Bionic impact-resistant composite laminate structure, preparation method and skin

Abstract

The invention discloses a bionic impact-resistant composite laminate structure, a preparation method and a skin, and the bionic impact-resistant composite laminate structure comprises an air hole layer which is provided with a plurality of air holes; the cushioning layer is arranged on one side of the air hole layer; the cushioning layer is provided with a plurality of damping holes; the unidirectional fiber spiral layer is arranged on one side, deviating from the air hole layer, of the cushioning layer; the unidirectional fiber spiral layer comprises a plurality of layer plate units, and the arrangement direction of the plurality of layer plate units is parallel to the arrangement direction of the air hole layer, the cushioning layer and the unidirectional fiber spiral layer; and the plurality of laminate units are spirally stacked at a preset rotation angle. The three layered structures of the air hole layer, the cushioning layer and the one-way fiber spiral layer are overlapped, multi-layer dispersion and absorption of impact energy are achieved through mutual combination and synergistic effect of the structures of the different layers, the strength and toughness of the material and the stability of the structure are improved on the whole while buffering and energy absorption are guaranteed, and the service life of the material is prolonged. The structure has the characteristic of high impact resistance, and high stability of the structure can be maintained, so that the probability of fracture under high stress is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of composite laminate structures for skins, and in particular to a bionic impact-resistant composite laminate structure, a preparation method and a skin. Background Art

[0002] With the rapid development of high-end manufacturing industries such as aerospace, rail transit, and intelligent manufacturing, composite materials are increasingly used in key components of high-end equipment such as aircraft, ships, and high-speed rail intelligent trains, which puts higher requirements on the protective performance of key components of existing high-end equipment. As the external covering layer of aircraft, high-speed rail and other equipment, composite skins not only need to withstand various challenges of the external environment, such as hail, chemical corrosion, temperature changes, etc., but also need to effectively resist external impact forces, such as bird strikes, so as to protect equipment from damage and personnel safety. It can be seen that improving the impact resistance of equipment skins is crucial to ensuring the safety and reliability of equipment.

[0003] However, the composite laminate structure used in the skin in the existing technology is prone to breakage under high stress. Therefore, it is urgent to develop a new composite laminate structure with high impact resistance to meet the impact resistance requirements of equipment skins, so that high-end equipment such as aircraft and thrusters can develop in a safer, more reliable and efficient direction.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] The technical problem to be solved by the present application is to provide a bionic impact-resistant composite laminate structure, a preparation method and a skin in response to the above-mentioned defects of the prior art, aiming to improve the strength and toughness of the composite laminate structure to reduce the probability of fracture under high stress.

[0006] The technical solutions adopted by this application to solve the technical problems are as follows:

[0007] A bionic impact-resistant composite laminate structure, comprising:

[0008] a pore layer having a plurality of pores;

[0009] A shock absorbing layer is arranged on one side of the air hole layer; the shock absorbing layer has a plurality of shock absorbing holes;

[0010] A unidirectional fiber spiral layer is arranged on the side of the shock-absorbing layer away from the porous layer; the unidirectional fiber spiral layer includes a plurality of layer plate units, and the arrangement direction of the plurality of layer plate units is parallel to the arrangement direction of the porous layer, the shock-absorbing layer and the unidirectional fiber spiral layer; the plurality of layer plate units are spirally stacked at a preset rotation angle.

[0011] In the bionic impact-resistant composite laminate structure, centers of the air hole layer, the shock-absorbing layer and the unidirectional fiber spiral layer are arranged along a straight line.

[0012] The bionic impact-resistant composite laminate structure, wherein the pore layer comprises:

[0013] A plurality of first-layer straight plates are arranged in sequence along the arrangement direction of the plurality of layer plate units;

[0014] The pore layer plate is arranged between two adjacent first-layer straight plates; the pores are located on the pore layer plate.

[0015] The bionic impact-resistant composite layer structure, wherein the pores on the pore layer are arranged in a sinusoidal structure.

[0016] The bionic impact-resistant composite laminate structure, wherein the first layer of straight plates is a rigid layer of straight plates, and the porous layer plates are lightweight layer plates.

[0017] The bionic impact-resistant composite laminate structure, wherein the shock-absorbing layer comprises:

[0018] A plurality of second-layer straight plates are arranged in sequence along the arrangement direction of the plurality of layer plate units;

[0019] An array shock absorbing unit is arranged between two adjacent straight plates of the second layer;

[0020] The array cushioning unit comprises:

[0021] A plurality of columns are arranged in an array and spaced apart from each other to form the shock absorbing hole between two adjacent columns.

[0022] The bionic impact-resistant composite laminate structure, wherein a circular arc chamfer is provided at the connection between the column and the second straight plate.

[0023] The bionic impact-resistant composite laminate structure, wherein the rotation angle is an exponential rotation angle, a sinusoidal rotation angle or a linear rotation angle.

[0024] A skin comprising the bionic impact-resistant composite laminate structure as described in any one of the above items.

