Composite sandwich board based on double-curved-surface paper folding configuration

Abstract

The invention relates to a composite sandwich panel based on a double-curved-surface paper folding structure. The composite sandwich panel comprises a first panel, a second panel and a sandwich panel core layer, the sandwich board core layer comprises a plurality of hyperboloid origami unit cells which are arranged between the first panel and the second panel in an array; each double-curved-surface origami unit cell comprises a base part, a first arc-shaped supporting part and a second arc-shaped supporting part; the first arc-shaped supporting part extends from the base part to the front side and the rear side to form a first curved surface with a protruding middle part and two concave ends; the second arc-shaped supporting part extends to the left and right sides from the base part to form a second curved surface with a concave middle part and two upwarped ends; the cross section contours of the first curved surface and the second curved surface are arc curves; transition arcs are formed at the joint of the base part and the first arc-shaped supporting part and the joint of the base part and the second arc-shaped supporting part. The energy absorption efficiency and bending toughness of the structure are improved, the super-stable platform force response can be kept in the plastic deformation stage, and the excellent bending strength and bending toughness are shown under the bending load.

Description

Technical Field

[0001] The present invention relates to the technical field of novel composite material structures, and specifically to a composite sandwich panel based on a hyperbolic origami configuration. Background Art

[0002] Due to its comprehensive advantages such as lightweight, high specific strength / stiffness, excellent impact resistance, and multi-dimensional controllability, the sandwich structure has become the core solution in the field of modern impact protection engineering.

[0003] The flexible design space and adjustability of the origami structure provide rich possibilities for the realization of lightweight and high-mechanical-performance sandwich structures. Ma et al. studied the compressive energy absorption performance of the Miura origami structure and found that it has characteristics such as high porosity, high energy absorption, and excellent impact resistance, and it is expected to develop an efficient impact protection device based on this configuration. ([1] N Ma, S Han, Q Han, et al. Design and compressive behaviors of the gradient re-entrant origami honeycomb metamaterials. Thin-Walled Structures, 2024, 198:11652). On the other hand, Zhai et al. achieved free control of the positive, zero, and negative stiffness of the structure by designing the curved creases of the curved origami structure, and could regulate the stiffness and mechanical bearing capacity of the structure as needed under uniform loads, thus realizing a metamaterial with multiple functions at the same time. ([2] Zhai Z, Wang Y, Lin K, et al. In situ stiffness manipulation using elegant curved origami. Science advances, 2020, 6(47):eabe2000). The current technological development shows that the origami structure can be used as an excellent buffer energy-absorbing structure for the core material of the sandwich structure.

[0004] There are still the following technical problems in the engineering application of the origami structure in sandwich panels: First, there are still significant challenges in achieving efficient impact protection in low-porosity sandwich panels - the limited sandwich space significantly restricts the deformation freedom of the origami structure, resulting in its inability to effectively dissipate and absorb impact energy through large-scale plastic folding deformation; Second, although the origami-type topological structure realizes the active regulation of stiffness and mechanical response through geometric design, the existing research has not yet broken through the engineering application bottleneck in protective structures, especially the sudden failure modes such as brittle fracture and interface delamination commonly seen in traditional sandwich panels under extreme loadings are difficult to be effectively suppressed. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the object of the present invention is to provide a composite sandwich panel based on a hyperbolic origami configuration, which can maintain a super-stable platform force response during the plastic deformation stage, exhibit excellent flexural strength and flexural toughness under bending loads, and have reliable large deformation tolerance.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A composite sandwich panel based on a hyperbolic origami configuration, comprising a first panel, a second panel and a sandwich panel core layer; The sandwich panel core layer includes a plurality of hyperbolic origami unit cells arranged in an array between the first panel and the second panel; Each hyperbolic origami unit cell includes a base, a first arc-shaped support portion and a second arc-shaped support portion; The first arc-shaped support portion extends from the base to the front and rear sides, and a first curved surface with a middle protrusion and both ends concave is formed along the length direction of the first arc-shaped support portion; the second arc-shaped support portion extends from the base to the left and right sides, and a second curved surface with a middle concave and both ends upturned is formed along the length direction of the second arc-shaped support portion; The cross-sectional profiles of the first curved surface and the second curved surface are both arc-shaped curves; transition arcs are formed at the joints between the base and the first arc-shaped support portion and between the base and the second arc-shaped support portion; The highest point of the first arc-shaped support portion is connected to the first panel, and the lowest point of the second arc-shaped support portion is connected to the second panel; the front and rear adjacent hyperbolic origami unit cells are connected through the first arc-shaped support portion, and the left and right adjacent hyperbolic origami unit cells are connected through the second arc-shaped support portion.

[0007] Further, the outer arcs of the first curved surface and the second curved surface are the same.

[0008] Further, the outer arc of the first curved surface is controlled by a sine function in the x-z plane, and the outer arc of the second curved surface is controlled by a sine function in the y-z plane, and the opening directions of the two outer arcs are opposite.

