Composite structure consisting of a wound tubular braid

Abstract

The present invention relates to a composite structure composed of a wound tubular braid. A system for constructing a composite structure includes a braiding machine, a winding tool and a forming machine. The composite structure is composed of a wound tubular braid. The wound tubular braid is composed of a biaxial or triaxial tubular braid of unidirectional strips.

Description

Technical Field

[0001] The present disclosure relates to composite structures. More particularly, the present disclosure relates to a composite structure comprised of a coiled tubular braid. Background Art

[0002] More and more composite materials are being used in aircraft. Composite materials generally include reinforcing fibers bonded to a polymer resin matrix. The fibers may be unidirectional. Alternatively, the fibers may take the form of a woven cloth or fabric. The fibers and polymer resin are arranged and cured to form a composite structure. Some examples of composite materials that may be used in aircraft include aircraft windows and door frames.

[0003] There are various challenges when using traditional processes to manufacture composite structures. For example, a round or oval composite part may require a specific layup plan to produce the layup. The layup plan is often controlled by the limitations of existing processes. Examples of these existing processes include fiber placement or fabric manufacturing machines. However, fiber placement or fabric manufacturing machines are often specifically customized for a specific configuration or final structure of the finished product. Current processes based on automated fiber placement or weaving fabrics are expensive, time consuming, and may not be advantageous for parts with tight radius.

[0004] Some composite parts require apertures or holes defined within the structure. For example, aircraft window frames define holes. For composite parts with holes, orienting the reinforcing fibers can be particularly difficult and laborious. In addition, when using conventional manufacturing processes to manufacture composite parts with holes, a relatively large amount of material waste can be generated.

[0005] Therefore, while current methods and systems for manufacturing composite structures achieve their intended purposes, a need exists for a new and improved system and method for manufacturing composite structures. Summary of the invention

[0006] According to several aspects, a composite structure is disclosed. The composite structure includes a shaped roll formed of a tubular braid.

[0007] In another aspect of the present disclosure, a composite structure including a biaxial braid formed into a coil is disclosed.

[0008] According to several aspects, a composite structure including a biaxially braided tubular braid is disclosed.

[0009] In another aspect of the present disclosure, a composite laminate structure including a plurality of plies is disclosed. The composite structure includes biaxially woven fibers oriented in the same direction for each of the plurality of plies.

[0010] In another aspect of the present disclosure, a braiding machine is disclosed, which includes a mandrel, a braiding mechanism having reels that can all move relative to the mandrel, a unidirectional strip wound around each reel, a guide ring, and a control module. The guide ring guides the unidirectional strip wound around the corresponding reel onto the mandrel. The control module is in electronic communication with the braiding mechanism. The control module executes instructions to guide the movement of multiple reels so as to place the unidirectional strip on the mandrel to form a tubular braid.

[0011] In another aspect of the present disclosure, an apparatus for manufacturing a composite structure of a wound tubular braid is disclosed. The apparatus includes a tool defining an outer surface, a device for winding a tubular braid around the outer surface of the tool to produce a composite preform, a forming device for consolidating the composite preform, and a control module. The control module is in electronic communication with the device and the forming device. The control module executes instructions to direct the device to wind the tubular braid around the outer surface of the tool and operate the forming device to consolidate the composite preform.

[0012] According to several aspects, a method of forming a composite structure is disclosed. The method includes forming a wound tubular braid into a composite structure.

[0013] In yet another aspect of the present disclosure, a method of making a composite preform is disclosed. The method includes winding a tubular braid of unidirectional fibers while allowing the unidirectional fibers to shift relative to each other without bending.

[0014] In another aspect of the present disclosure, a method of forming a tubular braid is disclosed. The method includes braiding unidirectional strips into a tubular braid.

[0015] In another aspect of the present disclosure, a coiled tubular braid for a composite structure is disclosed. The coiled tubular braid includes a tubular braid coiled into a spiral shape.

[0016] This disclosure also includes the following clauses.

[0017] 1. A composite structure 26 comprising:

[0018] A shaped roll is formed from the tubular braid 22 .

[0019] 2. The composite structure 26 of clause 1, wherein the tubular braid 22 is selected from the group consisting of: unidirectional straps 32 and unidirectional drag straps.

[0020] 3. The composite structure 26 of clause 2, wherein the unidirectional strips 32 include unidirectional fibers 54.

[0021] 4. The composite structure 26 of clause 3, wherein the unidirectional fibers 54 are pre-impregnated with resin.

[0022] 5. The composite structure 26 of clause 4, wherein the resin is a thermosetting resin.

[0023] 6. The composite structure 26 of clause 4, wherein the resin is a thermoplastic.

[0024] 7. The composite structure 26 of any one of clauses 1 to 6, wherein the tubular braid 22 is constructed of a material selected from the group consisting of: thermoplastics cut into strips, thermoset strips that are substantially non-tack at room temperature, bonded dray roving prepregs to which an epoxy resin or thermoplastic adhesive is applied, substantially non-tack thermoset prepregs, and low-tack thermoset prepregs.

[0025] 8. The composite structure 26 of any of clauses 1 to 7, wherein the tubular braid 22 is consolidated and heated during forming.

[0026] 9. The composite structure 26 of clause 8, wherein the tubular braid is compacted flat during consolidation.

[0027] 10. The composite structure 26 of clause 9, wherein the tubular braid 22 defines a solid cross-section when consolidated.

[0028] 11. The composite structure 26 of clause 10, wherein the solid cross-section comprises a plurality of plies 99.

[0029] 12. The composite structure 26 of clause 11, wherein the tubular braid 22 is wound around the winding tool 18 before being consolidated.

[0030] 13. The composite structure 26 of clause 12, wherein the tubular braid 22 is arranged to be wound around the winding tool 18 in a helical pattern.

[0031] 14. The composite structure 26 of clause 12 or 13, wherein the winding tool 18 defines an outer surface 62 corresponding to an aperture 96 defined by the composite structure 26.

[0032] 15. The composite structure 26 of any of the preceding clauses, wherein the tubular braid 22 has a biaxial braid 56 .

[0033] 16. The composite structure 26 of any of the preceding clauses 1 to 14, wherein the tubular braid 22 comprises a triaxial braid 58.

[0034] 17. The composite structure 26 of any of the preceding clauses, wherein the tubular braid 22 comprises unidirectional fibers 54 compressed within a polymer matrix.

[0035] 18. A composite laminate structure 98 comprising a plurality of plies 99, the composite laminate structure 98 comprising:

[0036] The unidirectional fibers 54 in the biaxial braid 56 are oriented in the same direction for each of the plurality of plies 99 .

[0037] 19. The composite laminate structure 98 of clause 18, comprising unidirectional fibers 54 in a triaxial braid 58.

[0038] 20. The composite laminate structure 98 of clause 18 or 19, wherein the unidirectional fibers 54 are windings of the tubular braid 24.

[0039] 21. The composite laminate structure 98 of any of clauses 18 to 20, wherein the composite laminate structure 98 is constructed from a material selected from the group consisting of: unidirectional strips 32 and unidirectional drag strips.

