Continuous fiber reinforced composite material embedded bundle optical fiber and vertical leading method

Abstract

The application provides a continuous fiber reinforced composite embedded bundle optical fiber and vertical leading method, which comprises the following steps: laying a bundle optical fiber on a first prepreg base, heating the first prepreg base to strengthen the binding effect between the bundle optical fiber and the first prepreg base; laying a second prepreg base above the bundle optical fiber, encapsulating to form a composite material blank, and performing vacuum pre-pressing and heating treatment on the composite material blank to strengthen the binding effect between the bundle optical fiber and the second prepreg base, forming a groove structure through layer loss stacking in a preset area of the second prepreg base, filling a placeholder structure at the groove structure position, encapsulating to form a complete blank, and performing curing forming on the complete blank; after the curing forming is completed, the placeholder structure is removed from the second prepreg base, and the isolation material is removed, and the bundle optical fiber can be vertically led out from the groove structure and moved. The application can reduce the negative effect of the embedded bundle optical fiber on the mechanical properties of the composite material.

Description

Technical Field

[0001] This invention relates to the field of structure-function integrated composite materials technology, and more specifically, to a method for embedding bundled optical fibers in a continuous fiber reinforced composite material and vertically leading them out. Background Technology

[0002] The electrification of aviation systems is increasing, transforming them into networked computing platforms encompassing CAN, Ethernet, fiber optic networks, ARINC networks, thousands of electronic control devices, numerous cable interconnections, electronic sensors, and embedded software. This necessitates integrating hundreds of systems developed and manufactured by multiple vendors onto a single platform while adhering to standards such as Electrical Wiring Interconnection System (EWIS), DO254, and DO178B. These requirements make the design more complex and demanding. The increased number of electrical devices worsens the onboard electromagnetic compatibility environment, complicates electrical system interconnections, and increases signal sensitivity due to the diversity of system signals.

[0003] Optical fiber, with its thin diameter, small size, and light weight, is ideally suited for use on aircraft platforms with strict space and weight constraints. In signal transmission, optical fiber offers low transmission loss and high bandwidth. Furthermore, since optical fibers and waveguide devices are primarily dielectric materials, they emit no electromagnetic radiation and offer good stealth capabilities. Therefore, replacing cable-based transmission systems with fiber-optic-based transmission systems in avionics systems can significantly reduce the cost and weight of these systems, while also improving their immunity to electromagnetic interference (EMI) and electromagnetic pulse (EMP). Simultaneously, fiber-optic communication platforms can fully leverage the advancements in modern fiber optic communication and integrated photonics, employing simpler, more reliable, smaller, and lower-power optical components or modules to construct airborne fiber optic networks. This results in more integrated, faster, and more cost-effective aircraft electrical systems. Consequently, advanced fighter jets such as the F-2X and F-3X extensively utilize fiber optic transmission networks in their avionics systems. Each Boeing 787 aircraft is equipped with 110 fiber optic links, which are connected by 209 fiber optic connectors to split these links into 348 segments. The total length of fiber optic cables used in the entire aircraft is approximately 5,624 feet.

[0004] Aviation fiber optic cables are wiring components that connect various electronic devices on an aircraft and are used to transmit signals; they can be considered the "nerves" of the aircraft. In the design process of the new generation of aircraft, design methods such as "standardization" and "integration" have been adopted, which has improved the space utilization rate by nearly 100%. However, due to the spatial arrangement and maintenance requirements of fiber optic cables and conduits, a large range of laying channels still needs to be provided. The reduction in airborne space also makes the maintenance of cables and conduits more difficult.

[0005] Modern aircraft airframes widely utilize high-performance composite materials. Besides their significant advantages in mechanical properties, composite materials also offer high design flexibility. Introducing optical fibers into composite structures allows them to not only bear loads but also secure and protect the fibers, enabling multi-functional reuse, reducing the weight of fiber protection structures, achieving overall aircraft weight reduction, minimizing the space required for fiber optic cable and conduit installation, and improving airborne space utilization.

[0006] The optical fibers used in avionics systems are mostly bundled optical fibers. Bundled optical fibers have a certain width, and when introduced into the interior of composite materials, they can form vulnerable areas that may cause stress concentration, which can adversely affect the structural strength and safety stability of composite materials.