[0025] A method for preparing a bionic impact-resistant composite laminate structure based on any one of the above items comprises the following steps:

[0026] Inputting the three-dimensional model of the bionic impact-resistant composite laminate structure in advance on the 3D printer, and presetting the materials of the pore layer, the shock-absorbing layer and the unidirectional fiber spiral layer respectively;

[0027] Replace the printing material of the 3D printer and print layer by layer through the 3D printer.

[0028] Beneficial effect: The bionic impact-resistant composite laminate structure described in the present application adopts the superposition of three layered structures, namely the porous layer, the shock-absorbing layer and the unidirectional fiber spiral layer, and realizes the excellent performance of structural integration through the mutual combination and synergistic effect between different layer structures, delays the expansion of cracks on the surface of the device, and realizes multi-level dispersed absorption of impact energy. While ensuring buffering and energy absorption, the strength and toughness of the material and the stability of the structure are improved as a whole, so that the bionic impact-resistant composite laminate structure has high impact resistance and can maintain high stability of the structure, thereby reducing the probability of fracture under high stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is an electron microscope image of the structure of the pistol shrimp's large claws;

[0030] Figure 2 It is a schematic diagram of the overall structure of the bionic impact-resistant composite laminate structure described in the present application;

[0031] Figure 3 It is a schematic diagram of a partial decomposition structure of the bionic impact-resistant composite laminate structure described in the present application;

[0032] Figure 4 is a schematic diagram of the structure of the unidirectional fiber spiral layer described in the present application;

[0033] Figure 5 is a schematic diagram of the structure of the layer plate unit described in this application;

[0034] Figure 6 It is a schematic diagram of the total deformation of the bionic impact-resistant composite laminate structure described in the present application after being subjected to force;

[0035] Figure 7 It is an equivalent stress diagram of the bionic impact-resistant composite laminate structure described in the present application after being subjected to stress;

[0036] Figure 8 It is a flow chart of the method for preparing the bionic impact-resistant composite laminate structure described in the present application. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and effect of the present application clearer and more specific, the present application is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific examples described here are only used to explain the present application and are not used to limit the present application.

[0038] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be an intermediate element. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0039] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with those in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as here.

[0040] The present application provides a bionic impact-resistant composite laminate structure, such as Figure 2 As shown, the bionic impact-resistant composite laminate structure includes a porous layer 1, a shock-absorbing layer 2 and a unidirectional fiber spiral layer 3; the porous layer 1 has a plurality of pores 101; the shock-absorbing layer 2 is arranged on one side of the porous layer 1, and the shock-absorbing layer 2 has a plurality of shock-absorbing holes 201; the unidirectional fiber spiral layer 3 is arranged on the side of the shock-absorbing layer 2 away from the porous layer 1; the unidirectional fiber spiral layer 3 includes a plurality of layer plate units 31, and the arrangement direction of the plurality of layer plate units 31 is parallel to the arrangement direction of the porous layer 1, the shock-absorbing layer 2 and the unidirectional fiber spiral layer 3; the plurality of layer plate units 31 are spirally stacked at a preset rotation angle.

[0041] Specifically, the pores 101 provide a certain space for material deformation, so that the material has a certain buffer space. When impacted, the material can undergo slight elastic and plastic deformation. Such a design can prevent the material from brittle fracture under strong impact, improve the ductility of the material, and help absorb the rebound effect after a large impact force. The shock-absorbing holes 201 can force the impact energy to be transmitted in a more complex path; when the energy propagates between the holes, it is repeatedly reflected and scattered, so that the energy is gradually dissipated, reducing the accumulation of local energy and avoiding damage to the structure caused by excessive force in a single direction; at the same time, in complex mechanical structures, frequent impacts and vibrations can easily cause resonance, leading to fatigue damage to the structure. By providing shock-absorbing holes 201 in the shock-absorbing layer 2, the natural frequency of the structure can be adjusted to avoid the frequency range of external vibration sources, thereby preventing the occurrence of resonance. The spiral stacking design of the multiple layer plate units 31 adopts a structure that imitates the large claws of pistol shrimp (such as Figure 1 The spiral arrangement of the bionic impact-resistant composite laminate structure is more isotropic; when subjected to external force, the cracks generated in the material will twist as the fiber direction changes, thereby improving the impact resistance.

[0042] When the bionic impact-resistant composite laminate structure is combined with other structures to form a skin, the porous layer 1 is arranged outward, the shock-absorbing layer 2 is located on the inner side of the porous layer 1, and the unidirectional fiber spiral layer 3 is located on the inner side of the shock-absorbing layer 2. Then, when the skin is impacted by an external force, the porous layer 1 in the bionic impact-resistant composite laminate structure is first subjected to force, and the pores 101 can effectively absorb and dissipate the external impact load; under the action of the impact force, the porous layer 1 will undergo local deformation, and through this microscopic structural deformation, part of the impact energy is converted into internal energy, thereby reducing the energy transmitted to the interior and effectively reducing the degree of damage to the material under the impact load; after the shock-absorbing layer 2 receives the impact force transmitted by the porous layer 1, the impact loads from different directions can be evenly transmitted to the unidirectional fiber spiral layer 3 structure, avoiding the impact load direction disorder from affecting the lower structure; and when the unidirectional fiber spiral layer 3 is subjected to an external force, the cracks generated in the material will twist as the fiber direction changes, thereby improving the impact resistance.

