Inward concave unit cell energy absorption structure, honeycomb multi-cell structure and vehicle

Abstract

The invention relates to the technical field of vehicle energy absorption structures, in particular to a concave unit cell energy absorption structure, a honeycomb multi-cell structure and a vehicle. The inwards-concave unit cell energy absorption structure comprises an inwards-concave hexagonal structure, a first straight connecting rod, a second straight connecting rod, a first reinforcing rib and a second reinforcing rib, and the first reinforcing rib and the second reinforcing rib intersect in the inwards-concave hexagonal structure to form a third inwards-folding point. The cell walls of the inward-concave hexagonal structure can rotate around the end points to form plastic hinges, the negative Poisson's ratio effect is achieved, deformation coordination is enhanced, the cell walls in the structure continuously absorb external mechanical energy in the rotating and buckling process, transmission of impact force to other structures of the whole vehicle is relieved, and the energy absorption effect of impact load resistance is achieved. Due to the fact that the first reinforcing ribs and the second reinforcing ribs are added, a plurality of new nodes and rotating units are formed, the number of plastic hinges is remarkably increased, and the energy dissipation capacity of the structure in the impact process is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle energy absorption structures, and in particular to a concave single-cell energy absorption structure, a honeycomb multi-cell structure and a vehicle. Background Art

[0002] Longitudinal beams and anti-collision beams are the primary structures responsible for absorbing collision energy in the vehicle body. They are also the primary components that influence the overall vehicle's collision safety performance and are the primary differentiating factors in the collision safety performance of different vehicles. Due to their critical role, these components are typically designed as cavity-like structures. However, due to layout and space constraints, to maximize energy absorption efficiency within limited space, it is imperative to design a structure that fills the cavity to enhance the energy absorption function of the vehicle body structure. Summary of the Invention

[0003] One of the purposes of the present invention is to provide an inward-concave single-cell energy absorption structure to solve the technical problem in the prior art that the vehicle body beam structure needs to improve the energy absorption effect; the second purpose is to provide a honeycomb multi-cell structure; and the third purpose is to provide a vehicle.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows.

[0005] A concave unit cell energy absorption structure, comprising:

[0006] The concave hexagonal structure includes a first straight cell wall, a first oblique cell wall, a second oblique cell wall, a second straight cell wall, a third oblique cell wall, and a fourth oblique cell wall connected end to end in sequence, wherein the first straight cell wall is parallel to the second straight cell wall, has the same length, and is arranged opposite each other, the first oblique cell wall and the second oblique cell wall intersect at a first inflection point and fold inwardly toward the interior of the concave hexagonal structure, and the third oblique cell wall and the fourth oblique cell wall intersect at a second inflection point and fold inwardly toward the interior of the concave hexagonal structure;

[0007] A first straight connecting rod and a second straight connecting rod are both located outside the concave hexagonal structure and are parallel to the first straight cell wall, the first straight connecting rod is connected to the first inner inflection point, and the second straight connecting rod is connected to the second inner inflection point;

[0008] A first reinforcing rib and a second reinforcing rib, wherein the first end of the first reinforcing rib and the first end of the second reinforcing rib intersect inside the concave hexagonal structure to form a third inner inflection point, and the second end of the first reinforcing rib and the second end of the second reinforcing rib are respectively connected to the two ends of the second straight cell wall.

[0009] Through the above technical means, when the concave single-cell energy-absorbing structure is subjected to a planar impact, the cell walls of the concave hexagonal structure will rotate around the endpoints, forming plastic hinges with a negative Poisson's ratio effect, which enhances deformation coordination. The cell walls in the structure continuously absorb external mechanical energy during the rotation and buckling process, slowing down the transmission of impact force to other structures of the vehicle, and achieving the energy absorption effect of resisting impact loads; from the primary deformation of the concave hexagonal structure to the subsequent deformation of the reinforced triangular structure, a "two-stage energy absorption" mode is formed. The triangular structure provides rigid support during deformation, preventing the early yield of the local structure and causing overall collapse, and can also effectively prolong the energy absorption time; due to the addition of the first reinforcement rib and the second reinforcement rib, multiple new nodes and rotation units are formed, the number of plastic hinges is significantly increased, and the energy dissipation capacity of the structure during the impact process is significantly improved.

[0010] Furthermore, the concave unit cell energy absorption structure is symmetrically arranged about the perpendicular bisector of the first straight cell wall, and the concave hexagonal structure is symmetrically arranged about the line connecting the first inner inflection point and the second inner inflection point.

[0011] Through the above technical means, the concave single-cell energy-absorbing structure has a more uniform stress distribution and a symmetrical deformation path during the crush deformation process, further improving the stability of the structure and the energy dissipation efficiency. The equal-length and symmetrical first and second reinforcement ribs make the rotation points and plastic zones on both sides of the triangle more balanced, improving the controllability of the structure, and having a higher plastic deformation path during crushing, making the energy consumption process more sufficient.

[0012] Furthermore, the concave unit cell energy absorption structure also includes:

[0013] a first oblique connecting rod, one end of which is connected to the first inner inflection point and is located between the first straight connecting rod and the second oblique cell wall;

[0014] A second oblique connecting rod has one end connected to the second inner inflection point and is located between the second straight connecting rod and the third oblique cell wall.

[0015] Through the above technical means, the first straight connecting rod, the second straight connecting rod, the first oblique connecting rod and the second oblique connecting rod form a triangular structure. The triangular structure is located outside the concave hexagonal structure, which can further suppress premature local buckling or overall collapse of the structure and improve the overall deformation coordination of the structure. Due to the introduction of the first oblique connecting rod and the second oblique connecting rod, the number of plastic hinges of the concave unit cell energy absorption structure is further increased, and the absorbed energy will be further increased.