[0007] Optical fibers are inherently fragile, and significant bending can easily cause damage, affecting signal transmission. Furthermore, connecting them to connectors requires considerable operational space, making it difficult to install interfaces after embedding them within composite materials. Composite materials, as structural materials with excellent strength-to-stiffness ratios, are primarily used in aircraft skin and other cabin structures. Airborne electronic equipment is mostly housed within the composite material's inner walls. Therefore, whether the embedded optical fiber can be vertically led out and connected to relevant electronic equipment is a key factor affecting the application of composite material embedded optical fiber technology. Summary of the Invention

[0008] (a) Technical problems to be solved

[0009] The technical problem to be solved by this invention is that the overall diameter of the bundled optical fiber is large. When introduced into the interior of the composite material, it will form a vulnerable area that may cause stress concentration, which will have an adverse effect on the structural strength and safety stability of the composite material. Moreover, existing bundled optical fibers embedded in composite materials can generally only be led out along the length of the composite material, and cannot be led out along the thickness direction of the composite material (vertical lead-out).

[0010] (II) Technical Solution

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0012] A method for embedding bundled optical fibers and vertically extracting them into a continuous fiber-reinforced composite material is provided, which is used to lay out and extract bundled optical fibers inside the continuous fiber-reinforced composite material, including the following steps:

[0013] Bundled optical fibers are laid on a first prepreg substrate, wherein the bundled optical fibers are arranged at preset distances and are arranged in parallel on the first prepreg substrate, and an insulating material is placed in the contact area between the bundled optical fibers and the first prepreg substrate.

[0014] The first prepreg matrix is ​​heated to enhance the bonding effect between the bundled optical fibers and the first prepreg matrix;

[0015] A second prepreg matrix is ​​laid on top of the bundled optical fiber, and a composite material blank is formed by encapsulation. The composite material blank is then subjected to vacuum pre-compression heating treatment to enhance the bonding effect between the bundled optical fiber and the second prepreg matrix. In this case, an isolation material is placed in the contact area between the bundled optical fiber and the second prepreg matrix.

[0016] A groove structure is formed by layer stacking in a preset area of ​​the second prepreg matrix, and a placeholder structure is filled in the groove structure position to encapsulate and form a complete blank, and the complete blank is cured and molded.

[0017] After curing and molding, the occupant structure is removed from the second prepreg matrix, and the isolation material is removed. The bundled optical fiber can then be vertically led out and moved from the groove structure.

[0018] Preferably, filling the groove structure with a placeholder structure specifically includes the following steps:

[0019] Apply the release agent thoroughly to the contact area between the spacer structure and the second prepreg matrix;

[0020] Then fill the spacer structure into the groove structure position.

[0021] Preferably, if the occupant structure is made of a rigid material, a layer of flexible material is laid between the occupant structure and the bundled optical fibers.

[0022] Preferably, the insulating material is an insulating film or a release liner.

[0023] Preferably, the preset distance is not less than 10mm.

[0024] Preferably, both the first prepreg matrix and the second prepreg matrix are prepregs with continuous fiber reinforcement.

[0025] Preferably, the length direction of the bundled optical fiber is consistent with the length direction of the continuous fiber reinforcement in the first prepreg matrix, and the length direction of the bundled optical fiber is consistent with the length direction of the continuous fiber reinforcement in the second prepreg matrix.

[0026] Preferably, the continuous fiber reinforcement is at least one of glass fiber, quartz fiber, aramid fiber, carbon fiber, and polyimide fiber.

[0027] Preferably, the process of forming a groove structure in a predetermined area of ​​the second prepreg matrix by layer stacking specifically includes the following steps:

[0028] Windows are formed by scribing in a predetermined area of ​​each layer of prepreg;

[0029] The second prepreg matrix is ​​formed by stacking multiple layers of prepreg, and the windows are stacked to form the groove structure.

[0030] (III) Beneficial Effects

[0031] The above-described technical solution of the present invention has at least the following advantages:

[0032] 1. By embedding bundled optical fibers inside the composite matrix at preset intervals and in parallel arrangement, the negative effects of bundled optical fibers on the mechanical properties of the composite material are reduced.

[0033] 2. By rationally designing the divergence path and vertical outgoing turning radius of the bundled optical fibers, the impact on optical fiber transmission performance is negligible.

[0034] 3. The groove structure of the composite material is prepared by stacking prepreg layers to form a groove structure and filling the groove structure with a placeholder structure. The groove structure can not only vertically lead out the embedded bundled optical fiber, but also provide space for related interfaces.

[0035] 4. This invention can simultaneously achieve the curing and molding of the first prepreg matrix, the second prepreg matrix, and the groove structure through only one curing and molding process, which simplifies the production process and improves manufacturing efficiency.

[0036] 5. No embedded structures are introduced inside the composite material except for the bundled optical fiber itself. The bundled optical fiber can be connected to any connection device after being vertically led out from the groove structure. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a cross-sectional schematic diagram of the bundled optical fiber embedded portion provided in an embodiment of the present invention.

