Bionic sandwich tube structure based on bamboos

Abstract

The utility model 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 safety of passengers.

Description

Technical Field

[0001] This utility model relates to the field of automotive passive safety protection technology, specifically a biomimetic sandwich tube structure based on bamboo. Background Technology

[0002] With the continuous development of the automotive industry, the number of cars on the market is rapidly increasing, leading to a corresponding increase in the probability of car collisions. To reduce property damage caused by traffic accidents and better protect the personal safety of drivers and passengers, designing energy-absorbing structures with good crashworthiness is of great significance. During a collision, the energy-absorbing structure absorbs the energy generated by the impact through plastic deformation, thereby reducing injury to the driver and passengers.

[0003] Existing energy-absorbing boxes typically employ a single shape and structure, making them inadequate for handling the complex collision scenarios of real-world accidents. Furthermore, existing energy-absorbing structures present a trade-off between lightweight design and crashworthiness. Therefore, the crashworthiness of energy-absorbing structures needs further improvement.

[0004] Sandwich structures, as typical structural and functional integrated materials, possess excellent impact resistance and energy absorption characteristics, exhibiting good mechanical properties and high load-bearing efficiency in shear resistance. On the other hand, biological structures in nature, through continuous evolution, possess superior mechanical properties, and their excellent geometric topology provides a valuable reference for the design of energy-absorbing structures. Combining sandwich structures with biomimetic design principles to design energy-absorbing structures offers new insights for the design of automotive crash-resistant structures, and has significant research value. Utility Model Content

[0005] To address the issue of poor energy absorption performance in existing double-tube structures, this invention proposes a biomimetic sandwich tube structure based on bamboo. This invention combines biomimetic design theory and energy-absorbing structure design methods, using similarity analysis to select the microscopic topological structure of a bamboo cross-section as the biological prototype for the optimized design of the double-tube structure. Based on the structural and functional similarities between the bamboo cross-section structure and the double tube, the double tube is combined with a biomimetic sandwich structure, thereby designing a biomimetic sandwich tube structure with good impact resistance. This enhances the deformation stability of the double-tube structure and significantly improves its load-bearing capacity.

[0006] To achieve the above objectives, the following technical solution is provided:

[0007] A biomimetic sandwich tube structure based on bamboo is characterized by comprising a double tube and a biomimetic core structure. The double tube consists of an inner circular tube and an outer circular tube. The biomimetic core structure is distributed radially in a gradient from large to small between the inner and outer circular tubes. The biomimetic core structure is composed of single-arrow-shaped structures. Specifically, the circumference of the inner circular tube is first divided into 8 equal arc segments. Then, two adjacent division points of the inner circular tube are connected to the midpoint of the corresponding arc segment of the outer circular tube to form 8 single-arrow-shaped structures. By analogy, single-arrow-shaped biomimetic core structures of different orders can be formed, ultimately resulting in novel biomimetic sandwich tube structures of different orders.

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

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

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

[0011] Preferably, the angles of the single-arrowhead 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 and outer circular tubes.

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

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

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

[0016] The beneficial effects of this utility model are as follows:

[0017] 1. The biomimetic sandwich tube structure based on bamboo provided by this utility model is easy to process and suitable for mass production requirements.

[0018] 2. The biomimetic sandwich tube structure based on bamboo provided by this utility model is constructed based on the gradient distribution of the micro-topological structure of the bamboo cross section along the radial direction.

[0019] 3. The bamboo-based biomimetic sandwich tube structure provided by this utility model has stable deformation during compression, good energy absorption characteristics, and can effectively protect the safety of occupants.

[0020] 4. Under the same structural quality, the biomimetic sandwich tube structure based on bamboo provided by this utility model can improve the energy absorption characteristics of the double tube structure by increasing the order of the biomimetic core structure, which further highlights the excellent energy absorption performance of the biomimetic sandwich tube structure based on bamboo. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the first-order biomimetic sandwich tube structure of this utility model, wherein, Figure 1 a is a three-dimensional diagram of a first-order biomimetic sandwich tube structure. Figure 1 b is a cross-sectional view of a first-order biomimetic sandwich tube structure.

[0022] Figure 2 This is a schematic diagram of the second-order biomimetic sandwich tube structure of this utility model, wherein, Figure 2 a is a three-dimensional diagram of a second-order biomimetic sandwich tube structure. Figure 2 b is a cross-sectional view of a second-order biomimetic sandwich tube structure.

[0023] Figure 3 This is a schematic diagram of the three-order biomimetic sandwich tube structure of this utility model, wherein, Figure 3 a is a three-dimensional diagram of a third-order biomimetic sandwich tube structure. Figure 3 b is a cross-sectional view of a third-order biomimetic sandwich tube structure.

[0024] Figure 4 This is a deformed diagram of the biomimetic sandwich tube structure of this utility model.

[0025] Figure 5 This is a force-displacement curve of the biomimetic sandwich tube structure of this utility model. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] Example 1

[0028] like Figures 1 to 3As shown, a biomimetic sandwich tube structure based on bamboo includes a double tube and a biomimetic core structure. The double tube consists of an inner circular tube and an outer circular tube. The biomimetic core structure is distributed radially in a gradient from large to small between the inner and outer circular tubes. The biomimetic core structure is composed of single-arrow-shaped structures. First, the circumference of the inner circular tube is divided into 8 equal arc segments. Then, two adjacent division points of the inner circular tube arc segments are connected to the midpoint of the corresponding outer circular tube arc segments to form 8 single-arrow-shaped structures. By analogy, single-arrow-shaped biomimetic core structures of different orders can be formed, ultimately resulting in novel biomimetic sandwich tube structures of different orders.