[0016] Furthermore, the projection of the first oblique connecting rod on the first straight connecting rod is equal in length to the first straight connecting rod, and the projection of the second oblique connecting rod on the second straight connecting rod is equal in length to the second straight connecting rod.

[0017] Through the above technical means, the deformation balance is improved, and the force distribution of the isosceles structure is more uniform when it is crushed, avoiding local stress concentration and early failure; the isosceles triangle has natural geometric stability in structural mechanics, which helps to improve the impact resistance of the structure in the array state; since the connection is no longer a weak connection point, the triangular structure can coordinate plastic deformation such as bending and crushing during the energy absorption process, thereby improving the energy absorption capacity per unit area.

[0018] Furthermore, the first oblique connecting rod is parallel to the first reinforcing rib; and the second oblique connecting rod is parallel to the second reinforcing rib.

[0019] Through the above technical means, the deformation directions of the reinforcing ribs and connecting rods during loading tend to be consistent, which helps to control the deformation trajectory during crushing, improve the predictability and safety of the structure, and reduce the reduction in energy absorption efficiency due to structural distortion.

[0020] Furthermore, each component structure of the concave unit cell energy absorption structure is a rod, and the cross-sectional shape of the rod is circular, rectangular or triangular.

[0021] Through the above technical means, the appropriate rod cross-section can be selected according to different energy absorption needs and manufacturing requirements, thereby improving structural performance and manufacturing efficiency.

[0022] Furthermore, two concave unit cell energy absorbing structures are provided and are arranged perpendicular to each other, and the line connecting the first inner inflection point and the second inner inflection point of the two concave unit cell energy absorbing structures completely coincides.

[0023] Through these technical approaches, the frame composed of unit cells can achieve load absorption in multiple directions. This not only protects against vertical impacts but also effectively disperses lateral or oblique loads, improving structural stability and energy absorption under multi-axial impacts. Each unit cell already has multiple locations for plastic hinge formation. When combined into a three-dimensional structure, this increases the number of plastic deformation paths, helping to improve energy absorption efficiency per unit volume.

[0024] A honeycomb multicellular structure is formed by connecting concave single-cell energy-absorbing structures in an array in space; in each row, the second straight cell wall in one of the concave single-cell energy-absorbing structures is shared with the first straight cell wall in an adjacent concave single-cell energy-absorbing structure; in each column, the free end of the first straight connecting rod in one of the concave single-cell energy-absorbing structures is connected with the free end of the second straight connecting rod in an adjacent concave single-cell energy-absorbing structure.

[0025] Through the above technical means, the use of shared straight cell walls effectively reduces repeated structural units, achieving a balance between lightweight and high strength, making it suitable for engineering scenarios with high requirements for weight and strength per unit area. Because adjacent cells are connected in both rows and columns, the entire honeycomb multi-cellular structure can form an in-plane coordinated crushing when impacted, effectively dispersing local impact forces and improving overall energy absorption efficiency.

[0026] Furthermore, the concave unit cell energy absorption structure also includes a first oblique connecting rod and a second oblique connecting rod, one end of the first oblique connecting rod is connected to the first inner inflection point and is located between the first straight connecting rod and the second oblique cell wall, and one end of the second oblique connecting rod is connected to the second inner inflection point and is located between the second straight connecting rod and the third oblique cell wall; in each column, the free end of the first oblique connecting rod in one concave unit cell energy absorption structure is connected to the free end of the second oblique connecting rod in the adjacent concave unit cell energy absorption structure.

[0027] Through the above technical means, a stable connection is established between adjacent unit cell structures in each column through the first oblique connecting rod and the second oblique connecting rod, thereby forming multiple cross-unit triangular connection structures in the array structure, which helps to improve the overall stability and stiffness of the structure, effectively disperse and transmit external force impact during the energy absorption process, limit local collapse or unexpected deformation paths, and thus improve the structural controllability and stability during the energy absorption process.

[0028] A vehicle, wherein the beam skeleton structure of the vehicle is filled with a honeycomb multi-cellular structure.

[0029] Beneficial effects of the present invention:

[0030] (1) When the concave single-cell energy absorption structure provided in the embodiment of the present application is subjected to a planar impact, the cell walls of the concave hexagonal structure will rotate around the endpoints, forming a plastic hinge, which has a negative Poisson's ratio effect and enhances deformation coordination. During the rotation and buckling process, the cell walls in the structure continuously absorb external mechanical energy, slowing down the transmission of the impact force to other structures of the vehicle, and achieving an energy absorption effect that resists impact loads.

[0031] (2) In the concave unit cell energy absorption structure provided in the embodiment of the present application, a "two-stage energy absorption" mode is formed from the primary deformation of the concave hexagonal structure to the subsequent deformation of the reinforced triangular structure. The triangular structure provides rigid support during deformation, preventing the early yielding of the local structure and causing overall collapse, and can also effectively prolong the energy absorption time. Due to the addition of the first reinforcement rib and the second reinforcement rib, multiple new nodes and rotation units are formed, and the number of plastic hinges is significantly increased, which significantly improves the energy dissipation capacity of the structure during the impact process. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1A schematic diagram of a concave unit cell energy absorption structure provided by a first embodiment of the present invention;

[0033] Figure 2 A schematic diagram of a concave unit cell energy absorption structure provided by a second embodiment of the present invention;

[0034] Figure 3 A schematic diagram of a concave unit cell energy absorption structure provided by a third embodiment of the present invention;