[0039] Figure 2 This is a cross-sectional schematic diagram of the vertical lead-out portion of the bundled optical fiber provided in an embodiment of the present invention.

[0040] Figure 3 This is a schematic diagram of the wiring and lead-out of bundled optical fibers in a continuous fiber-reinforced composite material provided in an embodiment of the present invention.

[0041] The labels for the attached figures are as follows:

[0042] 1. First prepreg matrix; 2. Second prepreg matrix; 3. Groove structure; 4. Occupancy structure; 10. Bundled optical fiber. Detailed Implementation

[0043] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0044] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be located directly on or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to the other component.

[0045] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate that the device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance, process sequence, or the number of technical features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. The specific implementation of this invention will be described in more detail below with reference to specific embodiments:

[0047] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a method for embedding bundled optical fibers in a continuous fiber reinforced composite material and for vertically leading out the bundled optical fibers 10, which is used to lay out and lead out the bundled optical fibers 10 inside the continuous fiber reinforced composite material, including the following steps:

[0048] Bundled optical fibers 10 are laid on the first prepreg substrate 1, wherein the bundled optical fibers 10 are arranged at preset distances and are arranged in parallel on the first prepreg substrate 1, and an insulating material is placed in the contact area between the bundled optical fibers 10 and the first prepreg substrate 1.

[0049] Heating the first prepreg substrate 1 enhances the bonding effect between the bundled optical fiber 10 and the first prepreg substrate 1;

[0050] A second prepreg substrate 2 is laid on top of the bundled optical fiber 10, and a composite material blank is formed by encapsulation. The composite material blank is then subjected to vacuum pre-pressing and heating treatment to enhance the bonding effect between the bundled optical fiber 10 and the second prepreg substrate 2. In this case, an isolation material is placed in the contact area between the bundled optical fiber 10 and the second prepreg substrate 2.

[0051] In a predetermined area of ​​the second prepreg matrix 2, a groove structure 3 is formed by stacking layers, and a placeholder structure 4 is filled in the groove structure 3 to encapsulate and form a complete blank. The complete blank is then cured and molded.

[0052] After curing, the occupant structure 4 is removed from the second prepreg matrix 2, and the insulating material is removed. The bundled optical fiber 10 can then be vertically led out and moved from the groove structure 3. Specifically, the layup of the second prepreg can be designed according to the position, depth, shape, and size of the groove structure. The shape and size of the occupant structure 4 match the shape and size of the groove structure 3, and the temperature resistance of the occupant structure 4 needs to meet the molding requirements of the composite material system to ensure that no deformation occurs during the prepreg curing process, avoiding problems such as irregularity of the groove structure 3 or damage to the embedded optical fiber. The periphery of the groove structure 3 and the divergence and convergence areas of the bundled optical fiber can be thickened as needed to reduce the impact of the embedded optical fiber on the performance of the continuous fiber reinforced composite material. The groove structure 3 is formed on the second prepreg matrix 2 by the occupant structure 4, that is, the groove structure 3 is formed on the side wall of the finally formed composite material. The vertical lead-out of the bundled optical fiber 10 can be achieved through the groove structure 3.

[0053] like Figure 3 As shown, Figure 3 This is a schematic diagram of the wiring and lead-out of the bundled optical fiber in the continuous fiber reinforced composite material provided in this embodiment. In the figure, area A is the parallel arrangement area of ​​the bundled optical fiber, in which the bundled optical fiber 10 is completely embedded in the interior of the composite material. Area B is the bundled optical fiber concentration area, in which the bundled optical fiber 10 transitions from the parallel arrangement to the bundled lead-out method. Area C is the vertical lead-out area of ​​the bundled optical fiber, in which a groove structure 3 is formed. The bundled optical fiber 10 can be bundled and led out at the groove structure 3, realizing the vertical lead-out of the bundled optical fiber embedded in the composite material.

[0054] In one embodiment, the placement structure 4 is filled at the location of the groove structure 3, specifically including the following steps:

[0055] Apply the release agent thoroughly to the contact area between the occupant structure 4 and the second prepreg matrix 2;

[0056] Then fill the spacer structure 4 into the groove structure 3.

[0057] In one embodiment, if the occupant structure 4 is made of rigid material, a layer of flexible material is laid between the occupant structure 4 and the bundled optical fiber 10.

[0058] In one embodiment, the insulating material is an insulating film or a release liner. Specifically, the insulating material must meet the temperature resistance requirements, and covering the embedded optical fiber with the insulating material can prevent damage to the surface of the embedded optical fiber. An insulating material of a corresponding shape and size is laid on the surface of the groove structure to separate the second prepreg substrate from the focused light beam, preventing the focused light beam in the groove structure area from adhering to the second prepreg substrate.