[0009] Further, the hyperbolic origami unit cell is a saddle-shaped structure.

[0010] Further, the composite sandwich panel is prepared by integrated 3D printing.

[0011] Further, the composite sandwich panel is processed using an aluminum alloy substrate.

[0012] Generally speaking, the present invention has the following advantages: By adopting the hyperbolic origami topology as the core layer of the sandwich panel, the energy absorption efficiency and flexural toughness of the structure are significantly improved. It can maintain a super-stable platform force response in the plastic deformation stage, and exhibit excellent flexural strength and flexural toughness under bending loads, with reliable large deformation tolerance. This is mainly due to the unique deformation mechanism of the hyperbolic origami unit geometric configuration, which realizes uniform stress distribution and avoids the common stress concentration problem in traditional honeycomb structures. At the same time, it breaks through the technical bottleneck that it is difficult to synergistically improve the strength and toughness of traditional sandwich panels. Brief Description of the Drawings

[0013] Figure 1 It is a schematic structural diagram of a composite sandwich panel based on the hyperbolic origami configuration.

[0014] Figure 2 It is a schematic diagram of the force-displacement curve and specific energy absorption curve of the quasi-static compression test.

[0015] Figure 3 It is a schematic diagram of the force-displacement curve and specific energy absorption curve of the three-point bending test in the y-axis direction.

[0016] Figure 4 It is a schematic diagram of the force-displacement curve and specific energy absorption curve of the three-point bending test in the x-axis direction.

[0017] Figure 5 It is a schematic diagram of the hyperbolic origami unit cell.

[0018] Figure 6 It is a schematic diagram of another perspective of the hyperbolic origami unit cell.

[0019] In the figure: 1. First panel; 2. Hyperbolic origami unit cell; 3. Second panel; 4. x-direction crease controlled by sine function; 5. y-direction crease controlled by sine function. Detailed Description of the Preferred Embodiments

[0020] When the prior art conducts the anti-impact design of the energy absorption device, it is difficult to simultaneously achieve a low initial peak force and a stable platform force, and at the same time, the stress concentration phenomenon inside the structure is not fully eliminated. The present invention proposes an effective technical method to solve the above problems.

[0021] The following will further elaborate on the present invention in detail.

[0022] As Figure 1 、 Figure 5 、 Figure 6 shown, a composite sandwich panel based on the hyperbolic origami configuration includes a first panel 1, a second panel 3, and a sandwich panel core layer; The first panel 1 and the second panel 3 are both flat plates; the core layer of the sandwich panel includes a plurality of hyperbolic origami unit cells 2 arranged in an array between the first panel 1 and the second panel 3; Each hyperbolic origami unit cell 2 includes a base, a first arc-shaped support portion, and a second arc-shaped support portion; The first arc-shaped support portion extends from the base to the front and back sides, and a first curved surface with a middle protrusion and concave ends is formed along the length direction of the first arc-shaped support portion; the second arc-shaped support portion extends from the base to the left and right sides, and a second curved surface with a middle concave and upturned ends is formed along the length direction of the second arc-shaped support portion; The cross-sectional profiles of the first curved surface and the second curved surface are both arc-shaped curves; transition arcs are formed at the joints between the base and the first arc-shaped support portion and between the base and the second arc-shaped support portion; The highest point of the first arc-shaped support portion is connected to the first panel 1, and the lowest point of the second arc-shaped support portion is connected to the second panel 3; the adjacent hyperbolic origami unit cells 2 in the front and back are connected by the first arc-shaped support portion, and the adjacent hyperbolic origami unit cells 2 on the left and right are connected by the second arc-shaped support portion.

[0023] Preferably, the outer arcs of the first curved surface and the second curved surface are the same, and their creases are respectively controlled by sine functions with two different opening directions in the x-z plane and in the y-z plane, and the periods and amplitudes of the two sine functions are respectively equal. As Figure 5 、 Figure 6 shows the x-direction crease 4 controlled by the sine function and the y-direction crease 5 controlled by the sine function.

[0024] In this embodiment, the hyperbolic origami unit cell 2 is a saddle-shaped structure.

[0025] According to the designed model diagram, the aluminum alloy base material is processed by additive manufacturing technology, and a composite sandwich panel based on the hyperbolic origami configuration is integrally directly 3D printed.

[0026] Compared with the traditional sandwich panel structure, when the composite sandwich panel of the present invention is invaded by an impact load, a uniform stress distribution will be generated, making it have better and more stable energy absorption efficiency.

