A new type of bionic anti-delamination composite laminate

Abstract

This invention discloses a novel biomimetic anti-delamination composite laminate. The composite laminate has multiple through-holes, each containing a bidirectional colossal squid-inspired tentacle-like barb structure. Multiple barb structures, each consisting of a main barb and two integrally formed secondary hooks located on either side of the main barb, are fixed to the cylindrical surface of the bidirectional colossal squid-inspired tentacle-like barb structure. Both rod bodies one and two have hook-like structures formed by multiple nanotubes, mimicking the interbranchs of bird wing feathers. Connecting structures, formed by a mixture of resin and multiple fibers, are filled between the bidirectional colossal squid-inspired tentacle-like barb structure and the hole wall within the through-holes. These connecting structures are wound around the corresponding main barb, secondary hook, or nanotube. This invention exhibits good resistance to delamination and effectively prevents the generation or propagation of interlaminar cracks upon impact, reducing delamination damage.

Description

Technical Field

[0001] This invention belongs to the field of aerospace technology, and specifically relates to a novel biomimetic anti-delamination composite laminate. Background Technology

[0002] Composite materials have been widely used in the aerospace field due to their superior properties. With advancements in manufacturing technology and increased production capacity, more and more critical components on aircraft are made from composite materials. Composite components possess advantages such as excellent durability, reliability, corrosion resistance, and specific strength. The amount of composite materials used in large passenger aircraft has become an important parameter for measuring the performance superiority of commercial aircraft. The main structural panels of wide-body passenger aircraft are crucial components, serving as the primary load-bearing structure. Besides bearing and transmitting conventional aerodynamic loads, their main function is to protect the aircraft interior and passengers from harsh external environments. Composite laminates are widely used in these panels. However, composite laminates exhibit delamination damage, a different form of damage compared to traditional metal materials. Delamination damage occurs within the interlayer structure, is difficult to detect, and continues to propagate under sustained loading, leading to a decrease in the overall stiffness and strength of the panel structure. When delamination damage reaches a certain level, it can cause overall material failure, resulting in serious consequences. Therefore, there is an urgent need to design composite laminates structurally to enhance their resistance to delamination, effectively preventing the propagation of interlayer cracks, and thus reducing the damage caused by delamination. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a novel biomimetic anti-delamination composite laminate.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention discloses a novel biomimetic anti-delamination composite laminate, comprising a composite laminate layer, a bidirectional colossal squid-inspired tentacle barb structure rod, a bird wing feather mesonic feather branch hook structure, and a connecting structure.

[0006] The composite material laminate has multiple through holes arranged in an array, and each through hole contains a bidirectional imitation colossal squid tentacle barb structure rod. The bidirectional imitation colossal squid tentacle barb structure rod includes a main body, barb structures, and an interlocking structure. The main body consists of rod one and rod two arranged coaxially with the corresponding through holes. Multiple barb structure groups are fixed to the cylindrical surfaces of rod one and rod two, evenly distributed circumferentially. Each barb structure group consists of multiple barb structures evenly distributed axially. Each barb structure consists of an integrally formed main barb and two auxiliary hooks. The two auxiliary hooks are located on either side of the main barb and are perpendicular to the central axis of the main body. The main barbs on rod one and rod two are positioned opposite each other along the axial direction of the main body. The interlocking structure includes a lock head and a lock chamber. The lock head is fixed to one end of the first rod near the second rod. The second rod has a lock hole at one end near the first rod and a lock chamber communicating with the lock hole. The lock head passes through the lock hole and is embedded in the lock chamber, and the two end faces of the first and second rods are in contact with each other.

[0007] Both rod one and rod two have hook-like structures on their cylindrical surfaces, mimicking the barbules of bird wing feathers. These structures consist of multiple nanotubes spaced apart, each nanotube fixed at an angle to the cylindrical surface of rod one or rod two. A connecting structure fills the space between the main body and the hole wall within each through-hole, fixing each main body within the through-hole via the corresponding connecting structure. The connecting structure is formed by a mixture of resin and multiple fibers, with each fiber wound around a corresponding main barb, secondary hook, or nanotube. The resin fills the gap between each main body and the corresponding through-hole, fixing the main body within the through-hole.

[0008] Preferably, the composite material laminate is formed by stacking multiple layers of unidirectional carbon fiber resin composite material at a helical angle of 45°.

