Multi-directional impact-resistant paper-cut-origami synergistic metamaterial

Abstract

The invention discloses a paper-cut-origami synergistic metamaterial capable of resisting impact in multiple directions. The metamaterial is formed by combining a regular octahedron paper-cut structure and a Kresling origami structure. In the compression process, the buckling of the paper folding panel is promoted by utilizing the boundary constraint of the octahedral paper-cut structure, so that the energy absorption efficiency is improved. Compared with a traditional anti-chiral Kresling origami metamaterial, the structure has a higher specific energy absorption characteristic. In addition, the geometric composition of the structure has rotation periodicity, and the structure shows good multi-directional mechanical property consistency and rigidity adjustability under quasi-static compression load. The invention can solve the problem that the existing metamaterial is difficult to realize stable and controllable mechanical properties in a plurality of main bearing directions, and obviously improves the energy absorption efficiency of the structure under the condition of large deformation.

Description

Technical Field

[0001] This invention belongs to the field of mechanical metamaterials, specifically relating to a multi-directional impact-resistant paper-cutting and origami synergistic metamaterial. Background Technology

[0002] Traditional energy-absorbing structures, such as foam materials, honeycomb structures, or corrugated pipes, dissipate energy primarily through plastic deformation or buckling when subjected to impact loads. These structures often exhibit significant anisotropy, meaning their mechanical properties (such as energy absorption capacity, load-bearing efficiency, and deformation modes) vary considerably in different directions. This leads to instability in complex and variable impact environments (such as collisions from different directions or explosive shock waves), making it difficult to achieve predictable and balanced energy absorption. Furthermore, the deformation behavior of traditional structures is often uncontrollable, frequently resulting in random and localized failures, further limiting their energy absorption efficiency.

[0003] In recent years, origami and paper-cutting structures have been introduced into the field of energy absorption due to their rich geometric designability and unique deformation mechanisms. Origami structures can guide orderly deformation through predetermined folding patterns, achieving high energy absorption efficiency; paper-cutting structures introduce controllable hinges or flexible units into two-dimensional sheets through pattern cutting, giving them out-of-plane deformation capabilities. However, single origami structures often have relatively fixed deformation patterns, are sensitive to loading direction, and their anisotropy remains a prominent issue; while single paper-cutting structures may have shortcomings in in-plane load-bearing capacity and energy absorption density. Although there are some design attempts combining origami and paper-cutting concepts in existing technologies, they mostly focus on achieving specific deformation shapes or optimizing a single performance, failing to systematically solve the problem of achieving similar and controllable mechanical properties (such as initial peak force, plateau stress, energy absorption, etc.) in multiple major load-bearing directions. This results in existing structures still struggling to guarantee stable, reliable, and efficient performance when facing multi-directional impacts, limiting their widespread application in fields with stringent requirements for multi-directional impact protection, such as aerospace, vehicle protection, and precision equipment packaging. Summary of the Invention

[0004] In view of the above problems, the purpose of this invention is to provide a multi-directional impact-resistant paper-cutting-origination synergistic metamaterial to solve the problems that existing structures cannot cope with multi-directional impacts and do not have adjustable mechanical properties.

[0005] Therefore, the present invention adopts the following technical solution: A multi-directional impact-resistant paper-cutting-origination synergistic metamaterial, the metamaterial comprising an octahedral paper-cutting structure and at least one Kresling origami unit structure, wherein the octahedral paper-cutting structure and the Kresling origami unit structure are interlocked to form a composite structure; wherein the octahedral paper-cutting structure includes at least one unfolded state, and the geometric dimensions of the Kresling origami unit are set according to the unfolded state of the octahedral paper-cutting.

[0006] Furthermore, the number of the regular octahedral paper-cutting structure is 1, and the number of the Kresling origami unit structure is 6; one regular octahedral paper-cutting structure and six Kresling origami units constitute a metamaterial unit cell structure.