[0035] Figure 4 A schematic diagram of a plane impact of a honeycomb multi-cell structure formed by a concave single-cell energy-absorbing structure provided by the first embodiment of the present invention;

[0036] Figure 5 A schematic diagram of a plane impact of a honeycomb multi-cell structure formed by a concave single-cell energy-absorbing structure provided by the second embodiment of the present invention;

[0037] Figure 6 A schematic diagram of a plane impact of a honeycomb multi-cell structure formed by a concave single-cell energy-absorbing structure provided by the third embodiment of the present invention;

[0038] Figure 7 for Figure 4 The initial state of plane crushing of the honeycomb multicellular structure of Example 1;

[0039] Figure 8 for Figure 4 The crush diagram of the honeycomb multicellular structure of Example 1 under plane impact when the equivalent effect becomes 0.27;

[0040] Figure 9 for Figure 4 The crush diagram of the honeycomb multicellular structure of Example 1 under plane impact when the equivalent effect becomes 0.45;

[0041] Figure 10 for Figure 5 The initial state of plane crushing of the honeycomb multicellular structure of Example 2;

[0042] Figure 11 for Figure 5 The crush diagram of the honeycomb multicellular structure of Example 2 under plane impact when the equivalent effect becomes 0.27;

[0043] Figure 12 for Figure 5 The crush diagram of the honeycomb multicellular structure of Example 2 under plane impact when the equivalent effect becomes 0.45;

[0044] Figure 13 for Figure 6 The initial state of plane crushing of the honeycomb multicellular structure of Example 3;

[0045] Figure 14 for Figure 6 The crush diagram of the honeycomb multicellular structure of Example 3 under plane impact when the equivalent effect becomes 0.27;

[0046] Figure 15 for Figure 6 The crush diagram of the honeycomb multicellular structure of Example 3 under plane impact when the equivalent effect becomes 0.45;

[0047] Figure 16 Comparison of equivalent stress-strain curves of the honeycomb multi-cellular structures of Examples 1-3 of the present invention under plane impact.

[0048] in:

[0049] 1. First straight cell wall; 2. First oblique cell wall; 3. Second oblique cell wall; 4. Second straight cell wall; 5. Third oblique cell wall; 6. Fourth oblique cell wall; 7. First straight connecting rod; 8. Second straight connecting rod; 9. First reinforcing rib; 10. Second reinforcing rib; 11. First oblique connecting rod; 12. Second oblique connecting rod. DETAILED DESCRIPTION

[0050] The following describes the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the various details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0051] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0052] like Figure 1As shown, a concave single-cell energy absorption structure is proposed in the related art, and its main structure includes a concave hexagonal structure, a first straight connecting rod 7 and a second straight connecting rod 8. The concave hexagonal structure includes a first straight cell wall 1, a first oblique cell wall 2, a second oblique cell wall 3, a second straight cell wall 4, a third oblique cell wall 5 and a fourth oblique cell wall 6 connected end to end in sequence, the first straight cell wall 1 and the second straight cell wall 4 are parallel, equal in length and arranged opposite each other, the first oblique cell wall 2 and the second oblique cell wall 3 intersect at a first inflection point and fold inwardly toward the interior of the concave hexagonal structure, the third oblique cell wall 5 and the fourth oblique cell wall 6 intersect at a second inflection point and fold inwardly toward the interior of the concave hexagonal structure; the first straight connecting rod 7 and the second straight connecting rod 8 are both located outside the concave hexagonal structure and are parallel to the first straight cell wall 1, the first straight connecting rod 7 is connected to the first inflection point, and the second straight connecting rod 8 is connected to the second inflection point. Specifically, without considering the thickness, the extension directions of the concave hexagonal structure of the concave single-cell energy absorption structure, the first straight connecting rod 7, the second straight connecting rod 8, the first reinforcing rib 9 and the second reinforcing rib 10 are all parallel to the same plane, the first straight cell wall 1 intersects with the first oblique cell wall 2 at point F, the first oblique cell wall 2 intersects with the second oblique cell wall 3 at point E, the second oblique cell wall 3 intersects with the second straight cell wall 4 at point D, the second straight cell wall 4 intersects with the third oblique cell wall 5 at point C, the third oblique cell wall 5 intersects with the fourth oblique cell wall 6 at point B, and the fourth oblique cell wall 6 intersects with the first straight cell wall 1 at point A, one end of the first straight connecting rod 7 is point E and the free end is point I, one end of the second straight connecting rod 8 is point B and the free end is point H; the first inflection point is point E, and the second inflection point is point B.

[0053] The first straight connecting rod 7 of a concave unit cell energy absorbing structure is used to connect with the second straight connecting rod 8 of another concave unit cell energy absorbing structure. Specifically, the free end of the first straight connecting rod 7 is connected to the free end of the second straight connecting rod 8, so that a plurality of concave unit cell energy absorbing structures are arranged in a direction parallel to the first straight cell wall 1. The first straight cell wall 1 of a concave unit cell energy absorbing structure can be shared with the second straight cell wall 4 of another concave unit cell energy absorbing structure, so that a plurality of concave unit cell energy absorbing structures are arranged in a direction perpendicular to the first straight cell wall 1, thereby forming a plurality of concave unit cell energy absorbing structures as follows: Figure 4 The honeycomb multicellular structure shown.