[0009] Preferably, the through-hole is perpendicular to the composite laminate.

[0010] Preferably, the thickness of the composite material laminate is greater than 3 mm, the diameter of the bidirectional imitation colossal squid tentacle barb structure rod is 0.1 mm to 1 mm, and the diameter of the through hole is 0.1 mm larger than the diameter of the bidirectional imitation colossal squid tentacle barb structure rod.

[0011] Preferably, the volume of the bidirectional imitation coccine squid tentacle barb structure rod accounts for 2.0% of the volume of the composite material laminate.

[0012] Preferably, both rod one and rod two are made of carbon fiber-bismaleimide composite material, and the nanotubes are single-walled carbon fiber nanotubes.

[0013] Preferably, the nanotubes are adhered to the cylindrical surface of rod one or rod two by a mixture of acetone solution and epoxy resin without curing agent.

[0014] Preferably, the fiber is aramid pulp fiber, the resin is epoxy resin, and the concentration of aramid pulp fiber in the connecting structure is 2.0%.

[0015] Preferably, the composite laminate is in a prepreg state when each through hole is opened, and in the prepreg state, the connecting structure and the combined structure consisting of a bidirectional imitation colossal squid tentacle barb structure rod and an imitation bird wing feather mezzanine branch hook structure are sequentially injected into the through holes.

[0016] More preferably, the process of inserting the combined structure into the corresponding through hole is as follows: insert rod one and rod two from both ends of the corresponding through hole, so that the lock head passes through the lock hole and is embedded in the lock chamber, and rotate rod one and rod two relative to each other so that the lock head and the lock chamber are interlocked.

[0017] The present invention has the following beneficial effects:

[0018] 1. This invention possesses superior resistance to delamination, thereby inhibiting the generation of interlaminar cracks or effectively preventing their propagation when delamination damage occurs, thus reducing delamination damage. Specifically, this invention utilizes the bidirectional colossal squid-inspired tentacle barb structure and the nanotubes of the bird wing feather mesial barb interlocking structure to form a mechanical interlocking mechanism with the fiber hooks in the connecting structure. This increases the energy consumed when the composite laminate is damaged and the barbs are pulled out, thereby inhibiting the pull-out of the bidirectional colossal squid-inspired tentacle barb structure and improving the laminate's resistance to delamination, thus suppressing the generation or propagation of interlaminar cracks. Furthermore, when the laminate suffers severe delamination damage due to impact, the corresponding bidirectional... Part of the barbed tentacle structure rods and nanotubes of the colossal squid were pulled out, and interlaminar cracks appeared in the resin around the pulled-out parts of the bidirectional colossal squid barbed tentacle structure rods and nanotubes. At this time, the two surfaces of the interlaminar cracks were connected by the corresponding nanotubes and fibers like bridges. The nanotubes and fibers act as a crack bridging mechanism, preventing the further opening and propagation of the interlaminar cracks. At the same time, they shared part of the stress concentration acting on the tip of the interlaminar cracks, borne part of the tensile and shear stress, and friction and debonding occurred at the interface with the resin, consuming the energy for the propagation of the interlaminar cracks. This increased the energy required for the further propagation of the interlaminar cracks, further inhibiting the propagation of interlaminar cracks and reducing delamination damage.

[0019] 2. This invention creates multiple through holes in the composite laminate and incorporates bidirectional colossal squid-inspired tentacle barbs, bird-inspired wing feather mesonic feather branch hook structures, and connecting structures within these holes. This approach does not significantly increase the overall weight of the laminate. Furthermore, through the synergistic effect of these bidirectional colossal squid-inspired tentacle barbs, bird-inspired wing feather branch hook structures, and connecting structures, the invention enhances the laminate's anti-delamination capability, in-plane shear strength, interlaminar fracture toughness, and impact damage resistance while maintaining a lightweight overall weight.

[0020] 3. In this invention, the resin in the added connecting structure fills the gaps in the prepreg of the composite laminate caused by the addition of bidirectional imitation coccine tentacle barb structure rods and imitation bird wing feather mesial barb hook structure, forming a pure resin aggregation area, which effectively reduces the generation of low stiffness local areas on the laminate. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the stacking of unidirectional carbon fiber resin composite materials in the composite laminate of the present invention;

[0023] Figure 3 This is a schematic diagram of the composite material laminate structure in this invention;

[0024] Figure 4 This is a schematic diagram of the bidirectional imitation colossal squid tentacle barb structure rod and the imitation bird wing feather mesial barb hook connection structure in this invention.