[0040] 22. The composite laminate structure 98 of clause 21, wherein the unidirectional fibers 54 are disposed within a polymer matrix.

[0041] 23. The composite laminate structure 98 of clause 21 or 22, wherein the unidirectional fibers 54 are compressed within the polymer matrix.

[0042] 24. The composite laminate structure 98 of any of clauses 21 to 23, wherein the composite laminate structure 98 comprises a predetermined fiber to volume ratio.

[0043] 25. The composite laminate structure 98 of any one of clauses 21 to 24, wherein the polymer matrix is ​​a thermosetting resin.

[0044] 26. The composite laminate structure 98 of any one of clauses 21 to 24, wherein the polymer matrix is ​​a thermoplastic resin.

[0045] 27. A composite laminate structure 98 of any of the preceding clauses 18 to 26, wherein the unidirectional fibers 54 are selected from the group consisting of: thermoplastics cut into strips, thermoset strips that are substantially non-tack at room temperature, bonded roving prepregs to which an epoxy resin or thermoplastic adhesive is applied, substantially non-tack thermoset prepregs, and low-tack thermoset prepregs.

[0046] 28. A method 300 of forming a composite structure 26, the method 300 comprising:

[0047] The coiled tubular braid 24 is formed into a composite structure 26 .

[0048] 29. The method 300 of clause 28, further comprising manufacturing the tubular braid 22 from a material selected from the group consisting of: unidirectional straps 32 and unidirectional drag straps.

[0049] 30. The method 300 of clause 29, wherein the unidirectional strips 32 are comprised of unidirectional fibers 54.

[0050] 31. The method 300 of any of clauses 29 to 30 , further comprising winding the tubular braid 22 around the outer surface 62 of the winding tool 18 to produce the wound tubular braid 24 .

[0051] 32. The method 300 of clause 31, further comprising winding the tubular braid 22 into a helical pattern around the winding tool 18.

[0052] 33. The method 300 of clause 31 , wherein when the tubular braid 22 is wound around the winding tool 18, the unidirectional strips 32 slide relative to each other without bending.

[0053] 34. The method 300 of clause 31, further comprising pre-impregnating the wrapped tubular braid 24 with a resin.

[0054] 35. The method 300 of clause 34, further comprising consolidating the wound tubular braid 24 into the composite structure 26.

[0055] 36. The method 300 of clause 35, further comprising applying heat while consolidating the wrapped tubular braid 24.

[0056] 37. The method 300 of clause 36, wherein the wound tubular braid 24 is heated to a resin melting temperature.

[0057] 38. The method 300 of any of clauses 35 to 37, further comprising compacting the wound tubular braid 24 into a flat shape during consolidation.

[0058] 39. The method 300 of any of clauses 35 to 38, wherein when consolidating the wrapped tubular braid 24, the unidirectional strips 32 shear relative to each other without bending.

[0059] 40. The method 300 of any of clauses 35 to 39, wherein the composite structure 26 defines a solid cross-section when consolidated.

[0060] 41. The method 300 of any of clauses 28 to 40, wherein the tubular braid 22 comprises a biaxial braid 56.

[0061] 42. The method 300 of any of clauses 28 to 40, wherein the tubular braid comprises a triaxial braid 58.

[0062] 43. A wound tubular braid 24 for a composite structure, the wound tubular braid 24 comprising:

[0063] A tubular braid 22 is wound into a spiral shape.

[0064] 44. The coiled tubular braid 24 of clause 43, wherein the tubular braid 22 has a first free end 24B and a second free end 24A.

[0065] 45. The coiled tubular braid 24 of clause 43 or 44, wherein the tubular braid 22 defines a central bore 24C extending the length of the tubular braid 22.

[0066] 46. ​​The coiled tubular braid (24) of any of clauses 43 to 45, wherein the tubular braid (22) coiled into a helical shape is formed from a single length of tubular braid (22).

[0067] 47. The coiled tubular braid 24 of any of clauses 43 to 46, wherein the tubular braid 22 is formed from a braid 56, 58 of unidirectional strips 32.

[0068] 48. The coiled tubular braid (24) of any of clauses 43 to 47, wherein the braid is a helical braid (56).

[0069] 49. The coiled tubular braid (24) of any of clauses 43 to 48, wherein the braid is a triaxial braid (58).

[0070] The features, functions and advantages that have been discussed can be achieved in the present disclosure, further details of which can be seen with reference to the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

[0072] Figure 1 is a schematic diagram of a system for constructing a composite structure according to the present disclosure;

[0073] Figure 2 is a schematic diagram of a braiding machine for making a tubular braid according to the present disclosure;

[0074] Figure 3 According to the present disclosure, the Figure 2 The braiding machine shown;

[0075] Figure 4 According to the present disclosure Figure 3 An enlarged view of the unidirectional strip indicated by the section line 4-4 in FIG.

[0076] Figure 5 is a perspective view of a portion of a tubular braid having a plurality of braids according to the present disclosure. Figure 2 and Figure 3 A biaxial braid made by the braiding machine shown in;

[0077] Figure 6 is a perspective view of a portion of a tubular braid having a plurality of braids according to the present disclosure. Figure 2 and Figure 3 A triaxial braid made by the braiding machine shown in;

[0078] Figure 7 is an exemplary process flow diagram illustrating a method of forming a tubular braid using an expandable mandrel according to the present disclosure;

[0079] Figure 8 is an exemplary process flow diagram illustrating a method of forming a tubular braid using a non-expandable mandrel according to the present disclosure;

[0080] Fig. 9 is a front perspective view of a winding tool according to the present disclosure;

[0081] Fig. 9A According to the present disclosure Fig. 9 An alternative embodiment of a cross section of the winding tool viewed in the direction of the section line 9A-9A in FIG.

[0082] Fig. 9B According to the present disclosure Fig. 9 Another alternative embodiment of a cross section of the winding tool viewed in the direction of the section line 9B-9B in FIG.