[0043] Therefore, the bionic impact-resistant composite laminate structure described in the present application adopts the superposition of three layered structures, namely the porous layer 1, the shock-absorbing layer 2 and the unidirectional fiber spiral layer 3, and realizes the excellent performance of structural integration through the mutual combination and synergistic effect between different layer structures, delays the expansion of cracks on the surface of the device, and realizes multi-level dispersed absorption of impact energy. While ensuring buffering and energy absorption, the strength and toughness of the material and the stability of the structure are improved as a whole, so that the bionic impact-resistant composite laminate structure has high impact resistance and can maintain high stability of the structure, thereby reducing the probability of fracture under high stress.

[0044] In one embodiment of the present application, the centers of the porous layer 1, the shock absorbing layer 2 and the unidirectional fiber spiral layer 3 are arranged along a straight line to ensure that the material has optimal mechanical properties and structural stability when facing impact.

[0045] Specifically, if the centers of these three are not on the same straight line, the impact force may produce complex mechanical coupling effects inside the structure, causing stress concentration or offset, thereby increasing the risk of crack generation and expansion; it may even produce an eccentricity effect, resulting in asymmetric stress distribution inside the material, thereby reducing the impact resistance of the structure.

[0046] Therefore, in this embodiment, arranging the centers of the three along a straight line can ensure that the external impact force can be more evenly distributed in various areas during the transmission process inside the material; this arrangement allows the impact force to be transmitted along a unified path, thereby effectively dispersing the impact force and reducing local stress concentration; and, arranging the centers of the three along a straight line can effectively avoid the eccentricity effect and ensure that the material exhibits the best mechanical properties when impacted.

[0047] At the same time, in multi-material 3D printing, the centers are arranged along the same straight line so that each layer of the structure can be efficiently printed layer by layer according to the predetermined path. This not only improves manufacturing efficiency, but also ensures the close connection between the layers, further enhancing the integrity of the material.

[0048] like Figure 3 As shown, the porous layer 1 includes multiple first-layer straight plates 11 and multiple porous layer plates 12; the multiple first-layer straight plates 11 are arranged in sequence along the arrangement direction of the multiple layer plate units 31; the porous layer plate 12 is arranged between two adjacent first-layer straight plates 11; and the pores 101 are located on the porous layer plate 12.

[0049] A porous layer plate 12 is arranged between each two adjacent first-layer straight plates 11, and each of the porous layer plates 12 is provided with a plurality of pores 101. The structural design of the pores 101 in the present application is not just a simple "punching", but through the reasonable arrangement of the pores 101, the material exhibits higher bending stiffness and torsional stiffness on a macro scale. The edge effect of the pores 101 increases the surface area of ​​the material, so that it can better disperse external forces and improve the overall mechanical properties; and by setting reasonable pores 101, the mechanical properties of the material can be made more uniform in multiple directions. In composite materials, anisotropy is a common problem, and the design of the pore 101 structure can offset this unevenness to a certain extent, so that the material has a more balanced impact resistance in all directions.

[0050] In one embodiment of the present application, the pores 101 on the porous layer plate 12 are arranged in a sinusoidal structure. The pores 101 arranged in a sinusoidal structure are a pore structure with a periodic wave shape, a wavy geometric structure, which is characterized by the formation of periodic and continuous wave fluctuations on the surface or inside the material. This structure is usually composed of a series of smooth curves, similar to the sine wave curve in mathematics, showing regular ups and downs in space; these pores 101 are arranged in a sine wave-like curve so that the material forms uniform wave-shaped fluctuations in the longitudinal or transverse direction; and the height and spacing (wavelength) of each crest and trough of the sinusoidal structure are relatively consistent, presenting a regular wave pattern. The pores 101 with a sinusoidal structure not only provide the material with buffering and energy absorption characteristics, but also can effectively disperse stress, reduce stress concentration, and increase the surface area of ​​the material, thereby improving the overall bending stiffness and torsional stiffness.

[0051] The sinusoidal structure arrangement of the pores 101 on the porous layer plate 12 enables the material to better absorb energy and disperse stress when subjected to external force impact; when the material is subjected to external force, the porous layer plate 12 can distribute the stress to a larger area; at the same time, the mechanical properties and stability of the material are improved through changes in the waveform structure.

[0052] Therefore, the present application adopts a sinusoidal structure of the pores 101 rather than a simple circular pore 101 because the sinusoidal structure performs better in absorbing impact energy, dispersing stress, and improving bending stiffness and torsional stiffness; the sinusoidal structure can better improve the overall impact resistance and structural stability of the material, and is thus more suitable for use in situations requiring high impact resistance, such as key components of high-end equipment such as aerospace, rail transit, etc.

