Hybrid Braided Composite Parts

Abstract

To provide a system and method for manufacturing hybrid composite components.SOLUTION: The method includes braiding a first set of fibers to form a knitted fabric having a closed cross-sectional shape, braiding a second set of fibers chemically different from the first set of fibers within the knitted fabric, impregnating the knitted fabric with a resin, and curing the resin within the knitted fabric to form a hybrid composite component.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE This disclosure relates to the field of manufacturing techniques, and more particularly to the manufacture of composite parts. [Background technology]

[0002] Fiber-reinforced composite parts can be used in a variety of applications. For example, filament-wound fiberglass parts can form fuel supply tubes for transporting fuel between aircraft compartments, and even between different aircraft. To dissipate static charges and increase safety, the fiberglass can be painted with conductive paint or covered with copper mesh. However, this requires that the copper mesh be attached to the tube. Furthermore, filament winding limits the number and type of entanglements between the fibers, which limits the versatility of composite parts manufactured in this way. Summary of the Invention [Problem to be solved by the invention]

[0003] Therefore, a method and apparatus that takes into account at least some of the above problems and other potential problems is desirable. [Means for solving the problem]

[0004] Embodiments of the present disclosure provide braided composite parts that include both glass and carbon fibers. Carbon fibers are electrically conductive and therefore capable of dissipating static charges. Furthermore, because carbon and glass fibers are structurally similar, both fibers can be braided "dry" and impregnated with the same resins (e.g., thermoset and thermoplastic resins) and cured. This eliminates the need for separate attachment and bonding of static dissipative elements to the resulting tubular composite part, while still providing increased strength and maintaining desired production rates.

[0005] One embodiment is a method for manufacturing a hybrid composite part that includes braiding a first set of fibers to form a braid having a closed cross-sectional shape, braiding a second set of fibers within the braid, the second set of fibers being chemically distinct from the first set of fibers, impregnating the braid with a resin, and curing the resin within the braid to form the hybrid composite part.

[0006] A further embodiment is a non-transitory computer readable medium having programmed instructions operatively programmed when executed by a processor to perform a method for manufacturing a hybrid composite part, the method including braiding a first set of fibers to form a braid having a closed cross-sectional shape, braiding a second set of fibers within the braid, the second set of fibers being chemically distinct from the first set of fibers, impregnating the braid with a resin, and curing the resin within the braid to form the hybrid composite part.

[0007] A further embodiment is an apparatus for manufacturing a hybrid composite part that includes a first spool storing a first set of fibers, a second spool storing a second set of fibers that are chemically distinct from the first set of fibers, and a braider that braids the first set of fibers to form a braid having a perimeter that defines a closed cross-sectional shape and braids the second set of fibers within the braid.

[0008] Yet another embodiment is a hybrid composite part-like product, the product including a matrix of cured resin and a braid having a closed cross-sectional shape, the braid including a first set of interwoven fibers and a second set of interwoven fibers that are chemically distinct from the first set of interwoven fibers.

[0009] The apparatus, medium and method of the present invention are also set forth in the following clauses which are separate from the claims.

[0010] Item 1 1. A method for manufacturing a hybrid composite part, comprising: Braiding the first set of fibers to form a braid having a closed cross-sectional shape (202); braiding (204) a second set of fibers within the braid, the second set of fibers being chemically different from the first set of fibers; impregnating the knitted fabric with resin (206); and curing (208) the resin in the braid to form a hybrid composite part.

[0011] Section 2 braiding the first set of fibers comprises braiding glass fibers; Item 11. The method of item 1, wherein braiding the second set of fibers comprises braiding carbon fibers.

[0012] Section 3 braiding the first set of fibers comprises braiding electrically insulating fibers; Item 11. The method of item 1, wherein braiding the second set of fibers comprises braiding electrically conductive fibers.

[0013] Section 4 4. The method of claim 3, further comprising braiding an electrically conductive third set of fibers to form a Faraday cage, wherein the first set of fibers is sandwiched between the second set of fibers and the third set of fibers.

[0014] Section 5 Item 11. The method of item 1, wherein braiding the second set of fibers places the second set of fibers in an open pattern.

[0015] Section 6 Item 10. The method of item 1, further comprising selecting a volume ratio of the first set of fibers to the second set of fibers based on a predetermined level of thermal conductivity and electrical conductivity of the hybrid composite part.

[0016] Section 7 2. The method of claim 1, further comprising induction welding the first set of fibers to the second set of fibers by applying an electromagnetic wave to the knit.

[0017] Section 8 Item 1. An aircraft part assembled by the method described in item 1.

[0018] Section 9 1. A non-transitory computer readable medium having programmed instructions operatively programmed, when executed by a processor, to perform a method for manufacturing a hybrid composite part, the method comprising: Braiding the first set of fibers to form a braid having a closed cross-sectional shape (202); braiding (204) a second set of fibers within the braid, the second set of fibers being chemically different from the first set of fibers; impregnating the knitted fabric with resin (206); and curing (208) the resin in the braid to form a hybrid composite part.

[0019] Section 10 braiding the first set of fibers comprises braiding glass fibers; 10. The medium of claim 9, wherein braiding the second set of fibers comprises braiding carbon fibers.