[0054] The honeycomb multi-cell structure formed by the concave single-cell energy-absorbing structure can be used to fill hollow cavities such as vehicle body longitudinal beams or anti-collision beams. Through its unique geometric configuration, it undergoes complex deformation during impact, significantly improving the structure's energy absorption efficiency. During a planar impact, the cell walls of the concave hexagonal structure rotate about their endpoints, forming plastic hinges. This creates a negative Poisson's ratio and enhances deformation coordination. During this rotation and buckling, the cell walls within the structure continuously absorb external mechanical energy, mitigating the transmission of impact forces to other vehicle structures and achieving energy absorption against impact loads.

[0055] Researchers have found that the deformation mode of the concave hexagonal structure in the above-mentioned concave unit cell energy absorption structure is relatively unstable, and it is difficult to further improve the energy absorption. Figure 2 and 5 As shown, in some embodiments, the concave unit cell energy absorption structure further includes a first reinforcing rib 9 and a second reinforcing rib 10. The first end of the first reinforcing rib 9 and the first end of the second reinforcing rib 10 intersect inside the concave hexagonal structure to form a third inflection point, and the second end of the first reinforcing rib 9 and the second end of the second reinforcing rib 10 are respectively connected to the two ends of the second straight cell wall 4. Specifically, without considering the thickness, the concave hexagonal structure, the first straight connecting rod 7, the second straight connecting rod 8, the first reinforcing rib 9 and the second reinforcing rib 10 of the concave unit cell energy absorption structure are all parallel to the same plane, the first reinforcing rib 9 and the second reinforcing rib 10 intersect at point G, and the third inflection point is point G.

[0056] In this embodiment, the first and second reinforcing ribs 9, 10 added to the interior of the concave hexagonal structure, along with the second straight cell wall 4, form a stable triangular CDG structure. The triangular structure is the most basic and stable geometric unit in a load-bearing structure. Its introduction significantly inhibits premature local buckling or overall collapse of the structure, improving the overall deformation coordination of the structure. During the crushing process, the triangular CDG structure's strength is higher than that of the concave hexagonal structure. Therefore, during crushing, the concave hexagon deforms first, followed by the internal triangular structure, resulting in a relatively stable deformation pattern. Furthermore, the introduction of the first and second reinforcing ribs 9, 10 increases the number of plastic hinges in the concave unit cell energy absorption structure, resulting in higher energy absorption than a simple concave hexagonal structure.

[0057] Under impact load, the structure's deformation process can be divided into the following two stages. In the first stage, the indented hexagonal structure first deforms under the action of external force. Its oblique cell walls form plastic hinges around their connection points and rotate, causing the entire structure to collapse. This process absorbs the initial impact energy. In the second stage, as the crushing progresses, the indented hexagonal structure tends to collapse. At this point, the triangular structure formed by the reinforcing ribs gradually participates in the load and deformation. Because the triangular structure is relatively stronger, it only buckles and plastically deforms under higher loads, further absorbing the remaining impact energy.

[0058] From the primary deformation of the concave hexagonal structure to the subsequent deformation of the reinforced triangular structure, a "two-stage energy absorption" mode is formed. The triangular structure provides rigid support during deformation, preventing early yielding of the local structure and causing overall collapse, and can also effectively prolong the energy absorption time; due to the addition of the first reinforcement rib 9 and the second reinforcement rib 10, multiple new nodes and rotation units are formed, and the number of plastic hinges is significantly increased, which significantly improves the energy dissipation capacity of the structure during the impact process.

[0059] In some embodiments, the concave unit cell energy absorption structure is symmetrically arranged about the perpendicular midline of the first straight cell wall 1, and the concave hexagonal structure is symmetrically arranged about the line connecting the first inflection point and the second inflection point. That is, the concave hexagonal structure in the concave unit cell energy absorption structure is a left-right and top-bottom symmetrical structure, the lengths of the first straight cell wall 1 and the second straight cell wall 4 are equal, the lengths of the first oblique cell wall 2, the second oblique cell wall 3, the third oblique cell wall 5, and the fourth oblique cell wall 6 are equal, the lengths of the first straight connecting rod 7 and the second straight connecting rod 8 are equal, and the lengths of the first reinforcing rib 9 and the second reinforcing rib 10 are equal.

[0060] Due to the introduction of structural symmetry, the concave single-cell energy-absorbing structure has a more uniform stress distribution and a symmetrical deformation path during the crush deformation process, further improving the stability of the structure and the energy dissipation efficiency. In particular, since the first reinforcement rib 9 and the second reinforcement rib 10 are of equal length, and their ends are connected to the two ends of the second straight cell wall 4 (point C and point D), they intersect at the inner point G of the concave hexagonal structure at their first end, and the triangular structure CDG formed is an isosceles triangle. The geometric symmetry of the isosceles triangle structure is conducive to ensuring mechanical consistency. During the force-bearing process, the mechanical behaviors of the first reinforcement rib 9 and the second reinforcement rib 10 on both sides are similar, avoiding local yield or uneven collapse; the equal-length and symmetrical first reinforcement rib 9 and the second reinforcement rib 10 make the rotation points and the plastic zones on both sides of the triangle more balanced, improving the controllability of the structure, and having a higher plastic deformation path during crushing, making the energy consumption process more sufficient.

[0061] like Figure 3 and 6As shown, in some embodiments, the concave unit cell energy absorption structure further includes a first oblique connecting rod 11 and a second oblique connecting rod 12. One end of the first oblique connecting rod 11 is connected to the first inner inflection point and is located between the first straight connecting rod 7 and the second oblique cell wall 3; one end of the second oblique connecting rod 12 is connected to the second inner inflection point and is located between the second straight connecting rod 8 and the third oblique cell wall 5. One end of the first oblique connecting rod 11 is point E and the free end is point H, and one end of the second oblique connecting rod 12 is point B and the free end is point K.