[0053] In one implementation of the present embodiment, a pore 101 is provided at the center of the porous layer plate 12 , and other pores 101 on the porous layer plate 12 are evenly distributed on both sides of the porous layer plate 12 with the pore 101 at the center as the center.

[0054] The pores 101 are arranged extending inward from the surface of the pore layer 12, so that each pore 101 has a corresponding opening; due to the sinusoidal arrangement of the plurality of pores 101, the openings of two adjacent pores 101 face in opposite directions and are arranged in a staggered manner. The bottom of the pore 101 is in an arc shape, the opening of the pore 101 is in a square shape, and the centers of the arc bottoms of all pores 101 on the same pore layer 12 are located on the same straight line, so that the arrangement of the pores 101 in the pore layer 1 can not only absorb impact energy, but also improve the strength of the material. Due to the presence of the pores 101, the surface area of ​​the material and the edge effect enable the structure to provide greater bending stiffness and torsional stiffness, thereby increasing the overall strength of the structure.

[0055] It should be noted that the arrangement of the porous layer 1 in the present application should find the center of gravity according to the arrangement of the stacking areas of the porous layer 1, the shock-absorbing layer 2 and the unidirectional fiber spiral layer 3, and determine the center point of the porous layer 1 according to the center of gravity, and then determine the arrangement of the multiple pores 101 in the porous layer 1.

[0056] In one embodiment of the present application, the first straight plate 11 is a rigid layer straight plate, and is made of ceramic materials, cemented carbide, tool steel, titanium alloy, etc.; the porous layer plate 12 is a lightweight layer plate, and is made of foam materials, foamed aluminum, lightweight concrete, carbon fiber composite materials, aluminum alloy, magnesium alloy, polypropylene, etc.; the unidirectional fiber spiral layer 3 is made of fiber materials, such as nano-carbon tubes, nano-cellulose, and ultra-high molecular weight polyethylene fibers, which can be impact-resistant and lightweight at the same time.

[0057] Specifically, the first straight plate 11 is made of rigid material mainly to provide structural support and initial energy transfer when impacted; this material has high hardness and can effectively disperse energy under impact, is not easily deformed under impact, and can maintain its shape and structural integrity, so that it will not deform or break too much when it first contacts the impact force, and pass it to the next structural layer. The porous layer 12 uses lightweight material with flexibility and pore design to effectively produce a buffering effect inside the material, thereby reducing stress concentration transmitted to deeper levels; the pore 101 design of the lightweight material can also disperse stress, allowing it to absorb more energy in the case of local deformation.

[0058] In one embodiment of the present application, the porous layer 12 is made of polyurethane foam, the first straight plate 11 and the second straight plate 21 are both made of polymethyl methacrylate, and the unidirectional fiber spiral layer 3 is made of ultra-high molecular weight polyethylene fiber; the three-layer structure reasonably disperses the impact energy to achieve impact resistance.

[0059] In another embodiment of the present application, the porous layer plate 12 is made of reinforced polypropylene material, and the first straight plate 11 and the second straight plate 21 are both made of alumina ceramic material; the unidirectional fiber spiral structure material is a carbon fiber reinforced PLA composite material, which reasonably disperses the impact energy through the three-layer structure to play an impact-resistant role.

[0060] like Figure 3 As shown, the shock absorbing layer 2 includes a plurality of second-layer straight plates 21 and an array shock absorbing unit 22; the plurality of second-layer straight plates 21 are arranged in sequence along the arrangement direction of the plurality of layer plate units 31; the array shock absorbing unit 22 is disposed between two adjacent second-layer straight plates 21; the array shock absorbing unit 22 includes a plurality of columns 221, which are arranged in an array and spaced apart from each other to form the shock absorbing hole 201 between two adjacent columns 221.

[0061] In one embodiment of the present application, the material of the column 221 is a fiber material poly(3-hydroxybutyrate) / poly(ε-caprolactone) based material; the column 221 is a cylinder, so that when the impact load acts on the column 221, the energy will be evenly dispersed along the circumference of the column 221, and will not be concentrated at a specific point. In contrast, a square or other shaped column 221 is prone to stress concentration, especially at its corners or edges. This stress concentration can cause local damage to the material or rapid expansion of cracks, thereby weakening the overall impact resistance of the structure. In addition, when a cylindrical column 221 is used, the shape of the column 221 enables it to evenly bear the load when it is subjected to impact forces in all directions without the occurrence of local stress spikes; this uniform stress distribution helps to improve the overall impact resistance of the structure, making it more stable and durable under impact. At the same time, when using 3D printing or other advanced manufacturing technologies, the cylindrical design is easier to manufacture. The cylindrical geometric structure is relatively simple and does not require complex processing paths or precise cutting, which reduces the difficulty and cost of the manufacturing process of the column 221.

