Method and apparatus for forming a composite fuselage structure

Abstract

A method and apparatus for forming a composite fuselage structure. A laminate including a plurality of overwrapped braided thermoplastic members and an overwrapped braided thermoplastic skin is constructed. The laminate is placed between an internal tool and an external tool. The internal tool, the laminate, and the external tool are held in place together using a load restraint device. The internal tool, the laminate, the external tool, and the load restraint device form a consolidation mechanism. The consolidation mechanism is heated to form a composite structure.

Description

Technical Field

[0001] The present disclosure generally relates to composite manufacturing and, more particularly, to methods and apparatus for manufacturing a composite fuselage structure by integrating a fuselage skin and fuselage stringers formed of overbraided material. Background Art

[0002] Composite materials can be used to fabricate different types of aircraft structures. Currently, many aircraft structures are formed using thermosetting composite materials. However, when fabricating aircraft structures of larger sizes and shapes, such as fuselage barrel sections, using thermosetting composite materials (e.g., thermosetting resins) can be more challenging than desired. Additionally, the processes involved in using thermosetting composite materials for such structures can be more time-consuming and expensive than desired.

[0003] For example, the process of fabricating a fuselage barrel section using thermosetting composite materials can involve more facility resources (e.g., facility equipment) and tools than desired. Additionally, traditional methods involving the use of an autoclave to cure a fuselage barrel structure formed of thermosetting composite materials can be slower than required with respect to productivity requirements. Meeting such productivity requirements can require a more significant investment in capital, equipment, facility resources, or a combination thereof than desired.

[0004] Accordingly, there is a desire for a method and apparatus that takes into account at least some of the above problems and other possible problems. Summary of the Invention

[0005] In one illustrative example, a method for forming a composite structure is provided. A laminate including a plurality of overbraided thermoplastic members and an overbraided thermoplastic skin is constructed. The laminate is placed between an internal tool and an external tool. The internal tool, the laminate, and the external tool are held in place together using a load restraint device. The internal tool, the laminate, the external tool, and the load restraint device form a consolidation mechanism. The consolidation mechanism is heated to form a composite structure.

[0006] In another illustrative example, a method for forming a composite fuselage structure is provided. Bladders and a plurality of stringer bladders in the laminate are inflated to place fibers in an overbraided thermoplastic skin and a plurality of overbraided thermoplastic members under tension. The laminate is heated to melt the overbraided thermoplastic skin and the plurality of overbraided thermoplastic members. While melting the overbraided thermoplastic skin and the plurality of overbraided thermoplastic members, the overbraided thermoplastic skin and the plurality of overbraided thermoplastic members are joined. The laminate is cooled such that the overbraided thermoplastic skin and the plurality of overbraided thermoplastic members form an integrated structure, i.e., a composite fuselage structure.

[0007] In yet another illustrative example, a device includes an internal tool, a first intelligent sensor, a laminate, a second intelligent sensor, an external tool, and a load restraint device. The first intelligent sensor is positioned around the internal tool. The laminate is positioned around the first intelligent sensor, where the laminate includes a plurality of overbraided thermoplastic members and an overbraided thermoplastic skin. The second intelligent sensor is positioned around the laminate. The external tool is positioned around the second intelligent sensor. The load restraint device is configured to hold the internal tool, the first intelligent sensor, the laminate, the second intelligent sensor, and the external tool in place.

[0008] According to one aspect of the present disclosure, a method for forming a composite structure 101 includes:

[0009] Constructing 2202 a laminate 112 including a plurality of overbraided thermoplastic members 206 and an overbraided thermoplastic skin 210;

[0010] Placing 2204 the laminate 112 between an internal tool 108 and an external tool 110;

[0011] Using a load restraint device 117 to hold 2206 the internal tool 108, the laminate 112, and the external tool 110 together in place, where the internal tool 108, the laminate 112, the external tool 110, and the load restraint device 117 form a consolidation mechanism 104; and

[0012] Heating 2208 the consolidation mechanism 104 to form the composite structure 101.

[0013] Preferably, wherein constructing 2202 the laminate 112 includes:

[0014] Constructing the laminate 112 including a bladder 202, a plurality of partitions 204, a plurality of overbraided thermoplastic members 206, a plurality of stringer bladders 208, and an overbraided thermoplastic skin 210, the bladder 202 having a plurality of recessed portions 216, and the plurality of partitions 204 nested within the plurality of recessed portions 216.

[0015] Advantageously, wherein heating 2208 the consolidation mechanism 104 includes:

[0016] Inductively heating the consolidation mechanism 104 to consolidate the plurality of overbraided thermoplastic members 206 with the overbraided thermoplastic skin 210 to form an integrated composite structure 101.

[0017] Preferably, in the method, heating 2208 the consolidation mechanism 104 includes:

[0018] Inductively heat a first intelligent sensor 114 located between the internal tool 108 and the laminate 112 and a second intelligent sensor 115 located between the external tool 110 and the laminate 112 to consolidate the plurality of overbraided thermoplastic members 206 to the overbraided thermoplastic skin 210.

[0019] Preferably, the method further includes:

[0020] Pass a plurality of pressure tubes 238 through a plurality of stringer pockets 208.

[0021] Preferably, the method further includes:

[0022] Fix 1722 the plurality of pressure tubes 238 within the plurality of stringer pockets 208 using a plurality of plugs 106 located at the ends of the laminate 112.

[0023] Preferably, in the method, constructing the laminate 112 includes:

[0024] Position 1602 a first intelligent sensor 114 around the internal tool 108, wherein the internal tool 108 is supported by a support structure 116; and

[0025] Position 1702 a pocket 202 around the first intelligent sensor 114.

[0026] Preferably, in the method, constructing 2202 the laminate 112 further includes:

[0027] Position 1604 a plurality of partitions 204 within a plurality of recessed portions 216 of the pocket 202, wherein each of the plurality of partitions 204 is made of a nickel-iron alloy.

[0028] Preferably, in the method, constructing 2202 the laminate 112 further includes:

[0029] Position 1606 the plurality of overbraided thermoplastic members 206 on top of the plurality of partitions 204, wherein the shape of one of the overbraided thermoplastic members of the plurality of overbraided thermoplastic members is substantially similar to the shape of the corresponding partition on which the overbraided thermoplastic member is positioned among the plurality of partitions 204.

[0030] Preferably, in the method, constructing 2202 the laminate 112 further includes;

[0031] Position 1608 a plurality of stringer pockets 208 on top of the plurality of overbraided thermoplastic members 206; and

[0032] Place the overbraided thermoplastic skin 210 around the plurality of stringer bags 208 and the plurality of overbraided thermoplastic members 206 at 1610 to complete the laminate 112, wherein the overbraided thermoplastic skin 210 contacts the end sections of the plurality of overbraided thermoplastic members 206.

[0033] Preferably, the method further comprises:

[0034] Position 1712 a second smart sensor 115 around the overbraided thermoplastic skin 210; and

[0035] Position 1714 the external tool 110 around the second smart sensor 115, wherein the internal tool 108, the first smart sensor 114, the laminate 112, the second smart sensor 115 and the external tool 110 together form at least a part of the consolidation mechanism 104.

[0036] Preferably, the method further comprises:

[0037] Use a plurality of plugs 106 to plug 1722 a first end 126 and a second end 128 of the laminate 112, wherein a first plug 1006 among the plurality of plugs 106 used at the first end 126 of the laminate 112 and a second plug 1008 among the plurality of plugs 106 used at the second end 128 of the laminate 112 both include plug portions 1100, 1106, thermal insulation layers 1102, 1108 and sensor connectors 1104, 1110.

[0038] Preferably, the method further comprises:

[0039] Fix 1724 an end tool 105 to the plurality of plugs 106 to prepare for consolidating the plurality of overbraided thermoplastic members 206 to the overbraided thermoplastic skin 210.

[0040] Preferably, the method further comprises:

[0041] During consolidating the plurality of overbraided thermoplastic members 206 to the overbraided thermoplastic skin 210, pressurize the bags 202 and the plurality of stringer bags 208 in the laminate 112 to substantially the same pressure.

[0042] Preferably, the method further comprises:

[0043] During consolidating the plurality of overbraided thermoplastic members 206 to the overbraided thermoplastic skin 210, provide mechanical strength and stiffness to the plurality of overbraided thermoplastic members 206 via a plurality of partitions 204 in the laminate 112.

[0044] A portion of the aircraft composite barrel section 102 assembled according to the above method.

[0045] According to one aspect of the present disclosure, a method for forming a composite fuselage structure 102, the method comprising:

[0046] Inflating 2102 the bladder 202 and the plurality of stringer bladders 208 in the laminate 112 to place the fibers in the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206 under tension;

[0047] Heating 2104 the laminate 112 to melt the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206; and

[0048] While the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206 are melted, joining 2106 the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206; and

[0049] Cooling 2108 the laminate 112 such that the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206 form an integrated structure, namely the composite fuselage structure 102.

[0050] Advantageously, the composite fuselage structure 102 is assembled according to the above method.

[0051] According to one aspect of the present disclosure, an apparatus includes:

[0052] An internal tool 108;

[0053] A first intelligent sensor 114 positioned around the internal tool 108;

[0054] A laminate 112 positioned around the first intelligent sensor 114, the laminate 112 including a plurality of overbraided thermoplastic members 206 and an overbraided thermoplastic skin 210;

[0055] A second intelligent sensor 115 positioned around the laminate 112;

[0056] An external tool 110 positioned around the second intelligent sensor 115; and

[0057] A load restraint device 117 for holding the internal tool 108, the first intelligent sensor 114, the laminate 112, the second intelligent sensor 115, and the external tool 110 in place.

[0058] Advantageously, in the device, the laminate 112 further includes:

[0059] A plurality of partitions 204, each of the plurality of partitions 204 providing a well - defined surface and rigidity for a corresponding one of the plurality of overwrapped braided thermoplastic members 206.

[0060] Preferably, the device further includes:

[0061] A plurality of pressure tubes 238 extending through a plurality of stringer pockets 208 in the laminate 112; and

[0062] A pressure tube 240 extending through the pocket 202 in the laminate 112.

[0063] An aircraft composite barrel section 102 is formed using the above - described device.

