Skin with multiple bionic impact-resistant composite structures

Abstract

The present invention discloses a skin with a multiple biomimetic impact-resistant composite structure, wherein both the outer and inner impact-resistant layers are composed of a carbon fiber reinforced epoxy resin composite woven laminate layer and a plurality of bone-like structural layers; the bone-like structural layer comprises a unidirectional glass fiber corrugated plate, a unidirectional glass fiber support plate, and a plurality of bone-like units; the bone-like units comprise a carbon fiber tube, a filled carbon tube, and an epoxy resin; the carbon fiber tube is designed to imitate the cross-section of the bone structure and the feather shaft, and the carbon tube is filled with a gradient density distribution of carbon tubes inside the carbon fiber tube; the middle energy-absorbing layer is provided with a plurality of through-hole groups distributed in concentric circles, imitating the structure of antler bones, with the through-hole radius of each through-hole group gradually decreasing from the inside to the outside, and the through-holes are divided into separate small spaces by partitions, imitating the structure of cuttlebone. The present invention adopts multiple biomimetic composite materials, so that the skin structure has a higher ability to resist damage, absorb energy, and disperse energy when facing the impact of harsh environments, and has a higher lightness.

Description

Technical Field

[0001] The invention belongs to the field of aerospace technology, and in particular relates to a skin adopting a multiple bionic impact-resistant composite structure. Background Art

[0002] Composite materials have gained widespread application in aerospace due to their superior performance. With advancements in manufacturing technology and increased production capacity, an increasing number of critical aircraft components are being fabricated from composite materials. Composite components offer advantages such as excellent durability, reliability, corrosion resistance, and specific strength. The skin of an airliner is a crucial component. As the outermost layer of the aircraft, it comes into direct contact with the outside world. Its primary function, in addition to bearing and transmitting conventional aerodynamic loads, is to protect the aircraft's interior and passengers from the harsh external environment. The most common problem is impact damage to the aircraft's skin. For example, as an aircraft speeds down a runway preparing for takeoff, scattered gravel and rocks can cause impact damage to the skin. Falling hail can also cause impact damage. Furthermore, collisions with birds or other objects during high-altitude flight can also cause impact damage to the skin. The design of an aircraft's skin must consider various types of impacts that may occur during flight. The impact resistance of an aircraft's aircraft is crucial to ensuring the safety of passengers and crew. Therefore, it is extremely important to design the skin structure of passenger aircraft to enhance its ability to resist impact, improve its ability to absorb and disperse shock, and thus reduce the damage caused by harsh environments. Currently, how to improve the impact resistance of aircraft skin while maintaining lightweight remains a difficult problem. Summary of the Invention

[0003] The purpose of the present invention is to solve the problem that aircraft skin is easily damaged by impact. A composite structure combining a feather shaft cross-section structure, a bone structure, a antler bone structure, and a cuttlebone structure is provided, which is applied to aircraft skin to improve the impact resistance of the aircraft skin.

[0004] The technical solution adopted in the present invention is:

[0005] The present invention adopts a skin with multiple bionic impact-resistant composite structures, including an outer impact-resistant layer, an inner impact-resistant layer and an intermediate energy-absorbing layer. The outer impact-resistant layer and the inner impact-resistant layer are both composed of a carbon fiber reinforced epoxy resin composite material woven laminate and a plurality of bone-like structural layers; the bone-like structural layer includes a unidirectional glass fiber corrugated plate, a unidirectional glass fiber support plate and a plurality of bone-like units arranged side by side; the bone-like unit includes a carbon fiber tube, a filled carbon tube and epoxy resin; the carbon fiber tube is composed of an integrally formed arc surface piece 1, a combined arc surface piece and two arc surface pieces 2; the arc surface piece 1 is directly opposite to the combined arc surface piece, and the two ends of the arc surface piece 1 and the combined arc surface piece are respectively connected by an arc surface piece 2, enclosing a cylinder; The inner wall of the first curved piece is provided with a serrated structure; the combined curved piece is composed of two third curved pieces, the inner wall of which is concave; the carbon fiber tube is provided with a plurality of filled carbon tubes with a density that gradually decreases from the outside to the inside, and epoxy resin is provided in the gaps between the filled carbon tubes and between the filled carbon tubes and the inner wall of the carbon fiber tube; the unidirectional glass fiber corrugated plate is wound between the bone-like units arranged side by side; the unidirectional glass fiber support plate and the unidirectional glass fiber corrugated plate are wound around and bonded to the parts of the outer wall of the combined curved piece; the bone-like structural layers are stacked side by side. In the outer impact-resistant layer, the unidirectional glass fiber corrugated plate of the outermost bone-like structural layer is wound around the parts of the outer wall of the first curved piece and is bonded to the carbon fiber reinforced epoxy resin composite material woven layer; in the inner impact-resistant layer, the unidirectional glass fiber corrugated plate of the innermost bone-like structural layer is wound around the parts of the outer wall of the first curved piece and is bonded to the carbon fiber reinforced epoxy resin composite material woven layer.

