Paper folding improved round pipe anti-impact protection structure and application

Abstract

The invention belongs to the technical field of anti-impact protection, and relates to a paper folding improved round pipe anti-impact protection structure and application thereof.The paper folding improved round pipe anti-impact protection structure is of a thin-wall three-dimensional structure formed by folding a plane thin plate through set creases and comprises an arc face, a right triangle face and an inclined isosceles triangle face, and the arc face and the right triangle face are parallel to the out-of-plane crushing load direction; supporting is provided for the structure in the crushing process; the inclined isosceles triangle face and the two right triangle faces form a foot-shaped structure, support is formed on the arc face, the arc face is induced to generate more stable plastic hinges, and therefore the initial peak value crushing force is reduced, and the energy absorption efficiency is improved. The foot-shaped structures can be arranged on the inner side and the outer side of the arc surface or alternately, can be realized in a single body use, two-dimensional array or three-dimensional array mode, and is suitable for a sandwich structure core layer. The structure has relatively high energy absorption capacity, and is simple in structure, controllable in manufacturing process and suitable for engineering application in the field of impact resistance protection.

Description

Technical Field

[0001] This invention belongs to the field of impact protection technology. It relates to an origami-modified circular tube impact protection structure and its application, wherein the structural unit or modular array can be used for dynamic load protection. Background Technology

[0002] In fields such as protective engineering and transportation equipment, structures need to possess excellent energy absorption and impact resistance when subjected to transient high-energy loads such as explosions and shocks. Multi-layer composite panel structures, especially the "sandwich" configuration of panel-core-panel, are widely used in protective structure design due to their lightweight, high specific strength, and good energy dissipation characteristics. Existing sandwich structures have diverse core topologies, including honeycomb, foam, lattice, and origami configurations, but they often suffer from shortcomings such as excessively high initial peak force, unstable collapse, or complex manufacturing when subjected to dynamic loads.

[0003] Compared to sandwich structures, thin-walled circular tube structures, due to their simple geometry and ease of manufacturing, have long been considered the most typical and common energy-absorbing elements, widely used in automotive crash beams, buffer devices, and protective components. However, traditional circular tubes generally suffer from the following drawbacks under axial compression:

[0004] Excessive initial peak crushing force: When subjected to impact load, the circular tube often generates a sharp peak force in the initial buckling stage, which can easily transmit the excessive impact directly to the protected object, which is not conducive to mitigating the impact effect.

[0005] Insufficient energy absorption: The folding pattern formed by the round tube after buckling is relatively simple, and the plastic energy dissipation efficiency is limited, making it difficult to meet the protection requirements under high-energy impact.

[0006] Deformation modes are difficult to control: Due to the axial symmetry of circular tube structures, their unstable folds often exhibit irregular distribution, leading to uncontrollable energy dissipation processes and affecting the stability and reliability of energy absorption.

[0007] Therefore, although circular tubes are the most common thin-walled energy absorbers, their mechanical properties still have significant shortcomings, making it difficult to simultaneously meet the combined requirements of low initial peak crushing force and high energy absorption capacity. Therefore, it is necessary to conduct innovative optimization designs for circular tube structures to overcome these deficiencies and expand their application potential in the field of impact protection.

[0008] In recent years, the origami concept has provided new ideas for the design of sandwich core structures, but existing configurations still have shortcomings. Miura origami structures have weak collapse resistance and high initial peak stress; while cube strips offer improved performance, their complex processing and high cost make them difficult to scale up. Overall, existing origami sandwich structures lack modularity and standardization, resulting in high manufacturing costs and poor assembly flexibility, which limits their engineering application. To address this, patent CN 113829676 A proposes an origami truncated pyramid structure, which effectively reduces initial peak stress and improves energy absorption capacity. Summary of the Invention

[0009] The purpose of this invention is to optimize the design of thin-walled circular tube energy absorbers using a paper-folding method, while maintaining the low-cost advantage of traditional circular tube structures. This addresses the problems of high initial peak crushing force, low energy absorption efficiency, and difficulty in controlling deformation modes. Under conditions of controllable cost and simple process, an improved circular tube impact-resistant protective structure using paper-folding is proposed. The individual structural units can be used in impact-resistant protection fields such as vehicle energy-absorbing boxes; multiple units arranged in a two-dimensional or three-dimensional array can serve as the core layer of a "sandwich" structure, applied to blunt force protection in individual soldier protective equipment.