[0007] Furthermore, the metamaterial has a total of 8 loading planes and 4 loading axes. The geometry in the 4 loading directions is arranged clockwise, and the geometry in the other 4 directions is arranged counterclockwise. This design makes the geometry of the structure have rotational periodicity and exhibits an overall anti-handed characteristic.

[0008] Furthermore, the length of the slit when the regular octahedral paper-cut structure is unfolded is The length of the Kresling origami crease is Both satisfy .

[0009] Furthermore, the arrangement of the unit cell structure can be either a staggered arrangement or a mirror arrangement.

[0010] Furthermore, the octahedral paper-cutting structure refers to a paper-cutting structure formed by unfolding an octahedron by opening slits along each side of the octahedron. Its adjacent planes are connected only through vertices, and a single vertex connects only two planes. The total number of vertices increases from 6 before unfolding to 12. In order to ensure the connection relationship between vertices, the expansion and unfolding of the structure is achieved by offsetting and rotating each plane.

[0011] Furthermore, during the unfolding process of the octahedral paper-cut structure, the geometric elements of the metamaterial satisfy the following conditions: in, The side length of a regular octahedron. Let be the circumradius of the bottom and top surfaces of the cell structure. Let the radius of the circumscribed cylinder of the overall structure be denoted as . Let be the distance from the top and bottom surfaces to the adjacent intermediate nodes. The spacing between intermediate nodes, and the total height of the structure. , Let be the angle of the polygon at the middle node relative to the bottom face. This is the angle between the top surface and the bottom surface.

[0012] Furthermore, the aforementioned multi-directional impact resistance refers to the structure exhibiting similar mechanical properties in eight different loading directions.

[0013] Furthermore, the metamaterial exhibits two-stage stiffness during structural deformation, accompanied by a stiffness step phenomenon.

[0014] Furthermore, the matrix material of the metamaterial is selected from at least one of metallic materials, composite materials, or shape memory alloys; wherein the metallic material is selected from at least one of aluminum alloys and 316L stainless steel, and the composite material is selected from at least one of tough composite materials such as nylon and highly elastic recoverable rubber.

[0015] Furthermore, the metamaterial exhibits a higher specific energy absorption (SEA) compared to conventional antichiral Kresling structures.

[0016] The beneficial effects of this invention are as follows: This invention designs a multi-directional impact-resistant paper-cutting-origination synergistic metamaterial by combining regular octahedral paper cutting and Kresling origami. Geometrically, the structure exhibits rotational periodicity and reciprocal characteristics; mechanically, it demonstrates improved impact resistance and enhanced isotropy compared to traditional reciprocal Kresling structures, and its structural stiffness is adjustable. This metamaterial solves the problems of existing metamaterials being unable to withstand multi-directional impacts and lacking adjustable mechanical properties. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the paper-cutting part of an embodiment of the present invention, wherein (a) is a front view and (b) is a top view.

[0019] Figure 3 This is a schematic diagram of the origami portion of an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the structural array according to an embodiment of the present invention.

[0021] Figure 5 This is a comparison diagram of force-displacement curves in different loading directions according to an embodiment of the present invention.

[0022] Figure 6 This is a diagram showing the stiffness change during the compression process in an embodiment of the present invention.

[0023] Figure 7This is a comparison diagram of the force-displacement curves of the embodiment of the present invention and the traditional Kresling structure.

[0024] The diagram is labeled as follows: 1 - octahedral paper-cutting part, 2 - Kresling origami part, 3 - structural processing hole. Detailed Implementation

[0025] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail, clearly, and completely below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Furthermore, based on the embodiments of the present invention, any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art to all other embodiments obtained without creative effort should be included within the protection scope of the present invention.

