Wing-shaped multi-cambered-surface hollow cross-shaped honeycomb structure

Abstract

The invention provides a wing-shaped multi-cambered-surface hollowed-out cross-shaped honeycomb structure which comprises a plurality of cambered surfaces with the same angle, external tenons and internal mortises are arranged on the cambered surfaces at a certain distance, and every two cambered surfaces are connected through a straight edge, so that the closed structure is formed through end-to-end connection. According to the wing-shaped multi-cambered-surface hollowed-out cross-shaped honeycomb structure, the structure has a secondary deformation mechanism in the compression process by adopting a method of replacing a straight surface with a curved surface, so that the energy absorption effect of the structure is improved. On the premise that the structural strength is guaranteed, the load of the whole structure is reduced, and the light-weight design is superior.

Description

Technical Field

[0001] The present invention relates to the field of bionics, and specifically is a wing-shaped multi-arc hollow cross honeycomb structure. Background Art

[0002] As an emerging discipline, bionics has been widely used in many engineering fields. In nature, the wings of bats are curved. This curved structure can use its own curves to resist external forces, achieving lightweight while ensuring strength. The tubular thin-walled structure has a unique geometric design. This structure can absorb and disperse the energy caused by the impact through its own deformation, reduce the damage caused by the impact, and significantly improve the impact resistance and energy absorption capacity of the structure. This excellent performance enables it to be widely used in the fields of automobiles, ships, aerospace, etc.

[0003] So far, various styles of tubular thin-walled structures have been designed, including circular thin-walled structures, square thin-walled structures, conical thin-walled structures, etc. Among them, compared with other types of structures, the circular tubular thin-walled structure exhibits effective energy absorption capacity. However, due to its extremely low friction resistance, the traditional circular tubular thin-walled structure is prone to lateral splashing under impact loads, which affects the energy absorption efficiency and requires additional constraints to prevent splashing. Therefore, improving the deformation stability and energy absorption capacity of thin-walled structures while simplifying the process is a technical problem that needs to be solved urgently. Summary of the invention

[0004] In order to solve the current technical problems, the main purpose of the present invention is to provide a wing-shaped multi-arc hollow cross honeycomb structure, which has better deformation stability and energy absorption capacity than the traditional circular tubular thin-walled structure.

[0005] In order to realize the above-mentioned technical features, the purpose of the present invention is achieved as follows: a wing-shaped multi-arc hollow cross honeycomb structure, comprising a plurality of wing-shaped multi-arc hollow cross cells, each of which is arranged in sequence to form a wing-shaped multi-arc hollow cross honeycomb structure, wherein the cross section of the cell is composed of two groups of inwardly concave arc surfaces arranged symmetrically along the transverse direction, a group of outwardly convex arc surfaces arranged symmetrically along the transverse direction, straight edges connecting the inwardly concave arc surfaces and the outwardly convex arc surfaces, and outwardly convex arc surfaces arranged symmetrically along the longitudinal direction on both sides; one pair of inwardly concave arc surfaces, a pair of outwardly convex arc surfaces and a pair of outwardly convex arc surfaces on the same side in the longitudinal direction are respectively provided with inwardly concave and outwardly convex arc tenons and arc tenon grooves; one of the arc surfaces of another pair of inwardly concave arc surfaces on the same side in the longitudinal direction is provided with an arc tenon; the wing-shaped multi-arc hollow cross cell is a structure in which a certain wall thickness is formed by vertically stretching the cross section along the cross section.

[0006] Preferably, the inwardly concave arc surface, the outwardly convex arc surface, and the outwardly protruding arc surfaces on both sides of the wing-shaped multi-arc hollowed-out cross single cell are all arc surfaces with an angle of θ and equal lengths.

[0007] Preferably, the wing-shaped multi-arc hollowed-out cross honeycomb structure is assembled by interlocking multiple wing-shaped multi-arc hollowed-out cross single cells through circular arc tenons and circular arc mortises.

[0008] Preferably, the height of the wing-shaped multi-arc hollowed-out cross single cell is h , the wall thickness is t , the radius of the circle to which the inwardly concave arc surface, the outwardly convex arc surface, and the outwardly protruding arc surface belong is r 1, the radius of the circular arc tenon and the circular arc mortise is r 2, and the length of the straight edge is d .

[0009] Preferably, for the circular arc tenon and the circular arc mortise provided on the arc surface, the distance from the center of the circle to the arc surface is l .