[0020] Section 11 braiding the first set of fibers comprises braiding electrically insulating fibers; 10. The medium of clause 9, wherein braiding the second set of fibers comprises braiding electrically conductive fibers.

[0021] Item 12 12. The medium of claim 11, further comprising braiding an electrically conductive third set of fibers to form a Faraday cage, wherein the first set of fibers is sandwiched between the second set of fibers and the third set of fibers.

[0022] Section 13 10. The medium of claim 9, wherein braiding the second set of fibers places the second set of fibers in an open pattern.

[0023] Item 14 10. The medium of claim 9, further comprising selecting a volume ratio of the first set of fibers to the second set of fibers based on a predetermined level of thermal conductivity and electrical conductivity of the hybrid composite part.

[0024] Item 15 10. The medium of clause 9, further comprising induction welding the first set of fibers to the second set of fibers by applying an electromagnetic wave to the knit.

[0025] Section 16 10. An aircraft part assembled in a manner determined by instructions stored on a computer readable medium as described in claim 9.

[0026] Section 17 1. An apparatus for manufacturing a hybrid composite part, comprising: a first spool (116) storing a first set of fibers (126); a second spool (118) storing a second set of fibers (128) that is chemically different from the first set of fibers; a braiding machine (140) for braiding the first set of fibers to form a braid (170) having a perimeter of a closed cross-sectional shape, and braiding a second set of fibers within the braid.

[0027] Section 18 20. The apparatus of claim 17, further comprising a mandrel (150), the braid being braided over the mandrel, the mandrel being positioned within the braid.

[0028] Section 19 20. The apparatus of claim 17, further comprising a controller (112) for directing operation of the braiding machine according to a numerically controlled (NC) program.

[0029] Section 20 the first set of fibers comprises glass fibers; Item 18. The apparatus of item 17, wherein the second set of fibers comprises carbon fibers.

[0030] Section 21 the first set of fibers comprises electrically insulating fibers; 20. The apparatus of claim 17, wherein the second set of fibers comprises electrically conductive fibers.

[0031] Section 22 Item 17. Manufacturing aircraft parts using the apparatus described in item 17.

[0032] Section 23 A hybrid composite part-like product, A matrix of a cured resin (162); and a knitted fabric (170) having a closed cross-sectional shape, the knitted fabric comprising: a first set of braided fibers (126); a second set of braided fibers (128) that is chemically distinct from the first set of braided fibers.

[0033] Section 24 the first set of fibers comprises glass fibers; 24. The article of claim 23, wherein the second set of fibers comprises carbon fibers.

[0034] Section 25 the first set of fibers comprises electrically insulating fibers; 24. The article of claim 23, wherein the second set of fibers comprises electrically conductive fibers.

[0035] Section 26 26. The article of claim 25, wherein the knit further comprises a third set of fibers that are electrically conductive, the first set of fibers being sandwiched between the second set of fibers and the third set of fibers, and the article forms a Faraday cage.

[0036] Section 27 24. The article of claim 23, wherein the second set of fibers is in an open pattern.

[0037] Section 28 1. A method for induction welding of composite parts, comprising: Obtaining (1202) a first composite part including fibers impregnated with a thermoplastic material; Obtaining a second composite part (1204) including a braided electrically conductive fiber impregnated with a thermoplastic material and a braided electrically insulating fiber; placing the first composite part in contact with the second composite part at locations occupied by the electrically conductive fibers (1206); and induction welding (1208) the first composite part to the second composite part at the location.

[0038] Section 29 29. The method of claim 28, wherein the first composite component comprises a tube having a first diameter and the second composite component comprises a tube having a second diameter larger than the first diameter.

[0039] Section 30 30. The method of claim 29, wherein the placing comprises nesting the first composite part within the second composite part such that a periphery of the first composite part contacts the second composite part.

[0040] Section 31 29. The method of claim 28, wherein the first composite component comprises a tube having a first diameter and the second composite component comprises a tube having a second diameter smaller than the first diameter.

[0041] Section 32 32. The method of claim 31, wherein the placing comprises nesting the second composite part within the first composite part such that a periphery of the second composite part contacts the first composite part.

[0042] Item 33 30. The method of claim 28, wherein the induction welding is performed by passing an induction coil around the second composite part.

[0043] Section 34 29. The method of claim 28, wherein the induction welding is performed by rotating the second composite part.

[0044] Section 35 30. The method of claim 28, wherein induction welding comprises exposing electrically conductive fibers located on an exterior of the second composite part to a magnetic field.

[0045] Section 36 30. The method of claim 28, wherein induction welding comprises exposing electrically conductive fibers located on an interior surface of the second composite part defining the hollow portion to a magnetic field.

[0046] Section 37 29. An aircraft part assembled by the method described in paragraph 28.

[0047] Section 38 A non-transitory computer readable medium having programmed instructions operatively programmed, when executed by a processor, to perform a method of induction welding a hybrid composite component, the method comprising: Obtaining (1202) a first composite part including fibers impregnated with a thermoplastic material; Obtaining a second composite part (1204) including a braided electrically conductive fiber impregnated with a thermoplastic material and a braided electrically insulating fiber; placing the first composite part in contact with the second composite part at locations occupied by the electrically conductive fibers (1206); and induction welding (1208) the first composite part to the second composite part at the location.