[0026] The present invention will now be described in detail with reference to the accompanying drawings of the embodiments. However, the present invention is not limited to the following embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] like Figure 1 As shown, the multi-directional impact-resistant paper-cutting-origination synergistic metamaterial is composed of a regular octahedral paper cutout (1) and six Kresling origami units (2). Each plane of the regular octahedral paper cutout (1) is an equilateral triangle. The Kresling origami unit (2) unfolds into a rhombus. The Kresling origami unit is embedded in the gap of the unfolded regular octahedral paper cutout. The two satisfy a geometric synergistic relationship, that is, the side length of the rhombus is equal to the side length of the equilateral triangle, and the length of the unfolded gap is equal to the side length of the paper cutout. Equal to the length of Kresling's origami crease .in, and The locations referred to are respectively as follows Figure 2 and Figure 3 As shown.

[0028] Figure 2 (a) shows the front view of a regular octahedron paper cutout. Figure 2 (b) shows a top view of the octahedral paper cutting; in the figure, the vertices are numbered counterclockwise starting from the bottom face, with the bottom vertices numbered A, B and C, the middle vertices numbered D, E, F, G, H and I, and the top face numbered J, K and L. The side length of a regular octahedron. For the bottom surface of the structure ( ) and top surface ( The circumradius of the outer circle of the overall structure, and the circumradius of the outer cylinder of the overall structure. , Let be the distance from the top and bottom surfaces to the adjacent intermediate nodes. The spacing between intermediate nodes, and the total height of the structure. , Let be the angle of the polygon at the middle node relative to the bottom face. This represents the angle of rotation of the top face relative to the bottom face. The octahedral paper cutting is achieved by unfolding the octahedron through slits along its edges. Adjacent planes are connected only by vertices, and a single vertex connects only two planes. The total number of vertices increases from 6 to 12. Specifically, the expansion and unfolding of the structure is achieved by offsetting each plane. During the expansion process, to maintain vertex connections, each plane rotates while being offset. The unfolding process can be defined by the above geometric parameters and satisfies the following system of equations: Conversely, the geometric parameters corresponding to each state during the unfolding process of a regular octahedron paper cut can also be solved using the above set of equations. Furthermore, in practical applications, different unit cell structures can be designed according to requirements.

[0029] The structural geometric parameters of the embodiment are shown in the table below: Table 1 Structural geometric parameters like Figure 4 The diagram shown is a schematic representation of an arrangement structure according to an embodiment of the present invention.

[0030] The example structure was manufactured using SLS (Selective Laser Sintering) technology, with PA12 (nylon) as the printing material. Its characteristics include a tensile strength of 0.98 g / cm³, an elastic modulus of 788 MPa, a Poisson's ratio of 0.24, and a yield stress of 30 MPa. Residual PA12 powder was removed through a pre-drilled hole (3).

[0031] Please see Figure 5 Figure 1 shows the force-displacement curves of the structure of the present invention under different loading directions. As shown in the figure, the stress-strain curves of the structure under different loading directions show almost no deviation, exhibiting good similarity in multi-directional mechanical properties.

[0032] Please see Figure 6 Figure 1 shows the stiffness change of the structure during compression. As shown, the stiffness jumps from 36 N / mm to 295 N / mm during deformation, an increase of approximately 7.2 times. This demonstrates that the metamaterial possesses significant potential for adjustable stiffness, meaning that unit cell structures with different stiffness states could potentially meet diverse structural stiffness requirements.

[0033] Please see Figure 7The figure shows the force-displacement curves of the present invention and the traditional anti-chiral Kresling structure under quasi-static compression. As can be seen from the figure, the specific energy absorption (SEA) of the two metamaterials are 4.59 J / kg and 1.12 J / kg, respectively. The SEA of the present invention can be increased by 3.1 times compared with the traditional anti-chiral Kresling structure, demonstrating excellent energy absorption efficiency.

[0034] Specific Energy Absorbed Amount (SEA): The energy absorbed per unit mass of material, used to characterize the energy absorption efficiency of a material from an energy perspective. The specific calculation is as follows: , in, It is the displacement when the material is dense. It is the force generated by loading. It is the quality of metamaterials.