[0010] Preferably, the circular arc tenons on the transverse arc surface in the wing-shaped multi-arc hollowed-out cross single cell are symmetric about the center point and satisfy the dimensional relationship: r 2 = 0.25 r 1; In the formula: r 1 is the radius of the circle to which the arc surface belongs; r 2 is the radius of the circle to which the circular arc tenon and the circular arc mortise belong.

[0011] Preferably, the center of the circular arc mortise on the arc surface in the wing-shaped multi-arc hollowed-out cross single cell is located at a position l above the arc surface and satisfies the dimensional relationship: l = 0.25 r 2.

[0012] Preferably, the d = 2.5 r 2.

[0013] The present invention has the following beneficial effects: The multi-arc cross structure of the present invention can enhance the overall energy absorption capacity of the structure. When external pressure is received, the curved edges gradually fold and buckle, and the symmetric parts above and below the curved edges change from curved to straight and then fit together, playing a role in bearing part of the energy. Then the interior deforms into a structure approximately in the shape of a rectangle. At this time, the curved edges of the arcs in the longitudinal direction closely adhere to form the sides of the rectangle, providing a new support for the structure and then entering the second deformation stage. This progressive and multi-stage energy dissipation mechanism by means of surface buckling can effectively improve the energy absorption efficiency. At the same time, the hollowed-out design takes into account both lightweight and structural stiffness, and has the comprehensive performance advantages of strong anti-overload capacity, high energy absorption efficiency and weight optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the drawings and embodiments.

[0015] Figure 1 Isometric view of the wing-shaped multi-arc hollow cross honeycomb unit cell of the present invention.

[0016] Figure 2 Front view of the wing-shaped multi-arc hollow cross honeycomb unit cell of the present invention.

[0017] Figure 3 Isometric view of the wing-shaped multi-arc hollow cross honeycomb structure of the present invention.

[0018] Figure 4 Front view of the wing-shaped multi-arc hollow cross honeycomb structure of the present invention.

[0019] Figure 5 Reaction force-strain curve diagrams of the wing-shaped multi-arc hollow cross honeycomb structure of the present invention and the traditional dumbbell-shaped structure under quasi-static compression.

[0020] Figure 6 Specific energy absorption-strain curve diagrams of the wing-shaped multi-arc hollow cross honeycomb structure of the present invention and the traditional dumbbell-shaped structure under quasi-static compression.

[0021] In the figures: inner concave arc surface 1, outward convex arc surface 2, outward protruding arc surface 3, arc tenon 4 and arc mortise 5, straight edge 6. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The embodiments of the present invention will be further described below in conjunction with the drawings.

[0023] Example 1: See Figure 1-4, A wing-shaped multi-arc hollow cross honeycomb structure, including multiple wing-shaped multi-arc hollow cross single cells, and each single cell is arranged in sequence to form the wing-shaped multi-arc hollow cross honeycomb structure. The cross-section of the single cell is composed of two groups of inwardly concave arc surfaces 1 symmetrically arranged along the transverse direction, one group of outwardly convex arc surfaces 2 symmetrically arranged along the transverse direction, straight edges 6 connecting the inwardly concave arc surfaces 1 and the outwardly convex arc surfaces 2, and outwardly protruding arc surfaces 3 symmetrically arranged along the longitudinal direction on both sides, thus forming a closed cross-section connected end to end; on one pair of inwardly concave arc surfaces 1, paired outwardly convex arc surfaces 2, and paired outwardly protruding arc surfaces 3 on the same side along the longitudinal direction, inwardly concave and outwardly convex circular arc tenons 4 and circular arc mortises 5 are respectively provided; on one of the arc surfaces of the other pair of inwardly concave arc surfaces 1 on the same side along the longitudinal direction, a circular arc tenon 4 is provided; the wing-shaped multi-arc hollow cross single cell is a structure formed by stretching the cross-section along the vertical direction of the cross-section to form a certain wall thickness. By adopting the above structure, based on the traditional dumbbell-shaped thin-wall structure and combining the bionic idea of the bat's shape, using the connection of multi-arc surfaces, and setting tenons and mortises at the same time, the structure can absorb more energy than the traditional structure when being impacted and obtain better mechanical properties.

[0024] Further, a circular arc tenon 4 and a circular arc mortise 5 are respectively provided on the outer outwardly convex arc surface 2 and the outwardly protruding arc surface 3. However, differently, on the two groups of inwardly concave arc surfaces 1 on the inner side, only three arc surfaces are provided with two circular arc tenons 4 and one circular arc mortise 5.