[0006] The intermediate energy-absorbing layer is made of thermoplastic resin material and is provided with a plurality of through-hole groups distributed in concentric circles. Each through-hole group is composed of a plurality of through-holes uniformly distributed along the circumference and of equal diameter. From the inside to the outside, the through-hole radius of each through-hole group gradually decreases. A plurality of partitions uniformly distributed along the axial direction of the through-hole are bonded in each through-hole. The two sides of the through-holes in the intermediate energy-absorbing layer are respectively bonded to the unidirectional glass fiber support plate of the outer impact-resistant layer and the carbon fiber reinforced epoxy resin composite material woven layer of the inner impact-resistant layer.

[0007] Preferably, the diameter of the circumscribed circle of the carbon fiber tube is 1mm-2mm, the radius of the arc piece 1 and the arc piece 2 is 2.5mm, and the radius of the arc piece 3 is 1mm-2mm; the width of each sawtooth of the serrated structure is 1.5mm-3mm and the height is 0.4mm-1.3mm.

[0008] Preferably, the carbon fiber reinforced epoxy resin composite material braided laminate layer is formed by spirally stacking a plurality of carbon fiber reinforced epoxy resin composite material braided layers at an angle of 22.5° and forming the layers by hot pressing.

[0009] More preferably, the carbon fiber reinforced epoxy resin composite material braided layer is braided from carbon fiber reinforced epoxy resin composite fiber bundles.

[0010] More preferably, the carbon fiber reinforced epoxy resin composite fiber bundle is formed by winding a plurality of carbon fiber reinforced epoxy resin composite fibers; the carbon fiber reinforced epoxy resin composite fiber is formed by mixing carbon fiber and epoxy resin in a mass ratio of 5:5, and the diameter of the carbon fiber reinforced epoxy resin composite fiber is 7 μm.

[0011] Preferably, the carbon fiber tube is processed by a core mold hot pressing method.

[0012] Preferably, the radius difference of the circumference of each through hole in adjacent through hole groups is 0.1 mm, and the radius difference of the through holes in adjacent through hole groups is 0.1 mm.

[0013] Preferably, the partition is a straight plate with a thickness of 0.3mm-0.6mm, and the spacing between adjacent partitions is 0.5mm-2mm.

[0014] Preferably, the bonding is carried out using epoxy resin adhesive.

[0015] Preferably, the unidirectional glass fiber corrugated plate and the unidirectional glass fiber support plate are respectively replaced by a woven glass fiber corrugated plate and a woven glass fiber support plate with a two-dimensional plain weave, and the side-by-side stacking of each bone-like structure layer is replaced by spiral stacking of each bone-like structure layer at an angle of 7.2°-18°. If the next angle exceeds 180°, a cycle is ended, and after multiple cycles of rotation, the partition is set to a sinusoidal surface with a wavelength of 0.75mm, an amplitude of 0.1mm, a partition thickness of 0.25mm, and a spacing between adjacent partitions of 0.8mm.

[0016] The present invention has the following beneficial effects:

[0017] The outermost impact layer of the present invention primarily resists deformation during impact. The intermediate energy-absorbing layer absorbs impact energy passing through the outer impact layer. The innermost impact layer also resists deformation during impact, serving as the final barrier to protect the aircraft's interior, resisting the impact force resulting from the weakening of the outer impact layer and the intermediate energy-absorbing layer. Furthermore, the present invention utilizes a variety of biomimetic composite materials, ensuring that the skin structure possesses both excellent impact resistance and high lightness, without compromising the aircraft's flight speed.