[0062] Without considering the thickness, the first oblique connecting rod 11 and the second oblique connecting rod 12 and the extending directions of the rods in the concave hexagonal structure, the straight connecting rod and the reinforcing ribs are all parallel to the same plane.

[0063] In the process of forming a honeycomb multi-cellular structure by arranging the concave single-cell energy absorbing structures in an array, the first oblique connecting rod 11 of a concave single-cell energy absorbing structure is used to connect with the second oblique connecting rod 12 of another concave single-cell energy absorbing structure. Specifically, the free end of the first oblique connecting rod 11 is connected to the free end of the second oblique connecting rod 12, so that several concave single-cell energy absorbing structures are arranged in a direction parallel to the first straight cell wall 1. In this way, a triangular structure can be formed between two adjacent concave single-cell energy absorbing structures through the first straight connecting rod 7, the second straight connecting rod 8, the first oblique connecting rod 11 and the second oblique connecting rod 12. The triangular structure is located outside the concave hexagonal structure.

[0064] This triangular structure achieves stable spatial support and mechanical synergy between multiple concave unit cell energy absorption structures. The external triangular structure forms a geometric closure, avoiding large displacement or unstable deformation of the single first straight connecting rod 7 and the second straight connecting rod 8 when impacted; when under pressure, the adjacent structures synergistically deform through the external connecting triangles, delaying the structural destruction time and improving the structural energy consumption efficiency.

[0065] The introduction of the external triangular structure can further suppress premature local buckling or overall collapse of the structure and improve the overall deformation coordination of the structure. Due to the introduction of the first oblique connecting rod 11 and the second oblique connecting rod 12, the number of plastic hinges of the concave unit cell energy absorption structure is further increased, and the absorbed energy will be further increased.

[0066] In some embodiments, the projection of the first oblique connecting rod 11 on the first straight connecting rod 7 is equal in length to the first straight connecting rod 7, and the projection of the second oblique connecting rod 12 on the second straight connecting rod 8 is equal in length to the second straight connecting rod 8. This ensures that the triangular structure formed between the two concave unit-cell energy-absorbing structures by the first straight connecting rod 7, the second straight connecting rod 8, the first oblique connecting rod 11, and the second oblique connecting rod 12 is an isosceles triangle. This embodiment can achieve greater deformation balance, more uniform force distribution when the isosceles structure is crushed, and avoid local stress concentration and premature failure. The isosceles triangle has a natural geometric stability in structural mechanics, which helps improve the impact resistance of the structure in the array state. Because the connection is no longer a weak point, the triangular structure can coordinately undergo plastic deformation such as bending and crushing during the energy absorption process, thereby improving the energy absorption capacity per unit area.

[0067] In some embodiments, the first oblique connecting rod 11 is parallel to the first reinforcing rib 9 ; the second oblique connecting rod 12 is parallel to the second reinforcing rib 10 .

[0068] Since the stiffeners primarily enhance the structure's flexural rigidity and maintain the stability of the deformation path, while the diagonal connecting rods provide structural connection between the unit cells, aligning the two allows the inner and outer structures to deform synergistically under compression / impact loads, enhancing overall structural consistency. This parallel arrangement aligns the stiffeners and connecting rods' deformation directions during loading, helping to control the deformation trajectory during crushing, improving structural predictability and safety, and mitigating the reduction in energy absorption efficiency caused by structural distortion.

[0069] In some embodiments, each component of the concave unit cell energy absorption structure is a rod, and the cross-section of each rod is circular, rectangular, or triangular. The component structures specifically include, but are not limited to, a first straight cell wall 1, a second straight cell wall 4, a first oblique cell wall 2, a second oblique cell wall 3, a third oblique cell wall 5, a fourth oblique cell wall 6, a first straight connecting rod 7, a second straight connecting rod 8, a first reinforcing rib 9, a second reinforcing rib 10, a first oblique connecting rod 11, and a second oblique connecting rod 12. A "rod" refers to a predominantly linear structural unit with a length significantly greater than its cross-sectional dimensions, serving as the boundary and internal support for the overall unit cell structure. A circular cross-section offers uniform force distribution, good bending strength, and ease of machining, making it suitable for lightweight energy absorption structures. A rectangular cross-section facilitates directional arrangement and has high bending inertia, offering advantages in scenarios requiring directional stability. A triangular cross-section offers high structural stability. The appropriate rod cross-section can be selected based on different energy absorption needs and manufacturing requirements, thereby improving structural performance and manufacturing efficiency. Furthermore, the relative spatial density of the unit cell array can be directly altered by varying the cross-sectional dimensions of the rods.

[0070] The components of the concave unit cell energy absorption structure can be made of materials such as plastic, resin, and metal. They can also be 3D printed, with common 3D printing materials including nylon, ABS, aluminum alloy, and titanium alloy. The concave unit cell energy absorption structure is fabricated using additive manufacturing techniques, including but not limited to fused deposition modeling, direct metal laser sintering, selective laser melting, and stereolithography.

[0071] It should be noted that the various component structures in the concave single-cell energy absorbing structure provided above in the specific implementation method section of this document are not rods, and the extension direction of each rod is parallel to the same plane. The embodiment of the present invention also provides another concave single-cell energy absorbing structure, which includes two concave single-cell energy absorbing structures provided above, and the two concave single-cell energy absorbing structures are arranged perpendicular to each other, and the line connecting the first inflection point and the second inflection point of the two concave single-cell energy absorbing structures completely coincides. That is, a concave single-cell energy absorbing structure is rotated 90° around the axis formed by the line connecting the first inflection point and the second inflection point, and together with the concave single-cell energy absorbing structure before the rotation, it forms a three-dimensional concave single-cell energy absorbing structure, wherein the extension direction of each rod in one concave single-cell energy absorbing structure is parallel to the first plane, so that the extension direction of each rod in one concave single-cell energy absorbing structure is parallel to the second plane, and the first plane is orthogonal to the second plane.