[0048] Section 39 40. The medium of claim 38, wherein the first composite component comprises a tube having a first diameter and the second composite component comprises a tube having a second diameter greater than the first diameter.

[0049] Section 40 40. The medium of claim 38, wherein the placing comprises nesting the first composite part within the second composite part.

[0050] Section 41 40. The medium of claim 38, wherein the first composite component comprises a tube having a first diameter and the second composite component comprises a tube having a second diameter smaller than the first diameter.

[0051] Section 42 42. The medium of claim 41, wherein the placing comprises nesting the second composite part within the first composite part such that a periphery of the second composite part contacts the first composite part.

[0052] Section 43 40. The medium of claim 38, wherein the induction welding is performed by orbiting an induction coil around the second composite part.

[0053] Section 44 40. The medium of claim 38, wherein the induction welding is performed by rotating the second composite part.

[0054] Section 45 40. The medium of claim 38, wherein induction welding comprises exposing electrically conductive fibers located on an exterior of the second composite part to a magnetic field.

[0055] Section 46 40. The medium of claim 38, wherein induction welding comprises exposing electrically conductive fibers located on an interior surface of the second composite part defining the hollow portion to a magnetic field.

[0056] Section 47 39. An aircraft component assembled according to a method determined by instructions stored on a computer readable medium as described in claim 38.

[0057] Section 48 1. A system for forming an induction weld between composite components, comprising: a first composite part (1010) comprising fibers impregnated with a thermoplastic material; a second composite component (1020) including braided electrically conductive fibers impregnated with a thermoplastic material and braided electrically insulating fibers, the second composite component being held in contact with the first composite component at a location occupied by the electrically conductive fibers; an induction coil (1030) that orbits the composite part while generating a magnetic field.

[0058] Section 49 49. The system of claim 48, wherein the first composite part comprises a tube having a first diameter, the second composite part comprises a tube having a second diameter larger than the first diameter, and the first composite part is nested within the second composite part.

[0059] Item 50 49. The system of claim 48, wherein the first composite part comprises a tube having a first diameter, the second composite part comprises a tube having a second diameter smaller than the first diameter, and the second composite part is nested within the first composite part.

[0060] Section 51 49. The system of claim 48, wherein the first composite part and the second composite part form a longitudinal lap joint.

[0061] Section 52 49. The system of claim 48, wherein the second composite part comprises an exterior on which the electrically conductive fibers are disposed.

[0062] Section 53 49. The system of claim 48, wherein the second composite part has an interior surface defining a hollow portion in which the electrically conductive fiber is disposed.

[0063] Section 54 49. The system of claim 48, wherein the electrically insulating fibers comprise glass fibers.

[0064] Section 55 49. The system of claim 48, wherein the electrically conductive fibers comprise carbon fibers.

[0065] Section 56 Item 49. Manufacturing aircraft parts using the system described in item 48.

[0066] Other exemplary embodiments (e.g., methods and computer-readable media relating to the above embodiments) are described below. The described features, functions, and advantages may be achieved independently in various embodiments or may be combined in yet other embodiments, the details of which can be understood with reference to the following description and drawings.

[0067] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings in which the same reference numbers represent the same or similar elements, in which: [Brief description of the drawings]

[0068] [Figure 1] FIG. 1 is a block diagram of a manufacturing environment including a hybrid braiding system in an exemplary embodiment. [Diagram 2] 1 is a flow chart illustrating a method for manufacturing an exemplary embodiment hybrid braided composite part. [Diagram 3]FIG. 2 is a perspective view of a braiding machine for producing an exemplary embodiment preform. [Figure 4] FIG. 1 is a perspective view of an exemplary embodiment hybrid braided composite component. [Diagram 5] FIG. 1 illustrates an enlarged view of a portion of a braid of an exemplary embodiment hybrid braided composite. [Figure 6] FIG. 1 illustrates an enlarged view of a portion of a braid of an exemplary embodiment hybrid braided composite. [Figure 7] FIG. 1 is a front view of an exemplary embodiment hybrid braided composite component. [Figure 8] FIG. 1 is a front view of an exemplary embodiment hybrid braided composite component. [Figure 9] FIG. 1 is a system diagram illustrating resin infusion and autoclaving of a preform for an exemplary embodiment hybrid braided composite part. [Figure 10] 1 is a cross-sectional view of a hybrid braided composite component undergoing induction welding according to an exemplary embodiment; [Figure 11] 1 is a cross-sectional view of a hybrid braided composite component undergoing induction welding according to an exemplary embodiment; [Figure 12] 1 is a flow chart illustrating a method for induction welding an exemplary embodiment hybrid braided composite component. [Figure 13] 1 is a cross-sectional view of a further hybrid braided composite component according to an exemplary embodiment. [Figure 14] 1 illustrates a flowchart of an aircraft manufacturing and repair method in accordance with an illustrative embodiment. [Figure 15] FIG. 1 is a block diagram of an aircraft in an illustrative embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0069] The drawings and the following description provide specific and exemplary embodiments of the present disclosure. It should be understood that a person skilled in the art can conceive of various arrangements for implementing the principles of the present disclosure even if they are not explicitly described or illustrated in the present application, and that they are also included in the scope of the present disclosure. Furthermore, all examples described in the present application are intended to aid in the understanding of the principles of the present disclosure, and are not limited to the specifically described examples and conditions. In other words, the present disclosure is not limited to the specific embodiments and examples described below, but is defined by the claims and their equivalents.