[0018] 2. The overall structure of the outer and inner impact-resistant layers in this invention is modeled after bone structure, enhancing the impact-resistant deformation resistance of the impacted surface. The carbon fiber tubes serve as the primary load-bearing structure. Their walls mimic the cross-sectional structure of a bird's feather shaft. The combination of an inner serrated structure and outer curved surfaces of varying radii effectively resists impact. The infill carbon tubes are distributed in a gradient density, conserving material while enhancing the impact resistance of the entire bone-like structure.

[0019] 3. The intermediate energy-absorbing layer of the present invention is first designed with multiple concentrically arranged through-hole groups, modeled after the structure of antler bone. The through-hole radius of each through-hole group gradually decreases from the innermost to the outermost. The through-holes of varying sizes absorb energy and disperse the impact force, significantly slowing the spread of impact energy. Furthermore, the intermediate energy-absorbing layer is modeled after the structure of cuttlebone. The through-holes are then separated into individual spaces, further enhancing the intermediate energy-absorbing layer's ability to absorb impact energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention.

[0021] Figure 2 Schematic diagram of the structure of the bone-mimicking structure layer in the present invention.

[0022] Figure 3 Schematic diagram of the structure of the middle energy absorbing layer in the present invention.

[0023] Figure 4 Schematic diagram of the structure of the spiral stacking of the bone-mimicking structure layers in the present invention.

[0024] Figure 5 This is a schematic diagram of the structure of the partition in the present invention in the shape of a sinusoidal surface. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] like Figure 1 As shown, this embodiment adopts a skin with a multiple bionic impact-resistant composite structure, including an outer impact-resistant layer 1, an inner impact-resistant layer 3 and a middle energy-absorbing layer 2.

[0027] like Figure 1 and Figure 2As shown, the outer impact-resistant layer 1 and the inner impact-resistant layer 3 are both composed of a carbon fiber reinforced epoxy resin composite material woven laminate layer and a plurality of bone-like structural layers; the bone-like structural layer includes a unidirectional glass fiber wave plate 101 of a bone-like plate structure, a unidirectional glass fiber support plate 105 of a bone-like plate structure and a plurality of bone-like units arranged side by side; the bone-like unit includes a carbon fiber tube 102, a filled carbon tube 103 and an epoxy resin 104 of a matrix-like structure; the carbon fiber tube 102 is composed of an integrally formed arc surface piece 1, a combined arc surface piece and two arc surface pieces 2; the arc surface piece 1 is directly opposite to the combined arc surface piece, and the two ends of the arc surface piece 1 and the combined arc surface piece are respectively connected by an arc surface piece 2, enclosing The cylindrical surface is formed; the inner wall of the arc surface piece 1 is provided with a serrated structure; the combined arc surface piece is composed of two arc surface pieces 3, and the inner wall of the arc surface piece 3 is a concave surface; the carbon fiber tube 102 is provided with a plurality of filled carbon tubes 103 with a density gradually decreasing from the outside to the inside, and the gaps between the filled carbon tubes 103 and the gaps between the filled carbon tubes 103 and the inner wall of the carbon fiber tube 102 are provided with epoxy resin; the unidirectional glass fiber wave plate is interspersed and wound between the bone-like units arranged side by side; the unidirectional glass fiber support plate 105 and the unidirectional glass fiber wave plate 101 are wound around the parts of the outer wall of the combined arc surface piece and bonded; the bone-like structure layers are stacked side by side (no corners are set). In the outer impact-resistant layer 1, the unidirectional glass fiber corrugated plate 101 of the outermost bone-like structural layer is wound around the outer wall of the curved surface piece, and all parts are laminated and bonded with the carbon fiber reinforced epoxy resin composite material woven layer; in the inner impact-resistant layer 3, the unidirectional glass fiber corrugated plate 101 of the innermost bone-like structural layer is wound around the outer wall of the curved surface piece, and all parts are laminated and bonded with the carbon fiber reinforced epoxy resin composite material woven layer.

[0028] like Figure 1 and Figure 3 As shown, the intermediate energy-absorbing layer 2 is made of a thermoplastic resin material (PEEK) that mimics the structure of antler and cuttlebone. First, it features multiple through-hole groups arranged in concentric circles 202, similar to the structure of antler. Each through-hole group consists of multiple through-holes 201 of equal diameter, evenly distributed along the circumference. From the inside out, the radius of each through-hole group decreases. Similarly to the cuttlebone structure, each through-hole is bonded with multiple partitions 203 evenly distributed along the axial direction of the through-hole, dividing the through-hole into small cylindrical structures. The through-holes in the intermediate energy-absorbing layer 2 are bonded to the unidirectional glass fiber support plate 105 of the outer impact layer 1 and the carbon fiber-reinforced epoxy resin composite woven laminate of the inner impact layer 3, respectively, on either side.