[0062] In one embodiment of the present application, the thickness of the column 221 is equal to the thickness of the second straight plate 21, so as to ensure the structural stability of the bionic impact-resistant composite layer, optimize the absorption and dispersion of impact energy, and improve the overall mechanical properties of the area where the shock-absorbing layer 2 is located.

[0063] Specifically, when the second straight plate 21 is impacted, due to the equal height distribution of the second straight plate 21 and the column 221, the second straight plate 21 can evenly transfer the pressure to the column 221 without causing some parts of the structure to lose support or produce uneven stress concentration, and the equal thickness ensures that each column 221 participates in bearing the external load, maintaining the stability and integrity of the overall structure; the mechanical properties of the entire area are more uniform, and the uniform distribution of mechanical properties can ensure that the structure is not easy to deform or lose stability when subjected to force, thereby improving the bending stiffness and compressive strength. The column 221 is consistent in thickness with the second straight plate 21, which means that each column 221 can be evenly stressed along its entire thickness when impacted, so that the energy absorption and buffering effect of each column 221 can be maximized. During the transmission of the impact force, due to the buffering and absorption of multiple columns 221, the energy is decomposed and dissipated layer by layer, thereby improving the overall energy absorption effect of the bionic impact-resistant composite laminate structure.

[0064] In one embodiment of the present application, the length of the second straight plate 21 is 60kμm, the thickness of the second straight plate 21 is 2kμm, and the diameter of the column 221 is 2kμm; wherein k is an adjustment coefficient, and the value range of k is 1≤k≤10, thereby ensuring the lightweight of the overall structure while ensuring the impact resistance of the overall structure.

[0065] A circular chamfer is provided at the connection between the column 221 and the second straight plate 21 to avoid stress concentration; the radius R of the circular chamfer is in the range of 0<R≤5μm.

[0066] The unidirectional fiber helical layer 3 is mainly used to deflect cracks and prevent them from extending too long. When the rotation angle, i.e., the rotation angle, is selected, each adjacent layer in the region of the unidirectional fiber helical layer 3 (i.e., each of the layer plate units 31) should rotate at the corresponding axis position according to the rotation angle.

[0067] like Figure 4 and Figure 5 As shown, the layer plate unit 31 includes a plurality of cylinders 311, the central axes of the plurality of cylinders 311 are parallel to each other and are in the same plane; and every two adjacent cylinders 311 are in contact with each other. The central axis of the unidirectional fiber spiral layer 3 is used as a fixed rotation center. The rotation angle is an exponential rotation angle, a sinusoidal rotation angle or a linear rotation angle.

[0068] Specifically, different rotation angles can be selected according to the type of impact load; an exponential rotation angle is used when the impact load is concentrated and the impact force is large, a sinusoidal rotation angle is used when the impact load is dispersed and the impact force is weak, and a linear rotation angle is used when it is an ordinary impact load. The exponential rotation angle refers to the angle at which adjacent layers rotate when the material is subjected to shear stress in a layered material; the angle can be calculated in the following way: let θ be the exponential rotation angle, γ be the shear strain, and n be the number of material layers. The relationship between the exponential rotation angle θ and the shear strain γ can be expressed as: θ = (1 / n) × ln (1 + γ). As the shear strain increases, the rotation angle between adjacent layers will also increase. The sinusoidal rotation angle means that each layer (i.e., each of the laminate units 31) has its specific elastic modulus and Poisson's ratio. When the structure is subjected to external force, each layer will deform according to its own elastic properties. In general, a linear rotation angle is used, and each layer rotates a small angle relative to the adjacent layer as the linear rotation angle.

[0069] The linear rotation angle has a value range of 6° to 12°; in one embodiment of the present application, the linear rotation angle is 9.1°; the diameter of the cylinder 311 is 2kμm (k is an adjustment coefficient, and the value range of k is 1≤k≤10).

[0070] The layer plate unit 31 is composed of a plurality of the cylinders 311, and its spiral shape prevents the structure from directly transmitting the impact load when it is impacted, but guides the impact force to be gradually dispersed and absorbed along the spiral path; it can provide multi-level damping and buffering effects, so that each layer can absorb part of the energy independently while maintaining the integrity of the structure. This dispersion and absorption process can significantly reduce the damage to the material caused by the impact force and increase the ductility and energy absorption capacity of the material.

[0071] At the same time, unidirectional fibers have anisotropic properties, with higher strength and stiffness in the fiber direction, while the strength perpendicular to the fiber direction is relatively low. Therefore, in the present application, by splicing the cylinders 311 of multiple unidirectional fibers in a spiral structure, it can be ensured that higher tensile and bending resistance can be provided in multiple directions, and any external load can be effectively converted and dispersed, thereby maximizing the use of the anisotropic properties of the material.

[0072] In one embodiment of the present application, the axial length of the cylinder 311 is 300 μm, and the diameter of the cylinder 311 is 2 μm to 20 μm, so as to limit the size of the overall structure; the first straight plate 11 and the second straight plate 21 are both rectangular parallelepiped straight plates with a thickness of 10 μm and a side length of 300 μm. The diameter of the column 221 is 10 μm, the axial length of the column 221 is 10 μm, and the thickness of the pore layer 12 is 15 μm; the radius R of the arc chamfer is 1 μm.