[0064] According to one aspect of the present disclosure, a method for forming a composite structure 101, the method comprising:

[0065] Using a load restraint device 117 to hold an internal tool 108, a laminate 112, and an external tool 110 in place together;

[0066] Pressurizing 2004 the pocket 202 and the plurality of stringer pockets 208 in the laminate 112 to expand the pocket 202 and the plurality of stringer pockets 208, thereby pushing the overwrapped braided thermoplastic skin 210 and the plurality of overwrapped braided thermoplastic members 206 in the laminate 112 together; and

[0067] Co - consolidating 2006 the overwrapped braided thermoplastic skin 210 and the plurality of overwrapped braided thermoplastic members 206 while the pocket 202 and the plurality of stringer pockets 208 are pressurized to form the composite structure 101.

[0068] Advantageously, in the method, co - consolidating 2006 the overwrapped braided thermoplastic skin 210 and the plurality of overwrapped braided thermoplastic members 206 includes:

[0069] Inductively heating a first smart sensor 114 and a second smart sensor 114 in the laminate 112 to melt the overwrapped braided thermoplastic skin 210 and the plurality of overwrapped braided thermoplastic members 206, thereby joining the overwrapped braided thermoplastic skin 210 and the plurality of overwrapped braided thermoplastic members 206 together.

[0070] Preferably, in the method, inductively heating the first smart sensor 114 and the second smart sensor 114 includes:

[0071] Generating magnetic energy using a first induction coil 118 embedded in the internal tool 108 and a second induction coil 120 embedded in the external tool 110; and

[0072] Converting the magnetic energy into thermal energy using the first intelligent sensor 114 and the second intelligent sensor 114.

[0073] Preferably, in the method, pressurizing 2004 the bladder 202 and the plurality of stringer bladders 208 in the laminate 112 includes:

[0074] Pressurizing the plurality of stringer bladders 208 using an inert gas within a plurality of pressure tubes 238 extending through the plurality of stringer bladders 208.

[0075] Preferably, in the method, pressurizing 2004 the bladder 202 and the plurality of stringer bladders 208 in the laminate 112 includes:

[0076] Pressurizing the bladder 202 using an inert gas within a pressure tube extending through the bladder 202.

[0077] Preferably, the method further includes:

[0078] During induction heating, supporting each of the plurality of coated woven thermoplastic members 206 using a well-defined surface provided by a corresponding one of a plurality of partitions 204 in the laminate 112.

[0079] Preferably, the method further includes:

[0080] Cooling 2108 the laminate 112 such that the coated woven thermoplastic skin 210 and the plurality of coated woven thermoplastic members 206 joined together form a single integrated composite structure 101.

[0081] Preferably, the method further includes:

[0082] Using a plurality of plugs to fix 1722 a first end 126 and a second end 128 of the laminate 112 to prevent longitudinal expansion of the bladder 202 or the plurality of stringer bladders 208 during induction heating.

[0083] Preferably, the method further includes:

[0084] Constructing 2202, 2204 the laminate 112 on top of the internal tool 108;

[0085] Securing 2204 the external tool 110 around the laminate 112; and

[0086] While the laminate 112 is built on top of the internal tool 108 and the external tool 110 is fixed around the laminate 112, compressively load 2206 the internal tool 108.

[0087] A portion of the aircraft composite barrel section 102 assembled according to the above method.

[0088] According to one aspect of the present disclosure, an apparatus includes:

[0089] A bladder 202 having a plurality of recessed portions 212;

[0090] A plurality of partitions 204 positioned within the plurality of recessed portions 212;

[0091] A plurality of overbraided thermoplastic members 206 positioned on top of the plurality of partitions 204;

[0092] A plurality of stringer bladders 208 positioned on top of the plurality of overbraided thermoplastic members 206; and

[0093] An overbraided thermoplastic skin 210 positioned on top of the plurality of stringer bladders 208 and the plurality of overbraided thermoplastic members 206.

[0094] Advantageously, in the apparatus, the partitions in the plurality of partitions 204 are made of a nickel-iron alloy.

[0095] Preferably, in the apparatus, the nickel-iron alloy is an invar alloy containing about 40% to about 43% nickel.

[0096] Preferably, in the apparatus, the plurality of partitions 204 have a first coefficient of thermal expansion 227 that is closer to the second coefficient of thermal expansion 237 of the plurality of overbraided thermoplastic members 206.

[0097] Preferably, in the apparatus, the bladder 202, the plurality of partitions 204, the plurality of overbraided thermoplastic members 206, the plurality of stringer bladders 208, and the overbraided thermoplastic skin 210 form a laminate 112.

[0098] Preferably, in the apparatus, the laminate 112 is positioned between a first smart sensor 114 lined with an internal tool 108 and a second smart sensor 114 lined with an external tool 110, and wherein the overbraided thermoplastic skin 210 is consolidated with the plurality of overbraided thermoplastic members 206 by induction heating via the first smart sensor 114 and the second smart sensor 114.

[0099] Preferably, in the device, the internal tool 108 is embedded with a first induction coil 118, and the external tool 110 is embedded with a second induction coil 120.

[0100] Preferably, the device further comprises:

[0101] A plurality of plugs 106 for plugging the first end 126 and the second end 128 of the laminate 112.

[0102] Preferably, in the device, the first plug 1006 among the plurality of plugs 106 and the second plug 1008 among the plurality of plugs 106 each comprise:

[0103] Plug portions 1100, 1106 into which a pressure tube 1112 extends from the plurality of stringer bags 208;

[0104] Thermal insulation layers 1102, 1108; and

[0105] Sensor connectors 1104, 1110.

[0106] Preferably, in the device, the sensor connectors 1104, 1110 are water-cooled.

[0107] Preferably, the device further comprises:

[0108] A plurality of pressure tubes 238 extending through the plurality of stringer bags 208.

[0109] A method of forming an aircraft composite barrel section 102 using the above device.

[0110] According to one aspect of the present disclosure, a system 103 comprises:

[0111] An internal tool 108 comprising a dielectric material and embedded with a first induction coil 118;

[0112] An external tool 110 comprising the dielectric material, embedded with a second induction coil 120 and designed in shape and size to surround the internal tool 108;

[0113] A first intelligent sensor 114 lined with the internal tool 108; and

[0114] A second intelligent sensor 114 lined with the external tool 110,

[0115] Wherein, when the first induction coil 118 and the second induction coil 120 are used to inductively heat the laminate 112 positioned between the inner tool 108 and the outer tool 110, both the first smart sensor 114 and the second smart sensor 114 contribute to distributing heat and ensuring thermal uniformity.

[0116] The composite fuselage structure 102 is formed using the system 103 as described above.

[0117] According to one aspect of the present disclosure, a system 103 includes:

[0118] An inner tool 108;

[0119] A first smart sensor 114 positioned around the inner tool 108;

[0120] A laminate 112 positioned around the first smart sensor 114, the laminate 112 including:

[0121] A bladder 202 having a plurality of recessed portions 212;

[0122] A plurality of partitions 204 positioned within the plurality of recessed portions 212;

[0123] A plurality of overbraided thermoplastic members 206 positioned on the plurality of partitions 204;

[0124] A plurality of stringer bladders 208 positioned in contact with the plurality of overbraided thermoplastic members 206; and

[0125] An overbraided thermoplastic skin 210 positioned over the plurality of stringer bladders 208 and the plurality of overbraided thermoplastic members 206 such that each of the plurality of stringer bladders 208 is sandwiched between the overbraided thermoplastic skin 210 and a corresponding overbraided thermoplastic member of the plurality of overbraided thermoplastic members 206;

[0126] A second smart sensor 115 positioned around the laminate 112; and

[0127] An outer tool 110 positioned around the second smart sensor 115.

[0128] Advantageously, the system 103 further includes:

[0129] A plurality of plugs 106 for covering a first end 126 and a second end 128 of the laminate 112.

[0130] Preferably, in the system 103, the internal tool 108 is embedded with a first induction coil 118, and the external tool 110 is embedded with a second induction coil 120, and the system further includes:

[0131] A plurality of connector devices 107 for connecting the first induction coil 118 and the second induction coil 120.

[0132] Preferably, the system 103 further includes:

[0133] An end tool 105 for positioning and fixing the plurality of plugs 106.

[0134] The aircraft composite barrel section 102 is formed using the system 103 as described above.

[0135] According to one aspect of the present disclosure, a method of forming a composite structure 101, the method comprising:

[0136] Inflating a plurality of stringer bladders 208 in the laminate 112 to apply a force against the plurality of overbraided thermoplastic members 206 and the overbraided thermoplastic skin 210;

[0137] During the inflation of the plurality of stringer bladders 208, constraining the laminate 112 via a dielectric material embedded within a non-dielectric material; and

[0138] During the inflation of the plurality of stringer bladders 208, constraining the non-dielectric material via the dielectric material.

[0139] Advantageously, the method further includes:

[0140] Constructing the laminate 112 including the bladder 202, the plurality of stringer bladders 208, the plurality of overbraided thermoplastic members 206, and the overbraided thermoplastic skin 210; and

[0141] Positioning the laminate 112 between an internal tool 108 and an external tool 110, both the internal tool and the external tool including the dielectric material and the non-dielectric material.

[0142] Preferably, in the method, inflating the plurality of stringer bladders 208 in the laminate 112 includes:

[0143] Heating the plurality of stringer bladders 208.

[0144] Preferably, in the method, inflating the plurality of stringer bladders 208 in the laminate 112 includes:

[0145] Pressurize the plurality of stringer bladders 208 with inert gas flowing into the plurality of stringer bladders 208 from a plurality of pressurizing tubes.

[0146] Preferably, in the method, constraining the laminate 112 includes:

[0147] Pressing the laminate 112 against an external tool 110 including the dielectric material, wherein the dielectric material is a ceramic material, and the non-dielectric material embedded in the dielectric material is a plurality of induction coils.

[0148] Preferably, in the method, expanding the plurality of stringer bladders 208 in the laminate 112 includes:

[0149] Expanding the plurality of stringer bladders 208 to tension the plurality of overbraided thermoplastic members 206 via the expansion.

[0150] Preferably, in the method, expanding the plurality of stringer bladders 208 in the laminate 112 includes:

[0151] Resisting a compressive load on the plurality of overbraided thermoplastic members 206 by the expansion of the plurality of stringer bladders 208.

[0152] A portion of the aircraft composite barrel section 102 assembled according to the above method.

[0153] According to one aspect of the present disclosure, a method for forming a composite structure 101, the method comprising:

[0154] Co-consolidating 2304 a plurality of consolidated overbraided thermoplastic preforms 206, 210 in a circumferentially constrained circumferential laminate 112; and

[0155] During co-consolidation, tensioning 2306 the fibers of the plurality of consolidated overbraided thermoplastic preforms 206, 210.