[0072] The framework, composed of unit cells, can absorb loads in multiple directions, effectively dispersing lateral or oblique loads while not only handling vertical impacts but also improving structural stability and energy absorption under multi-axial impacts. The two groups of unit cells are arranged orthogonally to form a stable spatial geometric framework, enabling the structure to maintain a relatively uniform stress distribution during crushing deformation, mitigating premature failure caused by localized overload. Each unit cell already possesses multiple locations for plastic hinge formation. When combined into a three-dimensional structure, the number of plastic deformation paths increases, helping to improve energy absorption efficiency per unit volume.

[0073] like Figure 5 As shown, an embodiment of the present invention further provides a honeycomb multi-cellular structure, which is formed by connecting concave single-cell energy absorbing structures in an array in space; in each row, the second straight cell wall 4 in one of the concave single-cell energy absorbing structures is shared with the first straight cell wall 1 in the adjacent concave single-cell energy absorbing structure; in each column, the free end of the first straight connecting rod 7 in one of the concave single-cell energy absorbing structures is connected with the free end of the second straight connecting rod 8 in the adjacent concave single-cell energy absorbing structure.

[0074] By sharing straight cell walls, the repetitive structural units are effectively reduced, achieving a balance between lightweight and high strength, making it suitable for engineering scenarios with high requirements for weight and strength per unit area. Since adjacent cells are connected in both row and column directions, the entire honeycomb multicellular structure can form in-plane coordinated crushing when impacted, which can effectively disperse local impact forces and improve overall energy absorption efficiency. A single concave cell energy absorption structure itself contains multiple potential plastic deformation paths. After being connected in an array, a continuous multi-directional plastic link is formed in the entire honeycomb multicellular structure, making the crushing process more stable and gentle, avoiding brittle fracture or stress concentration.

[0075] like Figure 6 As shown, in some embodiments, the concave unit cell energy absorption structure further includes a first oblique connecting rod 11 and a second oblique connecting rod 12, one end of the first oblique connecting rod 11 is connected to the first inner inflection point and is located between the first straight connecting rod 7 and the second oblique cell wall 3, and one end of the second oblique connecting rod 12 is connected to the second inner inflection point and is located between the second straight connecting rod 8 and the third oblique cell wall 5; in each column, the free end of the first oblique connecting rod 11 in one of the concave unit cell energy absorption structures is connected to the free end of the second oblique connecting rod 12 in the adjacent concave unit cell energy absorption structure. When arranged in an array, the above connection method can establish a stable connection between the adjacent unit cell structures in each column through the first oblique connecting rod 11 and the second oblique connecting rod 12, thereby forming a plurality of cross-unit triangular connection units in the array structure. These triangular connection units help to improve the overall stability and rigidity of the structure, effectively disperse and conduct external force impact during the energy absorption process, limit local collapse or unexpected deformation paths, and thus improve the controllability and stability of the structure during the energy absorption process.

[0076] The embodiment of the present invention also provides another honeycomb multi-cell structure, which is formed by connecting a new type of concave single-cell energy-absorbing structure in an array in space. Figure 1-3After any one of the concave single-cell energy-absorbing structures is rotated 90° around the axis formed by the line connecting the first inflection point and the second inflection point, it forms a new concave single-cell energy-absorbing structure together with the concave single-cell energy-absorbing structure before rotation, wherein the extension direction of each rod in one of the concave single-cell energy-absorbing structures is parallel to the first plane, and the extension direction of each rod in the other concave single-cell energy-absorbing structure is parallel to the second plane, and the first plane is orthogonal to the second plane. This honeycomb multi-cellular structure is based on the new concave single-cell energy-absorbing structure, and the volume structure is expanded through spatial rotation and three-dimensional connection. It has higher mechanical stability and isotropic energy absorption performance. Specifically, the honeycomb multi-cellular structure is formed by connecting multiple concave single-cell energy-absorbing structures in an array according to a predetermined arrangement rule in space. Each structural unit is composed of two concave single-cell energy-absorbing structures arranged perpendicular to each other. These two concave single-cell energy-absorbing structures are rotated 90° around the axis formed by the line connecting the first inflection point and the second inflection point and then overlapped, thereby realizing spatial coupling between the units in the three directions of X, Y, and Z. Compared with the honeycomb multi-cellular structure in the aforementioned embodiment, it can effectively absorb impact energy in three dimensions and is particularly suitable for multi-directional impact load environments; the spatial grid formed by the arrangement enables the structure to have good mechanical isotropic properties, which can effectively avoid failure caused by local structural weakness; the straight connecting rods, oblique connecting rods and reinforcing ribs constructed by multiple single-cell structures together form a three-dimensional cross-support system, which significantly improves the overall strength and stability of the structure.

[0077] In the concave single-cell energy-absorbing structure, the angle between the straight and oblique cell walls is denoted as α, the angle between the straight and oblique connecting rods is denoted as β, and the angle between the straight cell wall and the reinforcing rib is denoted as δ. By varying the length, relative spatial density, and angles α, β, and δ of the straight and oblique cell walls, the impact resistance, elastic modulus, and strength of the honeycomb multi-cell structure can be adjusted.

[0078] In order to verify the energy absorption effect of the honeycomb multi-cell structure composed of various concave single-cell energy absorption structures provided by the embodiments of the present invention, Examples 1-3 were constructed for experimental verification.