[0083] Fig.10 is a front perspective view of a winding tool according to the present disclosure, wherein a wound tubular braid is disposed on the winding tool;

[0084] Fig.11 is a front perspective view of a coiled tubular braid according to the present disclosure;

[0085] Fig.12 is a front perspective view of a forming machine according to the present disclosure in an open position;

[0086] Fig.13 According to the present disclosure Fig.12 A cross-sectional view of the forming machine in a closed position, viewed in the direction of section line 13-13;

[0087] Fig.14 is a front perspective view of a former in accordance with the present disclosure in an open position with a coiled tubular braid loaded therein;

[0088] Fig.15 According to the present disclosure Fig.14 A cross-sectional view of the former in an open position, with a wound tubular braid loaded therein, as viewed in the direction of section line 15-15;

[0089] Fig.16According to the present disclosure Fig.14 a cross-sectional view of the former in a closed position, with a wound tubular braid loaded therein, as viewed in the direction of section line 16-16;

[0090] Fig.17 is a top view of a composite structure according to the present disclosure;

[0091] Fig.18 is Fig.17 A cross-sectional view of the composite structure viewed in the direction of section line 18-18;

[0092] Fig.19 is an exemplary process flow diagram illustrating a method of forming a composite structure according to the present disclosure;

[0093] Fig. 20 is an exemplary process flow diagram illustrating a method of winding the tubular braid according to the present disclosure;

[0094] Fig.21 is a flow chart of aircraft production and maintenance methods; and

[0095] Fig. 22 It is a block diagram of the aircraft. DETAILED DESCRIPTION

[0096] The present invention discloses a composite structure consisting of a shaped winding of a tubular braid. The tubular braid is composed of a unidirectional strip or a unidirectional tow of unidirectional fibers. A braiding machine for making the tubular braid is also disclosed. The braiding machine includes a braiding mechanism and a mandrel. A plurality of reels are mounted to the braiding mechanism, the plurality of reels having a unidirectional strip or a unidirectional tow wound around each reel. The braiding mechanism controls the placement of the unidirectional strip or the unidirectional tow from the reels onto the mandrel to form the tubular braid. The tubular braid can have a biaxial braid or a triaxial braid.

[0097] Also disclosed is an apparatus for manufacturing a composite structure by winding a tubular braid around a tool. The braid may first be removed from a mandrel and wound around the outer surface of the tool to form a wound tubular braid. The mandrel may be held together with the wound tubular braid and form a portion of the wound tubular braid. The tubular braid may be cut to remove the mandrel. When the tubular braid is wound around the tool, the unidirectional strips or unidirectional tows do not shrink. In other words, when the tubular braid is wound around the tool, the unidirectional strips or unidirectional tows slide or shear relative to each other. This relative sliding or shearing of the unidirectional strips or unidirectional tows allows the construction of a structure without wrinkles, but with a fiber direction that is advantageously oriented relative to the final structure. The wound tubular braid is then removed from the tool and heated and compacted into a flattened state by a forming machine to form a composite structure. Again, when the tubular braid is compacted into a flattened state, the unidirectional strips or unidirectional tows do not shrink and do not slide or shear relative to each other.

[0098] Allowing the unidirectional fibers to slide or shear relative to each other during winding and consolidation of the composite preform results in a composite structure having more fibers that are advantageously oriented relative to the structure for each laminate ply formed. In addition, since more fibers are advantageously oriented relative to the structure for each laminate ply makes the structure more efficient, the resulting composite structure also requires fewer laminate plies to achieve strength targets. This in turn results in a reduced weight of the component. Compared to conventional layup processes, the disclosed process for manufacturing a composite structure is fast, which in turn enables higher productivity. In addition, the disclosed process for manufacturing a composite structure also results in reduced waste and labor-intensive post-processing compared to conventional processes.

[0099] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

[0100] Reference Figure 1, a schematic diagram of a system 10 for constructing a composite structure is shown. The system 10 generally includes a tool 12 and a work product 14 with which the tool 12 interacts. The tool 12 includes a braiding machine 16, a winding tool 18, and a forming machine 20. The work product 14 includes a tubular braid 22, a wound tubular braid 24, and a composite structure 26. The wound tubular braid 24 may also be referred to as the winding of the tubular braid. The tubular braid 22 is formed by the braiding machine 16. The wound tubular braid 24 is formed by the tubular braid 22 by the winding tool 18. The composite structure 26 is formed by the wound tubular braid 24 by the forming machine 20. The composite structure 26 is any frame that surrounds and provides support for a hole, which requires specific fiber orientation and laying to meet design requirements. For example, the composite structure 26 may be a window frame for an aircraft, a door frame for an aircraft, and the like. The tool 12 may include other machines, such as molding or post-processing machines, cutting devices, and the like, without departing from the scope of the present disclosure. Likewise, the workpiece 14 may include additional variations of the tubular braid 22, the coiled tubular braid 24, and the composite structure 26. The system 10 may be applied in the context of aircraft manufacturing and repair, as described below. For example, the system 10 may be used for component and subassembly manufacturing of aircraft including fuselages and interiors, system integration of aircraft, and routine maintenance and overhaul of aircraft.

[0101] Reference Figure 2 , a schematic side view of a braiding machine 16 is shown. The braiding machine 16 includes a braiding mechanism 28 and a mandrel 30. The braiding mechanism 28 is configured to braid a unidirectional strip 32 or a unidirectional tow onto the mandrel 30, as described below. The mandrel 30 is supported by a retainer 31 and is advanced by the retainer 31 along the central axis "A" of the braiding mechanism 28.

[0102] Reference Figure 3 And continue to refer to Figure 2 , showing that in Figure 2 3-3 in the direction of the section line 3-3 in FIG. The braiding mechanism 28 includes a bracket 34 supported by a base plate 36. The bracket 34 is annular and defines an aperture 34A. The mandrel 30 passes through the aperture 34A during braiding along the central axis "A". A plurality of reels 38 are mounted to the bracket 34. The reels 38 are each movable annularly relative to the mandrel 30 about the central axis of the bracket 34. The unidirectional strip 32 is wound around each reel 38. Although in Figure 2 Five reels 38 are schematically shown in FIG. Figure 3 2, a plurality of reels 38 are shown, but it should be understood that any number of reels 38 may be used depending on the desired properties of the tubular braid 22. For example, the braiding mechanism 28 may include as few as forty reels 38 or as many as two hundred reels 38. The reels 38 generally include a warp reel 38A and a weft reel 38B. The warp reel 38A is rotated in a clockwise direction C ( Figure 3 ), the weft reel 38B is moved in the counterclockwise direction CC (as shown in FIG. Figure 3 The warp reel 38A and the weft reel 38B preferably move at the same speed.

[0103] The braiding mechanism 28 also includes a guide ring 40 positioned around the mandrel 30. The guide ring 40 guides the unidirectional strip 32 wound around the corresponding reel 38 onto the mandrel 30. Specifically, the unidirectional strip 32 is guided from the corresponding reel 38 through the converging area 42 onto the mandrel 30. The point where the unidirectional strip 32 first comes into contact with the mandrel 30 is indicated as the drop point 44.

[0104] The mandrel 30 is used as a substrate, and the unidirectional strips 32 are woven on the substrate by the weaving mechanism 28 to form the tubular braid 22. The mandrel 30 can have various shapes, but is preferably an elongated cylinder. The diameter of the mandrel 30 can be 5.08 cm (2 inches). However, it should be understood that the mandrel 30 can have other diameters, depending on the design requirements of the composite structure 26. The size or volume of the mandrel 30 can be controlled. For example, the mandrel 30 is an expandable tube, such as a silicone balloon. However, the mandrel 30 can have a fixed size or volume. For example, the mandrel 30 is composed of a solid semi-rigid material, such as but not limited to ethylene propylene diene monomer (EPDM), rubber, silicone, neoprene or natural rubber. The mandrel 30 can be composed of a film polymer compatible with the composition of the unidirectional strips 32.