[0156] Advantageously, according to the above method, wherein co-consolidating 2304 the plurality of consolidated overbraided thermoplastic preforms 206, 210 includes:

[0157] Heating the circumferential laminate 112 to co-consolidate the plurality of consolidated overbraided thermoplastic preforms 206, 210.

[0158] Preferably, in the method, heating the circumferential laminate 112 includes:

[0159] Inductively heating the circumferential laminate 112 to co-consolidate the plurality of consolidated overbraided thermoplastic preforms 206, 210.

[0160] Preferably, in the method, co-consolidating 2304 the plurality of consolidated overwrapped braided thermoplastic preforms 206, 210 includes:

[0161] Using a plurality of induction coils and a plurality of intelligent sensors to heat the circumferential laminate 112 to co-consolidate the plurality of consolidated overwrapped braided thermoplastic preforms 206, 210.

[0162] Preferably, in the method, co-consolidating 2304 the plurality of consolidated overwrapped braided thermoplastic preforms 206, 210 includes:

[0163] Inflating a plurality of stringer pockets 208 and pockets 202 in the circumferential laminate 112 to apply a force against the plurality of consolidated overwrapped braided thermoplastic preforms 206, 210.

[0164] Preferably, in the method, inflating the plurality of stringer pockets 208 and the pockets 202 includes:

[0165] Pressurizing the plurality of stringer pockets 208 and the pockets 202 in the circumferential laminate 112 with an inert gas.

[0166] A portion of the aircraft composite barrel section 102 assembled according to the above method.

[0167] According to one aspect of the present invention, a tow bonding and trimming device includes:

[0168] A bonding-trimming system 1301 for bonding and trimming thermoplastic tows 1404 into a braided structure 1306; and

[0169] A support system 1302 to which the bonding-trimming system 1301 is attached, the size and shape of the support system 1302 being designed to operably position the bonding-trimming system 1301 relative to a cylindrical thermoplastic laminate 306.

[0170] Advantageously, in the tow bonding and trimming device, the support system 1302 includes:

[0171] A support ring 1303, the size and shape of the support ring being designed to completely surround a circumferential surface 1304, wherein the bonding-trimming system 1301 is fixed to the support ring 1303.

[0172] Preferably, in the tow bonding and trimming device, the bonding-trimming system 1301 includes:

[0173] A bonding welder 1400 fixed to a portion of the support system 1302, wherein the bonding welder 1400 is resistance heated.

[0174] Preferably, in the tow bonding and trimming device, the bonding-trimming system 1301 includes:

[0175] A trimmer 1402, which is fixed to a part of the support system 1302, wherein the trimmer 1402 uses laser energy to trim the thermoplastic tow 1404.

[0176] Preferably, the tow bonding and trimming device further includes:

[0177] A conduction member 1308, which is positioned between the braided structure 1306 and the thermoplastic tow 1404.

[0178] Preferably, in the tow bonding and trimming device, the cross-sectional shape of the conduction member 1308 is wedge-shaped.

[0179] Preferably, in the tow bonding and trimming device, the conduction member 1308 is heat-conductive and is used to absorb the laser energy emitted by the trimmer 1402 to protect the braided structure 1306.

[0180] Preferably, in the tow bonding and trimming device, the thermoplastic tow 1404 is received from a braiding loop and the thermoplastic tow 1404 passes over the conduction member 1308.

[0181] Preferably, in the tow bonding and trimming device, the support system 1302 travels together with the braiding loop that provides the thermoplastic tow 1404.

[0182] Preferably, in the tow bonding and trimming device, the bonding-trimming system 1301 is one of a plurality of bonding-trimming systems distributed along the support system 1302.

[0183] In the described tow bonding and trimming device, the braided structure 1306 includes a plurality of thermoplastic sheets covering and braiding continuous thermoplastic composite fibers.

[0184] According to one aspect of the present disclosure, a method for bonding and trimming a thermoplastic tow 1404, the method includes:

[0185] Laying 2502 the thermoplastic tow 1404 received from a braiding system on top of the braided structure 1306 on a surface 1304; and

[0186] Bonding and welding 2504 the thermoplastic tow 1404 to the braided structure 1306; and

[0187] Trim a portion of the thermoplastic tow 1404 such that the thermoplastic tow 1404 received over the braided structure 1306 is trimmed.

[0188] Advantageously, the method further comprises:

[0189] Receiving a portion of the thermoplastic tow 1404 over a conductive member 1308 positioned between the braided structure 1306 and the thermoplastic tow 1404.

[0190] Preferably, in the method, adhesively welding 2504 the thermoplastic tow 1404 comprises:

[0191] Adhesively welding the thermoplastic tow 1404 to the braided structure 1306 using an adhesive welder 1400 secured to a support ring 1303.

[0192] Preferably, in the method, adhesively welding 2504 the thermoplastic tow 1404 comprises:

[0193] Adhesively welding the thermoplastic tow 1404 to the braided structure 1306 using an adhesive welder 1400 secured to a support ring 1303 surrounding the surface 1304, wherein the adhesive welder 1400 is resistance heated.

[0194] Preferably, the method further comprises:

[0195] Supporting the portion of the thermoplastic tow 1404 by the conductive member 1308.

[0196] Preferably, in the method, trimming 2506 the portion of the thermoplastic tow 1404 comprises:

[0197] Applying laser energy to the portion of the thermoplastic tow 1404 supported by the conductive member 1308.

[0198] Preferably, in the method, applying the laser energy comprises:

[0199] Absorbing the laser energy by the conductive member 1308 to protect the braided structure 1306 while the thermoplastic tow 1404 is being trimmed.

[0200] Preferably, in the method, laying 2502 the thermoplastic tow 1404 comprises:

[0201] Lay the thermoplastic tow 1404 on top of the surface 1304, which is formed by at least one of a tool surface 1304, a bulkhead 502, a bladder 400, a stringer bladder 702, a partially formed woven ply 1306, a preform 800, 600, or an integrated composite structure 101.

[0202] Preferably, in the method, laying 2502 the thermoplastic tow 1404 includes:

[0203] Lay the thermoplastic tow 1404 to add local features to the woven structure 1306.

[0204] A portion of an aircraft composite barrel section 102 assembled according to the above method.

[0205] According to one aspect of the present disclosure, a method for bonding and trimming a thermoplastic tow 1404, the method includes:

[0206] Lay 2602 the thermoplastic tow 1404 received from a weaving system on top of a woven structure 1306 on a surface 1304; and

[0207] Bond and weld 2604 the thermoplastic tow 1404 received from the weaving system to the woven structure 1306; and

[0208] Trim 2606 the thermoplastic tow 1404 by applying laser energy to a portion of the thermoplastic tow 1404.

[0209] Advantageously, the method further includes:

[0210] Support the portion of the thermoplastic tow 1404 by a conducting member 1308.

[0211] Preferably, in the method, trimming 2606 the thermoplastic tow 1404 includes:

[0212] Apply the laser energy to the portion of the thermoplastic tow 1404 supported by the conducting member 1308.

[0213] A portion of an aircraft composite barrel section 102 assembled according to the above method.

[0214] According to one aspect of the present disclosure, a bonding-trimming mechanism includes:

[0215] A support ring 1303, the size and shape of the support ring 1303 being designed to completely surround a circumferential surface 1304;

[0216] Adhesion-trimming system 1301, which is fixed to the support ring 1303 and is used to adhere the thermoplastic tow 1404 to the woven structure 1306. Among them, the adhesion-trimming system 1301 includes:

[0217] An adhesion welder 1400, which is fixed to a part of the support ring 1303. Among them, the adhesion welder 1400 is resistance-heated; and

[0218] A trimmer 1402, which is fixed to a part of the support ring 1303. Among them, the trimmer 1402 uses laser energy to trim the thermoplastic tow 1404; and

[0219] A conduction component 1308, which is positioned between the woven structure 1306 and the thermoplastic tow 1404.

[0220] Advantageously, in the adhesion-trimming mechanism, the cross-sectional shape of the conduction component 1308 is wedge-shaped and is thermally conductive to absorb the laser energy emitted by the trimmer 1402, thereby protecting the woven structure 1306 during the trimming of the thermoplastic tow 1404.

[0221] Preferably, in the adhesion-trimming mechanism, the adhesion-trimming system 1301 is one of a plurality of adhesion-trimming systems 1301 distributed along the support ring 1303.

[0222] Preferably, in the adhesion-trimming mechanism, the woven structure 1306 includes a plurality of thermoplastic sheets covering and weaving continuous thermoplastic composite fibers.

[0223] Preferably, in the adhesion-trimming mechanism, the surface 1304 is formed by at least one of the tool surface 1304, the partition 502, the bladder 400, the longitudinal beam bladder 702, the partially formed woven ply 1306, the preform 800, 600 or the integrated composite structure 101.

[0224] In various embodiments of the present disclosure, the features and functions can be implemented independently, or the features and functions can be combined in other embodiments. Further details can be seen by referring to the following description and drawings. Description of the Drawings

[0225] The novel features considered to be characteristics of the exemplary embodiments are set forth in the appended claims. However, the exemplary embodiments and their preferred usage modes, further objectives and features will be best understood by referring to the following detailed description of the exemplary embodiments of the present disclosure when read in conjunction with the drawings.

[0226] Figure 1 is a block diagram of a manufacturing environment according to an example embodiment.

[0227] Figure 2 is a more detailed illustration of a laminate according to an example embodiment.

[0228] Figure 3A is an illustration of an isometric view of a consolidation mechanism according to an example embodiment.

[0229] Figure 3B is according to an example embodiment Figure 3A is an illustration of a cross-sectional view of a consolidation mechanism of

[0230] Figure 4 is according to an example embodiment of the Figure 3B is taken between lines 4-4 in Figure 3A and Figure 3B is an illustration of a part of an internal tool of

[0231] Figure 5 is according to an example embodiment of an addition to Figure 4 is an illustration of a separator added to a laminate of

[0232] Figure 6 is according to an example embodiment of an addition to Figure 5 is an illustration of a co-braided thermoplastic member added to a laminate of

[0233] Figure 7 is according to an example embodiment of an addition to Figure 6 is an illustration of a stringer pocket added to a laminate of

[0234] Figure 8 is according to an example embodiment of an addition to Figure 7 is an illustration of a co-braided thermoplastic skin added to a laminate of

[0235] Figure 9 is according to an example embodiment of a second intelligent sensor and an external tool positioned around Figure 8 is an illustration of a laminate of

[0236] Figure 10 is an illustration of a cross-sectional view of a system for supporting a consolidation mechanism during consolidation according to an example embodiment.