[0035] In summary, this invention proposes a multi-directional impact-resistant paper-cutting-origination synergistic metamaterial that can achieve the same mechanical properties in multiple directions and adjustable structural stiffness. Furthermore, it significantly improves the energy absorption of metamaterials compared to traditional anti-chiral Kresling metamaterials, which helps to expand the applications of metamaterials.

[0036] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of 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 principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-directional impact-resistant paper-cutting-origami synergistic metamaterial, characterized in that, The metamaterial includes an octahedral paper-cut structure and at least one Kresling origami unit structure, wherein the octahedral paper-cut structure and the Kresling origami unit structure are interlocked to form a combined structure; wherein the octahedral paper-cut structure includes at least one unfolded state, and the geometric dimensions of the Kresling origami unit are set according to the unfolded state of the octahedral paper-cut.

2. The multi-directional impact-resistant paper-cutting-origination synergistic metamaterial as described in claim 1, characterized in that, The number of the regular octahedral paper-cutting structure is 1, and the number of the Kresling origami unit structure is 6.

3. The multi-directional impact-resistant paper-cutting-origination synergistic metamaterial as described in claim 1, characterized in that, The metamaterial has a structure with 8 loading planes and 4 loading axes. The geometry of the 4 loading directions is arranged clockwise, and the geometry of the other 4 is arranged counterclockwise.

4. The multi-directional impact-resistant paper-cutting-origination synergistic metamaterial as described in claim 1, characterized in that, The length of the slit when the octahedral paper-cut structure is unfolded is The length of the Kresling origami crease is Both satisfy .

5. The multi-directional impact-resistant paper-cutting-origination synergistic metamaterial as described in claim 1, characterized in that, The arrangement of unit cells can be either staggered or mirrored.

6. The multi-directional impact-resistant paper-cutting-origination synergistic metamaterial as described in claim 1, characterized in that, The aforementioned octahedral paper-cutting structure refers to a paper-cutting structure formed by unfolding an octahedron by opening slits along each side of the octahedron. Its adjacent planes are connected only through vertices, and a single vertex connects only two planes. The total number of vertices increases from 6 before unfolding to 12. In order to ensure the connection relationship between vertices, the expansion and unfolding of the structure is achieved by offsetting and rotating each plane.

7. The multi-directional impact-resistant paper-cutting-origination synergistic metamaterial as described in claim 1 or 6, characterized in that, During the unfolding process of the regular octahedral paper-cut structure, the geometric elements of the metamaterial satisfy the following conditions: ； in, The side length of a regular octahedron. The circumradius of the bottom and top surfaces of the cell structure is denoted by , and the circumradius of the overall structure's cylinder is denoted by . , Let be the distance from the top and bottom surfaces to the adjacent intermediate nodes. The spacing between intermediate nodes, and the total height of the structure. , Let be the angle of the polygon at the middle node relative to the bottom face. This is the angle of rotation of the top surface relative to the bottom surface.

8. The multi-directional impact-resistant paper-cutting-origination synergistic metamaterial as described in claim 1, characterized in that, The aforementioned multi-directional impact resistance refers to the structure exhibiting similar mechanical properties in eight different loading directions.

9. The multi-directional impact-resistant paper-cutting-origination synergistic metamaterial as described in claim 1, characterized in that, The metamaterial exhibits two-stage stiffness during structural deformation, accompanied by a stiffness step phenomenon.

10. The multi-directional impact-resistant paper-cutting-origination synergistic metamaterial as described in claim 1, characterized in that, The matrix material of the metamaterial is selected from at least one of metallic materials, composite materials, or shape memory alloys; wherein the metallic material is selected from at least one of aluminum alloys and 316L stainless steel, and the composite material is selected from at least one of tough composite materials such as nylon and high-elasticity recoverable rubber.

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