[0105] The expansion mechanism 48 is connected to the mandrel 30 through a supply line 50. The expansion mechanism 48 provides pressurized air or other gas or liquid to the mandrel 30. The expansion mechanism 48 cycles the mandrel 30 between a collapsed state and an expanded state.

[0106] Temporarily go to Figure 4 , showing that Figure 2 Cross-section Figure 4-4Magnified view of the indicated unidirectional tape 32. The unidirectional tape 32 includes unidirectional fibers 54 in the form of a continuous strip held together by heat or adhesive bonding. The unidirectional fibers 54 are parallel to each other. The unidirectional fibers 54 may be pre-impregnated with a resin. The resin may be a thermoplastic, such as polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), etc., or the resin may be a thermosetting resin, such as an epoxy resin, a cyanate ester resin, etc. The unidirectional fibers 54 may be held together by relatively thin retaining wires (not shown). The retaining wires are not woven together with the unidirectional fibers 54. Instead, the retaining wires are deposited on the top and bottom sides of the unidirectional tape 32. The unidirectional tape 32 may be composed of unidirectional tows. The unidirectional tows include unidirectional fibers held together by stitching lines that cross several carbon tows. The unidirectional tape 32 may be comprised of a slit thermoplastic tape, a substantially tack-free thermoset tape at room temperature, a bonded roving prepreg to which an epoxy or thermoplastic adhesive has been applied, a substantially tack-free thermoset prepreg, or a low tack thermoset prepreg.

[0107] Back to Figure 2 and Figure 3 The operation of the knitting machine 16 is controlled by the control module 52 ( Figure 2 ) is controlled. The control module 52 communicates with the braiding mechanism 28, the retainer 31 and the expansion mechanism 48. The control module 52 may refer to an electronic circuit, a combinational logic circuit, a field programmable gate array (FPGA), a processor (shared, dedicated or group) that executes code, or a combination of some or all of the above, such as in a system on a chip, or a part of these. In addition, the control module 52 may be microprocessor-based, such as a computer having at least one processor, memory (RAM and / or ROM) and associated input and output buses. The processor may operate under the control of an operating system residing in the memory. The operating system may manage computer resources so that a computer program code embodied as one or more computer software applications (e.g., an application residing in the memory) may have instructions executed by the processor. The processor may execute the application directly, in which case the operating system may be omitted.

[0108] The control module 52 controls the movement of the mandrel 30 and the movement of the reel 38 via the holder 31 to braid the unidirectional strip 32 onto the mandrel 30 to form the tubular braid 22. For example, the control module 52 executes the command by commanding the expansion mechanism 48 to provide pressurized air to the mandrel 30 to expand the mandrel 30 to an expanded state. The control module 52 executes the command to guide the mandrel 30 in the axial direction "A" ( Figure 230 is moved through the carriage 34 on the braiding machine 16. When the mandrel 30 moves through the carriage 34, the control module 52 executes instructions to move the warp reel 38A in the clockwise C direction and the weft reel 38B in the counterclockwise CC direction around the mandrel 30. The unidirectional strips 32 are pulled out from the corresponding reels 38. The unidirectional strips 32 from the warp reels 38A and the weft reels 38B are interlocked or woven together to form the tubular braid 22 on the mandrel 30. The control module 52 can receive an indication that the unidirectional strips 32 are wound around the mandrel 30. Specifically, the indication means that the braiding machine 16 has completed placing the unidirectional strips 32 on the mandrel 30 to form the tubular braid 22. For example, the indication can be a manual input from a user. Alternatively, a sensor can provide an indication that the braiding machine 16 has completed manufacturing the tubular braid 22. In response to receiving the indication, the control module 52 instructs the expansion mechanism 48 to release air to shrink the mandrel 30.

[0109] In the event that the mandrel 30 is not expandable, the tubular braid 22 may be cut to remove the mandrel 30. For example, a cutting machine (not shown) or a worker may be used to cut the tubular braid 22 along the entire length of the tubular braid 22, thereby allowing the mandrel 30 to be removed. Figure 2 Alternatively, in the case where the mandrel 30 is composed of a film polymer that is compatible with the composition of the unidirectional strips 32, the mandrel 30 is held together with the tubular braid 22 and forms a part of the tubular braid 22.

[0110] The control module 52 may execute instructions to provide air via the expansion mechanism 48 so that the mandrel 30 is only partially expanded. Once the control module 52 receives an indication that the unidirectional strip 32 is wound around the mandrel 30, the control module 52 then executes instructions to provide air through the expansion mechanism 48, thereby further expanding the mandrel 30, which in turn places the unidirectional fibers 54 in tension. Alternatively, the mandrel 30 may remain partially expanded during braiding. Full expansion of the mandrel 30 allows for fiber angle lay-up close to zero and avoids any collapse or volume shrinkage of the mandrel 30, wherein the braid of the unidirectional strip 32 is tight. Partial expansion of the mandrel 30 to a point where the mandrel is geometrically stable allows for a relatively flexible or loose braid of the unidirectional strip 32. This in turn allows the unidirectional strip 32 to slide or shear during winding and forming, as described below. In both cases, controlling the size or volume of the mandrel 30 provides the ability to customize the geometry of the tubular braid 22 braided onto the mandrel 30.

[0111] Figure 5 Shown in Figure 25-5 in the embodiment provided, the tubular braid 22 comprises a biaxial braid 56. In the biaxial braid 56, a matrix of parallel unidirectional strips 32A is interwoven or woven into a matrix of orthogonal parallel unidirectional strips 32B. The parallel unidirectional strips 32A are arranged at an offset angle ɑ to the orthogonal parallel unidirectional strips 32B. The offset angle ɑ is determined based on the specific application, however, a steeper braid angle results in increased flexibility. However, as described below, the angle ɑ can be changed when the unidirectional strips are wound or formed.

[0112] Back to Figure 2 , the braiding machine 16 can also be configured to form a tubular braid 22 having a triaxial braid. To form a tubular braid 22 having a triaxial braid, a unidirectional ribbon 32 is inserted from fixed reels 32C (only one of which is shown) along the length "L" of the mandrel 30. The fixed reels 32C do not rotate along the frame 34. It should be understood that any number of fixed reels 32C may be employed.

[0113] Figure 6 Shown in Figure 2 6-6 in the direction of arrows 6-6. The triaxial braid 58 is similar to the biaxial braid 56 ( Figure 5 ), however, the additional base of the parallel unidirectional strips 32C is parallel to the central axis "A" ( Figure 2 ) extends the axial length of the tubular braid 22 and is interwoven into parallel unidirectional strips 32A and orthogonal parallel unidirectional strips 32B. The unidirectional strips 32C are supplied from a fixed reel 32C. Likewise, as described below, the skew angle ɑ can be changed when the unidirectional strips are wound or formed. The triaxial braid 58 can provide enhanced structural strength in the longitudinal direction of the tubular braid 22.