[0237] Figure 11A is according to an example embodiment of Figure 10 is an illustration of a part of a consolidation mechanism of

[0238] Figure 11B is according to an example embodiment of Figure 11A is an illustration of an enlarged view of a configuration of a pressure tube of

[0239] Figure 11C Illustration of an enlarged view of another configuration of a pressure tube according to an exemplary embodiment Figure 11A Illustration of an enlarged view of yet another configuration of a pressure tube according to an exemplary embodiment

[0240] Figure 11D Illustration of a cross-sectional view of a laminate taken along line 12-12 in Figure 11A Illustration of a cross-sectional view of a laminate taken along line 12-12 in

[0241] Figure 12 Illustration of a cross-sectional view of a laminate taken along line 12-12 in Figure 11A Illustration of a cross-sectional view of a laminate taken along line 12-12 in

[0242] Figure 13A Illustration of an isometric view of an adhesive-trimming mechanism according to an exemplary embodiment

[0243] Figure 13B Illustration of a cross-sectional view of an adhesive-trimming mechanism according to an exemplary embodiment Figure 13A Illustration of a cross-sectional view of an adhesive-trimming mechanism according to an exemplary embodiment

[0244] Figure 14 Illustration of a cross-sectional view of a portion of an adhesive-trimming mechanism in Figure 13A and Figure 13B Illustration of a cross-sectional view of a portion of an adhesive-trimming mechanism in

[0245] Figure 15 Flowchart of a process for forming a composite structure according to an exemplary embodiment

[0246] Figure 16 Flowchart of a process for constructing a laminate according to an exemplary embodiment

[0247] Figure 17 Flowchart of a process for constructing a system including a consolidation mechanism according to an exemplary embodiment

[0248] Figure 18 Flowchart of a process for constructing a system to form a composite airframe structure according to an exemplary embodiment

[0249] Figure 19 Flowchart of a process for inductively consolidating a co-braided thermoplastic skin and a co-braided thermoplastic member to form a composite airframe structure according to an exemplary embodiment

[0250] Figure 20 Flowchart of a process for forming a composite structure according to an exemplary embodiment

[0251] Figure 21 Flowchart of a process for forming a composite airframe structure according to an exemplary embodiment

[0252] Figure 22 is a flowchart of a process for forming a composite structure according to an example embodiment.

[0253] Figure 23 is a flowchart of a process for forming a composite structure according to an example embodiment.

[0254] Figure 24 is a flowchart of a process for forming a composite structure according to an example embodiment.

[0255] Figure 25 is a flowchart of a process for bonding and trimming a thermoplastic tow according to an example embodiment.

[0256] Figure 26 is a flowchart of a process for bonding and trimming a thermoplastic tow according to an example embodiment.

[0257] Figure 27 is an illustration of an aircraft manufacturing and maintenance method according to an example embodiment.

[0258] Figure 28 is a block diagram of an aircraft according to an example embodiment. Detailed Description

[0259] The example embodiments described below provide methods, apparatuses, and systems for quickly and efficiently manufacturing composite structures, such as fuselage barrel sections, at reduced cost and weight. In particular, using thermoplastic materials to manufacture composite structures, such as fuselage barrel sections, can help reduce the total manufacturing cost and production time.

[0260] The example embodiments describe methods, apparatuses, and systems that eliminate the need for an autoclave for curing fuselage barrel structures. Using an autoclave can be more expensive than desired. In addition, due to its size and complexity, an autoclave has a thermal mass requirement, which makes using an autoclave more time-consuming and less efficient than required for manufacturing fuselage barrel sections. By eliminating the need for an autoclave, the example embodiments described herein reduce the cost and time required to manufacture fuselage barrel sections. For example, at least some of the example methods for manufacturing the fuselage barrel structures described herein may take one-tenth of the time required when using an autoclave.

[0261] In addition, using the systems described herein, less total heating is required because the thermoplastic materials fully react and thus do not require curing. Compared to those systems involving autoclaves, the systems described herein require less total equipment and less complex equipment to manufacture fuselage barrel sections.

[0262] The exemplary embodiments describe the formation of a composite structure, such as a fuselage barrel section, using overbraided thermoplastic stringers consolidated to an overbraided thermoplastic skin. Induction heating is used to perform this consolidation in a relatively inexpensive, rapid, and reliable manner. As used herein, "consolidation" or "consolidation process" refers to the process of heating a component made of overbraided thermoplastic material to its melting point such that the components can be joined, fused, or integrated with each other. This heating is performed using an intelligent susceptor that allows for rapid heating to a selected temperature and then precisely maintaining that temperature. The process may also include cooling the components after the joining or integration process to produce a fully integrated structure.

[0263] Once the integrated fuselage barrel structure has been manufactured, other fuselage components can be easily welded or otherwise attached to the fuselage barrel structure. For example, but not limited to, skin tear strips, pad-ups, and local reinforcements for door cutouts and service door areas can be inductively welded to the fuselage barrel structure via high-speed production fiber placement and stacked placement of thermoplastic materials. The fuselage and window frames and other components (e.g., tear strips, stiffeners, gussets, shear ties, system brackets, etc.) can also be welded in place using induction welding techniques.

[0264] Accordingly, the exemplary embodiments described below provide methods, apparatuses, and systems for forming a composite structure using thermoplastic materials and induction heating. In one exemplary embodiment, a laminate is constructed, where the laminate includes a plurality of overbraided thermoplastic members and an overbraided thermoplastic skin. The laminate may also include a bladder having a plurality of recessed portions, a plurality of partitions within the plurality of recessed portions, and a plurality of stringer bladders. The laminate is placed between an internal tool and an external tool. A load restraint device is used to hold the internal tool, the laminate, and the external tool in place. A heating consolidation mechanism is used to form the composite structure. This heating, which can be performed via induction and using an intelligent susceptor, co-consolidates the plurality of overbraided thermoplastic members with the overbraided thermoplastic skin to form the composite structure.

[0265] Now referring to the drawings, Figure 1 is a block diagram of a manufacturing environment 100 according to an exemplary embodiment. In the manufacturing environment 100, a composite structure 101 is formed. In these illustrative examples, the composite structure 101 takes the form of a composite fuselage structure 102. The composite fuselage structure 102 can be, for example, a composite barrel section. In other illustrative examples, the composite structure 101 can take some other form.

[0266] The composite structure 101 is formed using the system 103. The system 103 includes a consolidation mechanism 104, an end effector 105, a plurality of plugs 106, and a plurality of connector devices 107. In these illustrative examples, the consolidation mechanism 104 includes an internal tool 108, an external tool 110, a laminate 112, a first intelligent sensor 114, a second intelligent sensor 115, a support structure 116, and a load restraint device 117.

[0267] The internal tool 108 includes a plurality of induction coils 118 embedded within the internal tool 108. In some examples, the internal tool 108 also has a plurality of rods 119 embedded therein. The rods 119 may take the form of, for example but not limited to, fiberglass rods. The rods 119 are used to reinforce the internal tool 108 and load the internal tool 108 during compression.

[0268] Similar to the internal tool 108, the external tool 110 includes a plurality of induction coils 120 embedded within the external tool 110. The internal tool 108 and the external tool 110 may be made of the same material or different types of materials. In one illustrative example, both the internal tool 108 and the external tool 110 are made of ceramic materials.

[0269] The laminate 112 is positioned between the internal tool 108 and the external tool 110. In particular, the laminate 112 is positioned between the first intelligent sensor 114 and the second intelligent sensor 115, which are located between the internal tool 108 and the external tool 110. For example, the first intelligent sensor 114 is positioned between the laminate 112 and the internal tool 108. The second intelligent sensor 115 is positioned between the laminate 112 and the external tool 110.

[0270] In these illustrative examples, the first intelligent sensor 114 and the second intelligent sensor 115 are considered to be separate from the internal tool 108 and the external tool 110, respectively. However, in other illustrative examples, the first intelligent sensor 114 may be integrated with the internal tool 108 or otherwise considered part of the internal tool 108, and the second intelligent sensor 115 may be integrated with the external tool 110 or otherwise considered part of the external tool 110. For example, the first intelligent sensor 114 and the second intelligent sensor 115 may be considered to be liners for the internal tool 108 and the external tool 110, respectively.

[0271] Both the first intelligent sensor 114 and the second intelligent sensor 115 are conductive and have high thermal conductivity. Both of these intelligent sensors absorb electromagnetic energy and convert this electromagnetic energy into heat. For example, the induction coils 118 and the induction coils 120 may generate an electromagnetic flux field. The first intelligent sensor 114 and the second intelligent sensor 115 may be positioned within the electromagnetic flux field and include a magnetically conductive material that generates heat in response to the electromagnetic flux field.

[0272] “Smart sensors”, such as the first smart sensor 114 or the second smart sensor 115, are typically composed of one or more materials that effectively generate heat until a threshold temperature (i.e., the Curie temperature) is reached. When parts of the smart sensor reach the threshold temperature, the magnetic permeability of those parts decreases. This decrease in magnetic permeability limits the heat generation of those parts of the smart sensor and transfers the magnetic flux to the lower temperature parts, causing these lower temperature parts to heat up faster until the threshold temperature is reached.

[0273] In this way, when the laminate 112 is inductively heated via the induction coil 118 and the induction coil 120, the first smart sensor 114 and the second smart sensor 115 are used to assist in heat distribution and ensure thermal uniformity. This inductive heating is used to thermally cure the overwrapped braided thermoplastic component within the laminate 112, as described below in Figure 2 described.

[0274] The support structure 116 provides support for the consolidation mechanism 104 and is used to hold the internal tool 108 in place. In some examples, the support structure 116 is referred to as a mandrel or an internal mandrel. The internal tool 108 is positioned around the support structure 116.

[0275] The load restraint device 117 is positioned around the external tool 110 and helps to hold the various components of the consolidation mechanism 104 in place. In particular, the load restraint device 117 helps to hold the internal tool 108, the first smart sensor 114, the laminate 112, the second smart sensor 115, and the external tool 110 in place relative to each other during the formation of the composite structure 101.