[0025] Further, the wing-shaped multi-arc hollow cross honeycomb structure is connected up and down by the outer outwardly convex arc surface 2, the inwardly concave arc surface 1, and the circular arc tenon 4 and the circular arc mortise 5 above of the wing-shaped multi-arc hollow cross single cell, so that the straight edges 6 are fitted together; on the left and right, it is directly connected by the outer circular arc tenon 4 and one circular arc mortise 5. By adopting the above connection structure, the effective connection of a single wing-shaped multi-arc hollow cross honeycomb single cell can be realized.

[0026] Further, the cross-section shape of the wing-shaped multi-arc hollow cross honeycomb structure is cross-shaped. Through the hollowing process and the design of increasing curves as much as possible, while ensuring the structural strength, the load of the overall structure is reduced, and it has excellent performance in lightweight design.

[0027] Further, the inwardly concave arc surface 1, the outwardly convex arc surface 2, and the outwardly protruding arc surfaces 3 on the transverse direction of the wing-shaped multi-arc hollow cross single cell are all arc surfaces with an angle of θ and have equal lengths.

[0028] Further, the height of the wing-shaped multi-arc hollow cross single cell is h , the wall thickness is t , and the radii of the circles to which the inwardly concave arc surface 1, the outwardly convex arc surface 2, and the outwardly protruding arc surface 3 belongr 1. The radii of the arc tenons 4 and arc mortises 5 r 2. The length of the straight edge 6 is d .

[0029] Furthermore, for the arc tenons 4 and arc mortises 5 provided on the arc surface, the distance from their centers to the arc surface is l .

[0030] Furthermore, the arc tenons 4 on the transverse arc surfaces in the wing-shaped multi-arc surface hollowed-out cross-shaped single cell are symmetric about the center point and satisfy the dimensional relationship: r 2 = 0.25 r 1; Where: r 1 is the radius of the circle to which the arc surface belongs; r 2 is the radius of the circle to which the arc tenons 4 and arc mortises 5 belong.

[0031] Preferably, the center of the arc mortise 5 on the arc surface in the wing-shaped multi-arc surface hollowed-out cross-shaped single cell is located at a position l above the arc surface and satisfies the dimensional relationship: l = 0.25 r 2.

[0032] Preferably, the d = 2.5 r 2.

[0033] Example 2: To further illustrate the above structure, this embodiment provides the modeling process of the above structure, which is specifically as follows: The wing-shaped multi-arc surface hollowed-out cross honeycomb single cell is evolved by imitating the shape of a bat and combining the traditional dumbbell structure. By the method of changing straight to curved, the number of arc surfaces is increased. First step, draw a sketch of the wing-shaped multi-arc surface hollowed-out cross honeycomb single cell, and take arcs with the same radius and an angle of θ = 90° that bulge outwards in the up-down and left-right directions respectively, and take four arcs with the same radius and an angle of θ =Connect with a 90° arc. Second step, take a straight line perpendicular to the tangents at the two endpoints of the upper and lower arcs, define its length, and connect it to the middle arc. Third step, on the upper and lower symmetric arcs, draw a straight line at the farthest end from the arc, draw it inside the arc above and outside the arc below; perform the above symmetric operation on the left and right symmetric arcs. Fourth step, on the upper right arc in the middle, take a straight line inside it in the same way; on the two arcs below the middle, take a straight line outside it. Fifth step, draw a circle at the other end of the straight line and define the radius. Sixth step, for the circle inside the arc, cut off the inferior arc outside it; for the circle outside the arc, cut off the inferior arc inside it. Seventh step, perform thin-walled stretching to obtain a wing-shaped multi-arc surface hollow cross honeycomb unit cell.

[0034] Example 3: In order to verify the performance of a wing-shaped multi-arc surface hollow cross honeycomb structure in the present invention, corresponding comparative tests are carried out, specifically as Figure 5 , by comparing the crashworthiness of the wing-shaped multi-arc surface hollow cross honeycomb structure and the traditional dumbbell-shaped structure under the same mass, the reaction force-strain curves of the two structures are obtained. From Figure 5 It can be seen that the initial peak force of the traditional dumbbell-shaped structure is 25.7% higher than that of the wing-shaped multi-arc surface hollow cross honeycomb structure.