[0070] Composite parts, such as carbon fiber reinforced polymer (CFRP) parts, are first laid up in multiple layers, collectively referred to as preforms. The individual fibers within each layer of the preform are aligned parallel to one another, but different layers may exhibit different fiber orientations and different dimensions to enhance the strength of the resulting composite part. The preform may contain a viscous resin that solidifies to cure the preform into a composite part (e.g., for an aircraft). Fibers impregnated with uncured thermosetting or thermoplastic resins are referred to as "prepregs." Other types of fibers include "dry fibers" that are not impregnated with thermosetting resins, but may contain tackifiers and binders. Dry fibers may be infused with resin before curing. For thermosetting resins, the cure is a unidirectional process, but for thermoplastic resins, the resin may be reheated to a viscous form.

[0071] 1 is a block diagram of a manufacturing environment 100 including an exemplary embodiment of a hybrid braiding system 110. The hybrid braiding system 110 comprises any systems, components, or devices operable to perform three-dimensional braiding of chemically distinct fibers to form a preform for a hybrid composite part. In one embodiment, the hybrid braiding system 110 braids carbon and glass fibers together into a braid for a preform.

[0072] 1, the hybrid braiding system 110 includes a controller 112 that instructs the components of the hybrid braiding system 110 according to a numerical control (NC) program stored in a memory 114. For example, the controller 112 may operate a braiding machine 140 according to the NC program. The controller 112 may be implemented, for example, as custom circuitry, a hardware processor that executes programmed instructions, or a combination thereof.

[0073] The hybrid braiding system 110 further comprises a spool 116 supplying a first type of fiber 126 and a spool 118 supplying a second type of fiber 128. The fiber 128 is chemically different from the fiber 126 (e.g., exhibits a different chemical structure than the fiber 126). The braiding machine 140 combines the fibers 126 and the fibers 128 into a braid according to instructions from the controller 112. In one embodiment, the braiding machine 140 comprises an industrial braiding machine that produces preforms for tubular composite parts.

[0074] 1 further illustrates preform 160 including a woven fabric 170 including fibers 126 and fibers 128. The fabric has a periphery that defines a closed cross-sectional shape. The fabric 170 of preform 160 may be braided over and surround mandrel 150 resulting in preform 160 having a tubular shape, with mandrel 150 being placed within preform 160. In some embodiments, preform 160 comprises prepreg that is pre-impregnated with resin 162. In such embodiments, resin 162 is already impregnated into fibers 126 and fibers 128 during storage on spools 116 and 118, for example in the form of a prepreg tape.

[0075] An exemplary operation of the hybrid braiding system 110 is described in detail with reference to Figure 2. In this embodiment, it is assumed that the fibers 126 and the fibers 128 are held on spools in a braiding machine 140, and the controller 112 is loaded with an NC program for producing a particular type of braided preform for a hybrid composite part.

[0076] 2 is a flow chart illustrating a method 200 for manufacturing a hybrid braided composite component according to an exemplary embodiment. Although the steps of the method 200 are described with respect to the manufacturing environment 100 of FIG. 1, one of ordinary skill in the art will appreciate that the method 200 may be performed in other systems. Not all steps of the flow chart described herein may include other steps not shown. Additionally, the steps described herein may be performed in a different order.

[0077] In step 202, the controller 112 directs the braider 140 to braid a first set of fibers 126 (e.g., electrically insulating glass fibers) to form a braid 170 having a closed cross-sectional shape. In one embodiment, the fibers 126 are applied in different patterns around the circumference of the mandrel 150 such that the fibers 126 form a braid. The braid may comprise an open pattern braid, may comprise a biaxial or triaxial braid, may comprise other shapes or patterns exhibiting desired fiber angles, or a combination thereof.

[0078] In step 204, the controller 112 directs the braider 140 to braid the second set of fibers 128 (e.g., electrically conductive carbon fibers) into the braid 170. This includes weaving the fibers 128 into the braid formed in step 202. In one embodiment, the second set of fibers 128 are woven into an outer portion of the braid (e.g., an outer surface of the preform 160), while in another embodiment, the second set of fibers 128 are woven into an inner portion of the braid (e.g., forming an inner surface of the preform 160 adjacent the mandrel 150). In a further embodiment, braiding the second set of fibers includes braiding the second set of fibers into an open pattern (e.g., an open pattern). ).

[0079] As mentioned above, the second set of fibers 128 are chemically different from the first set of fibers 126. This allows the fibers 128 to perform a different role than the fibers 126 by making the braid 170 conductive (instead of insulating) or by adjusting the structural properties of the braid 170, for example replacing the function of the copper mesh to which it is bonded. In one embodiment, the fibers 128 are applied in a different pattern integrated into the braid 170, so that the fibers 128 are interwoven with the fibers 126. Although the fibers 128 are chemically different from the fibers 126, this does not preclude the fibers 128 and the fibers 126 from being the same size (e.g., the same diameter and length). An embodiment in which the fibers are the same size provides the advantage of simplifying the braiding process and ensuring that the resulting preform is physically uniform.

