Gradient energy-absorbing structure based on paper roll structure and its preparation method

Abstract

This invention provides a gradient energy-absorbing structure based on a rolled paper structure and its preparation method, belonging to the field of impact energy-absorbing structure technology. It achieves high-performance energy absorption and solves the problems of low maximum load and stable energy absorption. The gradient energy-absorbing structure based on the rolled paper structure comprises multiple rolled paper units stacked and spirally rolled layer by layer. Each rolled paper unit includes an outer rolled paper and an inner rolled paper forming a two-layer structure, or an outer rolled paper, at least one intermediate rolled paper, and an inner rolled paper forming a multi-layer structure. The width of each rolled paper unit decreases sequentially from the outside to the inside, and a slit is formed between adjacent layers of rolled paper. The preparation method is as follows: a thin sheet is cut into strips of different widths; multiple strips of different widths are aligned at their bottoms to form multiple rolled paper units with one side thicker than the other, and the rolled paper units are stacked layer by layer; starting from one end, the rolled paper is rolled to ensure that the thicker side at the bottom is tightly adhered, thus obtaining the gradient energy-absorbing structure based on the rolled paper structure.

Description

Technical Field

[0001] This invention relates to a gradient energy-absorbing structure based on a paper roll structure and its preparation method, belonging to the field of impact energy-absorbing structure technology. Background Technology

[0002] In today's era of increasingly advanced land, sea, and air transportation, while people enjoy the convenience brought by high-speed vehicles such as cars, trains, ships, and airplanes, they sometimes inevitably encounter traffic accidents while enjoying the convenience of travel. Therefore, how to use scientific methods to minimize the damage and loss caused by collisions has become a key issue of social concern. To this end, during an impact, the deformation of the structure itself, such as buckling and fracture, can dissipate or absorb the energy of the collision impact, thereby reducing injury to people and property damage. Energy-absorbing structures are used in aerospace, railways, ships, and other fields.

[0003] The design of energy-absorbing devices needs to meet requirements such as low maximum load, structural deformation stability, and light weight and low cost. Currently, commonly used materials include circular tube structures and metal foam. However, metal foam materials have drawbacks such as numerous defects and high processing costs, limiting their industrial application. With increasingly stringent collision safety standards, traditional energy-absorbing elements can no longer meet the ever-more demanding energy consumption requirements. Therefore, developing new energy-absorbing structures is essential. Summary of the Invention

[0004] One of the objectives of this invention is to provide a gradient energy-absorbing structure based on a paper roll structure. By rationally designing the gaps in the paper roll structure, high-performance energy absorption is achieved, and the problem of low maximum load and stable energy absorption is solved by using a gradient curling method.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A gradient energy-absorbing structure based on a paper roll structure comprises multiple paper roll units stacked and spirally rolled. Each paper roll unit includes an outer roll and an inner roll forming a two-layer structure or an outer roll, at least one intermediate roll, and an inner roll forming a multi-layer structure. The width of each paper roll unit decreases sequentially from the outside to the inside, and a slit is formed between adjacent layers of paper rolls.

[0007] Based on the gradient energy-absorbing structure of the above-mentioned paper roll structure, the outer roll, middle roll and inner roll are all made of aluminum with a density of 2.7 g / cm3, a modulus of 72000 MPa and a thickness of 0.5 to 5 mm.

[0008] Based on the gradient energy absorption structure of the above-mentioned paper roll structure, the width ratio of the outer roll, the middle roll, and the inner roll is (40-50):(35-43):10.

[0009] Based on the gradient energy absorption structure of the paper roll structure, the cross-sectional shape is circular, triangular, or petal-shaped.

[0010] Another objective of this invention is to provide a method for preparing a gradient energy-absorbing structure based on a paper roll structure.

[0011] To achieve the above objectives, the present invention employs the following technical solution:

[0012] A method for fabricating a gradient energy-absorbing structure based on a paper roll structure includes the following steps:

[0013] (1) Cut the thin sheet into strips of different widths;

[0014] (2) Align the bottoms of multiple thin strips of different widths to form multiple paper roll units with one side thick and the other side thin, and stack the paper roll units layer by layer;

[0015] (3) Starting from one end, roll it up to ensure that the thicker side at the bottom is tightly attached, thus obtaining the gradient energy absorption structure based on the paper roll structure. The tightness of the paper roll structure is described by the following formula: Tightness = Volume of paper roll material / Macroscopic volume of paper roll structure. The tightness of the paper roll structure should be maintained above 90%.

