwich tube structure receives the impact of the collision resistance force.

[0016] The beneficial effects of the present invention are:

[0017] 1. The bamboo-based bionic sandwich tube structure provided by the present invention is easy to process and is suitable for mass production requirements.

[0018] 2. The bamboo-based bionic sandwich tube structure provided by the present invention is constructed based on the gradient distribution of the microscopic topological structure of the bamboo cross section along the radial direction.

[0019] 3. The bamboo-based bionic sandwich tube structure provided by the present invention has stable deformation during compression and good energy absorption characteristics, and can well protect the safety of passengers.

[0020] 4. Under the condition of the same structural quality, the bamboo-based bionic sandwich tube structure provided by the present invention can improve the energy absorption characteristics of the double-tube structure by increasing the order of the bionic sandwich structure, which further highlights the excellent energy absorption performance of the bamboo-based bionic sandwich tube structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the first-order bionic sandwich tube structure of the present invention, wherein: Figure 1 a is a stereogram of the first-order bionic sandwich tube structure. Figure 1 b is the cross-sectional view of the first-order bionic sandwich tube structure.

[0022] Figure 2 It is a schematic diagram of the second-order bionic sandwich tube structure of the present invention, wherein: Figure 2 a is a stereoscopic diagram of the second-order bionic sandwich tube structure. Figure 2 b is the cross-sectional view of the second-order bionic sandwich tube structure.

[0023] Figure 3 Schematic diagram of the three-order bionic sandwich tube structure of the present invention, wherein: Figure 3 a is a three-dimensional diagram of the three-order bionic sandwich tube structure. Figure 3 b is the cross-sectional view of the third-order bionic sandwich tube structure.

[0024] Figure 4 This is a deformation diagram of the bionic sandwich tube structure of the present invention.

[0025] Figure 5 It is a force-displacement curve diagram of the bionic sandwich tube structure of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] like Figures 1 to 3As shown, a bamboo-based bionic sandwich tube structure comprises a double tube and a bionic sandwich structure, wherein the double tube is composed of an inner circular tube and an outer circular tube, and the bionic sandwich structure is distributed between the inner circular tube and the outer circular tube in a gradient from large to small along the radial direction; the bionic sandwich structure is composed of a single-arrow-shaped structure, wherein the circumference of the inner circular tube is first divided into 8 arc segments, and then two adjacent equally divided points of the inner circular tube arc segment are connected with the midpoint of the corresponding outer circular tube arc segment to form 8 single-arrow-shaped structures; by analogy, single-arrow-shaped bionic sandwich structures of different orders can be formed, and finally novel bionic sandwich tube structures of different orders are obtained;

[0029] All bionic sandwich tube structures involved in the present invention have an outer diameter of 150mm, a height of 220mm and a mass of 279.92g. Under the condition of ensuring that the mass remains unchanged, the wall thickness of the structure changes with the change of the hierarchical order. The wall thicknesses of the double circular tube, the first-order bionic sandwich tube structure, the second-order bionic sandwich tube structure and the third-order bionic sandwich tube structure are 0.667mm, 0.339mm, 0.261mm and 0.212mm respectively.

[0030] like Figure 1 The first-order bionic sandwich tube structure shown is composed of inner and outer circular tubes and a bionic sandwich structure. The inner circular tube arc is divided into 8 equal parts, and a first-order single-arrow-shaped structure is formed by connecting two adjacent equal-division points 1 and 3 and the first midpoint 2 of the corresponding arc segment of the outer circle. The adjacent inner arc equal-division points and the corresponding midpoints of the outer arc segments are connected in turn, and finally a first-order bionic sandwich tube structure is formed.

[0031] Example 2

[0032] like Figure 2 The second-order bionic sandwich tube structure shown is based on the first-order bionic sandwich tube structure. A second-order single-arrow-shaped structure is formed by connecting the midpoints 11 and 13 of the first-order single-arrow-shaped structure edge and the second midpoint 12 of the corresponding outer arc segment, thereby finally forming a second-order bionic sandwich tube structure.

[0033] Example 3

[0034] like Figure 3 The third-order bionic sandwich tube structure shown is based on the second-order bionic sandwich tube structure. A third-order single-arrow-shaped structure is formed by connecting the midpoints 21 and 23 of the second-order single-arrow-shaped structure edge and the third midpoint 22 of the corresponding outer arc segment, thereby finally forming a third-order bionic sandwich tube structure.