[0073] In one implementation of this embodiment, the diameter of the cylinder 311 is 10 μm, and there are 30 cylinders 311 in the layer plate unit 31 .

[0074] In another embodiment of the present embodiment, the diameter of the cylinder 311 is 5 μm, and there are 30 cylinders 311 in the layer plate unit 31; the first layer of straight plate 11 and the second layer of straight plate 21 are both rectangular parallelepiped straight plates with a thickness of 5 μm and a side length of 150 μm. The diameter of the column 221 is 5 μm, the axial length of the column 221 is 5 μm, the thickness of the pore layer plate 12 is 8 μm; the radius R of the arc chamfer is 0.5 μm.

[0075] In one embodiment of the present application, the thickness of the air hole layer 1 and the shock absorbing layer 2 are both less than the thickness of the unidirectional fiber spiral layer 3, so as to realize the functional division of materials, optimize energy absorption and transmission, enhance structural stability, and achieve a balance between weight and performance. This design enables the bionic impact-resistant composite laminate structure to give full play to the role of each layer when facing an impact, ensuring efficient protection and long-term stability of the overall structure.

[0076] Specifically, as the outermost layer, the main function of the porous layer 1 is to initially absorb and disperse the impact energy. This layer cushions the initial impact force through its light weight and energy absorption characteristics, and transfers part of the energy to the lower layer; since it mainly undertakes the primary energy absorption function, its thickness can be relatively thin. The shock-absorbing layer 2 located on the inner side of the porous layer 1 has the main function of further dispersing and buffering the transmitted impact energy, preventing stress concentration, thereby effectively dispersing the energy in the middle stage, and avoiding the lower layer material from directly bearing excessive stress. As the innermost layer, the unidirectional fiber spiral layer 3 has the main function of providing the final structural support and impact resistance. It not only needs to withstand the remaining impact energy after dispersion by the first two layers, but also ensure the stability and toughness of the entire structure, so that the unidirectional fiber spiral layer 3 requires a larger thickness to ensure its strength and bearing capacity.

[0077] Therefore, in this embodiment, the smaller thickness of the pore layer 1 and the shock absorbing layer 2 is designed relative to the unidirectional fiber spiral layer 3 to gradually absorb and disperse the impact energy layer by layer, thereby allowing each layer to effectively consume energy within its functional range and transfer the remaining energy to the next layer for further processing. As the last load-bearing layer, the unidirectional fiber spiral layer 3 needs to process the remaining energy after the first two layers consume it and ensure that the material will not be damaged due to excessive stress. The larger thickness design ensures that the unidirectional fiber spiral layer 3 can absorb more energy and provide sufficient structural support.

[0078] In one embodiment of the present application, the sum A of the thicknesses of the porous layer 1 and the shock absorbing layer 2 is greater than the thickness B of the unidirectional fiber spiral layer 3, and the ratio between A and B is 3:2.

[0079] Specifically, since the porous layer 1 and the shock-absorbing layer 2 on the outside of the unidirectional fiber spiral layer 3 both require a certain thickness to arrange the pores 101 and the shock-absorbing holes, it is ensured that the pore 101 structure and the shock-absorbing structure provide sufficient protection in energy absorption and buffering, and at the same time the unidirectional fiber spiral structure plays a key role in bearing residual impact and maintaining overall strength and stability. Therefore, in this embodiment, factors such as weight, strength, and impact resistance are comprehensively considered, and the sum of the thicknesses of the porous layer 1 and the shock-absorbing layer 2 is set to the thickness of the unidirectional fiber spiral layer 3 in a ratio of 3:2, so that the bionic impact-resistant composite laminate structure achieves the best balance in impact resistance, structural stability and lightweight.

[0080] In one embodiment of the present application, based on comprehensive considerations of optimizing the overall impact resistance, energy absorption capacity and structural stability of the material, the thickness ratio of the porous layer 1, the shock absorbing layer 2 and the unidirectional fiber spiral layer 3 is 1:1.5:2.

[0081] Specifically, the design of layers of different thicknesses is to achieve a progressive energy absorption mechanism, that is, the outer layer (the porous layer 1) absorbs the impact energy first, then the middle layer (the shock absorbing layer 2) further disperses and absorbs the energy, and finally the inner layer (the unidirectional fiber spiral layer 3) provides the final support and energy absorption. This layered design maximizes the role of each layer in the entire impact process through the change of thickness, avoiding premature failure of a single layer. In addition, by setting different thickness ratios, the stress transfer between the layers can be optimized to ensure that the stress is evenly distributed between the layers. The porous layer 1 has the smallest thickness, and its main function is to disperse the initial impact stress; the shock absorbing layer 2 increases the thickness to balance and further disperse the stress; the unidirectional fiber spiral layer 3 is the thickest, ensuring the overall stability of the structure and the ultimate bearing capacity. This ratio finds the best balance between energy absorption, stress dispersion and structural stability, ensuring that the material can provide excellent protection in high-impact environments while maintaining the characteristics of lightweight.