[0080] Steps 202-204 can be repeated in any desired order until a fully convoluted preform 160 is produced. In one embodiment, the number and type of repetitions of steps 202-204 are determined by selecting a volume ratio of the first set of fibers to the second set of fibers based on the desired / predetermined levels of thermal and electrical conductivity of the hybrid composite part. As used herein, fiber volume ratio is the ratio of the volume occupied by one set of fibers to the volume occupied by the other set of fibers.

[0081] In further embodiments, additional sets of fibers that are chemically distinct from the other sets of fibers are incorporated into the braid 170 as part of the braiding process. For example, a Faraday cage (e.g., an arrangement of fibers that eliminates electrostatic and electromagnetic influences) may be formed by braiding a third set of electrically conductive fibers into the braid, where in one embodiment the first set of fibers is electrically insulating and sandwiched between the second and third sets of electrically conductive fibers. The preform 160 may then be removed from the braiding machine 140 and / or mandrel 150 as desired. In further embodiments, the electrically conductive and electrically insulating braids are formed separately and the braids are layered over one another like a sleeve.

[0082] In step 206, the braid 170 is impregnated with a resin 162, such as a thermoplastic or thermosetting resin. In embodiments where the resin is thermosetting, the resin is applied at ambient temperature. In contrast, in embodiments where the resin is thermoplastic, the resin is applied at or near its melting point. In embodiments where the fibers are incorporated into a prepreg tape, step 206 is performed as part of steps 202-204. In embodiments where the preform 160 is braided as a dry preform, the preform 160 is transferred to a separate chamber for impregnation with the resin. In some embodiments, the preform 160 is further consolidated to give the preform 160 a desired shape.

[0083] In step 208, the resin 162 in the braid 170 is cured to form a hybrid composite part. In the case of a thermoplastic resin, the thermoplastic resin is cooled below its melting point. In the case of a thermosetting resin, the thermosetting resin is heated to a curing temperature.

[0084] Method 200 provides technical advantages over conventional braid preform manufacturing methods because it allows for the rapid production of hybrid braid preforms with a variety of unique structural and electrical properties resulting from the combination of fibers with different chemical compositions. Furthermore, because the different types of fibers are added / incorporated as part of the braiding process rather than as part of an additive process, the production of the hybrid braid preform does not slow down the manufacturing process, allowing the manufacturing process to continue at the rate currently being performed, i.e., without the need for an additional step of gluing the copper mesh.

[0085] FIG. 3 is a perspective view of a robot 310 (braiding robot) for manufacturing the preform of the exemplary embodiment. In this embodiment, the robot 310 comprises a part of an industrial braid layup system 300. In the industrial braid layup system 300, a plurality of bobbins 330 having lanes 332 of fiber tape are arranged in a circumferential pattern (e.g., along a frame 320). The different fiber tape lanes comprise fibers of different chemical compositions, and the fiber tape lanes 332 can be realized as prepregs or dry fiber tapes. An end effector 312 of the robot 310 controls the axial displacement in a direction A, and the bobbins 330 move dynamically along the frame 320 in a direction 342 and move in a controlled planetary orbit around the preform 350 relative to each other to place the lanes 332 on the preform 350 in a manner that results in a braid. The movement of the lanes in a direction 340 produces a braid along the outside of a cylindrical mandrel (not shown, but present below the preform 350).

[0086] FIGURE 4 is a perspective view of an exemplary embodiment hybrid braided composite component 400. In FIGURE 4, the hybrid braided composite component 400 includes a braid 410 within a matrix 430 of a cured resin. The braid includes a first set of woven fibers 440 and a second set of woven fibers 450 that are chemically different from the first set of woven fibers. The braid 410 has a closed cross-sectional shape that results in a hollow portion 420. During manufacturing, a layup mandrel replaces the hollow portion 420. The back side of the layup mandrel is not shown for clarity.

[0087] 5-6 are close-up views of a portion of the braid of the hybrid braided composite part 400 of an exemplary embodiment, corresponding to portion 5 of FIG. 4. These figures provide examples of the interweaving of different types of fibers. According to FIG. 5, the fibers 510 and fibers 520 in the braid 500 are chemically different and run both left and right along the diamond shape of the braid 500. The fibers 510 and fibers 520 alternate to provide the braid 500 with desired chemical and / or structural properties. These types of patterns may result in the fibers 520 forming a "knit within a braid," with the fibers 520 interwoven with the fibers 510 and with each other. Although the fibers are illustrated as interwoven with each other, in further embodiments, the fibers are repeated in a predetermined amount or ratio to provide the desired properties. In still further embodiments, certain layers, such as layers on the inner or outer surfaces of the preform or layers within the preform, are formed of only one type of fiber, while other layers are interwoven with each other.

[0088] Figure 6 shows a similar case to Figure 5, except that while fibers 610 in braid 600 run both left and right, fibers 620 run in only one direction. This allows fibers 620 to form a striped pattern, while fibers 610 form a weaved pattern that is woven into the striped pattern. This arrangement of fibers with different chemical compositions may be particularly desirable if fibers 620 provide electrical conductivity to allow dissipation of static charges, as fibers 620 can be spaced further apart if necessary and do not need to be weaved.