[0035] Example 4 Numerical calculation of bionic sandwich tube structure

[0036] The pipe wall material is aluminum alloy, with Young's modulus E = 68GPa, Poisson's ratio ν = 0.33, and density ρ = 2.7×10 -3 kg / m3 , yield stress σ y =71.0MPa, ultimate stress σ u =130.7MPa. The ABAQUS / Explicit explicit dynamics module is used for numerical calculation to establish a finite element model of the bionic sandwich tube structure. The bottom end of the bionic sandwich tube structure is fixed, and the indenter impacts the bionic sandwich tube structure at a uniform speed of 10m / s. The indenter is meshed using discrete four-node rigid quadrilateral elements (R3D4), and the bionic sandwich tube structure is meshed using four-node shell elements (S4R), with a mesh size of 1.5mm. The interaction between the indenter and the bionic sandwich tube structure and the self-contact of the bionic sandwich tube structure are set to general contact, the contact properties are set to penalty contact, the friction coefficient is 0.2, and the Isotropic material model is used to describe the physical properties of the bionic sandwich tube structure. The deformation diagram, cross-sectional diagram and wrinkle unit of the bionic sandwich tube structure are shown in the figure. Figure 4 As shown in Figure 1, with the increase of the order, the deformation of the bionic sandwich tube structure is more progressive, and the number of wrinkles is also increasing. The force-displacement curve of the bionic sandwich tube structure is shown in Figure 1. Figure 5 As shown, with the increase of order, the fluctuation amplitude of the curve gradually slows down, the platform force increases, and the specific energy absorption of the third-order bionic sandwich tube structure is 1.4 times that of the first-order bionic sandwich tube structure, which highlights the advantages of the energy absorption characteristics of the bionic sandwich tube structure.

[0037] Compared with the double circular tube, the bionic sandwich tube structure has a more stable deformation, forming more wrinkle units. The number of wrinkles increases with the increase of the hierarchical order, and the gradualness of the deformation process is better. The force-displacement curve of the bionic sandwich tube structure has a small fluctuation amplitude, and the platform force increases with the increase of the order. The specific energy absorption of the third-order bionic sandwich tube structure is 1.8 times that of the double circular tube.

[0038] Compared with other multi-cell structures, see Table 1, which compares the energy absorption characteristics of different tubular structures. To ensure the fairness of the comparison, all tubes have the same material parameters and mass (279.92g), different wall thicknesses (see Table 1), and the same loading speed, constraints and mesh division are used to calculate the energy absorption performance of all tube structures in Table 1. The calculation results show that the bionic sandwich tube structure in the patent of this invention has a larger platform force and specific energy absorption.

[0039] Table 1 Comparison of energy absorption performance of multi-cell tube structures

[0040]

[0041]

[0042] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A bamboo-based bionic sandwich tube structure, characterized in that: The invention comprises a double tube and a bionic sandwich structure, wherein the double tube is composed of an inner circular tube and an outer circular tube, and the bionic sandwich structure is distributed between the inner circular tube and the outer circular tube in a gradient manner from large to small along the radial direction; the bionic sandwich structure is composed of a single-arrow-shaped structure, specifically, the circumference of the inner circular tube is first divided into 8 arc segments, and then two adjacent equally divided points of the inner circular tube are connected with the midpoint of the corresponding arc segment of the outer circular tube to form 8 single-arrow-shaped structures; and by analogy, single-arrow-shaped bionic sandwich structures of different orders can be formed to obtain novel bionic sandwich tube structures of different orders.

2. The bamboo-based bionic sandwich tube structure according to claim 1, characterized in that: The single-arrow-shaped structures are evenly distributed between the inner circular tube and the outer circular tube.

3. The bamboo-based bionic sandwich tube structure according to claim 1, characterized in that: The geometric dimensions of the single-arrow-shaped structure gradually decrease along the radial direction.

4. The bamboo-based bionic sandwich tube structure according to claim 1, characterized in that: The side lengths of single-arrow-shaped structures of the same order are the same.

5. The bamboo-based bionic sandwich tube structure according to claim 1, characterized in that: The angles of single-arrow-shaped structures of the same order are the same.

6. The bamboo-based bionic sandwich tube structure according to claim 1, characterized in that: The wall thickness of the single-arrow-shaped structure of the same order is the same as the wall thickness of the inner tube and the outer tube.

7. The bamboo-based bionic sandwich tube structure according to claim 1, characterized in that: The material of the bamboo-based bionic sandwich tube structure is metal.

8. The bamboo-based bionic sandwich tube structure according to claim 1, characterized in that: The bamboo-based bionic sandwich tube structure can be prepared by wire cutting or 3D printing technology.

9. The bamboo-based bionic sandwich tube structure according to claim 1, characterized in that: The bottom of the bamboo-based bionic sandwich tube structure is fixed to the front longitudinal beam, and the top of the bamboo-based bionic sandwich tube structure receives the impact of the collision resistance force.

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