[0059] In one embodiment, the preset distance is not less than 10mm.

[0060] In one embodiment, both the first prepreg matrix 1 and the second prepreg matrix 2 are prepregs with continuous fiber reinforcement.

[0061] In one embodiment, the length direction of the bundled optical fiber 10 is consistent with the length direction of the continuous fiber reinforcement in the first prepreg matrix 1, and the length direction of the bundled optical fiber 10 is consistent with the length direction of the continuous fiber reinforcement in the second prepreg matrix 2.

[0062] In one embodiment, the continuous fiber reinforcement is at least one of glass fiber, quartz fiber, aramid fiber, carbon fiber, and polyimide fiber.

[0063] In one embodiment, a groove structure 3 is formed in a predetermined area of ​​the second prepreg matrix 2 by layer stacking, specifically including the following steps:

[0064] Windows are formed by scribing in a predetermined area of ​​each layer of prepreg;

[0065] Multilayer prepregs are stacked to form a second prepreg matrix 2, and windows are stacked to form a groove structure 3.

[0066] The following are specific embodiments provided by the present invention:

[0067] Example 1

[0068] Vertically led out of a carbon fiber reinforced composite thin plate structure with interlayer embedded bundled optical fibers (12 dielectrics)

[0069] 1. The outer diameter of the bundled optical fiber is approximately 155 μm; the grade of the carbon fiber reinforced composite material is AC631 / CCF800; the occupant material is Airpad rubber, grade A400; the thickness of the thin plate composed of the bundled optical fiber and the carbon fiber reinforced composite material is 2.5 mm, and the embedding depth of the bundled optical fiber in the carbon fiber reinforced composite material is 1.25 mm.

[0070] 2. Cut and lay AC631 / CCF800 prepreg according to design requirements. When laying up the bundled optical fibers, lay a non-porous isolation film in the groove structure area. Lay bundled optical fibers 10 on the surface of the first prepreg substrate 1. The part of the bundled optical fibers 10 that exceeds the preset groove area is buried in a divergent and parallel arrangement. The spacing between single optical fibers is 12mm. Cover the bundled optical fibers with a non-porous isolation film. Use an electric iron at 70℃ to iron the optical fibers and the surrounding area to achieve a stable bond between the bundled optical fibers and the first prepreg.

[0071] 3. After the bundled optical fiber is buried, the second prepreg substrate is laid to encapsulate the preform into which the bundled optical fiber has been buried. Vacuum pre-pressing is performed for 1.5 hours at a temperature of 90°C to enhance the bonding effect between the second prepreg and the bundled optical fiber and to fix the position and spacing of the individual optical fibers.

[0072] 4. After completing the vacuum pre-compression treatment, continue with the AC631 / CCF800 prepreg laying operation. Process the placeholder structure according to the design requirements, and fill the groove structure of the molded blank with the placeholder structure fully coated with release agent. Encapsulate the complete blank with the embedded bundled optical fiber and placeholder structure, and transfer it to an autoclave to complete the curing process. The curing temperature is 200℃, the curing pressure is 0.6MPa, and the curing time is 6 hours, to obtain a carbon fiber reinforced composite material with the preset groove structure and embedded bundled optical fiber.

[0073] Vertical fiber insertion loss <1dB, and the tensile properties retention rate of carbon fiber reinforced composite material embedded in bundled fiber ≥90%.

[0074] Example 2

[0075] Vertically led out of a thick plate structure of carbon fiber reinforced composite material with interlayer embedded bundled optical fibers (6 dielectrics)

[0076] 1. The outer diameter of the bundled optical fiber is approximately 155 μm; the grade of the carbon fiber reinforced composite material is AC631 / CCF800; the occupant material is Airpad rubber, grade A400; the thickness of the thin plate composed of the bundled optical fiber and the carbon fiber reinforced composite material is 2.5 mm, and the embedding depth of the bundled optical fiber in the carbon fiber reinforced composite material is 1.25 mm.

[0077] 2. Cut and lay AC631 / CCF800 prepreg according to design requirements. When laying up the bundled optical fibers, lay a non-porous isolation film in the groove structure area. Lay bundled optical fibers 10 on the surface of the first prepreg substrate 1. The part of the bundled optical fibers 10 that exceeds the preset groove area is buried in a divergent and parallel arrangement. The spacing between single optical fibers is 12mm. Cover the bundled optical fibers with a non-porous isolation film. Use an electric iron at 70℃ to iron the optical fibers and the surrounding area to achieve a stable bond between the bundled optical fibers and the first prepreg.