[0029] As a preferred embodiment, the diameter of the circumscribed circle of the carbon fiber tube 102 is 2 mm, the radius of the arcuate piece 1 and the arcuate piece 2 is 2.5 mm, and the radius of the arcuate piece 3 is 1.6 mm; each tooth of the serrated structure has a width of 2 mm and a height of 1 mm.

[0030] As a preferred embodiment, the carbon fiber reinforced epoxy resin composite material braided laminate layer is formed by spirally stacking a plurality of carbon fiber reinforced epoxy resin composite material braided layers at an angle of 22.5° and forming the layers by hot pressing.

[0031] More preferably, the carbon fiber reinforced epoxy resin composite material braided layer is braided from carbon fiber reinforced epoxy resin composite fiber bundles.

[0032] More preferably, the carbon fiber reinforced epoxy resin composite fiber bundle is formed by winding a plurality of carbon fiber reinforced epoxy resin composite fibers; the carbon fiber reinforced epoxy resin composite fiber is formed by mixing carbon fiber and epoxy resin in a mass ratio of 5:5, and the diameter of the carbon fiber reinforced epoxy resin composite fiber is 7 μm.

[0033] As a preferred embodiment, the carbon fiber tube 102 is processed by a core mold hot pressing method, that is, a silicone airbag core mold is used to support the carbon fiber prepreg, and then the carbon fiber tube 102 is formed by hot pressing and curing on the outside.

[0034] As a preferred embodiment, the radius difference between the circumferences of the through holes in adjacent through hole groups is 0.1 mm.

[0035] As a preferred embodiment, the difference in through-hole radius between adjacent through-hole groups is 0.1 mm.

[0036] As a preferred embodiment, the thickness of the partition is 0.5 mm, and the distance between adjacent partitions is 1 mm.

[0037] As a preferred embodiment, epoxy resin is used for bonding.

[0038] As a preferred embodiment, the unidirectional glass fiber wave plate 101 and the unidirectional glass fiber support plate 105 are replaced by a woven glass fiber wave plate and a woven glass fiber support plate with a two-dimensional plain weave, respectively. The side-by-side stacking of the bone-like structural layers is replaced by the spiral stacking of the bone-like structural layers at an angle of 12°. The rotation angle reaches 180° as one cycle, and multiple cycles are rotated, such as Figure 4 As shown, the partition is set to be a sinusoidal surface with a wavelength of 0.75 mm, an amplitude of 0.1 mm, a thickness of 0.25 mm, and a spacing of 0.8 mm between adjacent partitions. Figure 5 shown.