[0089] 7-8 are front views of an exemplary embodiment of a hybrid braided composite component. FIGS. 7-8 correspond to arrow 7 in FIG. 4 and provide other possible braiding configurations. In FIG. 7, the hybrid braided composite component 400 includes an outer layer 710 of fibers that are electrically conductive to dissipate static charges. The electrical conductivity of the outer layer 710 can be highly controlled to provide protection against lightning strikes and similar events while allowing for the dissipation of static charges. For example, the outer layer 710 can be designed to have a resistance of 10 megaohms (MΩ). In a further example, the electrically conductive fibers of the outer layer 710 can act as a fuse to stop the conduction of electrical energy in response to a high amperage event.

[0090] The hybrid braided composite component 400 also includes an inner layer 720 of electrically insulating fabric. For example, the outer layer 710 may form a Faraday cage, bandpass filter, or bandstop filter for electrical energy. The layers are woven together. Additionally, the hybrid braided composite component 400 forms a closed tubular shape through which a fluid (e.g., fuel) can flow.

[0091] In Figure 8, a wiring harness 810 is disposed within the hollow portion 20 of the hybrid braided composite part. This arrangement of conductive and optionally insulated fibers in the outer layer 710 or inner layer 720 forms a Faraday cage that surrounds the hollow portion 420 of the part. This electrically isolates the wiring harness 810 from other sources of electrical energy that may be present in the aircraft.

[0092] Figure 9 is a system diagram illustrating resin infusion and autoclaving of a preform 910 for a hybrid braided composite part of an exemplary embodiment. As shown in Figure 9, after the preform 910 is removed from the braiding machine and / or mandrel, it is placed into a resin infusion chamber 920 where resin is added into the braid of the preform through the application of pressure and / or heat. The preform 910 is then consolidated and / or cured in an autoclave 930 prior to curing into a composite part.

[0093] Further description provided herein relates to performing induction welding of suitable combinations of the hybrid braided composite components described above. Figures 10-11 are cross-sectional views of an exemplary embodiment of a hybrid braided composite component (e.g., any of the hybrid braided composite components described above) undergoing induction welding.

[0094] In FIG. 10, a first composite component 1010 (e.g., a tube) includes a layer 1012 of fiber impregnated with a thermoplastic material (e.g., PEEK (polyetheretherketone), PEKK (polyetherketoneketone)) having an exterior surface / outside 1014. The first composite component 1010 has a diameter D1 that is smaller than a diameter D2 of a second composite component 1020 (e.g., another tube). The second composite component 1020 includes an outer layer 1022 of electrically insulating braided fiber (e.g., fiberglass) and further includes an inner layer 1024 of electrically conductive braided fiber (e.g., carbon fiber) (or a combination of insulating and conductive fibers). The inner layer 1024 includes an inner surface 1026 that defines a hollow portion 1028 of the second composite component 1020 within which the first composite component 1010 nests. An induction coil 1030 orbits around the second composite part 1020 while generating a magnetic field, which causes the electrically conductive fibers to act as susceptors and generate heat, which heats the thermoplastic above its melting point. The molten thermoplastics in the two composite parts intermix and, after cooling, the two composite parts become one integral part.

[0095] In FIG. 11, a first composite component 1110 (e.g., a tube) includes a layer 1112 of fibers (e.g., insulating fibers such as fiberglass) impregnated with a thermoplastic (e.g., PEEK, PEKK). The first composite component 1110 has a diameter D1 that is greater than a diameter D2 of a second composite component 1120 (e.g., another tube). The layer 1112 includes an inner surface 1114 that defines a hollow portion 1116 of the first composite component 1110 within which a second composite component 1120 nests. The second composite component 1120 includes an inner layer 1122 of electrically insulating braided fibers and further includes an outer layer 1124 of electrically conductive braided fibers (or a combination of insulating and conductive fibers). The outer layer 1124 defines an outer surface / outside 1126 of the second composite component 1120. An induction coil 1130 orbits around the second composite part 1120 while generating a magnetic field. In a further embodiment, the composite part is rotated about its center and the surface of the composite part is moved along an arc relative to the induction coil to facilitate induction welding. This causes the electrically conductive fibers to act as a susceptor and generate heat that heats the thermoplastic above its melting point. In an embodiment where the outer composite part provides electrical insulation, the induction coil may be moved along the inside of the composite part. Additionally, the temperature away from the weld interface may be kept below a desired level (e.g., below the melting point of the thermoplastic) by design. For example, the placement of glass fibers, as opposed to carbon fibers, may help control the temperature at and around the weld interface (i.e., by reducing the amount of induction heating that occurs at a particular location). At the weld interface (and / or elsewhere), the molten thermoplastic in the two composite parts intermixes and, after cooling, the two composite parts become one integral part.

[0096] 12 is a flow chart illustrating a method 1200 for induction welding a hybrid braided composite component according to an example embodiment. Step 1202 includes obtaining a first composite part 1010 including fibers impregnated with a thermoplastic resin. This may include a technician or a robotic arm picking up the first composite part 1010 and placing it in a desired location.