[0114] Reference Figure 7 , and continue to refer to Figures 2 to 6 , a flow chart is shown that illustrates a method 100 of forming a tubular braid 22 in which the size or volume of the mandrel 30 is controlled. The method 100 begins at box 102. In box 102, the control module 52 controls the size or volume of the mandrel 30 before braiding. In one embodiment, the mandrel 30 can be expanded by the expansion mechanism 48. Therefore, the control module 52 instructs the expansion mechanism 48 to provide air to expand the mandrel 30. The mandrel 30 can be fully or partially expanded. The method 100 then proceeds to box 104.

[0115] In block 104, the method 100 includes braiding the unidirectional ribbon 32 around the mandrel 30 to form the tubular braid 22. For example, the control module 52 commands the mandrel 30 to move axially in the direction "A" while commanding the reel 38 to rotate, thereby forming a braid of the unidirectional ribbon 32 on the mandrel 30, as described above. Depending on the configuration of the braiding mechanism 28, the biaxial braid 56 ( Figure 5 ) or triaxial braid 58 ( Figure 6 ) are formed on the mandrel 30, and the method 100 proceeds to box 106 or box 108.

[0116] In block 106, the braiding machine 16 braids the biaxial braid 56 ( Figure 5 ) braids the tubular braid 22. In block 108, the braiding machine 16 braids the tubular braid 22 with the triaxial braid 58 ( Figure 6 ) braiding the tubular braid 22. In either case, the method 100 proceeds to block 110.

[0117] In block 110, the control module 52 controls the size or volume of the mandrel 30 after the braiding is completed. For example, the control module 52 instructs the expansion mechanism 48 to collapse the mandrel 30, thereby allowing the tubular braid 22 to be easily removed from the mandrel 30.

[0118] Reference Figure 8 , and continue to refer to Figures 2 to 6 , a flow chart is shown that illustrates a method 200 of forming a tubular braid 22, wherein the mandrel 30 is non-expandable. The method 200 begins at block 202. In block 202, the method 200 includes placing the unidirectional strips 32 on the mandrel 30. For example, a combination of unidirectional strips 32A, 32B, or 32C may be placed on the mandrel 30. The method 200 then proceeds to block 204.

[0119] At block 204, the control module 52 commands the spindle 30 to move along the central axis "A" ( Figure 2 ) axially. At block 206, as the spindle 30 moves along the central axis "A", the control module 52 commands the warp reel 38A and the weft reel axis 38B to rotate in opposite directions about the central axis "A". Depending on which type of braid 56, 58 ( Figure 5 , Figure 6 ), method 200 proceeds to box 208 or box 210.

[0120] At block 208, the unidirectional strips 32A, 32B are interlaced together to form a biaxial braid 56 ( Figure 5). For example, when the mandrel 30 moves along the central axis "A", the warp reel 38A and the weft reel 38B rotate in opposite directions. The movement of the mandrel 30 pulls out the unidirectional tape 32 disposed on the warp reel 38A and the weft reel 38B. Figure 2 ) moves, the counter-rotation of the warp reel 38A and the weft reel 38B causes the unidirectional strips 32A from the warp reel 38A to interlace with the unidirectional strips 32B from the weft reel 38B. At block 212, the tubular braid 22 has been formed with the biaxial braid 56 ( Figure 5 ).

[0121] At block 210, the unidirectional strips 32A, 32B, and 32C are interlaced together to form a triaxial braid 58 ( Figure 6 ). For example, when the mandrel 30 moves along the central axis "A", the warp reel 38A and the weft reel 38B rotate in opposite directions. The movement of the mandrel 30 pulls out the unidirectional strip 32A disposed on the warp reel 38A, the unidirectional strip 32B disposed on the weft reel 32B, and the unidirectional strip 32C disposed on the fixed reel 38C. When the mandrel 30 moves along the central axis "A" ( Figure 2 ) moves, the counter-rotation of the warp reel 38A and the weft reel 38B causes the unidirectional strip 32A from the warp reel 38A to be interlaced with the unidirectional strip 32B from the weft reel 38B and with the unidirectional strip 32C from the fixed reel 38C. At block 214, the tubular braid 22 has been formed with the triaxial braid 58 ( Figure 6 ).

[0122] In either case, when the tubular braid 22 has been formed, the method 200 ends. In the case where the mandrel 30 is removable, the method 200 may also include cutting the tubular braid 22 along the entire length of the tubular braid 22 to facilitate removal of the mandrel 30. In the case where the mandrel 30 is formed of a film polymer that is compatible with the composition of the unidirectional tape 32, the mandrel 30 is retained with the tubular braid 22 and forms a portion of the tubular braid 22.

[0123] Go to Fig. 9 , the winding tool 18 will now be described. The winding tool 18 generally includes a body portion 60 that extends vertically. It should be understood that the body portion 60 may extend horizontally or at an angle. The body portion 60 has an outer surface 62. The outer surface 62 generally follows the shape of the composite structure 26. Therefore, the cross-sectional shape of the body portion 60 varies depending on the final shape of the composite structure 26. In the embodiment provided, the body portion 60 has a rectangular cross-section with rounded corners 64. However, as Fig. 9A As shown, the main body portion 60 may have a circular cross-section. Alternatively, as shown Fig. 9BAs shown, the body portion 60 may have an elliptical or oval cross-section. It should be understood that the body portion 60 may have other cross-sections without departing from the scope of the present invention.

[0124] Reference Fig.10 , to form the wound tubular braid 24, the tubular braid 22 is wound around the outer surface 62 of the winding tool 18. The tubular braid 22 can be wound around the winding tool 18 manually or in an automated process using an apparatus 65 (e.g., a robotic arm or manipulator, etc.). The wound tubular braid 24 is comprised of stacked turns 66 of the tubular braid 22. Although five stacked turns 66 are shown in the embodiment provided, it should be understood that the tubular braid 22 can be wound around the winding tool 18 any number of times, thereby producing any number of stacked turns 66. It should be understood that the number of stacked turns 66 depends on the number of plies desired in the composite structure 26 and the thickness of the composite structure 26. In the case where the tubular braid 22 has a triaxial braid 58, when the tubular braid 22 is wound around the winding tool 18, the unidirectional tape 32C ( Figure 6 ) is oriented generally parallel to the outer surface 62 of the winding tool 18. Thus, the unidirectional strip 32C ( Figure 6 ) is arranged to be substantially parallel to the hole and / or periphery of the composite structure 26.

[0125] Once the coiled tubular braid 24 is formed, the coiled tubular braid 24 is separated from the coiling tool 18, as shown. Fig.11 As shown. The wound tubular braid 24 can be separated from the winding tool 18 manually or in an automated process using a robotic arm or manipulator (not shown), etc. The wound tubular braid 24 has a first free end 24A and a second free end 24B. Fig.11 As shown, the wound tubular braid 24 has a spiral or convoluted shape and is formed from a single length of tubular braid 22. The wound tubular braid 24 is hollow and defines a central hole 24C extending through the wound tubular braid 24. When separated from the winding tool 18, the wound tubular braid 24 has sufficient strength to maintain the overall shape provided by the winding tool 18. To form the composite structure 26, the wound tubular braid 24 is placed in the forming machine 20, as described below.