[0016] The advantages of this invention are:

[0017] This invention discloses a gradient energy-absorbing structure based on a rolled paper structure and its preparation method, which is formed by cross-inserting and rolling multiple different thin sheets. Since the bottoms of the thin sheets of varying widths are connected, a slit is formed between adjacent layers of rolled sheets in the upper layer. The size of the slit is approximately equal to the width of each sheet, and the height of the slit can be adjusted according to the width of each sheet. Through this technical solution, the rolled sheet structure absorbs impact energy through crushing under impact loads. Furthermore, due to the gradient structure design, the minimum crushing threshold for energy absorption can be effectively controlled, increasing energy absorption. The design offers more adjustable parameters, including structural parameters and sheet types, which can be adjusted according to actual working conditions. The structure is simple and easy to manufacture. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0019] Figure 1 This is a schematic diagram of the gradient energy absorption structure based on the paper roll structure of the present invention;

[0020] Figure 2 A cross-sectional view of a single cell;

[0021] Figure 3 This is a diagram of the preparation process;

[0022] Figure 4 This is a schematic diagram of compression curves for three embodiments of the energy-absorbing paper roll structure of the present invention; Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "one side," "one end," and "one side," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0027] Please see Figure 1 and Figure 2This invention provides a gradient energy-absorbing structure based on a paper roll structure, comprising multiple paper roll units stacked and spirally rolled layer by layer. Each paper roll unit includes an outer roll 1 and an inner roll 4 forming a two-layer structure, or an outer roll 1 with at least one intermediate roll and an inner roll 4 forming a multi-layer structure. The width of each paper roll unit decreases sequentially from the outside in, and a slit is formed between adjacent layers. The number of layers and the thickness of each layer are selected according to actual needs. The curled shape of the structure is related to the processing method; through continuous folding and bending, different shapes such as circles, triangles, and petals can be prepared according to different engineering requirements.

[0028] See Figure 3 A method for preparing a gradient energy-absorbing structure based on a paper roll structure includes the following steps:

[0029] (1) Cut the thin sheet into strips of different widths;

[0030] (2) Align the bottoms of multiple thin strips of different widths to form multiple paper roll units with one side thick and the other side thin, and stack the paper roll units layer by layer;

[0031] (3) Starting from one end, roll the paper roll to ensure that the thicker side at the bottom is tightly fitted. The tightness of the paper roll structure is described by the following formula: Tightness = Volume of paper roll material / Macroscopic volume of paper roll structure. To ensure the stability of the structure, the tightness of the paper roll structure should be maintained above 90%. At this point, a paper roll structure that thins with increasing height will appear at the top of the structure, thus obtaining the gradient energy-absorbing structure based on the paper roll structure.

[0032] Example 1

[0033] In this example, aluminum was used as the sheet material with a density of 2.7 g / cm³. 3 The modulus is 72000MPa, and the aluminum sheet thickness is 0.5mm.

[0034] Example structural dimensions: The design uses two widths of thin sheets, where the outer roll paper 1 is a wide thin sheet with a width of 50mm, and the inner roll paper 4 is a narrow thin sheet with a width of 10mm.

[0035] Example 2

[0036] In this example, aluminum was used as the sheet material, with a density of 2.7 g / cm³, a modulus of 72000 MPa, and a sheet thickness of 0.5 mm.

[0037] Example structural dimensions: The design uses three widths of sheet material, with the outer roll 1 being 50mm wide, the middle roll 4 being 40mm wide, and the inner roll 4 being 10mm wide.

[0038] Example 3

[0039] In this example, aluminum was used as the sheet material with a density of 2.7 g / cm³. 3 The modulus is 72000MPa, and the aluminum sheet thickness is 0.5mm.

[0040] Example structural dimensions: The design uses four widths of sheet material, where the outer roll 1 is 50mm wide, the first intermediate roll 2 is 43mm wide, the second intermediate roll 3 is 35mm wide, and the inner roll 4 is 10mm wide.