[0025] Figure 5 This is a schematic diagram of the bidirectional imitation coccine squid tentacle barb structure rod in this invention when rod one and rod two are separated;

[0026] Figure 6 for Figure 5 Top view;

[0027] Figure 7 This is a schematic diagram of the barb structure in this invention;

[0028] Figure 8 This is a schematic diagram of the lock head and part of the rod body in this invention;

[0029] Figure 9 This is a schematic diagram of the keyhole, lock chamber, and part of the second rod in this invention;

[0030] Figure 10 for Figure 9 A partial sectional view;

[0031] Figure 11This is a schematic diagram of the composite material laminate and connection structure in this invention;

[0032] Figure 12 This is a schematic diagram of the combined structure being placed inside the corresponding through hole in this invention. Detailed Implementation

[0033] The present invention will now be further described with reference to the accompanying drawings.

[0034] like Figure 1 As shown, the present invention discloses a novel biomimetic anti-delamination composite laminate, comprising a composite laminate layer 1, a bidirectional colossal squid tentacle barb structure 2, a bird wing feather mesonic feather branch hook structure 3, and a connecting structure 4.

[0035] like Figure 2 and Figure 3 As shown, the composite laminate 1 is composed of multiple layers of unidirectional carbon fiber resin composite material stacked at a 45° helical angle. Multiple through-holes (which can be opened with a needle) are arranged in an array on the composite laminate 1, each through-hole being perpendicular to the surface of the composite laminate 1, and each through-hole containing a bidirectional imitation colossal squid tentacle barb structure 2. The thickness of the composite laminate 1 is greater than 3 mm, the diameter of the bidirectional imitation colossal squid tentacle barb structure 2 is 0.1 mm to 1 mm, and the diameter of the through-holes is 0.1 mm larger than the diameter of the bidirectional imitation colossal squid tentacle barb structure 2.

[0036] like Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10As shown, the bidirectional imitation colossal squid tentacle barb structure rod 2 includes a main body 201, barb structures 205, and an interlocking structure 206. The main body 201 consists of a first rod 203 and a second rod 204 arranged coaxially with the corresponding through holes. Multiple barb structure groups are fixed on the cylindrical surfaces of both the first rod 203 and the second rod 204, evenly distributed circumferentially. Each barb structure group consists of multiple barb structures 205 evenly distributed axially. Each barb structure 205 consists of an integrally formed main barb 207 and two auxiliary hooks 208. The two auxiliary hooks 208 are located on both sides of the main barb 207 and are perpendicular to the central axis of the main body 201. The main barbs 207 on the first rod 203 and the main barbs 207 on the second rod 204 are arranged opposite to each other along the axial direction of the main body 201. The interlocking structure 206 includes a lock head 209 and a lock chamber 211. The lock head 209 is fixed to one end of rod 1 203 near rod 204. Rod 204 has a lock hole 210 at one end near rod 1 203, and a lock chamber 211 communicating with the lock hole 210. The lock head 209 passes through the lock hole 210 and is embedded in the lock chamber 211. The two adjacent end faces of rod 1 203 and rod 204 are in contact. Both rod 1 203 and rod 204 are made of carbon fiber-bismaleimide composite material.

[0037] Both rod 1 (203) and rod 2 (204) have a hook-and-loop structure 3 on their cylindrical surfaces, mimicking the barbules of bird wing feathers. This hook-and-loop structure 3 is composed of multiple nanotubes 202 arranged at intervals, and each nanotube 202 is tilted and fixed to the cylindrical surface of rod 1 (203) or rod 2 (204). A connecting structure 4 fills the space between the main body 201 and the hole wall within each through-hole, and each main body 201 is fixed to the through-hole via the corresponding connecting structure 4. For example... Figure 11 As shown, the connecting structure 4 is formed by mixing resin 302 and multiple fibers 301, with each fiber 301 wound around the corresponding main barb 207, secondary hook 208, or nanotube 202, forming a mechanical interlock. This inhibits the pull-out of rod 1 203 and rod 204 when delamination damage occurs in the composite laminate 1, thereby suppressing further crack propagation. The resin 302 fills the gap between each main body 201 and the corresponding through hole, thus fixing the main body 201 within the through hole. The nanotube 202 is a single-walled carbon fiber nanotube.