[0276] The consolidation mechanism 104 has a first end 122 and a second end 124. The laminate 112 within the consolidation mechanism 104 has a first end 126 and a second end 128. In these illustrative examples, plugs 106 are located at the first end 126 and the second end 128 of the laminate 112. End tools 105 are located at the first end 122 and the second end 124 of the consolidation mechanism 104 and are used to support and fix the plugs 106.

[0277] The connector device 107 is used to connect the induction coil 118 to the induction coil 120. The connector device 107 can be located at both the first end 122 and the second end 124 of the consolidation mechanism 104. The connector device 107 can take different forms. In one illustrative example, each of the connector devices 107 takes the form of a knife switch connector 127. The knife switch connector 127 can be, for example, a copper bar or some other highly conductive material that can rotate about a fixed pivot point 129.

[0278] The consolidation mechanism 104 is inductively heated using induction coils 118 and 120. In particular, the first intelligent sensor 114 and the second intelligent sensor 115 are inductively heated via the induction coils 118 and 120. These intelligent sensors help ensure thermal uniformity in the laminate 112 within selected tolerances during consolidation. In an illustrative example of forming the composite airframe structure 102, the result of this consolidation is the integration of a plurality of airframe stringers 130 with the airframe skin 132.

[0279] In these illustrative examples, the airframe skin 132 can be a circumferential skin. For example, the airframe skin 132 can be used to form a complete airframe barrel section. In other illustrative examples, the airframe skin 132 can be curved and formed as a semi-airframe barrel section, a quarter-airframe barrel section, or some other type of partial airframe barrel section.

[0280] Figure 2 is in accordance with an example embodiment Figure 1 A more detailed illustration of the laminate 112. The laminate 112 includes a bladder 202, a plurality of partitions 204, a plurality of overbraided thermoplastic members 206, a plurality of stringer bladders 208, and an overbraided thermoplastic skin 210. When used in the system 103 to form the composite structure 101, these components of the laminate 112 are positioned relative to each other in a specific manner.

[0281] In these illustrative examples, the bladder 202 is shaped such that the bladder 202 has a plurality of recessed portions 212 and a plurality of caps 214. Each of the recessed portions 212 is located between two of the caps 214. The recessed portion 216 is an example of one of the recessed portions 212. The recessed portion 216 is located between the cap 218 and the cap 220 of the cap 214. The recessed portion 216 includes a main section 222, a stepped section 224, and a stepped section 226. The stepped section 224 is located at a first edge of the recessed portion 216 near the cap 218. The stepped section 226 is located at a second edge of the recessed portion 216 near the cap 220. The main section 222 extends between the stepped section 224 and the stepped section 226. In some examples, the main section 222 includes a base section (which can form the "cap" portion of a cap-shaped stringer) and two web sections that extend from the base section to the stepped section 224 and the stepped section 226.

[0282] The bladder 202 can be constructed of a material that provides a desired level of elasticity and compliance at elevated temperatures. In these illustrative examples, the bladder 202 can be constructed of aluminum, which can be an aluminum alloy. Aluminum provides a desired level of elasticity and compliance at elevated temperatures (e.g., temperatures above about 500 degrees Fahrenheit). In one illustrative example, the bladder 202 is constructed of an aluminum alloy, such as 5083 aluminum alloy, which is aluminum alloyed with magnesium and trace amounts of manganese and chromium. In other examples, the bladder 202 can be referred to as an in-mold line (IML) bladder.

[0283] The separator 204 is positioned within the recessed portion 212 of the bladder 202. For example, each of the separators 204 can be positioned within a corresponding one of the recessed portions 212. The separator 204 is used to provide a stable, rigid, and smooth surface for the overwrapped braided thermoplastic member 206. Each of the separators 204 is constructed of a selected material to provide a desired level of strength for the separator 204 without the separator 204 being thicker than desired. In addition, each of the separators 204 is constructed of a selected material such that the separator 204 has a first coefficient of thermal expansion 227.

[0284] The separator 228 is an example of one of the separators 204. When used in the laminate 112, the separator 228 can be positioned within the recessed portion 216. The thickness of the separator 228 can be between about 1 / 6 inch and about 1 / 10 inch. In one illustrative example, the thickness of the separator 228 is about 1 / 8 inch. In these illustrative examples, the separator 228 can be constructed of a nickel-iron alloy. In one illustrative example, the separator 228 is constructed of an Invar alloy (such as Invar alloy 42) that contains between about 40% and about 43% nickel. In some illustrative examples, the separator 228 can be referred to as an Invar separator.

[0285] The separator 228 can be shaped to substantially conform to or match the recessed portion 216 of the bladder 202. For example, the separator 228 can have a main section 230, a flange section 232, and a flange section 234. The main section 230 substantially matches the main section 222 of the recessed portion 216. Thus, in some cases, the main section 230 includes a base section and two web sections that extend from the base section to the flange section 232 and the flange section 234. The flange section 232 is shaped to fit within or lie on top of the stepped section 224. Similarly, the flange section 234 is shaped to fit within or lie on top of the stepped section 226.

[0286] The overbraided thermoplastic member 206 is positioned above the separator 204. In particular, each of the overbraided thermoplastic members 206 is positioned relative to a corresponding separator in the separator 204. The overbraided thermoplastic member 206 has a shape similar to that of the separator 204. In these illustrative examples, the separator 204 and the overbraided thermoplastic member 206 have a thickness that ensures that the overbraided thermoplastic member 206 does not extend beyond the profile (e.g., the circumferential profile) of the bladder 202 defined by the cap 214 of the bladder 202.

[0287] The overbraided thermoplastic member 206 can be formed using available equipment and techniques for continuous fibers of overbraided thermoplastic composites. Overbraiding enables the use of a large number of spools of continuous fiber thermoplastic material at one time. For example, in the case of overbraiding, the number of spools can be in the hundreds, enabling a high rate of material application.

[0288] The overbraided thermoplastic member 206 has a second coefficient of thermal expansion 235. In these illustrative examples, the first coefficient of thermal expansion 227 of the separator 204 is within the desired range of the second coefficient of thermal expansion 235 of the overbraided thermoplastic member 206.

[0289] For example, the separator 204 can be made of such a material that the first coefficient of thermal expansion 227 of the separator 204 is closer to the second coefficient of thermal expansion 235 of the overbraided thermoplastic member 206 than the third coefficient of thermal expansion 237 of the bladder 202. In some cases, the material of the separator 204 can be selected such that the first coefficient of thermal expansion 227 of the separator 204 is as close as possible to the second coefficient of thermal expansion 235 of the overbraided thermoplastic member 206.

[0290] In the case where the separator 204 and the overbraided thermoplastic member 206 have close coefficients of thermal expansion, the separator 204 can maintain the desired strength and stiffness during induction heating to help the overbraided thermoplastic member 206 maintain its smoothness and shape during induction heating. For example, the aluminum that makes up the bladder 202 can have a third coefficient of thermal expansion 237 that is not close to the second coefficient of thermal expansion 235 of the overbraided thermoplastic member 206. For example, the third coefficient of thermal expansion 237 can be much lower than the second coefficient of thermal expansion 235. Thus, during induction heating, the bladder 202 can soften. In the absence of the separator 204, the softening of the bladder 202 may cause undesirable fluctuations in the overbraided thermoplastic member 206. Thus, the separator 204 provides a well-defined surface for the overbraided thermoplastic member 206 while reducing or eliminating potential problems associated with the difference in the coefficients of thermal expansion between the bladder 202 and the overbraided thermoplastic member 206.

[0291] The stringer bladder 208 is positioned over the overbraided thermoplastic member 206. The stringer bladder 208 is shaped to nest within the remaining space in the recessed portion 212 of the bladder 202 without extending beyond the profile (e.g., the circumferential profile) of the bladder 202.

[0292] In these illustrative examples, the stringer bladder 208 can be constructed of aluminum (which can be an aluminum alloy). Aluminum can provide a desired level of elasticity and compliance at elevated temperatures (e.g., temperatures above about 500 degrees Fahrenheit). For example, during induction heating, the aluminum can become compliant and soft such that the stringer bladder 208 provides substantially uniform pressure over the overbraided thermoplastic member 206. In other words, the stringer bladder 208 constructed of aluminum helps to provide uniform pneumatic pressure to help ensure that no pressure gradients are created. In one illustrative example, the stringer bladder 208 is constructed of an aluminum alloy, such as 5083 aluminum alloy, which is aluminum alloyed with magnesium and trace amounts of manganese and chromium.

[0293] The overbraided thermoplastic skin 210 is positioned over the stringer bladder 208 in such a way that the overbraided thermoplastic skin 210 also contacts the portion 236 of the overbraided thermoplastic member 206 and the cap 214 of the bladder 202. During induction heating, the overbraided thermoplastic skin 210 is consolidated with the overbraided thermoplastic member 206.

[0294] Specifically, the overbraided thermoplastic skin 210 and the overbraided thermoplastic member 206 are co-consolidated. Induction heating is used to heat the overbraided thermoplastic skin 210 and the overbraided thermoplastic member 206 to melting such that the overbraided thermoplastic skin 210 and the overbraided thermoplastic member 206 are integrated or joined together. In this way, after consolidation and cooling, the overbraided thermoplastic skin 210 and the overbraided thermoplastic member 206 together form Figure 1 a single integrated structural composite structure 101. In some cases, one or more additional consolidation processes can be performed to integrate or join other structural features to the composite structure 101.

[0295] More specifically, the overbraided thermoplastic skin 210 is consolidated with the portion 236 of the overbraided thermoplastic member 206 to form the integrated composite structure 101. When the composite structure 101 takes the form of a composite fuselage structure 102, the overbraided thermoplastic skin 210 forms the fuselage skin 132, while the overbraided thermoplastic member 206 forms the fuselage stringers 130.

[0296] In these illustrative examples, multiple pressurizing tubes 238 may be inserted into or through the stringer bladder 208. The pressurizing tubes 238 may extend at least partially into the stringer bladder 208. The pressurizing tubes 238 assist in applying pressure within the stringer bladder 208. For example, a pressurizing system (not shown) may be connected to the pressurizing tubes 238 via a conduit to allow an inert gas to flow through the pressurizing tubes 238.