[0041] Using the above materials and structural dimensions for modeling and finite element simulation calculations, a comparison of stress-displacement curves under quasi-static compression is presented below among the three embodiments:

[0042] Please see Figure 4 The solid black line represents the stress-displacement curve of the two-layer gradient in Example 1, the dashed black line represents the stress-displacement curve of the three-layer gradient in Example 2, and the dotted black line represents the stress-displacement curve of the four-layer gradient in Example 3. As can be seen from the figure, the three structures have different crushing mechanisms. Specifically, they are as follows:

[0043] The yield strength of Example 1 is 125 MPa, and the plateau stress is around 60 MPa, which remains almost unchanged throughout the compression process.

[0044] The yield strength of Example 2 is 60 MPa, the plateau stress in the first stage is about 50 MPa, and the strengthening occurs when the compressive displacement is about 10 mm, and the plateau stress increases to about 60 MPa.

[0045] The yield strength of Example 3 is 50 MPa. The plateau stress in the first stage is about 30 MPa. Strengthening occurs when the compressive displacement is about 7 mm. The plateau stress in the second stage increases to about 50 MPa. Secondary strengthening occurs when the compressive displacement is about 12 mm, and the plateau stress increases to 70 MPa.

[0046] The results show that by designing different gradients, the crushing curve of the structure can be designed, thereby achieving different energy absorption effects. The structure is easy to design and fabricate.

[0047] Based on the above data, the technical effects achieved by this invention are as follows:

[0048] 1. Simulation results of this invention show that it has good impact energy absorption capacity;

[0049] 2. The material used in the proposed structure is a thin sheet of metal or non-metal, and the material is readily available;

[0050] 3. The energy-absorbing structure proposed in this paper is simple and easy to manufacture;

[0051] 4. This paper proposes that energy-absorbing structures have significant advantages over conventional energy-absorbing materials in terms of designability;

[0052] 5. By changing the structural parameters and material types of the paper roll, the energy absorption performance of the overall structure can be altered to meet the requirements of different occasions.

[0053] In summary, the present invention provides a gradient energy absorption structure based on a paper roll structure and its preparation method, which can be used to manufacture energy absorption devices for aircraft, high-speed trains, and automobiles. By selecting materials and designing the structure, the energy absorption curve can be continuously adjusted to enhance structural safety and human comfort, and it has a wide range of engineering application prospects.

[0054] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A gradient energy-absorbing structure based on a paper roll structure, characterized in that, It consists of multiple paper roll units stacked and spirally rolled. Each paper roll unit consists of an outer roll (1) and an inner roll (4) forming a two-layer structure or an outer roll (1), at least one intermediate roll and an inner roll (4) forming a multi-layer structure. The width of each paper roll unit decreases sequentially from the outside to the inside, and a slit is formed between adjacent two layers of paper rolls. The outer roll paper (1), the middle roll paper and the inner roll paper (4) are all made of aluminum, with a density of 2.7 g / cm³, a modulus of 72000 MPa and a thickness of 0.5 ~ 5 mm; The tightness of the paper roll structure is maintained at over 90%.

2. The gradient energy absorption structure based on the paper roll structure according to claim 1, characterized in that: The width ratio of the outer roll (1), the middle roll and the inner roll (4) is (40-50): (35-43):

10.

3. The gradient energy absorption structure based on the paper roll structure according to claim 1, characterized in that: The cross-sectional shape of the two-layer or multi-layer structure of the paper roll unit is one of the following: circular, triangular, or petal-shaped.

4. A method for preparing a gradient energy-absorbing structure based on a paper roll structure as described in any one of claims 1 to 3, characterized in that, Includes the following steps: (1) Cut the sheet into strips of different widths; (2) Align the bottoms of multiple thin strips of different widths to form multiple paper roll units with one side thick and the other side thin, and stack the paper roll units layer by layer; (3) Start rolling from one end to ensure that the thicker side at the bottom is tightly attached, thus obtaining the gradient energy absorption structure based on the paper roll structure. The tightness of the paper roll structure is as follows: tightness = volume of paper roll material / macroscopic volume of paper roll structure, and the tightness of the paper roll structure should be maintained above 90%.

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