[0038] In a preferred embodiment, the nanotube 202 is adhered to the cylindrical surface of rod 1 203 or rod 204 by a mixture of acetone solution and epoxy resin without curing agent.

[0039] As a preferred embodiment, the volume of the bidirectional imitation coccine squid tentacle barb structure rod 2 accounts for 2.0% of the volume of the composite laminate.

[0040] In a preferred embodiment, fiber 301 is made of aramid pulp fiber, and resin 302 is made of epoxy resin.

[0041] More preferably, the concentration of aramid pulp fiber in the connecting structure 4 is 2.0%.

[0042] In a preferred embodiment, when the composite laminate is opened with each through hole, the unidirectional carbon fiber resin composite material is in a prepreg state (the state before the final hot molding process). In the state of the unidirectional carbon fiber resin composite material being in the prepreg state, the connecting structure 4 is sequentially injected into the through hole and a combined structure consisting of a bidirectional imitation coccine tentacle barb structure 2 and an imitation bird wing feather mesonic feather branch hook structure 3 is inserted (which can be pressed in with a medical needle).

[0043] More preferably, the process of inserting the combined structure into the corresponding through hole is as follows: Figure 12 As shown, rod 203 and rod 204 are inserted from both ends of the through hole, so that the lock head 209 passes through the lock hole 210 and is embedded in the lock chamber 211. Rod 203 and rod 204 are rotated relative to each other, so that the lock head 209 is interlocked with the lock chamber 211.

[0044] More preferably, in the prepreg state of the unidirectional carbon fiber resin composite material, after sequentially injecting the connecting structure 4 and the combined structure consisting of the bidirectional imitation colossus tentacle barb structure 2 and the bird wing feather mesonic feather branch hook structure 3 into the through hole, the composite material laminate 1, the bidirectional imitation colossus tentacle barb structure 2, the bird wing feather mesonic feather branch hook structure 3 and the connecting structure 4 are thermoformed to obtain a novel biomimetic anti-delamination composite material laminate of this embodiment.

[0045] The working principle of this novel biomimetic anti-delamination composite laminate is as follows:

[0046] This invention can be used to manufacture wall panels for wide-body passenger aircraft. When the invention is subjected to impact, the impact force is dispersed to the vicinity of the bidirectional imitation colossus tentacle barb structure rod 2, the bird-like wing feather mesonic feather branch interlocking structure 3, and the connecting structure 4 within each adjacent through hole. Due to the interlocking of the barb structures 205 on the bidirectional imitation colossus tentacle barb structure rod 2 and the fibers 301 in the hook-locking connecting structure 4 of the bird-like wing feather mesonic feather branch interlocking structure 3, a mechanical interlock is formed. At the same time, the main barbs 207 of rod body 1 203 and rod body 2 204 on the bidirectional imitation colossus tentacle barb structure rod 2 are arranged opposite to each other, increasing the energy consumed by the pull-out of each rod when the composite laminate layer 1 is damaged, thereby inhibiting the pull-out of the bidirectional imitation colossus tentacle barb structure rod 2, improving the resistance to delamination, and thus inhibiting the generation or propagation of interlaminar cracks. When the invention is severely damaged by delamination due to impact, the corresponding bidirectional imitation colossus tentacle barbs... When a portion of the structural rod 2 and each nanotube 202 is pulled out, cracks appear in the resin 302 in the surrounding connecting structure 4. The corresponding nanotubes 202 in the bird-like wing feather barb interbranch hook structure 3 and the corresponding fibers 301 in the connecting structure 4 act like bridges, spanning the two surfaces of the interlaminar crack and connecting them together. This acts as a crack bridging mechanism, preventing the interlaminar crack from opening and expanding further. At the same time, the corresponding nanotubes 202 and fibers 301 share some of the stress concentration acting on the tip of the interlaminar crack, bear some of the tensile and shear stress, and experience friction and debonding at the interface with the resin 302, consuming the energy required for the interlaminar crack to expand. This increases the energy required for the interlaminar crack to expand, thereby increasing the resistance to the expansion of the interlaminar crack and inhibiting the further pulling out of the bidirectional colossal squid tentacles hook structure rod 2, thus inhibiting the further increase of delamination damage.