[0082] In one embodiment of the present application, the number of the layer plate units 31 is no less than 5, ensuring that the unidirectional fiber spiral layer 3 has sufficient thickness and number of layers to effectively cope with the impact, so that the structure can dissipate energy layer by layer during the impact process, thereby reducing the risk of damage, and helping to reduce stress concentration and prevent rapid expansion of cracks during the impact load dispersion process.

[0083] There are no less than 2 air hole layers 12, no less than 2 array shock absorbing units 22, no less than 2 layers of air holes 101, and no less than 2 layers of shock absorbing holes, ensuring that these areas can provide sufficient primary buffering and energy absorption. The two-layer design can ensure that during the initial impact, these areas can first absorb part of the energy and transfer the stress to the lower spiral stacking area for further processing; and the two-layer structure can provide support and buffering in different directions, thereby optimizing the distribution of stress and energy absorption effect.

[0084] At the same time, in the multi-material 3D printing process, the multi-layer structure helps to better control the distribution and performance of the materials. Providing no less than 5 layer plate units 31 and no less than two array cushioning units 22 and the pore layer plate 12 can ensure that each layer of material can be accurately superimposed during the printing process, avoiding printing quality problems or substandard material performance due to insufficient layers.

[0085] In one embodiment of the present application, a groove is provided on one side of the shock absorbing layer 2 close to the unidirectional fiber spiral layer 3, and the unidirectional fiber spiral layer 3 is embedded in the groove, thereby increasing the contact area between the shock absorbing layer 2 and the unidirectional fiber spiral layer 3, thereby avoiding the increase in the difficulty of impact resistance caused by the increase in pressure due to line contact.

[0086] According to experiments, Figure 6 As shown, when the air-hole layer 1 is at the outermost side and subjected to external force, the total deformation of the unidirectional fiber spiral layer 3 is the smallest (the unit of the total deformation is mm) through the transmission of force between the air-hole layer 1 and the shock-absorbing layer 2, and the overall impact resistance of the bionic impact-resistant composite laminate structure is greatly improved. Figure 7 As shown, when the porous layer 1 is at the outermost side and is subjected to external force, the equivalent stress of the unidirectional fiber spiral layer 3 is the smallest (the unit of equivalent stress is MPa) through the transmission of force by the porous layer 1 and the shock-absorbing layer 2, and the overall impact resistance of the bionic impact-resistant composite laminate structure is greatly improved.

[0087] The present application also provides a skin, which includes the bionic impact-resistant composite laminate structure as described in any one of the above items.

[0088] Based on any of the above bionic impact-resistant composite laminate structures, the present application also provides a method for preparing a bionic impact-resistant composite laminate structure, such as Figure 8 As shown, it includes the following steps:

[0089] S100, pre-inputting a three-dimensional model of the bionic impact-resistant composite laminate structure on a 3D printer, and pre-setting the materials of the pore layer, the shock-absorbing layer, and the unidirectional fiber spiral layer respectively;

[0090] S200, replace the printing material of the 3D printer, and print layer by layer through the 3D printer.

[0091] Specifically, after pre-setting the materials of the porous layer 1, the shock-absorbing layer 2 and the unidirectional fiber spiral layer 3 respectively, the unidirectional fiber spiral layer 3 is first prepared; then, the printing material of the 3D printer is replaced with a carbon fiber reinforced PLA composite material, and the unidirectional fiber spiral layer 3 located on the third layer is printed by the 3D printer.

[0092] Then, the printing material of the 3D printer is replaced with an alumina ceramic material, and the second layer of the straight plate 21 structure is printed by the 3D printer; the 3D printer material is then replaced with a poly(3-hydroxybutyrate) / poly(ε-caprolactone) based material to print the array-arranged column 221 structure, and then the printer material is replaced with an alumina ceramic material to print the second layer of the straight plate 21 structure, and then the material is successively replaced with a poly(3-hydroxybutyrate) / poly(ε-caprolactone) based material to print the second layer of the column 221 structure; when the number of layers of the second layer of the straight plate 21 and the column 221 structure reaches the preset standard, the porous layer 1 is ready to be prepared.

[0093] To prepare the porous layer 1, first replace the 3D printer material with alumina ceramic material to print the first straight plate 11 structure, then replace the 3D printer material with nano-reinforced polypropylene material to print the porous layer 12; and so on, when the number of layers of the first straight plate 11 and the porous layer 12 reaches a preset standard, stop printing; finally, the porous layer 1, the shock-absorbing layer 2 and the unidirectional fiber spiral layer 3 are prepared by printing in one piece with a 3D printer.