[0029] All biomimetic sandwich tube structures involved in this invention have an outer diameter of 150mm, a height of 220mm, and a mass of 279.92g. While maintaining a constant mass, the wall thickness varies with the different layer levels. The wall thicknesses of the double-circular tube, first-order biomimetic sandwich tube structure, second-order biomimetic sandwich tube structure, and third-order biomimetic sandwich tube structure are 0.667mm, 0.339mm, 0.261mm, and 0.212mm, respectively.

[0030] like Figure 1 The first-order biomimetic sandwich tube structure shown consists of inner and outer circular tubes and a biomimetic core structure. The inner circular tube is divided into 8 equal parts by connecting two adjacent dividing points 1 and 3 and the first midpoint 2 of the corresponding outer circular arc segment to form a first-order single arrowhead structure. The adjacent dividing points of the inner circular arc and the midpoint of the corresponding outer circular arc segment are connected in sequence to finally form a first-order biomimetic sandwich tube structure.

[0031] Example 2

[0032] like Figure 2 The second-order biomimetic sandwich tube structure shown is based on the first-order biomimetic sandwich tube structure. It forms a second-order single-arrow structure by connecting the midpoints 11 and 13 of the first-order single-arrow structure and the second midpoint 12 of the corresponding outer arc segment, thus forming the second-order biomimetic sandwich tube structure.

[0033] Example 3

[0034] like Figure 3 The third-order biomimetic sandwich tube structure shown is based on the second-order biomimetic sandwich tube structure. It forms a third-order single-arrow structure by connecting the midpoints 21 and 23 of the second-order single-arrow structure and the third midpoint 22 of the corresponding outer arc segment, thus forming the third-order biomimetic sandwich tube structure.

[0035] Example 4: Numerical Calculation of Bionic Sandwich Tube Structure

[0036] The pipe wall material is made of aluminum alloy with Young's modulus E = 68 GPa, Poisson's ratio ν = 0.33, and density ρ = 2.7 × 10⁻⁶. -3 kg / m3 Yield stress σ y =71.0MPa, ultimate stress σ u =130.7MPa. Numerical calculations were performed using the ABAQUS / Explicit explicit dynamics module to establish a finite element model of the biomimetic sandwich tube structure. The bottom of the biomimetic sandwich tube structure was fixed, and the indenter impacted it at a uniform velocity of 10m / s. The indenter was meshed using discrete, four-node rigid quadrilateral elements (R3D4), and the biomimetic sandwich tube structure was meshed using four-node shell elements (S4R), with a mesh size of 1.5mm. The interaction between the indenter and the biomimetic sandwich tube structure, as well as the self-contact of the biomimetic sandwich tube structure, were set as universal contact, with the contact nature set as penalized contact and a friction coefficient of 0.2. The Isotropic material model was used to describe the physical properties of the biomimetic sandwich tube structure. Deformation diagrams, cross-sectional views, and wrinkled elements of the biomimetic sandwich tube structure are shown below. Figure 4 As shown, with increasing order, the biomimetic sandwich tube structure exhibits better deformation asymmetry and an increasing number of folds. The force-displacement curve of the biomimetic sandwich tube structure is shown in the figure. Figure 5 As shown, with the increase of order, the fluctuation amplitude of the curve gradually slows down and the plateau force increases. 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 advantage of the energy absorption characteristics of the bionic sandwich tube structure.

[0037] Compared to a double-circular tube, the biomimetic sandwich tube structure exhibits more stable deformation, forming more folded units. The number of folds increases with the increase of the layer order, and the gradualness of the deformation process is better. The force-displacement curve of the biomimetic sandwich tube structure has a smaller fluctuation amplitude, and the plateau force increases with the increase of the layer order. The specific energy absorption of the third-order biomimetic sandwich tube structure is 1.8 times that of the double-circular tube.

[0038] Compared with other multicellular structures, see Table 1, which compares the energy absorption characteristics of different tubular structures. To ensure fairness in the comparison, all tubes had the same material parameters and mass (279.92g), but different wall thicknesses (see Table 1). The same loading speed, constraint conditions, and mesh generation were used to calculate the energy absorption performance of all tube structures in Table 1. The calculation results show that the biomimetic sandwich tube structure in this utility model patent has a greater plateau force and specific energy absorption.

[0039] Table 1 Comparison of energy absorption performance of multicellular tubular structures

[0040]

[0041]

[0042] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A biomimetic sandwich tube structure based on bamboo, characterized in that: The invention includes a double-tube and a biomimetic sandwich structure. The double-tube consists of an inner circular tube and an outer circular tube. The biomimetic sandwich structure is distributed radially in a gradient from large to small between the inner and outer circular tubes. The biomimetic sandwich structure is composed of single-arrow-shaped structures. Specifically, the circumference of the inner circular tube is first divided into 8 equal arc segments. Then, two adjacent division points of the inner circular tube are connected to the midpoint of the corresponding arc segment of the outer circular tube to form 8 single-arrow-shaped structures. By analogy, single-arrow-shaped biomimetic sandwich structures of different orders can be formed, resulting in novel biomimetic sandwich tube structures of different orders.

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

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

4. The bamboo-based biomimetic sandwich tube structure according to claim 1, characterized in that: Single-arrowhead structures of the same order have the same side length.

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

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

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

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

9. A bamboo-based biomimetic sandwich tube structure according to claim 1, characterized in that: The bottom of the bamboo-based biomimetic sandwich tube structure is fixed to the front longitudinal beam, while the top of the bamboo-based biomimetic sandwich tube structure withstands the impact of the impact force.

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