[0126] Fig.12A front perspective view of the forming machine 20 in an open position is shown. The forming machine 20 includes an upper die plate 70 and a lower die plate 72. In the embodiment provided, the upper die plate 70 can be lowered on a support member 74 via a motor 75 to cooperate with the lower die plate 72 in a closed position. Alternatively, the upper die plate 70 and the lower die plate 72 can be hinged together (not shown). The lower die plate 72 includes a lower die surface 76 and a forming mandrel 78 extending from the lower die surface 76. The size of the forming mandrel 78 is substantially the same as the size of the cross-section of the winding tool 18. A heating element 80 is disposed within the lower die plate 72. The heating element 80 is configured to heat the lower die surface 76. In the embodiment provided, the heating element 80 includes an electric wire that heats the lower die surface 76 via resistive heating. Alternatively, the heating element 80 may include hot oil pumped through a tube (not shown), an induction heater, an external heater, etc. Without departing from the scope of the present invention, the upper die plate 70 and / or the forming mandrel 78 may also include a heating element (not shown).

[0127] Fig.13 A cross section of the forming machine 20 is shown in a closed position, wherein the upper die plate 70 is mated with the lower die plate 72. The upper die plate 70 includes an upper die surface 82. An outer die surface 83 extends downwardly from the upper die surface 82. A recess 84 is formed in the upper die surface 82. When in the closed position, the forming mandrel 78 of the lower die plate 72 fits within the recess 84 of the upper die plate 70. In addition, the lower die surface 76, the forming mandrel 78, the upper die surface 82, and the outer die surface 83 cooperate to define a mold cavity 86 between the upper die plate 70 and the lower die plate 72. The mold cavity 86 surrounds the forming mandrel 78.

[0128] The forming machine 20 may also include a vacuum source 88 in communication with a vacuum port 90. The vacuum port 90 is disposed in the lower mold surface 76 and in communication with the mold cavity 86. The vacuum source 88 creates a vacuum in the mold cavity 86 to remove excess air, gas, and voids from the wound tubular braid 24 during forming. The vacuum port 90 may alternatively or additionally be disposed in the upper mold surface 82.

[0129] The forming machine 20 also includes a controller 92 in communication with the motor 75, the heating element 80, and the vacuum source 88. The controller 92 may also communicate with the device 65 for winding the tubular braid 22 around the winding tool 18 (see Fig.10). The controller 92 may refer to an electronic circuit, a combinational logic circuit, a field programmable gate array (FPGA), a processor (shared, dedicated, or group) that executes code, or a combination of some or all of the above, such as in a system on a chip, or a portion of these. In addition, the controller 92 may be microprocessor-based, such as a computer having at least one processor, memory (RAM and / or ROM), and associated input and output buses. The processor may operate under the control of an operating system residing in the memory. The operating system may manage computer resources so that computer program code embodied as one or more computer software applications (e.g., applications residing in the memory) may have instructions executed by the processor. The processor may execute the application directly, in which case the operating system may be omitted.

[0130] Controller 92 controls the movement of upper die plate 70 and lower die plate 72 via motor 75. Controller 92 also controls the temperature applied to mold cavity 86 during the forming of wound tubular braid 24 into composite structure 26 via heating element 80. In one embodiment, controller 92 controls the movement of upper die plate 70 and lower die plate 72 via motor 75. Controller 92 also controls the temperature applied to mold cavity 86 during the forming of wound tubular braid 24 into composite structure 26 via heating element 80. Figure 4 ) to control the temperature in the mold cavity 86. Thermoplastic resins may include resin melting temperatures ranging from about 205°C to over 400°C, and thermosetting resins include resin melting temperatures of about 177°C. As used herein, the term "about" is known to those skilled in the art. Alternatively, the term "about" refers to + / -10°C. The controller 92 also controls the rate at which the mold cavity 86 is cooled to ensure crosslinking of the thermosetting polymer in the unidirectional strip 32. The controller 92 also controls the application of vacuum to the mold cavity 86 via the vacuum source 88. As described above, the vacuum removes excess air, gas, volatiles, and voids from the wound tubular braid 24 in the mold cavity 86. The controller 92 may also control the resin injection (not shown) of the wound tubular braid 24 during formation. Resin injection may be desirable in the case where the unidirectional strip 32 employs a thermosetting resin and the unidirectional fibers 54 are bonded together with an adhesive to form a tow or strip. The bonding provides sufficient adhesive to hold the unimpregnated fibers together to form a tow of the strip. Resin infusion impregnates the unidirectional fibers 54 with resin.

[0131] Reference Fig.14 and Fig.15 , the former 20 is shown with the coiled tubular braid 24 disposed therein prior to forming. The coiled tubular braid 24 is disposed on the lower die surface 76 and around the forming mandrel 78. Thus, when disposed within the former 20, the coiled tubular braid 24 remains helically or spirally wound.

[0132] Fig.16The forming machine 20 is shown in a closed position with the wound tubular braid 24 disposed therein. To form the composite structure 26, the wound tubular braid 24 is consolidated, i.e., compressed, within the mold cavity 86 by the upper mold plate 70 and the lower mold plate 72. For example, the controller 92 executes instructions to actuate the upper mold plate 70 and the lower mold plate 72 toward each other via the motor 75 until the upper mold plate 70 is pressed against the lower mold plate 72. The upper mold plate 70 is pressed against the lower mold plate 72 to consolidate the wound tubular braid 24. Next, the controller 92 applies heat to the wound tubular braid 24 via the heating element 80. As described above, the set temperature and the heating and cooling times are determined based on factors related to the material of the resin used in the wound tubular braid 24. In one embodiment, the temperature is from about 205°C to over 400°C, and in another embodiment, the temperature is set to about 177°C. Prior to or during heating, controller 92 applies a vacuum to mold cavity 86 via vacuum source 88 to remove excess air, gases, volatiles, and voids from coiled tubular braid 24 during consolidation and / or heating. Once consolidation, heating, and cooling are complete, controller 92 commands motor 75 to open former 20 and remove composite structure 26. Composite structure 26 may be removed manually or via a robotic arm or manipulator (not shown).

[0133] The composite structure 26 may be overmolded to create additional features, such as connectors or ribs (not shown). The composite structure 26 may also be trimmed to achieve a final profile.