Claims

1. A novel biomimetic anti-delamination composite laminate, comprising a composite laminate layer, characterized in that: It also includes a bidirectional imitation colossal squid tentacle barb structure rod, an imitation bird wing feather mesial barb interbranch hook structure, and a connecting structure; the composite material laminate has multiple through holes arranged in an array, and each through hole contains a bidirectional imitation colossal squid tentacle barb structure rod; the bidirectional imitation colossal squid tentacle barb structure rod includes a main body, barb structures, and interlocking structures; the main body consists of rod body one and rod body two arranged coaxially with the corresponding through holes, and multiple barb structure groups evenly distributed along the circumference are fixed on the cylindrical surfaces of rod body one and rod body two, and the barb structure groups are composed of axially arranged... The structure consists of multiple evenly distributed barb structures, each barb consisting of an integrally formed main barb and two auxiliary hooks. The two auxiliary hooks are located on both sides of the main barb and are perpendicular to the central axis of the main body. The main barbs on rod one and rod two are arranged opposite to each other along the axial direction of the main body. The interlocking structure includes a lock head and a lock chamber. The lock head is fixed to one end of rod one near rod two. A lock hole is opened on one end of rod two near rod one, and a lock chamber is opened that communicates with the lock hole. The lock head passes through the lock hole and is embedded in the lock chamber. The two end faces of rod one and rod two that are close to each other are in contact. Both rod one and rod two have a hook-and-loop structure on their cylindrical surfaces, mimicking the barbules of bird wings. This hook-and-loop structure is composed of multiple nanotubes arranged at intervals, and each nanotube is tilted and fixed to the cylindrical surface of rod one or rod two. Each through hole is filled with a connecting structure between the main body and the hole wall, and each main body is fixed to the through hole by the corresponding connecting structure. The connecting structure is formed by mixing resin and multiple fibers, and each fiber is wound around the corresponding main barb, secondary hook, or nanotube. The resin fills the gap between each main body and the corresponding through hole, fixing the main body in the through hole.

2. The novel biomimetic anti-delamination composite laminate according to claim 1, characterized in that: The composite material laminate is composed of multiple layers of unidirectional carbon fiber resin composite material stacked at a helical angle of 45°.

3. The novel biomimetic anti-delamination composite laminate according to claim 1, characterized in that: The through-hole is perpendicular to the composite material laminate.

4. The novel biomimetic anti-delamination composite laminate according to claim 1, characterized in that: The thickness of the composite material laminate is greater than 3 mm, the diameter of the bidirectional imitation colossal squid tentacle barb structure rod is 0.1 mm to 1 mm, and the diameter of the through hole is 0.1 mm larger than the diameter of the bidirectional imitation colossal squid tentacle barb structure rod.

5. A novel biomimetic anti-delamination composite laminate according to claim 1, characterized in that: The volume of the bidirectional imitation coccine squid tentacle barb structure rod accounts for 2.0% of the volume of the composite laminate.

6. A novel biomimetic anti-delamination composite laminate according to claim 1, characterized in that: Both rod one and rod two are made of carbon fiber-bismaleimide composite material, and the nanotubes are single-walled carbon fiber nanotubes.

7. A novel biomimetic anti-delamination composite laminate according to claim 1, characterized in that: The nanotubes are adhered to the cylindrical surface of rod one or rod two by a mixture of acetone solution and epoxy resin without curing agent.

8. A novel biomimetic anti-delamination composite laminate according to claim 1, characterized in that: The fiber is aramid pulp fiber, the resin is epoxy resin, and the concentration of aramid pulp fiber in the connecting structure is 2.0%.

9. A novel biomimetic anti-delamination composite laminate according to claim 1, characterized in that: When the composite laminate is in the prepreg state, each through hole is opened. In the prepreg state, the connecting structure is injected into the through hole in sequence, and a combined structure consisting of bidirectional imitation colossal squid tentacle barb structure rod and imitation bird wing feather mesial barb hook structure is placed in.

10. A novel biomimetic anti-delamination composite laminate according to claim 9, characterized in that: The process of inserting the combined structure into the corresponding through hole is as follows: insert rod one and rod two from both ends of the corresponding through hole, so that the lock head passes through the lock hole and is embedded in the lock chamber, and rotate rod one and rod two relative to each other so that the lock head and the lock chamber are interlocked.

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