[0297] In some examples, each of the pressurizing tubes extends into but does not fully extend through the corresponding stringer bladder within the stringer bladder 208. For example, the pressurizing tube 238 may lead to the corresponding bladder within the stringer bladder 208. This allows the inert gas flowing through the pressurizing tube 238 to exit the pressurizing tube 238 and enter the stringer bladder 208, thereby pressurizing the stringer bladder 208. In other examples, each of the pressurizing tubes 238 may extend through the entire length of the corresponding stringer bladder within the stringer bladder 208. However, in these cases, the pressurizing tubes 238 have openings (e.g., perforations, slits, holes, or some other type of opening) that allow the inert gas to enter the stringer bladder 208. The pressurizing system controls the flow of the inert gas and uses the inert gas to control the pressure within the stringer bladder 208.

[0298] In one illustrative example, the pressurizing tube 238 is made of aluminum. In other examples, the pressurizing tube 238 may be composed of stainless steel, some other type of material, or a combination thereof. The pressurizing system may use an inert gas to increase the pressure within the pressurizing tube 238 and thereby increase the pressure within the stringer bladder 208. During induction heating, this pressurization helps the stringer bladder 208 expand to provide support to the overbraided thermoplastic member 206, thereby preventing the overbraided thermoplastic material from collapsing (or caving inwards) or otherwise moving out of the desired shape. Additionally, this pressurization helps the stringer bladder 208 expand to provide a smooth surface for the overbraided thermoplastic member 206 and the overbraided thermoplastic skin 210.

[0299] Furthermore, the pressure within the bladder 202 may also be controlled using the pressurizing tube 240 that extends into the bladder 202 and the above-described pressurizing system. For example, the pressurizing tube 240 may also be composed of aluminum. In other examples, the pressurizing tube 240 may be composed of stainless steel, some other material, or a combination thereof. The pressurizing system may use an inert gas to control the pressure within the pressurizing tube 240 and thereby control the pressure within the bladder 202, similar to the pressurizing tube 238.

[0300] In one illustrative example, the pressurizing tube 240 enters the bladder 202 without extending all the way through the bladder 202. In this way, the inert gas can flow out of the pressurizing tube 240 and into the bladder 202, thereby pressurizing the bladder 202. In other examples, the pressurizing tube 240 has an opening (e.g., perforation, slit, hole, or some other type of opening) that allows the gas to flow from the pressurizing tube 240 into the bladder 202.

[0301] During consolidation, each of the stringer bladders 208 is pressurized to substantially the same pressure (i.e., the same pressure within a selected tolerance). This helps to ensure uniform inflation of each of the stringer bladders 208 such that the same force is applied to each of the overbraided thermoplastic members 206 during consolidation. In some cases, the bladder 202 and the stringer bladders 208 are pressurized to substantially the same pressure during consolidation of the overbraided thermoplastic member 206 to the overbraided thermoplastic skin 210. Increasing the pressure within the bladder 202 and the stringer bladders 208 causes some expansion, which places the preforms (i.e., the overbraided thermoplastic member 206 and the overbraided thermoplastic skin 210) under tension during handling. Additionally, this expansion helps to co-consolidate the laminate 112 by pushing or compressing the laminate 112 against the external tool 110 during handling.

[0302] Having Figure 1 and Figure 2 of the laminate 112 Figure 1 The system 103 allows consolidation of the overbraided thermoplastic member 206 with the overbraided thermoplastic skin 210, thereby rapidly forming the composite structure 101 in an efficient manner. In particular, induction heating via the induction coils 118, induction coils 120, first smart sensor 114, and second smart sensor 115 helps to ensure a rapid and reliable consolidation process.

[0303] Figure 1 in the manufacturing environment 100 and the system 103 and Figure 1 and Figure 2 The illustration of the laminate 112 in does not imply a physical or architectural limitation on the manner in which the illustrative embodiments can be implemented. Other components can be used in addition to or in place of the components shown. Some components may be optional. Additionally, these boxes are presented to illustrate some functional components. When implemented in the illustrative embodiments, one or more of these boxes can be combined, divided, or combined and divided into different boxes.

[0304] Figure 3A and Figure 3B are illustrations of a consolidation mechanism according to an example embodiment. Figure 3A is an illustration of an isometric cross-sectional view of a consolidation mechanism. The consolidation mechanism 300 is Figure 1 an example of one implementation of the consolidation mechanism 104 in.

[0305] The consolidation mechanism 300 includes a support structure 302, an internal tool 304, a laminate 306, an external tool 308, and a load restraint device 310. The consolidation mechanism 300 further includes a first intelligent sensor 311 and a second intelligent sensor 312. The first intelligent sensor 311 is positioned between the internal tool 304 and the laminate 306, and the second intelligent sensor 312 is positioned between the laminate 306 and the external tool 308.

[0306] The support structure 302, the internal tool 304, the laminate 306, the external tool 308, and the load restraint device 310 are respectively Figure 1 examples of the implementations of the support structure 116, the internal tool 108, the laminate 112, the external tool 110, and the load restraint device 117 in Figure 1 The first intelligent sensor 311 and the second intelligent sensor 312 are respectively examples of the implementations of the first intelligent sensor 114 and the second intelligent sensor 115 in

[0307] Figure 3B is Figure 3A a cross-sectional view of the consolidation mechanism in Figure 3B The cross-sectional view of the consolidation mechanism 300 in Figure 3B is taken along a plane perpendicular to the longitudinal axis 301 passing through the consolidation mechanism 104. In particular, Figure 3A the cross-sectional view of the consolidation mechanism 300 in

[0308] is taken with respect to the line 3B-3B in Figure 1 Figure 1 In these illustrative examples, the support structure 302 provides support for the internal tool 304 and is separate from the internal tool 304. In other illustrative examples, the support structure 302 may be considered as part of the internal tool 304 or integrated with the internal tool 304. The internal tool 304 has an induction coil 313 embedded therein. The induction coil 313 is an example of one implementation of the induction coil 118 in

[0309] In one or more illustrative examples, the internal tool 304, the stack 306, the external tool 308, and the load restraint device 310 are substantially cylindrical structures. For example, the internal tool 304, the stack 306, the external tool 308, and the load restraint device 310 can be concentrically aligned relative to the longitudinal axis 301. In one illustrative example, the internal tool 304 is formed of a single cylindrical structure. In other illustrative examples, the internal tool 304 is formed of two halves that can be put together to form a cylindrical structure.

[0310] Both the internal tool 304 and the external tool 308 can be constructed of a ceramic material. The ceramic material is a dielectric material that is "transparent" to the magnetic energy generated by the induction coils 313 and 314 and does not react with the magnetic energy. In this way, the magnetic energy can pass through the ceramic material to interact with the first intelligent receptor 311 and the second intelligent receptor 312. The first intelligent receptor 311 and the second intelligent receptor 312 convert the magnetic energy into heat energy, but the ceramic material is considered "opaque" to heat energy such that the heat energy does not pass through the ceramic material. In this way, the ceramic material helps prevent the loss of heat energy during induction heating by acting as a thermal insulator. Additionally, the ceramic material has a low coefficient of thermal expansion, which helps the internal tool 304 and the external tool 308 withstand the thermal gradients associated with the other components of the consolidation mechanism 300 during induction heating.

[0311] In these illustrative examples, the internal tool 304 includes a rod 316 embedded within the ceramic material. The rod 316 is positioned substantially parallel to the longitudinal axis 301. Additionally, the rod 316 can be circumferentially positioned about the longitudinal axis 301. As Figure 3A and Figure 3B shown, the rod 316 is positioned closer to the longitudinal axis 301 than the induction coil 313. The rod 316 is Figure 2 an example of an implementation of the rod 119 in

[0312] In these examples, the rod 316 is a fiberglass rod. The rod 316 is constructed of fiberglass, which is a dielectric material, and helps provide a compressive load within the internal tool 304. When the various components of the consolidation mechanism 300 are added to the internal tool 304, the rod 316 helps place the ceramic material of the internal tool 304 in a compressive state, which contributes to the long-term durability of the internal tool 304. In this way, the rod 316 strengthens the internal tool 304 and loads the internal tool 108 during compression.

[0313] In these illustrative examples, the outer tool 308 is composed of two halves placed around the laminate 306. For example, a fastener system (not shown) can be used to connect the two halves of the outer tool 308. In some cases, a load restraint device 310 is used to hold the two halves of the outer tool 308 in place. Similarly, the load restraint device 310 can be composed of two halves that are placed around the outer tool 308 to hold the outer tool 308, the laminate 306, and the inner tool 304 together. A fastener system (not shown) can be used to connect the two halves of the load restraint device 310. In some cases, the same fastener system can be used to connect the two halves of both the outer tool 308 and the load restraint device 310. The fastener system can include, for example, a clamping system (e.g., a hydraulic clamp) that allows for easy clamping and easy release. In other illustrative examples, the outer tool 308, the load restraint device 310, or both can be a single cylindrical structure.

[0314] Figures 4 to 8 An illustration of the Figure 3A and Figure 3B construction of the laminate 306 over the inner tool 304 is shown according to an example embodiment. Figure 4 is a cross-section taken between lines 4-4 in Figure 3B according to an example embodiment and Figure 3A and Figure 3B shows a portion of the inner tool 304. The first smart sensor 311 is positioned around the inner tool 304 such that when current flows through the induction coil 118, the first smart sensor 311 is positioned within the electromagnetic flux field generated by the induction coil 118.

[0315] The bladder 400 is positioned over and around the first smart sensor 311. The bladder 400 is Figure 2 an example implementation of the bladder 202 in Figure 3A and Figure 3B is the first component added to form the laminate 306. In this illustrative example, the bladder 400 is an aluminum bladder. During the induction consolidation process, the bladder 400 is pressurized. In the absence of pressure, the bladder 400 can be considered "deflated". "When pressure is applied to the bladder 400, the bladder 400 can be considered "inflated". The pressure can be applied to the bladder 400 via an inert gas that flows through a pressurization tube (not shown in this view) that extends through the bladder 400 or through a channel that extends through the bladder 400.

[0316] The pocket 400 includes a recessed portion 402 formed between the caps 404. The recessed portion 402 is used to assist in indicating the position of the formed fuselage stringer. The recessed portion 406 is an example of one of the recessed portions 402. The recessed portion 406 is formed between the cap 408 and the cap 410 in the caps 404.

[0317] The recessed portion 406 is shaped such that the recessed portion 406 includes a main section 412, a stepped section 414, and a stepped section 415. The stepped section 414 is located between the main section 412 and the cap 408, and the stepped section 415 is located between the main section 412 and the cap 410. The stepped section 414 has a depth 416, and the stepped section 415 has a depth 418. The depth 416 is measured as the distance between the cap 408 and the main section 412, and the depth 418 is measured as the distance between the cap 410 and the main section 412. In this illustrative example, the depth 416 and the depth 418 are substantially equal.