[0078] 3. After the bundled optical fiber is buried, the second prepreg substrate is laid to encapsulate the preform into which the bundled optical fiber has been buried. Vacuum pre-pressing is performed for 1.5 hours at a temperature of 90°C to enhance the bonding effect between the second prepreg and the bundled optical fiber and to fix the position and spacing of the individual optical fibers.

[0079] 4. After completing the vacuum pre-compression treatment, continue with the AC631 / CCF800 prepreg laying operation. Process the placeholder structure according to the design requirements, and fill the groove structure of the molded blank with the placeholder structure fully coated with release agent. Encapsulate the complete blank with the embedded bundled optical fiber and placeholder structure, and transfer it to an autoclave to complete the curing process. The curing temperature is 200℃, the curing pressure is 0.6MPa, and the curing time is 6 hours, to obtain a carbon fiber reinforced composite material with the preset groove structure and embedded bundled optical fiber.

[0080] Vertical fiber insertion loss <1dB, and the tensile properties retention rate of carbon fiber reinforced composite material embedded in bundled fiber ≥90%.

[0081] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for embedding bundled optical fibers and vertically leading them out of a continuous fiber reinforced composite material, characterized in that, Includes the following steps: Bundled optical fibers are laid on a first prepreg substrate, wherein the bundled optical fibers are arranged at preset distances and are arranged in parallel on the first prepreg substrate, and an insulating material is placed in the contact area between the bundled optical fibers and the first prepreg substrate. The first prepreg matrix is ​​heated to enhance the bonding effect between the bundled optical fibers and the first prepreg matrix; A second prepreg matrix is ​​laid on top of the bundled optical fiber, and a composite material blank is formed by encapsulation. The composite material blank is then subjected to vacuum pre-compression heating treatment to enhance the bonding effect between the bundled optical fiber and the second prepreg matrix. In this case, an isolation material is placed in the contact area between the bundled optical fiber and the second prepreg matrix. A groove structure is formed by layer stacking in a preset area of ​​the second prepreg matrix, and a placeholder structure is filled in the groove structure position to encapsulate and form a complete blank, and the complete blank is cured and molded. After curing and molding, the occupant structure is removed from the second prepreg matrix, and the isolation material is removed. The bundled optical fiber can then be vertically led out and moved from the groove structure.

2. The method for embedding bundled optical fibers and vertically leading out of continuous fiber reinforced composite materials as described in claim 1, characterized in that, The process of filling the groove structure with a placeholder structure specifically includes the following steps: Apply the release agent thoroughly to the contact area between the spacer structure and the second prepreg matrix; Then fill the spacer structure into the groove structure position.

3. The method for embedding bundled optical fibers and vertically leading out of continuous fiber reinforced composite materials as described in claim 2, characterized in that, If the occupant structure is made of rigid material, a layer of flexible material is laid between the occupant structure and the bundled optical fibers.

4. The method for embedding bundled optical fibers and vertically leading out of continuous fiber reinforced composite materials as described in claim 1, characterized in that, The isolation material is an isolation film or a release cloth.

5. The method for embedding bundled optical fibers and vertically leading out of continuous fiber reinforced composite materials as described in claim 1, characterized in that, The preset distance is not less than 10mm.

6. The method for embedding bundled optical fibers and vertically leading out of continuous fiber reinforced composite materials as described in claim 1, characterized in that, Both the first prepreg matrix and the second prepreg matrix are prepregs with continuous fiber reinforcement.

7. The method for embedding bundled optical fibers and vertically leading out of continuous fiber reinforced composite materials as described in claim 6, characterized in that, The length direction of the bundled optical fiber is consistent with the length direction of the continuous fiber reinforcement in the first prepreg matrix, and the length direction of the bundled optical fiber is consistent with the length direction of the continuous fiber reinforcement in the second prepreg matrix.

8. The method for embedding bundled optical fibers and vertically leading out of continuous fiber reinforced composite materials as described in claim 7, characterized in that, The continuous fiber reinforcement is at least one of glass fiber, quartz fiber, aramid fiber, carbon fiber, and polyimide fiber.

9. The method for embedding bundled optical fibers and vertically leading out of continuous fiber reinforced composite materials as described in claim 1, characterized in that, The process of forming a groove structure in a predetermined area of ​​the second prepreg matrix by layer stacking specifically includes the following steps: Windows are formed by scribing in a predetermined area of ​​each layer of prepreg; The second prepreg matrix is ​​formed by stacking multiple layers of prepreg, and the windows are stacked to form the groove structure.

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