[0035] Specifically refer to Figure 6 , which is the specific energy absorption-strain comparison diagram of the wing-shaped multi-arc surface hollow cross honeycomb structure and the traditional dumbbell-shaped structure under quasi-static compression. It can be obtained from the figure that the energy absorption level of the wing-shaped multi-arc surface hollow cross honeycomb structure is 32% higher than that of the traditional dumbbell-shaped structure. Compared with other honeycomb structures, this structure has a good energy absorption effect. This is because a secondary support mechanism is introduced in the wing-shaped multi-arc surface hollow cross honeycomb structure during the compression process. When the first compression is completed, the arc surfaces inside the wing-shaped multi-arc surface hollow cross honeycomb structure change from curved to straight and highly coincide, forming an approximately rectangular frame inside, thus entering the secondary deformation stage. This shows that the multi-deformation support mechanism can make the structure have a better energy absorption effect than other structures. The present invention has the following advantages: 1. The secondary deformation mechanism of the present invention can enhance the overall energy absorption effect of the structure. When receiving external pressure, the internal arc surface will change from curved to straight, and then form secondary support to further absorb energy.

[0036] 2. When the compression ratio of the present invention reaches about 60%, a short-term negative Poisson's ratio effect will occur, which is mainly manifested in that when compressing to the lower arc surface, the arc surfaces of the two wings will compress it inward, and then the structure will shrink inside.

Claims

1. A wing-shaped multi-arc surface hollowed-out cross honeycomb structure, characterized in that: It includes multiple wing-shaped multi-arc hollow cross single cells, and each single cell is arranged in sequence to form a wing-shaped multi-arc hollow cross honeycomb structure. The cross-section of the single cell is composed of two groups of inwardly concave arc surfaces (1) symmetrically arranged along the transverse direction, one group of outwardly convex arc surfaces (2) symmetrically arranged along the transverse direction, straight edges (6) connecting the inwardly concave arc surfaces (1) and the outwardly convex arc surfaces (2), and outwardly protruding arc surfaces (3) symmetrically arranged along the longitudinal direction on both sides; arc tenons (4) and arc mortises (5) that are concave inward and convex outward are respectively arranged on one pair of the inwardly concave arc surfaces (1), the paired outwardly convex arc surfaces (2), and the paired outwardly protruding arc surfaces (3) on the same side along the longitudinal direction; an arc tenon (4) is arranged on one of the arc surfaces of the other pair of inwardly concave arc surfaces (1) on the same side along the longitudinal direction; the wing-shaped multi-arc hollow cross single cell is a structure formed by stretching the cross-section along the vertical direction of the cross-section to form a certain wall thickness.

2. The wing-shaped multi-arc surface hollowed-out cross honeycomb structure according to claim 1, wherein: The inward concave arc surface (1), the outward convex arc surface (2) in the transverse direction of the wing-shaped multi-arc hollow cross single cell, and the outer convex arc surfaces (3) on both sides are all arc surfaces with an angle of θ , and they have equal lengths.

3. The wing-shaped multi-arc surface hollow cross honeycomb structure according to claim 1, characterized in that: The described wing-shaped multi-arc hollow cross honeycomb structure is assembled by the mutual engagement of multiple wing-shaped multi-arc hollow cross single cells through arc tenons (4) and arc mortises (5).

4. The wing-shaped multi-arc surface hollow cross honeycomb structure according to claim 1, characterized in that: The height of the wing-shaped multi-arc hollowed-out cross single cell is h , and the wall thickness is t . The radii of the circles to which the inner concave arc surface (1), the outer convex arc surface (2), and the outer protruding arc surface (3) belong are r 1, the radii of the circular tenon (4) and the circular mortise (5) are r 2, and the length of the straight edge (6) is d .

5. The wing-shaped multi-arc surface hollow cross honeycomb structure according to claim 4, characterized in that: The circular arc tenon (4) and circular arc mortise (5) provided on the arc surface, the distance from the center of the circle to the arc surface is l .

6. The wing-shaped multi-arc hollow cross honeycomb structure according to claim 5, characterized in that: The circular arc tenons (4) on the transverse arc surfaces in the wing-shaped multi-arc surface hollowed-out cross single cell are symmetric about the center point and satisfy the dimensional relationship: r 2 = 0.25 r 1; In the formula: r 1 is the radius of the circle to which the arc surface belongs; r 2 is the radius of the circle to which the arc tenon (4) and the arc mortise (5) belong.

7. The wing-shaped multi-arc hollow cross honeycomb structure according to claim 3, characterized in that: The center of the circular arc mortise groove (5) on the arc surface in the wing-shaped multi-arc surface hollowed-out cross unit cell is located at a position on the arc surface l and satisfies the dimensional relationship: l = 0.25 r 2.

8. The wing-shaped multi-arc hollow cross honeycomb structure according to claim 4, characterized in that: The said d = 2.5 r 2.

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