[0079] Example 1:

[0080] like Figure 4 The honeycomb multicellular structure shown is composed of Figure 1The concave unit cell energy absorption structure shown is arranged and connected in a 10*8 array in space, adopting a strictly symmetrical structure. The first straight cell wall 1 and the second straight cell wall 4 are both 15 mm long, the first oblique cell wall 2, the second oblique cell wall 3, the third oblique cell wall 5, and the fourth oblique cell wall 6 are all 10 mm long, the first straight connecting rod 7 and the second straight connecting rod 8 are both 7.5 mm long, and the angle α is 60°. The out-of-plane thickness is 10 mm, the relative density is 13%, and each cell wall has a rectangular cross-section. To ensure accuracy, the honeycomb multi-cell structure is divided into a shell unit grid with a unit cell size of 1.5 mm.

[0081] Example 2:

[0082] like Figure 5 The honeycomb multicellular structure shown is composed of Figure 2 The concave unit cell energy absorption structure shown is arranged and connected in a 10*8 array in space. With the exception of the first and second reinforcing ribs 9 and 10, the structure is strictly symmetrical in both front-to-back and left-to-right directions. The first and second reinforcing ribs 9 and 10 are symmetrical about the perpendicular midline of the straight cell walls. The first and second straight cell walls 1 and 4 are each 15 mm long, while the first, second, third, and fourth oblique cell walls 2, 3, 5, and 6 are each 10 mm long. The first and second straight connecting rods 7 and 8 are each 7.5 mm long. The angle α is 60°, and the angle δ is 30°. The out-of-plane thickness is 10 mm, the relative density is 13%, and each cell wall has a rectangular cross-section. To ensure accuracy, the honeycomb multi-cell structure is meshed with shell elements with a cell size of 1.5 mm.

[0083] Example 3:

[0084] like Figure 6 The honeycomb multicellular structure shown is composed of Figure 3The concave cell energy absorption structure shown is arranged in a 10*8 array in space. With the exception of the first and second oblique connecting rods 11, 12, and the first and second reinforcing ribs 9 and 10, the structure is strictly symmetrical in terms of front-to-back and left-to-right directions. The first and second oblique connecting rods 11, 12 are symmetrical about the perpendicular midline of the straight cell walls, while the first and second reinforcing ribs 9 and 10 are also symmetrical about the perpendicular midline of the straight cell walls. The first and second straight cell walls 1, 4 are both 15 mm long, the first, second, third, and fourth oblique cell walls 2, 3, 5, and 6 are all 10 mm long, and the first and second straight connecting rods 7, 8 are both 7.5 mm long. The angle α is 60°, and the angles β and δ are both 30°. The out-of-plane thickness is 10 mm, the relative density is 13%, and each cell wall has a rectangular cross-section. To ensure accuracy, the multicellular structures of the honeycomb multicellular structure are divided into shell unit grids with a unit size of 1.5 mm.

[0085] To ensure the same relative density, the unit thicknesses of the honeycomb multi-cellular structures in Examples 1-3 are set to 0.63 mm, 0.52 mm, and 0.42 mm, respectively.

[0086] The honeycomb multi-cellular structures in Examples 1-3 were subjected to the same impact loading speed (2.8 m / s) Figure 4-6 The impact test was conducted in the direction shown to study the deformation mode under quasi-static compression conditions. The finite element calculation parameter settings such as impact loading speed, boundary conditions, and number of grids used in the three embodiments are the same.

[0087] Figure 7-Figure 9 This is a deformation diagram of the honeycomb multicellular structure in Example 1 during a planar impact. As can be seen from the diagram, the cell walls of the concave hexagonal structure rotate around their endpoints, forming plastic hinges. This exhibits a negative Poisson's ratio effect, but the deformation mode is relatively unstable.

[0088] Figure 10-12 This is the deformation diagram of the plane impact process of the honeycomb multi-cellular structure in Example 2. It can be seen that the deformation process is divided into two stages. Figure 10 The static state is crushed to Figure 11 The polyhedral structure shown in Figure 11 The multicellular structure in the Figure 12state. Since the two reinforcing ribs (DG, CG) added to the concave hexagon of the honeycomb multicellular structure in Example 2 form a stable isosceles triangle structure with the straight cell wall DC, the triangular structure is stronger than the concave hexagonal structure during the crushing process. Therefore, during the crushing process, the concave hexagonal structure deforms first, followed by the crushing of the triangular structure. In addition, since the plastic hinges of the honeycomb multicellular structure in Example 2 are significantly more than those of the simple concave hexagonal structure in Example 1, the energy absorbed during the crushing process of the multicellular structure is much higher than that absorbed by the corresponding honeycomb multicellular structure in Example 1.

[0089] Figure 13-15 This is the deformation diagram of the plane impact process of the honeycomb multi-cellular structure in Example 3. It can be seen that the deformation process is divided into two stages. Figure 13 The static state is crushed to Figure 14 The quadrilateral polyhedral structure shown in Figure 14 The quadrilateral polyhedral structure in the Figure 15 state. Since the two reinforcing ribs (DG, CG) added to the concave hexagon of the honeycomb multicellular structure in Example 3 form a stable isosceles triangle structure with the straight cell wall DC, adjacent single-cell structures also form stable isosceles triangle structures in the same way. During the crushing process, the triangular structure has higher strength than the concave hexagonal structure. Therefore, during crushing, the concave hexagonal structure deforms first, followed by the triangular structure. Since the plastic hinges of the honeycomb multicellular structure in Example 3 are significantly more than those of the simple concave hexagonal structure in Example 1 and the single-cell structure with a triangular structure in Example 2, the energy absorbed during the crushing of the quadrilateral multicellular is much higher than the energy absorbed by the corresponding honeycomb multicellular structures in Examples 1 and 2.