[0094] The 3D printer adopts a 3D printer of the prior art, and the printing temperature is between 180°C and 250°C, the printing platform temperature is 55°C, the filling density is 35%, the flow rate is 100%, the layer thickness is 0.1mm, the nozzle printing accuracy is 0.4mm, the printing speed is 30mm / s to 100mm / s, the printing speed of the outer wall is 20mm / s to 80mm / s, the printing speed of the inner wall is 30mm / s to 90mm / s, the printing speed of the layer plate unit at the bottom is 40mm / s to 100mm / s, and the printing speed of the first layer of straight plate at the top is 40mm / s to 100mm / s; the printing speed of the support structure is 50mm / s to 150mm / s, the printing speed of the support top plate is 50mm / s to 90mm / s, and the empty driving speed is 100mm / s to 300mm / s.

[0095] In Example 1 of the present invention, the printing temperature of the 3D printer is 210°C, the printing speed is 40mm / s, the printing speed of the outer wall is 50mm / s, the printing speed of the inner wall is 60mm / s, the printing speed of the layer unit at the bottom is 50mm / s, the printing speed of the first layer of straight plate at the top is 50mm / s, the printing speed of the support structure is 80mm / s, the printing speed of the supporting top plate is 60mm / s, the idling speed of the supporting top plate is 150mm / s, and the idling speed when printing the layer unit at the bottom is 60mm / s.

[0096] In Example 2 of the present invention, the printing temperature of the 3D printer is 215°C, the printing speed is 60mm / s, the printing speed of the outer wall is 60mm / s, the printing speed of the inner wall is 70mm / s, the printing speed of the layer unit at the bottom is 70mm / s, the printing speed of the first layer of straight plate at the top is 70mm / s, the printing speed of the support structure is 100mm / s, the printing speed of the supporting top plate is 70mm / s, the idling speed when printing the supporting top plate is 150mm / s; the idling speed when printing the layer unit at the bottom is 60mm / s.

[0097] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0098] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0099] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0100] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0101] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0102] Of course, the description of the above-mentioned embodiments of the present invention is relatively detailed, but it cannot be understood as limiting the scope of protection of the present invention. The present invention may also have many other implementation methods. Based on this implementation method, other implementation methods obtained by ordinary technicians in this field without any creative work all belong to the scope of protection of the present invention. The scope of protection of the present invention shall be based on the attached claims.

Claims

1. A bionic impact-resistant composite laminate structure, characterized in that: It includes: a pore layer having a plurality of pores; A shock absorbing layer is arranged on one side of the pore layer; The shock absorbing layer has a plurality of shock absorbing holes; A unidirectional fiber spiral layer is arranged on the side of the shock-absorbing layer away from the porous layer; the unidirectional fiber spiral layer includes a plurality of layer plate units, and the arrangement direction of the plurality of layer plate units is parallel to the arrangement direction of the porous layer, the shock-absorbing layer and the unidirectional fiber spiral layer; the plurality of layer plate units are spirally stacked at a preset rotation angle.

2. The bionic impact-resistant composite laminate structure according to claim 1, characterized in that: The centers of the air hole layer, the shock absorbing layer and the unidirectional fiber spiral layer are arranged along a straight line.

3. The bionic impact-resistant composite laminate structure according to claim 1, characterized in that: The pore layer comprises: A plurality of first-layer straight plates are arranged in sequence along the arrangement direction of the plurality of layer plate units; The pore layer plate is arranged between two adjacent first-layer straight plates; the pores are located on the pore layer plate.

4. The bionic impact-resistant composite laminate structure according to claim 3 is characterized in that: The pores on the pore layer plate are arranged in a sinusoidal structure.

5. The bionic impact-resistant composite laminate structure according to claim 3 is characterized in that: The first straight board is a rigid straight board, and the air-porous board is a light board.

6. The bionic impact-resistant composite laminate structure according to claim 1, characterized in that: The shock absorbing layer comprises: A plurality of second-layer straight plates are arranged in sequence along the arrangement direction of the plurality of layer plate units; An array shock absorbing unit is arranged between two adjacent straight plates of the second layer; The array cushioning unit comprises: A plurality of columns are arranged in an array and spaced apart from each other to form the shock absorbing hole between two adjacent columns.

7. The bionic impact-resistant composite laminate structure according to claim 6, characterized in that: A circular chamfer is provided at a connection point between the column and the second layer of straight plate.

8. The bionic impact-resistant composite laminate structure according to claim 1, characterized in that: The rotation angle is an exponential rotation angle, a sinusoidal rotation angle or a linear rotation angle.

9. A skin, characterized in that: It comprises the bionic impact-resistant composite laminate structure as claimed in any one of claims 1 to 8.

10. A method for preparing the bionic impact-resistant composite laminate structure according to any one of claims 1 to 8, characterized in that: It includes the following steps: Inputting the three-dimensional model of the bionic impact-resistant composite laminate structure in advance on the 3D printer, and presetting the materials of the pore layer, the shock-absorbing layer and the unidirectional fiber spiral layer respectively; Replace the printing material of the 3D printer and print layer by layer through the 3D printer.

Images