[0318] In this illustrative example, the recessed portion 406 (i.e., the main section 412, the stepped section 414, and the stepped section 415) is shaped to receive a separator that is shaped to form a "hat-shaped" stringer. For example, the main section 412 may include a base section 420 (forming the "hat" portion of the hat-shaped stringer) and web sections 422 and 424 extending from the base section 420 to the stepped section 414 and the stepped section 415, respectively. In other illustrative examples, the recessed portion 406 may be shaped to receive some other type of separator.

[0319] Figure 5 is added to according to an example embodiment Figure 4 of the laminate 306. The separator 500 is positioned within the recessed portion 402 of the pocket 400. The separator 500 is Figure 2 an example of one implementation of the separator 204 in. In particular, each of the separators 500 is positioned within a corresponding recessed portion of the recessed portion 402.

[0320] In addition, each of the separators 500 is shaped such that the separator substantially conforms to or matches the shape of the corresponding recessed portion in which it is placed. In these illustrative examples, the separator 500 is shaped to be able to form a "hat-shaped" stringer.

[0321] As previously mentioned, the separator 500 may have a coefficient of thermal expansion that is sufficiently close to that of the overbraided thermoplastic member that will subsequently be positioned on top of the separator 500, thereby reducing or preventing undue stress from being introduced into the thermoplastic material. The separator 500 is used to provide strength and stiffness during induction heating because the pocket 400 softens during induction heating.

[0322] For example, the separator 502 in the separator 500 is positioned within the recessed portion 406. The separator 502 is Figure 2 an example implementation of the separator 228 in

[0323] The separator 502 is shaped to substantially conform to or match the shape of the recessed portion 406. Specifically, the separator 502 is shaped to substantially match the shape of the main section 412, the stepped section 414, and the stepped section 415 of the recessed portion 406.

[0324] Figure 6 is an overbraided thermoplastic member added according to an example embodiment to Figure 5 the laminate 306. The overbraided thermoplastic member 600 is positioned over the separator 500. The overbraided thermoplastic member 600 is Figure 2 an example implementation of the overbraided thermoplastic member 206 in

[0325] In some illustrative examples, after the separator 500 is added to the laminate 306, the overbraided thermoplastic member 600 is laid directly over the separator 500. In other illustrative examples, the overbraided thermoplastic member 600 can be added to the laminate 306 simultaneously with the separator 500. For example, the overbraided thermoplastic member 600 can be laid over the separator 500 before being added to the laminate 306. The separator 500 can then be used to transport and position the overbraided thermoplastic member 600 in the respective recessed portions of the bladder 400.

[0326] In addition, each of the overbraided thermoplastic members 600 substantially conforms to the shape of the corresponding separator. The overbraided thermoplastic members 600 will ultimately form "hat-shaped" stringers.

[0327] As an example, the overwrapped braided thermoplastic member 602 is positioned above the separator 502, which is positioned within the recessed portion 406 of the bladder 400. The overwrapped braided thermoplastic member 602 substantially conforms to the shape of the separator 502. Specifically, the overwrapped braided thermoplastic member 602 substantially conforms to the shape of the main section 504, the flange sections 506 and 508 of the separator 502. This shaping of the overwrapped braided thermoplastic member 602 results in the overwrapped braided thermoplastic member 602 having a main section 604, flange sections 606 and 608.

[0328] In this illustrative example, the flange section 606 of the overwrapped braided thermoplastic member 602 and the flange section 506 of the separator 502 have a combined thickness that is substantially equal to the depth 416 of the stepped section 414 of the recessed portion 406 of the bladder 400. Similarly, the flange section 608 of the overwrapped braided thermoplastic member 602 and the flange section 508 of the separator 502 have a combined thickness that is substantially equal to the depth 418 of the stepped section 415 of the recessed portion 406 of the bladder 400. In this way, the overwrapped braided thermoplastic member 602 does not extend beyond the circumferential profile of the cap 408 or the cap 410.

[0329] Figure 7 is an illustration of a stringer bladder added to the Figure 6 of the laminate 306 according to an example embodiment. The stringer bladder 700 is positioned above the overwrapped braided thermoplastic member 600. The stringer bladder 700 is Figure 1 an example of one implementation of the stringer bladder 208 in

[0330] Each of the stringer bladders 700 is positioned above a corresponding overwrapped braided thermoplastic member in the overwrapped braided thermoplastic member 600. For example, the stringer bladder 702 is positioned above the overwrapped braided thermoplastic member 602.

[0331] In this illustrative example, the stringer bladder 702 is shaped to ensure that the overwrapped braided thermoplastic member 602 maintains its shape during heating. The recessed portion 406 of the bladder 400, the separator 502, and the stringer bladder 702 together support both sides of the overwrapped braided thermoplastic member 602 while holding the overwrapped braided thermoplastic member 602 in place. The shape and dimensions of the stringer bladder 702 are designed such that the side 704 of the stringer bladder 702 follows the general circumferential profile formed by the cap 404 of the bladder 400.

[0332] Similar to bladder 400, the stringer bladder 700 is pressurized during induction consolidation. Without pressurization, the stringer bladder 700 can be considered "deflated". Once pressurized, the stringer bladder 700 can be considered "inflated".

[0333] Figure 8 is an illustration of a co-braided thermoplastic skin added to the Figure 7 laminate 306 according to an example embodiment. The co-braided thermoplastic skin 800 is positioned over the cap 404 of the bladder 400, the stringer bladder 700, and selected portions of the co-braided thermoplastic member 600. In particular, the co-braided thermoplastic skin 800 is positioned such that the co-braided thermoplastic skin 800 contacts the flange segments of the co-braided thermoplastic member 600. For example, the co-braided thermoplastic skin 800 contacts the flange segments 606 and 608 of the co-braided thermoplastic member 602.

[0334] In this illustrative example, the co-braided thermoplastic skin 800 surrounds the entire circumference of the portion of the laminate 306 formed by the bladder 400, the separator 500, the co-braided thermoplastic member 600, and the stringer bladder 700. In these illustrative examples, the addition of the co-braided thermoplastic skin 800 completes the formation of the laminate 306.

[0335] Figure 9 is an illustration of a second smart sensor 312 and an external tool 308 positioned around the Figure 8 laminate 306 according to an example embodiment. The second smart sensor 312 is positioned around the co-braided thermoplastic skin 800. The external tool 308 is positioned around the second smart sensor 312. This placement ensures that when current flows through the induction coil 314, the second smart sensor 312 is positioned within the electromagnetic flux field generated by the induction coil 314.

[0336] The first smart sensor 311 and the second smart sensor 312 are used to heat and cause consolidation of the co-braided thermoplastic skin 800 and the co-braided thermoplastic member 600 via the induction coils 313 and 314. This consolidation results in a final airframe structure that consists of an airframe skin with integrated airframe stringers.

[0337] Figure 10 is an illustration of a longitudinal cross-sectional view of a system for supporting the consolidation mechanism 300 during consolidation according to an example embodiment. This cross-sectional view of the system 1000 and thus the consolidation mechanism 300 is taken along a plane that is substantially parallel to the longitudinal axis 301. In particular, this cross-sectional view is taken relative to the Figure 3A line 10-10 in the Figure 3A and includes additional components not shown in the Figure 1An example implementation of system 113 in

[0338] As Figure 10 shown, the laminate 306 has a first end 1002 and a second end 1004. The system 1000 includes a plurality of plugs 1005 for plugging these ends. In particular, plug 1006 and plug 1008 are respectively used to plug the first end 1002 and the second end 1004 of the laminate 306.

[0339] The plugs 1005 help ensure that the various components of the laminate 306 remain in place during induction heating. For example, the plugs 1005 do not longitudinally expand to such an extent that the bladder 400 and the stringer bladder 700 can expand to thereby reduce the undesired longitudinal expansion of the bladder 400 and the stringer bladder 700. For example, compared with the bladder 400 and the stringer bladder 700, the plugs 1005 may not expand at all or may only expand slightly. The size of the plugs 1005 can be selected to help ensure that the various components of the laminate 306 remain in place during induction heating.

[0340] In addition, the plugs 1005 provide an easy and effective way to load and unload components in the system 1000. The plugs 1005 can be removed to allow the various components of the laminate 306 to be longitudinally unloaded. For example, when the plugs 1005 are removed, the bladder 400 and the stringer bladder 700 can slide out of the system 1000 in the longitudinal direction.

[0341] The system 1000 also includes an end tool 1010 for positioning and fixing the ends of the plugs 1006 and 1008. The end tool 1010 can be, for example, a structural frame or system that helps to fix the plugs 1006 and 1008 in place relative to the laminate 306.

[0342] The connector device 1012 is used to connect the induction coil 313 to the induction coil 314. In an illustrative example, at a specific end of the consolidation mechanism 300, each of the connector devices 1012 is used to connect the induction coil in the induction coil 313 embedded in the internal tool 304 to the corresponding induction coil in the induction coil 314 embedded in the external tool 308. In some illustrative examples, each of the connector devices 1012 is a knife switch connection. For example, each of the connector devices 1012 may include a copper bar or some other highly conductive material that can rotate around a fixed pivot point.

[0343] In this example, the connector device 1012 includes connector devices 1014, 1016, 1018, and 1020. The connector device 1014 connects the coil 1022 of the induction coil 313 to the coil 1024 of the induction coil 314 at the end 1026 of the consolidation mechanism 300. The connector device 1016 connects the coil 1022 to the coil 1024 at the end 1028 of the consolidation mechanism 300. The connector device 1018 connects the coil 1030 of the induction coil 313 to the coil 1032 of the induction coil 314 at the end 1026 of the consolidation mechanism 300. The connector device 1020 connects the coil 1030 to the coil 1032 at the end 1028 of the consolidation mechanism 300.

[0344] In some illustrative examples, the consolidation mechanism 300 further includes pressure bladders 1038. Each of the pressure bladders 1038 is configured to apply pressure at a corresponding plug in the plug 1005. The pressure bladder 1040 is an example of the pressure bladders 1038. The pressure bladder 1040 is configured to apply pressure in a manner that improves the electrical contact between the first smart sensor 311 and the second smart sensor 312 (not labeled in this view) and the connector device 1014. The pressure bladder 1040 may take the form of a stainless steel bladder.