[0097] Step 1204 comprises obtaining a second composite part 1020 including braided electrically conductive fibers impregnated with a thermoplastic resin and braided electrically insulating fibers. Step 1204 may be performed similarly to step 1202.

[0098] Step 1206 comprises placing the first composite component 1010 in contact with the second composite component 1020 at the location of the electrically conductive fibers. That is, the composite components are placed together such that the first composite component 1010 contacts the location of the second composite component 1020 where the electrically conductive fibers are woven (e.g., the inner layer 1024). In some embodiments, this includes nesting one composite component inside the other composite component to make an extension tube. This means that the periphery of one component may contact the other component. That is, the placement of the first composite component ensures that the electrically conductive fibers are placed at the desired weld interface. In further embodiments, the periphery of one composite component contacts the other composite component.

[0099] Step 1208 comprises induction welding the first composite component to the second composite component at the location. In one embodiment, induction welding is performed by orbiting an induction coil 1030 around the second composite component 1020. In a further embodiment, the second composite component 1020 (and / or the first composite component) is rotated while the induction coil 1030 remains in place. In an embodiment in which tubular composite components are welded together, induction welding comprises exposing electrically conductive fibers located on the exterior (or interior surface defining the hollow portion) of the second composite component to a magnetic field. This heats the electrically conductive fibers of the second composite component 1020 causing the thermoplastic material at the intersections of the composite components to melt and intermingle. Upon cooling, the thermoplastic material solidifies into a single, integral component. In a further embodiment, induction welding the first set of fibers to the second set of fibers may be performed by applying an electromagnetic field to the braid.

[0100] Figure 13 is a cross-sectional view of a further example embodiment hybrid braided composite part 1300. According to Figure 13, multiple fiberglass layers 1320 are laid up or braided on a mandrel 1310. Then, fewer carbon fiber layers 1330 are laid up on top of the fiberglass layers 1320, and one to two additional fiberglass layers 1340 are placed on top of the carbon fiber layers 1330. During induction welding, heating of the carbon fibers in the carbon fiber layers 1330 melts the thermoplastic of the one to two additional fiberglass layers.

[0101] example In the following examples, additional processes, systems and methods are described with respect to preforms for hybrid braided composite parts.

[0102] More specifically, with reference to the drawings, embodiments of the present disclosure may be described with respect to an aircraft manufacturing and service method 1400 as shown in FIG. 14 and an aircraft 1402 as shown in FIG. 15. During pre-production, the method 1400 may include specification design 1404 and material procurement 1406 of the aircraft 1402. During production, component and subassembly manufacturing 1408 and system integration 1410 of the aircraft 1402 occurs. The aircraft 1402 may then undergo certification and delivery 1402 and enter service 1414. While in service with a customer, the aircraft 1402 is scheduled for routine repair and service 1416 (which may include modification, rebuild, conversion, etc.). Apparatus and methods embodied herein may be used during one or more appropriate stages of manufacturing and maintenance method 1400 (e.g., specification design 1404, material procurement 1406, component and subassembly manufacturing 1408, system integration 1410, certification and delivery 1412, in-service 1414, repair and maintenance 1416) and / or in appropriate parts of aircraft 1402 (e.g., airframe 1418, systems 1420, interior 1422, propulsion system 1424, electrical system 1426, hydraulic system 1428, environmental system 1430).

[0103] Each process of method 1400 may be performed by a system integrator, a third party, and / or an operator (e.g., a customer). For purposes of illustration, a system integrator may include, but is not limited to, an aircraft manufacturer, a major system subcontractor, a third party may include, but is not limited to, a vendor, a subcontractor, a supplier, and an operator may be an airline, a leasing company, a military, a maintenance contractor, etc.

[0104] 15 , an aircraft 1402 produced by method 1400 may include an airframe 1418, a number of systems 1420, and an interior 1422. Examples of systems 1420 include one or more of a propulsion system 1424, an electrical system 1426, a hydraulic system 1428, and an environmental system 1430. Any number of other systems may also be included. Although an aerospace example is shown, the principles of the invention are applicable to other industries, such as the automotive industry.

[0105] As discussed above, the apparatus and methods implemented herein may be used during one or more stages of manufacturing and service method 1400. For example, the components and subassemblies corresponding to component and subassembly manufacturing 1408 may be manufactured similar to the components and subassemblies manufactured while the aircraft 1402 is in service. Also, one or more apparatus embodiments, method embodiments, or a combination thereof may be used during subassembly manufacturing 1408 and / or system integration 1410, for example, to expedite or reduce the cost of assembly of the aircraft 1402. Similarly, one or more apparatus embodiments, method embodiments, or a combination thereof may be used during the in-service of the aircraft 1402, for example, but not limited to, during repair and service 1416. For example, the methods and systems described herein may be used during material procurement 1406, component and subassembly manufacturing 1408, system integration 1410, in-service 1414, and / or repair and service 1416, and / or the airframe 1418 and / or interior 1422. These methods and systems may also be used in systems 1420 , such as propulsion system 1424 , electrical system 1426 , hydraulic system 1428 , and / or environmental system 1430 .