[0027] Figure 2Shows the mechanical property test results of a composite sandwich panel designed based on a novel hyperbolic origami configuration, including the force-displacement curve and specific energy absorption-displacement curve under quasi-static loading calculated by finite element. Specific energy absorption means the energy absorption capacity per unit mass. From the force-displacement curve, it can be seen that there is no significant initial peak load during the quasi-static compression process of the composite sandwich panel, and after the core layer structure of the sandwich panel enters the plastic deformation stage, it shows a stable plateau stress response. This typical progressive crushing characteristic indicates that the structure has excellent energy absorption capacity and stable impact protection performance, and its specific energy absorption can reach up to 4.25 J / g. By comparing the stress nephograms, it is found that the hyperbolic origami configuration shows good stress distribution characteristics during compression: on the one hand, the origami units achieve uniform distribution of the stress field through geometric coordinated deformation, effectively avoiding stress concentration; on the other hand, its unique hyperbolic topological structure maintains a stable mechanical response during deformation, which can not only continuously absorb energy through plastic deformation but also shows good structural load-bearing capacity.

[0028] Figure 3 Shows the force-displacement response and energy absorption characteristics of the core layer of the sandwich panel in the three-point bending test in the y-axis direction. Consistent with its quasi-static compression response, the structure shows a progressive energy absorption mode during the three-point bending loading process: neither obvious initial load peak is observed, nor does it show a unique double-platform force response characteristic. This staged load-bearing behavior is due to the energy absorption effect generated by the pores in the core layer and the progressive delamination deformation mechanism gradually activated by the origami units during deformation. It is worth noting that when the bending deformation of the structure reaches three times the plate thickness (6 mm), the core layer still maintains the complete ductile deformation characteristic without fracture failure, fully verifying the excellent bending toughness and structural integrity of this configuration. The synergistic effect of its progressive delamination deformation mode and double-platform mechanical response provides an effective solution for achieving the balance between controllable energy dissipation and structural bending resistance.

[0029] Figure 4 The three-point bending test in the x-axis direction further reveals the anisotropic mechanical properties of the core layer. The results show that this direction exhibits better ultimate bending force, and its value reaches 333.48 N. However, compared with the y-axis direction, its specific energy absorption value drops from 1.87 J / g to 1.73 J / g. Therefore, in this direction, the sandwich panel has better load-bearing performance. This is attributed to the unique topological anisotropy of the hyperbolic origami configuration - the continuous arched arrangement of the x-direction corrugated units effectively improves the bending stiffness of the structure, and at the same time, the progressive delamination buckling mechanism of the origami units ensures a certain amount of energy absorption. At the same time, when the bending deformation reaches 3 times the plate thickness, the core layer still maintains the structural integrity through the coordinated deformation of the hyperbolic origami units. This large deformation tolerance verifies the reliable service potential of this configuration under complex load conditions.

[0030] By adopting the hyperbolic origami topological structure as the core layer of the sandwich panel, the present invention significantly improves the energy absorption efficiency and flexural toughness of the structure. This is mainly due to the unique deformation mechanism of the hyperbolic origami unit geometry configuration, which realizes uniform stress distribution, avoids the common stress concentration problem of traditional honeycomb structures, and at the same time breaks through the technical bottleneck that it is difficult to synergistically improve the strength and toughness of traditional sandwich panels.

[0031] 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 other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A composite sandwich panel based on a hyperbolic origami configuration, characterized in that: It includes a first panel, a second panel and a sandwich panel core layer; The sandwich panel core layer includes a plurality of hyperbolic origami unit cells arranged in an array between the first panel and the second panel; Each hyperbolic origami unit cell includes a base, a first arc-shaped support portion and a second arc-shaped support portion; The first arc-shaped support portion extends from the base to the front and back sides, and a first curved surface with a middle protrusion and concave ends is formed along the length direction of the first arc-shaped support portion; The second arc-shaped support portion extends from the base to the left and right sides, and a second curved surface with a middle concave and upturned ends is formed along the length direction of the second arc-shaped support portion; The cross-sectional profiles of the first curved surface and the second curved surface are both arc curves; transition arcs are formed at the connections between the base and the first arc-shaped support portion and between the base and the second arc-shaped support portion; The highest point of the first arc-shaped support portion is connected to the first panel, and the lowest point of the second arc-shaped support portion is connected to the second panel; the front and rear adjacent hyperbolic origami unit cells are connected by the first arc-shaped support portion, and the left and right adjacent hyperbolic origami unit cells are connected by the second arc-shaped support portion.

2. The composite sandwich panel based on the hyperbolic origami configuration according to claim 1, wherein: The outer arc of the first curved surface is the same as the outer arc of the second curved surface.

3. The composite sandwich panel based on the hyperbolic origami configuration according to claim 2, wherein: The outer arc of the first curved surface is controlled by a sine function in the x-z plane, and the outer arc of the second curved surface is controlled by a sine function in the y-z plane, and the opening directions of the two outer arcs are opposite.

4. A composite sandwich panel based on a hyperbolic origami configuration according to claim 1, characterized in that: The hyperbolic origami unit cell is a saddle-shaped structure.

5. A composite sandwich panel based on a hyperbolic origami configuration according to claim 1, characterized in that: The composite sandwich panel is prepared by integrated 3D printing.

6. The composite sandwich panel based on the hyperbolic origami configuration according to claim 1, characterized in that: The composite sandwich panel is processed with an aluminum alloy substrate.

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