[0134] Fig.17 An embodiment of a composite structure 26 formed using the braiding machine 16, winding tool 18, and forming machine 20 described above is shown. The composite structure 26 includes a frame portion 94 that defines an aperture 96. In the embodiment provided, the composite structure 26 is shown as a window frame for an aircraft. However, it should be understood that the composite structure 26 can be any component that defines an aperture, and in particular also any component that includes tight corners or radii. For example, the composite structure 26 can be a door frame or any other type of entry frame. Return to Reference Fig.16 , the lower die surface 76, the upper die surface 82 and the forming mandrel 78 cooperate to define the shape of the frame portion 94. In particular, the shape of the aperture 96 corresponds to the shape of the forming mandrel 78, which in turn corresponds to the shape of the winding tool 18 ( Fig. 9 ). Thus, the main body portion 60 of the winding tool 18 has a shape substantially similar to the hole 96 and is wound around the tubular braid 24 ( Fig.11 ) forms the outer periphery of the composite structure 26. In the case where the tubular braid 22 has a triaxial braid 58, the unidirectional strips 32C ( Figure 6 ) is arranged substantially parallel to the periphery of the hole 96. Return to Fig.17During the forming process in the forming machine 20, the tubular braid 22 ( Figure 5 and Figure 6 ) is compacted into a flat shape during consolidation. In other words, the composite structure 26 has a solid cross-section.

[0135] Fig.18 Shown in Fig.17 FIG. 2 is an enlarged cross-section of the composite structure 26 viewed in the direction of the section line 18-18 in FIG. The composite structure 26 has a composite laminate structure 98 including a plurality of plies 99. Each of the plurality of plies 99 corresponds to a stacked turn 66 ( Fig.10 ). Thus, each of the plurality of plies 99 comprises a flat biaxial braid 56 ( Figure 5 ) or flat triaxial braid 58 ( Figure 6 During consolidation and heating, the unidirectional strips 32 ( Figure 5 and Figure 6 ) forms a polymer matrix, so that the plurality of plies 99 are formed of unidirectional fibers 54 ( Figure 4 ) orientation. For each of the plurality of plies 99, the biaxial braid 56 or triaxial braid 58 is oriented to form an annular configuration having a large volume of unidirectional fibers 54 in a desired direction, thereby increasing the efficiency of the composite structure 26. In other words, at any given cross-section, for each of the plurality of plies 99, the unidirectional fibers 54 ( Figure 4 ) are oriented in the same direction. The composite laminate structure 98 includes a predetermined fiber to volume ratio, which may also be referred to as a fiber volume ratio. The fiber volume ratio represents the percentage of unidirectional fibers 54 in the composite laminate structure 98. The mechanical properties of the composite structure (such as, but not limited to, tensile strength) depend on the fiber to volume ratio. Therefore, the fiber to volume ratio of the composite laminate structure 98 is determined based on a specific application or requirement.

[0136] It should be understood that the forming machine 20 consolidates the wound tubular braid 24 into a near net shape. As a result, the composite structure 26 requires less trimming to produce the final profile than conventional processes. In addition, the extensive post-processing and machining typically required to manufacture composite structures is no longer required.

[0137] Now go to Fig.19 , an exemplary process flow diagram shows a process for using Figures 1 to 18 The method 300 of manufacturing the composite structure 26 using the system 10 described above is described. The method 300 begins at block 302. In block 302, the method 300 includes placing the unidirectional strips 32 on the mandrel 30. For example, a combination of unidirectional strips 32A, 32B, or 32C may be placed on the mandrel 30. The method 300 then proceeds to block 304.

[0138] At block 304, the control module 52 commands the spindle 30 to move along the central axis "A" ( Figure 2 ) axially. At block 306, as the spindle 30 moves along the central axis "A", the control module 52 commands the warp reel 38A and the weft reel 38B to rotate in opposite directions about the central axis "A". Depending on which type of braid 56, 58 ( Figure 5 , Figure 6 ), method 300 proceeds to box 308 or box 310.

[0139] At block 308, the unidirectional strips 32A, 32B are interlaced together to form a biaxial braid 56 ( Figure 5 ). For example, when the mandrel 30 moves along the central axis "A", the warp reel 38A and the weft reel 38B rotate in opposite directions. The movement of the mandrel 30 pulls out the unidirectional tape 32 disposed on the warp reel 38A and the weft reel 38B. When the mandrel 30 moves along the central axis "A" ( Figure 2 ), the counter-rotation of the warp reel 38A and the weft reel 38B causes the unidirectional strips 32A from the warp reel 38A to be interlaced with the unidirectional strips 32B from the weft reel 38B. At block 312, the tubular braid 22 has been formed with the biaxial braid 56 ( Figure 5 ).

[0140] At block 310, the unidirectional strips 32A, 32B, and 32C are interlaced together to form a triaxial braid 58 ( Figure 6 ). For example, when the mandrel 30 moves along the central axis "A", the warp reel 38A and the weft reel 38B rotate in opposite directions. The movement of the mandrel 30 pulls out the unidirectional strip 32A disposed on the warp reel 38A, the unidirectional strip 32B disposed on the weft reel 32B, and the unidirectional strip 32C disposed on the fixed reel 38C. When the mandrel 30 moves along the central axis "A" ( Figure 2 ), the counter-rotation of the warp reel 38A and the weft reel 38B causes the unidirectional strip 32A from the warp reel 38A to be interlaced with the unidirectional strip 32B from the weft reel 38B and with the unidirectional strip 32C from the fixed reel 38C. At block 314, the tubular braid 22 has been formed with the triaxial braid 58 ( Figure 6 ). Depending on the configuration of the mandrel 30 as described above, the mandrel 30 may be separated from the tubular braid 22 or remain in the tubular braid 22. From either block 312 or block 314, the method 300 proceeds to block 316.

[0141] Block 316 includes winding the tubular braid 22 around the winding tool 18. The winding of the tubular braid 22 forms the wound tubular braid 24 ( Fig.11). As described above, winding may be accomplished manually or via an automated process using device 65. Method 300 then proceeds to block 318.

[0142] Block 318 includes forming the wound tubular braid 24 into the composite structure 26. For example, the wound tubular braid 24 may be placed into the forming machine 20 ( Figure 14 to Figure 15 ). Then, the controller 92 causes the wound tubular braid 24 to consolidate, ie, flatten, to form a sheet 99 ( Fig.18 ). Then, the controller 92 heats the wound tubular braid 24 to form the composite structure 26 ( Fig.16 ).

[0143] Reference Fig. 20 , an exemplary process flow diagram shows a process for using Figures 1 to 11 The system 10 described above in the present invention forms a method 400 of winding a tubular braid 22. The method 400 begins at block 402. In block 402, the method 400 includes placing a unidirectional strip 32 on a mandrel 30. For example, a combination of unidirectional strips 32A, 32B, or 32C may be placed on the mandrel 30. The method 400 then proceeds to block 404.

[0144] At block 404, the control module 52 commands the spindle 30 to move along the central axis "A" ( Figure 2 ) axially. At block 406, as the spindle 30 moves along the central axis "A", the control module 52 commands the warp reel 38A and the weft reel 38B to rotate in opposite directions about the central axis "A". Depending on which type of braid 56, 58 ( Figure 5 , Figure 6 ), method 400 proceeds to box 408 or box 410.