[0010] The structural technical solution proposed in this invention is: The origami-inspired cylindrical impact-resistant protective structure is formed by folding a flat thin plate along predetermined creases to create a thin-walled three-dimensional structure; this thin-walled three-dimensional structure includes a central cylinder and four legs; The flat thin plate is a large square with a small square notch in the center. The four corners of the large square are cut off, and the shape of the four corners is an isosceles right triangle. The side length of the small square is one-third of the side length of the large square, and the leg length of the isosceles right triangle is one-sixth of the side length of the large square. The four vertices of the small square notch are a', b', e', and f'. The extensions of the four sides of the small square notch intersect the large square at eight points, namely a, b, c, d, e, f, g, and h. The four corners of the cut-off large square form points b1, b2, d1, d2, f1, f2, h1, and h2, respectively. Creases include aa', bb', b'c, e'd, e'e, f'f, f'g, a'h, h1a', h2a', b1b', b2b', d1e', d2e', f1f', and f2f'; When aa', bb', b'c, e'd, e'e, f'f, f'g, and a'h are valley folds and h1a', h2a', b1b', b2b', d1e', d2e', f1f', and f2f' are peak folds, all four feet are located outside the middle cylinder; When aa', bb', b'c, e'd, e'e, f'f, f'g, and a'h are peaks and h1a', h2a', b1b', b2b', d1e', d2e', f1f', and f2f' are valleys, all four feet are located inside the middle cylinder. When aa', bb', b'c, e'd, e'e, f'f, f'g, a'h, h1a', h2a', d1e', d2e' are valley breaks and b1b', b2b', f1f', f2f' are peak breaks, the two feet are located inside the middle cylinder and the two feet are located outside the middle cylinder; The bent structure contains three types of surfaces: circular arc surfaces, right-angled triangular surfaces, and isosceles triangular surfaces; Among them, the circular arc surface and the right-angled triangular surface are both parallel to the out-of-plane crushing load direction, providing support for the structure during the crushing process and improving the overall crushing resistance and energy absorption capacity. Isosceles triangular facets: These facets form a foot-like structure with an angle to the load direction, consisting of one isosceles triangle and two right-angled triangles. This structure supports the circular arc surface, inducing more and more stable plastic hinges during crushing, thereby improving energy absorption efficiency and reducing the initial peak force. Through this origami-like geometric design, a balance between low peak crushing force and high energy absorption performance is achieved in the circular tube structure for impact protection.

[0011] This invention relates to the field of protective structure design, specifically disclosing an origami-modified circular tube impact-resistant protective structure. The structure is formed by folding a planar thin plate through predetermined creases to create a thin-walled three-dimensional configuration, including an arc surface, a right-angled triangular surface, and an inclined isosceles triangular surface. The arc surface and the right-angled triangular surface are parallel to the out-of-plane crushing load direction, providing support for the structure during crushing. The inclined isosceles triangular surface, together with the two right-angled triangular surfaces, forms a foot-like structure, supporting the arc surface and inducing more and more stable plastic hinges, thereby reducing the initial peak crushing force and improving energy absorption efficiency. The foot-like structure can be arranged inside, outside, or alternately on the arc surface, and can be implemented as a single unit, in a two-dimensional array, or in a three-dimensional array, suitable for the core layer of a "sandwich" structure. This structure has high energy absorption capacity, while being simple in structure and controllable in manufacturing process, making it suitable for engineering applications in the field of impact protection.