[0090] Figure 16 The equivalent stress-strain curves of the honeycomb multi-cellular structures of Examples 1-3 above during a planar impact are shown. It can be clearly seen that the energy absorption effect of the honeycomb structure of Example 3 is higher than that of the honeycomb structure of Example 2, and the energy absorption effect of the honeycomb structure of Example 2 is higher than that of the honeycomb structure of Example 1.

[0091] The present invention also correspondingly protects a vehicle, wherein the beam skeleton structure of the vehicle is filled with the honeycomb multi-cellular structure provided by the embodiment of the present invention.

[0092] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention.

[0093] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "comprise", "include", "contain" and "have" are inclusive and therefore specify the presence of stated features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the specific order described or illustrated, unless the order of execution is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0094] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0095] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A concave unit cell energy absorption structure, characterized in that: include: The concave hexagonal structure comprises a first straight cell wall (1), a first oblique cell wall (2), a second oblique cell wall (3), a second straight cell wall (4), a third oblique cell wall (5) and a fourth oblique cell wall (6) connected end to end in sequence, wherein the first straight cell wall (1) and the second straight cell wall (4) are parallel, of equal length and arranged opposite each other, the first oblique cell wall (2) and the second oblique cell wall (3) intersect at a first inflection point and fold inwardly toward the interior of the concave hexagonal structure, and the third oblique cell wall (5) and the fourth oblique cell wall (6) intersect at a second inflection point and fold inwardly toward the interior of the concave hexagonal structure; A first straight connecting rod (7) and a second straight connecting rod (8) are both located outside the concave hexagonal structure and are parallel to the first straight cell wall (1); the first straight connecting rod (7) is connected to the first inner inflection point, and the second straight connecting rod (8) is connected to the second inner inflection point; A first reinforcing rib (9) and a second reinforcing rib (10), wherein the first end of the first reinforcing rib (9) and the first end of the second reinforcing rib (10) intersect inside the concave hexagonal structure to form a third inner inflection point, and the second end of the first reinforcing rib (9) and the second end of the second reinforcing rib (10) are respectively connected to the two ends of the second straight cell wall (4).

2. The concave unit cell energy absorption structure according to claim 1, characterized in that: The concave unit cell energy absorption structure is symmetrically arranged about the perpendicular midline of the first straight cell wall (1), and the concave hexagonal structure is symmetrically arranged about the line connecting the first inner inflection point and the second inner inflection point.

3. The concave unit cell energy absorption structure according to claim 2, characterized in that: The lengths of the first straight connecting rod (7) and the second straight connecting rod (8) are both half the length of the second straight cell wall (4).

4. The concave unit cell energy absorption structure according to claim 2, characterized in that: Also includes: a first oblique connecting rod (11), one end of which is connected to the first inner inflection point and is located between the first straight connecting rod (7) and the second oblique cell wall (3); A second oblique connecting rod (12) has one end connected to the second inner inflection point and is located between the second straight connecting rod (8) and the third oblique cell wall (5).

5. The concave unit cell energy absorption structure according to claim 4, characterized in that: The projection of the first oblique connecting rod (11) on the first straight connecting rod (7) is equal in length to the first straight connecting rod (7), and the projection of the second oblique connecting rod (12) on the second straight connecting rod (8) is equal in length to the second straight connecting rod (8).

6. The concave unit cell energy absorption structure according to claim 4, characterized in that: The first oblique connecting rod (11) is parallel to the first reinforcing rib (9); and the second oblique connecting rod (12) is parallel to the second reinforcing rib (10).

7. The concave unit cell energy absorption structure according to any one of claims 1 to 6, characterized in that: Each component structure of the concave unit cell energy absorption structure is a rod, and the cross-sectional shape of the rod is circular, rectangular or triangular.

8. The concave unit cell energy absorption structure according to any one of claims 1 to 6, characterized in that: There are two concave unit cell energy absorbing structures and they are arranged perpendicular to each other. The line connecting the first inner inflection point and the second inner inflection point of the two concave unit cell energy absorbing structures completely coincides.

9. A honeycomb multicellular structure, characterized in that: The concave unit cell energy absorption structure according to any one of claims 1 to 8 is arranged and connected in an array in space; In each row, the second straight cell wall (4) in one of the concave unit cell energy absorbing structures is shared with the first straight cell wall (1) in the adjacent concave unit cell energy absorbing structure; In each column, the free end of the first straight connecting rod (7) in one of the concave unit cell energy absorbing structures is connected to the free end of the second straight connecting rod (8) in the adjacent concave unit cell energy absorbing structure.

10. The honeycomb multi-cellular structure according to claim 9, characterized in that: The concave single cell energy absorption structure further comprises a first oblique connecting rod (11) and a second oblique connecting rod (12), one end of the first oblique connecting rod (11) is connected to the first inner inflection point and is located between the first straight connecting rod (7) and the second oblique cell wall (3), and one end of the second oblique connecting rod (12) is connected to the second inner inflection point and is located between the second straight connecting rod (8) and the third oblique cell wall (5); In each column, the free end of the first oblique connecting rod (11) in one of the concave unit cell energy absorbing structures is connected to the free end of the second oblique connecting rod (12) in the adjacent concave unit cell energy absorbing structure.

11. A vehicle, characterized in that: The beam skeleton structure of the vehicle is filled with the honeycomb multi-cellular structure as claimed in claim 9 or 10.

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