[0145] At block 408, the unidirectional strips 32A, 32B are interlaced together to form a biaxial braid 56 ( Figure 5 ). For example, when the mandrel 30 moves along the central axis "A", the warp reel 38A and the weft reel 38B rotate in opposite directions. The movement of the mandrel 30 pulls out the unidirectional tape 32 disposed on the warp reel 38A and the weft reel 38B. Figure 2 ) moves, the counter-rotation of the warp reel 38A and the weft reel 38B causes the unidirectional strips 32A from the warp reel 38A to interlace with the unidirectional strips 32B from the weft reel 38B. At block 412, the tubular braid 22 has been formed with the biaxial braid 56 ( Figure 5 ).

[0146] At block 410, the unidirectional strips 32A, 32B, and 32C are interlaced together to form a triaxial braid 58 ( Figure 6). For example, when the mandrel 30 moves along the central axis "A", the warp reel 38A and the weft reel 38B rotate in opposite directions. The movement of the mandrel 30 pulls out the unidirectional strip 32A disposed on the warp reel 38A, the unidirectional strip 32B disposed on the weft reel 32B, and the unidirectional strip 32C disposed on the fixed reel 38C. When the mandrel 30 moves along the central axis "A" ( Figure 2 ) moves, the counter-rotation of the warp reel 38A and the weft reel 38B causes the unidirectional strip 32A from the warp reel 38A to be interlaced with the unidirectional strip 32B from the weft reel 38B and with the unidirectional strip 32C from the fixed reel 38C. At block 414, the tubular braid 22 has been formed with the triaxial braid 58 ( Figure 6 ). Depending on the configuration of the mandrel 30 as described above, the mandrel 30 may be separated from the tubular braid 22 or remain in the tubular braid 22. The method 400 proceeds from block 412 or block 414 to block 416. Block 416 includes winding the tubular braid 22 around the winding tool 18. The winding of the tubular braid 22 forms the wound tubular braid 24 ( Fig.11 ). As described above, winding may be accomplished manually or via an automated process using device 65. The method 400 then proceeds to block 418.

[0147] Block 418 includes wrapping the unidirectional tape 32 ( Figures 5 and 6 ) slide or shear relative to each other. It should be appreciated that when the tubular braid 22 is wound around the winding tool 18, the unidirectional strips 32 slide or shear relative to each other without bending. This results in a wound tubular braid 24 having an increased number of unidirectional strips 32 oriented in the same direction as the perimeter of the composite structure 26, which in turn provides improved load bearing capabilities. Compared to conventional layup processes, the disclosed process for manufacturing the composite structure 26 is faster, thereby enabling higher production rates. Finally, the disclosed process produces less waste compared to conventional processes.

[0148] The system 10 and methods 100, 200, 300 and 400 described above can be used in Fig.21 Aircraft manufacturing and service method 500 is shown and described below. Fig. 22 502 is employed in the context of an aircraft 502 as shown. During pre-production, exemplary method 500 may include specification and design 504 of the aircraft 502 and material procurement 506. During production, component and subassembly manufacturing 508 and system integration 510 of the aircraft 502 occurs. Thereafter, the aircraft 502 may undergo certification and delivery 512 for entry into service 514. While in service with a customer, the aircraft 502 is scheduled for routine maintenance and overhaul 516 (which may also include modification, reconfiguration, refurbishment, etc.).

[0149] Each process of the systems and methods described herein may be performed or implemented by a system integrator, a third party, and / or an operator (e.g., a customer). For the purposes of this specification, a system integrator may include, but is not limited to, any number of aircraft manufacturers and main system subcontractors; a third party may include, but is not limited to, any number of vendors, subcontractors, and suppliers; and an operator may be an airline, a leasing company, a military entity, a service organization, etc.

[0150] like Fig. 22 As shown, an aircraft 502 manufactured by exemplary method 500 may include a fuselage 518 having a plurality of systems 520 and an interior 522. Embodiments of high-level systems 520 include one or more of a propulsion system 524, an electrical system 526, a hydraulic system 526, and an environmental system 530. Any number of other systems may be included. Although an aerospace embodiment is shown, the principles of the present invention may be applied to other industries, such as the automotive industry.

[0151] The above-described systems and methods may be employed during any one or more stages of the production and service method 500. For example, components or subassemblies corresponding to the production process 508 may be manufactured or processed in a manner similar to components or subassemblies produced while in service with the aircraft 502. Furthermore, during the production stages 508 and 510, the apparatus method or a combination thereof may be utilized, for example, by significantly speeding up assembly of the aircraft 502 or reducing the cost of the aircraft 502. Similarly, the apparatus method or a combination thereof may be utilized while in service with the aircraft 502, such as, but not limited to, maintenance and repair 516. The above-described systems 10 and methods 100, 200, 300, and 400 may be employed with component and subassembly manufacturing 508, system integration 510, routine maintenance and repair 516, airframe 518, and interior 522.

[0152] The description of the present disclosure is merely exemplary in nature, and variations that do not depart from the gist of the present disclosure are intended to be within the scope of the present disclosure. These variations should not be regarded as departing from the spirit and scope of the present disclosure.

Claims

1. A method (300) of forming a composite structure (26), the method (300) comprising: A tubular braid (22) is manufactured from a material selected from the group consisting of: a unidirectional strip (32) and a unidirectional tow tape, wherein the unidirectional strip (32) is composed of unidirectional fibers (54); winding the tubular braid (22) about an outer surface (62) of a winding tool (18) to form a coiled tubular braid (24) having stacked turns (66), the tubular braid (22) defining a central bore (24C) extending the length of the tubular braid (22); and The wound tubular braid (24) is formed into the composite structure (26) by consolidating the stacked turns (66) of the wound tubular braid (24) into a flat plurality of plies (99) having a solid cross-section.

2. The method (300) according to claim 1, wherein: The unidirectional fibers (54) are pre-impregnated with resin.

3. The method (300) according to claim 2, wherein: The resin is a thermosetting resin, or wherein the resin is a thermoplastic resin.

4. The method (300) according to any one of claims 1 to 3, wherein: The tubular braid (22) is constructed of a material selected from the group consisting of: thermoplastic slit tapes, thermoset tapes that are substantially tack-free at room temperature, bonded roving prepregs to which epoxy or thermoplastic adhesives are applied, substantially tack-free thermoset prepregs, and low tack thermoset prepregs.

5. The method (300) according to any one of claims 1 to 3, wherein: The tubular braid (22) is consolidated and heated during formation.

6. The method (300) of claim 1, wherein: The tubular braid (22) is arranged to be wound in a spiral pattern around the winding tool (18).

7. The method (300) of claim 1, wherein: The composite structure (26) has a composite laminate structure (98), wherein the composite laminate structure (98) comprises: Unidirectional fibers (54) are oriented in the same direction in the biaxial braid (56) for each of the plurality of plies (99), wherein the unidirectional fibers (54) are selected from the group consisting of: thermoplastic slit tapes, thermoset tapes that are substantially tack-free at room temperature, bonded roving prepregs to which an epoxy or thermoplastic adhesive is applied, substantially tack-free thermoset prepregs, and low tack thermoset prepregs.

8. The method (300) of any one of claims 1 to 3, wherein the unidirectional strips (32) slide relative to each other without bending when the tubular braid (22) is wound around the winding tool (18).

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