[0012] The beneficial effects of this invention are: by folding a flat thin plate into an improved circular tube structure using a paper-folding method, and only changing the folding method and geometric configuration, it can improve energy absorption capacity and enhance protective performance compared with related prior art. Quasi-static compression test results show that the energy absorption value (SEA) per unit mass of this structure is approximately 3.5 times that of related prior art structures (patent CN113829676 A). Attached Figure Description

[0013] Figure 1 To improve the impact-resistant protective structure of the round tube in origami, the solid black lines represent the folding edges, and the dashed black lines represent the folding valleys. Figure 2 The first, second, and third solid states of the folded circular tube impact-resistant protective structure for origami improvement include three views (front view, top view, and left view) and a solid view; Figure 3 A schematic diagram of a "sandwich" cushioning structure consisting of a single origami-modified circular tube impact-resistant protective structure, a top plate, and a bottom plate; Figure 4 A schematic diagram of a "sandwich" cushioning structure consisting of a two-dimensional array, a top plate, and a bottom plate, used to improve the impact resistance and protection structure of circular tubes for origami. Figure 5 A schematic diagram of a "sandwich" cushioning structure consisting of a three-dimensional array, a top plate, and a bottom plate, used to improve the impact resistance and protection structure of a circular tube for origami. Figure 6 The diagram shows a comparison of the compressive force-displacement curves of the PLA material 3D printing structure of this invention and the quasi-static compressive force curve of patent CN 113829676 A. The dashed line represents the structure of patent CN 113829676 A, and the solid line represents the structure proposed in this invention. Detailed Implementation The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] like Figures 1-6 As shown, an origami-inspired circular tube impact-resistant protective structure is disclosed. The structural unit is formed by folding a planar thin plate along predetermined creases to create a thin-walled three-dimensional structure. The structure includes three types of surfaces: an arc surface and a right-angled triangular surface, both parallel to the out-of-plane crushing load direction, which provide support during crushing to improve overall crush resistance and energy absorption capacity; and an inclined isosceles triangular surface, which forms a certain angle with the out-of-plane crushing load direction. The inclined isosceles triangular surface and the two right-angled triangular surfaces together form a foot-like structure to support the arc surface, inducing it to form more and more stable plastic hinges during crushing to improve energy absorption efficiency and reduce the initial peak crushing force.

[0015] The folding structure forms four foot-like structures to support the arc surface. The four foot-like structures are evenly distributed along the circumference and adopt one of the following three arrangement modes: the four foot-like structures are evenly distributed on the outer side of the arc surface; the four foot-like structures are evenly distributed on the inner side of the arc surface; the four foot-like structures are alternately arranged on the inner and outer sides of the arc surface.

[0016] The structure can be used in one of the following three modes: single unit independent use; two-dimensional array in the horizontal direction as the core layer of a sandwich structure; or three-dimensional array in three orthogonal directions as the core layer of a sandwich structure.

[0017] Creases include valley creases and peak creases, with valley lines being... Figure 1 The eight dashed lines in the middle, the peak line is Figure 1 The eight solid lines in the middle; all four feet are located outside the central cylinder; Creases include valley lines and peak lines, with valley lines being... Figure 1 The eight solid lines in the middle, the peak line is Figure 1 The eight dotted lines in the middle; all four feet are located inside the central cylinder; Creases include valley lines and peak lines, with valley lines being... Figure 1 The eight solid lines and four opposite dashed lines in the middle, the peak line is Figure 1 There are two opposite dotted lines on the outside; two feet are located inside the middle cylinder, and two feet are located outside the middle cylinder. This invention relates to an improved origami cylindrical tube impact-resistant protective structure, which can be used as the core layer of a "sandwich" cushioning structure. In a single-unit structure mode, a truncated pyramidal origami thin-walled energy-absorbing structure 1 is placed between a top plate 2 and a bottom plate 3, with its top and bottom edges contacting and fixed to the top plate 2 and bottom plate 3, respectively. In a two-dimensional array structure mode, multiple truncated pyramidal origami thin-walled energy-absorbing structures 1 are arranged along two perpendicular directions and placed between the top plate 2 and bottom plate 3, with their top and bottom edges contacting and fixed to the top plate 2 and bottom plate 3, respectively, forming a two-dimensional array core layer. In a three-dimensional array structure mode, multiple truncated pyramidal origami thin-walled energy-absorbing structures 1 are arranged along three orthogonal directions and placed between the top plate 2 and bottom plate 3, with their top and bottom edges contacting and fixed to the top plate 2 and bottom plate 3, respectively, forming a three-dimensional array core layer.