[0106] In one embodiment, the parts comprise a portion of the airframe 1418 and are manufactured during part and subassembly manufacturing 1408. The parts are then assembled into the aircraft during system integration 1410 and may then be utilized in service 1414 until wear renders the parts unusable. The parts may then be scrapped and replaced with newly manufactured parts during repair and maintenance 1416. The parts and methods of the present invention may be utilized during part and subassembly manufacturing 1408 to manufacture brand new parts.

[0107] Any of the various control elements (e.g., electrical or electronic elements) shown and described herein may be implemented as hardware, a processor executing software, a processor executing firmware, or a combination thereof. Dedicated hardware elements may be referred to as a "processor," "controller," or similar terminology. When provided by a processor, the functionality may be provided by a single dedicated processor, by a single shared processor, or by multiple individual processors (some of which may be shared). Furthermore, the explicit use of the terms "processor" and "controller" should not be construed as referring only to hardware capable of executing software, but may implicitly include, without limitation, digital signal processor (DSP) hardware, network processors, application specific integrated circuits (ASICs), other circuitry, field programmable gate arrays (FPGAs), read only memory (ROM) for storing software, random access memory (RAM), non-volatile storage, logic, and other physical hardware components or modules.

[0108] A control element may also be embodied as instructions executable by a processor or computer to perform the functions of the element. Examples of instructions are software, program code, and firmware. The instructions operate when executed by a processor to direct the processor to perform the functions of the element. The instructions may be stored in a storage device readable by the processor. Examples of storage devices are digital memory, solid state memory, magnetic storage media such as magnetic disks and magnetic tapes, hard drives, and optically readable digital data storage media.

[0109] Although specific embodiments are described herein, the scope of the disclosure is not limited to these specific embodiments, but is defined by the appended claims and their equivalents. [Explanation of symbols]

[0110] 400 Hybrid Braided Composite Parts 410 Knitting 420 Hollow part 430 Hardened resin matrix 440 First set of braided fibers 450 Second set of braided fibers

Claims

1. 1. A method for manufacturing a hybrid composite part, comprising: While braiding (202) a first set of fibers to form a braid having a closed cross-sectional shape on a mandrel, braiding (204) a second set of fibers having an electrical conductivity different from that of the first set of fibers on an inner or outer portion of the braid; impregnating the braid with resin (206); and curing (208) the resin in the braid to form a hybrid composite part.

2. braiding the first set of fibers comprises braiding glass fibers; The method of claim 1 , wherein braiding the second set of fibers comprises braiding carbon fibers.

3. braiding the first set of fibers comprises braiding electrically insulative fibers; The method of claim 1 , wherein braiding the second set of fibers comprises braiding electrically conductive fibers.

4. 4. The method of claim 3, further comprising forming a Faraday cage by braiding an electrically conductive third set of fibers, the first set of fibers being sandwiched between the second set of fibers and the third set of fibers.

5. The method of claim 1 , wherein braiding the second set of fibers forms the second set of fibers into an open pattern.

6. The method of claim 1 , further comprising selecting a volume ratio of the first set of fibers to the second set of fibers based on a predetermined level of thermal conductivity and electrical conductivity of the hybrid composite part.

7. 1. A non-transitory computer readable medium having programmed instructions operatively programmed when executed by a processor to perform a method for manufacturing a hybrid composite part, the method comprising: While braiding (202) a first set of fibers to form a braid having a closed cross-sectional shape on a mandrel, braiding (204) a second set of fibers having an electrical conductivity different from that of the first set of fibers on an inner or outer portion of the braid; impregnating the braid with resin (206); and curing (208) the resin in the braid to form a hybrid composite part.

8. 1. An apparatus for manufacturing a hybrid composite part, comprising: a first spool (116) storing a first set of fibers (126); a second spool (118) storing a second set of fibers (128) having an electrical conductivity different from that of the first set of fibers; A mandrel (150); a braider (140) that braids the first set of fibers to form a braid on the mandrel having a perimeter that forms a closed cross-sectional shape while braiding the second set of fibers onto an inner or outer portion of the braid.

9. The apparatus of claim 8, wherein the mandrel is located within the knitted fabric.

10. 10. The apparatus of claim 8, further comprising a controller (112) that directs operation of the braider according to a numerically controlled (NC) program.

11. the first set of fibers comprises electrically insulating fibers; The apparatus of claim 8 , wherein the second set of fibers comprises electrically conductive fibers.

12. A hybrid composite part-like product, A matrix of cured resin (162); A knitted fabric (170) having a closed cross-sectional shape, said knitted fabric comprising: a first set of braided fibers (126) comprising electrically insulating fibers; a second set of woven fibers (128) comprising electrically conductive fibers and having a different electrical conductivity than the first set of woven fibers; a third set of interwoven fibers that are electrically conductive; and Equipped with the third set of fibers is braided to form a Faraday cage; the first set of fibers being sandwiched between the second set of fibers and the third set of fibers; product.

13. the first set of woven fibers comprises glass fibers; The article of claim 12 , wherein the second set of braided fibers comprises carbon fibers.

14. the first set of interwoven fibers comprises electrically insulating fibers; The article of claim 12 , wherein the second set of interwoven fibers comprises electrically conductive fibers.

15. 13. The article of claim 12, wherein the second set of fibers forms an open pattern.

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