Claims

1. The skin adopts a multi-bionic impact-resistant composite structure, including an outer impact-resistant layer, an inner impact-resistant layer and an intermediate energy-absorbing layer, characterized by: The outer impact-resistant layer and the inner impact-resistant layer are both composed of a carbon fiber reinforced epoxy resin composite material woven laminate layer and a plurality of bone-like structural layers; the bone-like structural layer includes a unidirectional glass fiber corrugated plate, a unidirectional glass fiber support plate and a plurality of bone-like units arranged side by side; the bone-like unit includes a carbon fiber tube, a filled carbon tube and epoxy resin; the carbon fiber tube is composed of an integrally formed arc surface piece one, a combined arc surface piece and two arc surface pieces two; the arc surface piece one is directly opposite to the combined arc surface piece, and the two ends of the arc surface piece one and the combined arc surface piece are respectively connected by an arc surface piece two to form a cylinder; the inner wall of the arc surface piece one is provided with a serrated structure; the combined arc surface piece is composed of two arc surface pieces three, and the inner wall of the arc surface piece three is concave; the carbon fiber tube is provided with a gradient structure with a density gradually decreasing from the outside to the inside The invention relates to a plurality of filled carbon tubes with a high degree of distribution, and epoxy resin is provided in the gaps between the filled carbon tubes and in the gaps between the filled carbon tubes and the inner wall of the carbon fiber tube; the unidirectional glass fiber corrugated plate is interspersed and wound between the bone-like units arranged side by side; the unidirectional glass fiber support plate and the unidirectional glass fiber corrugated plate are wound around the parts of the outer wall of the combined arc surface piece and bonded; the bone-like structural layers are stacked and laid side by side; in the outer impact-resistant layer, the unidirectional glass fiber corrugated plate of the outermost bone-like structural layer is wound around the parts of the outer wall of the arc surface piece and bonded with the carbon fiber reinforced epoxy resin composite material braided layer; in the inner impact-resistant layer, the unidirectional glass fiber corrugated plate of the innermost bone-like structural layer is wound around the parts of the outer wall of the arc surface piece and bonded with the carbon fiber reinforced epoxy resin composite material braided layer; The intermediate energy-absorbing layer is made of thermoplastic resin material and is provided with a plurality of through-hole groups distributed in concentric circles. Each through-hole group is composed of a plurality of through-holes uniformly distributed along the circumference and of equal diameter. From the inside to the outside, the through-hole radius of each through-hole group gradually decreases. A plurality of partitions uniformly distributed along the axial direction of the through-hole are bonded in each through-hole. The two sides of the through-holes in the intermediate energy-absorbing layer are respectively bonded to the unidirectional glass fiber support plate of the outer impact-resistant layer and the carbon fiber reinforced epoxy resin composite material woven layer of the inner impact-resistant layer.

2. The skin with a multi-bionic impact-resistant composite structure according to claim 1, characterized in that: The diameter of the circumscribed circle of the carbon fiber tube is 1mm-2mm, the radius of the arc surface piece 1 and the arc surface piece 2 is 2.5mm, and the radius of the arc surface piece 3 is 1mm-2mm; the width of each sawtooth of the serrated structure is 1.5mm-3mm and the height is 0.4mm-1.3mm.

3. The skin with multiple bionic impact-resistant composite structures according to claim 1, characterized in that: The carbon fiber reinforced epoxy resin composite material braided laminate layer is formed by spirally stacking a plurality of carbon fiber reinforced epoxy resin composite material braided layers at an angle of 22.5 degrees and forming the layers by hot pressing.

4. The skin with a multi-bionic impact-resistant composite structure according to claim 3 is characterized in that: The carbon fiber reinforced epoxy resin composite material braided layer is braided from carbon fiber reinforced epoxy resin composite fiber bundles.

5. The skin with multiple bionic impact-resistant composite structures according to claim 4 is characterized in that: The carbon fiber reinforced epoxy resin composite fiber bundle is formed by winding a plurality of carbon fiber reinforced epoxy resin composite fibers; the carbon fiber reinforced epoxy resin composite fibers are mixed with carbon fiber and epoxy resin in a mass ratio of 5:5, and the diameter of the carbon fiber reinforced epoxy resin composite fibers is 7 μm.

6. The skin with multiple bionic impact-resistant composite structures according to claim 1, characterized in that: The carbon fiber tube is processed by a core mold hot pressing method.

7. The skin with multiple bionic impact-resistant composite structures according to claim 1, characterized in that: The radius difference of the circumference of each through hole in adjacent through hole groups is 0.1 mm, and the radius difference of the through holes in adjacent through hole groups is 0.1 mm.

8. The skin with multiple bionic impact-resistant composite structures according to claim 1, characterized in that: The partition is a straight plate with a thickness of 0.3mm-0.6mm, and the spacing between adjacent partitions is 0.5mm-2mm.

9. The skin with multiple bionic impact-resistant composite structures according to claim 1, characterized in that: The bonding is carried out by epoxy resin adhesive.

10. The skin with a multiple bionic impact-resistant composite structure according to any one of claims 1 to 7, characterized in that: The unidirectional glass fiber corrugated plate and the unidirectional glass fiber support plate are respectively replaced with a woven glass fiber corrugated plate and a woven glass fiber support plate with a two-dimensional plain weave. The side-by-side stacking of each bone-like structure layer is replaced with a spiral stacking of each bone-like structure layer at an angle of 7.2°-18°. If the next angle exceeds 180°, a cycle is ended. After rotating for multiple cycles, the partition is set to a sinusoidal surface with a wavelength of 0.75mm, an amplitude of 0.1mm, a partition thickness of 0.25mm, and a spacing of 0.8mm between adjacent partitions.

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