[0018] In the three structural modes described above, when the structure is subjected to impact loads, the top plate 2 or the bottom plate 3 serves as the impact-bearing surface; when the structure is subjected to explosive loads, the top plate 2 or the bottom plate 3 serves as the blast-facing surface. Through the plastic deformation of the paper-thin-walled energy-absorbing structure, impact or explosive energy can be effectively dissipated, achieving a buffer protection function.

[0019] Figure 3 In the middle, the side length of the large square is 90mm and the wall thickness is 1mm.

[0020] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An improved origami-style circular tube impact-resistant protective structure, characterized by: The protective structure is formed by folding a flat thin plate along set creases to create a thin-walled three-dimensional structure. The thin-walled three-dimensional structure includes a central cylinder and four legs; The flat sheet is a large square with a small square notch in the center. The four corners of the large square are cut off, and the shape of the four corners is an isosceles right triangle. The side length of the small square is one-third of the side length of the large square, and the leg length of the isosceles right triangle is one-sixth of the side length of the large square.

2. The origami-modified circular tube impact-resistant protective structure according to claim 1, characterized in that: The four vertices of the small square notch are a', b', e', and f'. The extensions of the four sides of the small square notch intersect the large square at eight points, namely a, b, c, d, e, f, g, and h. The four corners of the cut-off large square form points b1, b2, d1, d2, f1, f2, h1, and h2, respectively. Creases include aa', bb', b'c, e'd, e'e, f'f, f'g, a'h, h1a', h2a', b1b', b2b', d1e', d2e', f1f', and f2f'.

3. The origami-modified circular tube impact-resistant protective structure according to claim 2, characterized in that: aa', bb', b'c, e'd, e'e, f'f, f'g, a'h are valley folds and h1a', h2a', b1b', b2b', d1e', d2e', f1f', f2f' are peak folds, and all four feet are located outside the middle cylinder.

4. The origami-modified circular tube impact-resistant protective structure according to claim 2, characterized in that: aa', bb', b'c, e'd, e'e, f'f, f'g, a'h are peaks and h1a', h2a', b1b', b2b', d1e', d2e', f1f', f2f' are valleys, and all four feet are located inside the central cylinder.

5. The origami-modified circular tube impact-resistant protective structure according to claim 2, characterized in that: aa', bb', b'c, e'd, e'e, f'f, f'g, a'h, h1a', h2a', d1e', d2e' are valley folds and b1b', b2b', f1f', f2f' are peak folds. Two feet are located inside the middle cylinder and two feet are located outside the middle cylinder.

6. An application of the origami-improved circular tube impact-resistant protective structure as described in claim 1, characterized in that: This protective structure is used as the core layer of a "sandwich" cushioning structure.

7. The application of the origami-improved circular tube impact-resistant protective structure according to claim 6, characterized in that: In the single-structure mode, the protective structure is placed between the top plate and the bottom plate; the top of the protective structure is fixed in contact with the top plate, and the bottom of the protective structure is fixed in contact with the bottom plate.

8. The application of the origami-improved circular tube impact-resistant protective structure according to claim 6, characterized in that: In the two-dimensional array structure mode, multiple protective structures are arranged along two vertical directions and placed between the top plate and the bottom plate. The top of the protective structure is fixed in contact with the top plate, and the bottom of the protective structure is fixed in contact with the bottom plate, forming a two-dimensional array core layer.

9. The application of the origami-improved circular tube impact-resistant protective structure according to claim 6, characterized in that: In the three-dimensional array structure mode, multiple protective structures are arranged along three orthogonal directions and placed between the top plate and the bottom plate. The top of the protective structure is fixed in contact with the top plate, and the bottom of the protective structure is fixed in contact with the bottom plate, forming a three-dimensional array core layer.

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