[0345] Figure 11A is a diagram of a part of the Figure 10 consolidation mechanism 300 according to an example embodiment, in which the plugs 1006 and 1008 are seen more clearly. In this view, the partition 502 is visible. There is also a longitudinal beam bladder 702 located within the recessed portion of the partition 502, but not shown in this view. Additionally, the cross-sectional view is taken such that:

[0346] The plugs 1006 and 1008 are configured to plug the first end 1002 and the second end 1004 of the stack 306. The plugs 1006 and 1008 are similarly implemented. In these examples, the plug 1006 includes a plug portion 1100, a thermal insulation layer 1102, and a sensor connector 1104. The plug 1008 similarly includes a plug portion 1106, a thermal insulation layer 1108, and a sensor connector 1110.

[0347] The thermal insulation layers 1102 and 1108 respectively provide a way to insulate the sensor connectors 1104 and 1110. These thermal insulation layers can be made of, for example, dielectric materials. In these examples, the sensor connectors 1104 and 1110 are water-cooled sensor connectors. If the sensor connectors 1104 and 1110 become too hot, unwanted heating, oxide accumulation, or both may occur. Therefore, the sensor connectors 1104 and 1110 are water-cooled to prevent overheating.

[0348] The pressurized tube 1112 is Figure 2 an example implemented as one of the pressurized tubes 238 in, in these illustrative examples, the pressurized tube 1112 extends through the stringer pocket 702 (not shown in this view) of the laminate 306, beyond both ends of the stringer pocket 702, and exits from both the first end 1002 and the second end 1004 of the laminate 306. As shown, the pressurized tube 1112 includes an end 1114 and an end 1116. In these examples, the ends 1114 and 1116 of the pressurized tube 1112 extend into the plug portion 1100 and the plug portion 1106 respectively, but do not extend beyond these plug portions. In other words, the ends of the pressurized tube 1112 do not extend into the thermal insulation layer 1102 or the thermal insulation layer 1108. However, in some cases, the ends of the pressurized tube 1112 may extend all the way through and beyond the plugs 1006 and 1008.

[0349] A pressurization system (not shown) can be used to cause an inert gas to flow through the pressurized tube 1112 and into the stringer pocket 702 (not shown in this view). For example, the ends 1114 and 1116 can be open and connected to a pipe that is connected to the pressurization system to allow the inert gas to flow into the pressurized tube 1112. The pressurized tube 1112 can be implemented in various ways.

[0350] Figure 11B is of an example embodiment Figure 11A a diagrammatic illustration of an enlarged view of a configuration of the pressurized tube 1112. In Figure 11B it, the separator 502 of Figure 11A is not shown so that the stringer pocket 702 nested within the separator 502 can be seen more clearly. In this illustrative example, the pressurized tube 1112 is a discontinuous pressurized tube that enters the stringer pocket 702 rather than extending all the way through the stringer pocket 702.

[0351] In particular, the pressurizing tube 1112 includes an opening 1118 and an opening 1120 leading into the stringer bladder 702. In this manner, the inert gas flowing within the pressurizing tube 1112 can flow out of the pressurizing tube 1112 and directly into the stringer bladder 702 via the opening 1118 and the opening 1120, thereby pressurizing the stringer bladder 702. The opening 1118 and the opening 1120 can be sized according to the pressurization requirements.

[0352] Figure 11C According to an example implementation Figure 11A FIG. 1 is an illustration of an enlarged view of another configuration of the pressurized tube 1112. Figure 11C Not shown Figure 11A 102, so that the stringer bladder 702 nested within the bulkhead 502 can be more clearly seen. In this illustrative example, the pressurization tube 1112 is a continuous tube that extends all the way through the stringer bladder 702. In this example, the pressurization tube 1112 has one or more openings 1122 that allow the inert gas to flow out of the pressurization tube 1112 and into the stringer bladder 702, thereby pressurizing the stringer bladder 702. The openings 1122 can take different forms. For example, the openings 1122 can be slits, perforations, holes, or some other type of opening in the pressurization tube 1112.

[0353] Figure 11D According to an example implementation Figure 11A FIG. 1 is an illustration of an enlarged view of yet another configuration of the pressurized tube 1112. Figure 11D Not shown Figure 11A The bulkhead 502 is further illustrated so that the stringer bladder 702 nested within the bulkhead 502 can be more clearly seen. In this illustrative example, the pressurized tube 1112 is a multi-tube pressurized tube.

[0354] In particular, the pressurized tube 1112 includes a first tube 1123 and a second tube 1124. The first tube 1123 is a discontinuous tube that enters the stringer bladder 702 and has an end 1126 and an end 1128 that terminate within the stringer bladder 702. The second tube 1124 is a continuous tube that extends from end 1114 to end 1116 within the first tube 1123. For example, the second tube 1124 has a smaller diameter than the first tube 1123 and may be constructed of a harder material than the pressurized tube 1112 to provide structural support to the second tube 1124. In one example, the first tube 1123 is constructed of aluminum and the second tube 1124 is constructed of stainless steel. The second tube 1124 has one or more openings 1130 (e.g., perforations, slits, holes, etc.) that allow the inert gas to flow through the second tube 1124 to enter the stringer bladder 702.

[0355] An inert gas flows into the stringer bladder 702 to pressurize the stringer bladder 702, thereby ensuring the inflation of the stringer bladder 702. This inflation helps to ensure compression, thereby providing a smooth and well-defined surface for Figures 7 to 9 the overbraided thermoplastic member 602 shown.

[0356] Figure 12 is an illustration of a cross-sectional view of the laminate 306 taken relative to Figure 11A the line 12-12 in. In this illustrative example, the stringer bladder 702 is not shown so that the plug portion 1100 is visible.

[0357] A passage 1200 extends through the stringer bladder 702 and through the plug portion 1100 of the plug 1008. The passage 1200 is for receiving Figures 11A to 11D the pressurized tube 1112. A passage 1202 extends through the plug 1006 and beyond the bladder 400 (not shown in this view). The passage 1202 is for receiving a pressure bladder or a pressurized tube that is used to apply pressure to the bladder 400 during the induction consolidation process. The passage 1202 can be located at any position that facilitates the delivery of gas to the bladder 400.

[0358] Figure 13A and Figure 13B are illustrations of an adhesive-trimming mechanism according to an example embodiment. Figure 13A is an illustration of an isometric view of the adhesive-trimming mechanism 1300. The adhesive-trimming mechanism 1300 can also be referred to as a tow bonding and trimming device. Figure 13B is an illustration of a cross-sectional view of the adhesive-trimming mechanism 1300. The cross-sectional view of the adhesive-trimming mechanism 1300 is taken relative to Figure 13A the line 13B-13B in. The following description refers to Figure 13A and Figure 13B both.

[0359] The adhesive-trimming mechanism 1300 can be used to produce the "adhesive" and "trim" required for each braided ply of an overbraided thermoplastic part, such as Figures 6 to 10 either the overbraided thermoplastic member 600 or the overbraided thermoplastic skin 800 in.

[0360] In this illustrative example, bond-trim mechanism 1300 includes bond-trim system 1301. Bond-trim system 1301 is secured to support system 1302 of a surface 1304 of the present invention. In these illustrative examples, bond-trim system 1301 can be secured to support system 1302 using a fastener system, a clamping system, a mounting structure, some other type of attachment device, or a combination thereof. Woven layup 1306, which can be an example of a type of woven structure, is positioned around surface 1304. Woven layup 1306 can be a layup of plies of continuous thermoplastic composite fibers that are coated with a braid. Conductive component 1308 is positioned around woven layup 1306.

[0361] Although only one adhesive-trim system 1301 is shown secured to support system 1302, any number of adhesive-trim systems may be distributed along support system 1302. In these illustrative examples, support system 1302 includes support ring 1303. Support ring 1303 is sized and shaped to completely surround surface 1304.

[0362] The support system 1302 travels with a knitting ring or knitting machine (not shown in this view) to enable the addition and placement of plies in a direction along the longitudinal axis 1307 to create and add to the knitted layup 1306. In other words, plies can be added and placed longitudinally. In addition, the support system 1302 can rotate about the longitudinal axis 1307, or the bonding-trim system 1301 can move around the support system 1302 to enable the addition and placement of plies circumferentially around the surface 1304. A conductive component 1308, which may also be referred to as a "boot," also travels with the knitting ring or knitting machine.

[0363] In one illustrative example, surface 1304 may be Figure 8 The covered braided thermoplastic skin 800 was previously composed of Figure 7 1304, and the bladder 400, the stringer bladder 700, and the covered woven thermoplastic component 600. In this example, the covered woven thermoplastic skin 800 is laid on the surface 1304 as a woven layer 1306. The bonding-trim system 1301 can be used for bonding welding and trimming during or after laying the covered woven thermoplastic skin 800.

[0364] In other illustrative examples, surface 1304 may be a surface formed by spacer 500. In these examples, Figure 6 The covered woven thermoplastic component 600 is laid on the surface 1304 to form a woven layer 1306. The bonding-trim system 1301 can be used to perform bonding welding and trimming during or after laying the covered woven thermoplastic component 600, but before consolidating the covered woven thermoplastic component 600 with the covered woven thermoplastic skin 800. In some cases, whenFigure 6 When the overwrapped braided thermoplastic member 600 in [[ ]] is transported to the laminate 306 via the separator 500, the bonding-trimming system 1301 can be used to adhesively weld and trim the plies of the overwrapped braided thermoplastic member 600 that have been formed. For example, the size and shape of the support system 1302 can be designed to operably position the bonding-trimming system 1301 relative to the laminate 306, which can also be referred to as a cylindrical thermoplastic laminate.

[0365] The adhesive welding can be performed longitudinally, circumferentially, or both. Additionally, adhesive welding can be used to add and lay down plies in a manner that allows for the formation of complex preform structures. For example, the braided ply 1306 can include multiple plies that are not all continuous layers. Some plies can be partial layers. In some cases, the braided ply 1306 includes padups and pad downs. Thus, the braided ply 1306 can have a thickness and profile that vary along the braided ply 1306. Adhesive welding is used to help maintain the structural integrity of the braided ply 1306.

[0366] In other illustrative examples, the bonding-trimming system 1301 can be used to add local features to the braided ply 1306. For example, when the braided ply 1306 takes the form of Figure 8 the overwrapped braided thermoplastic skin 800 in [[ ]], the bonding-trimming system 1301 can be used to adhesively weld and trim local features (e.g., padups) added to the overwrapped braided thermoplastic skin 800.

[0367] In this manner, the bonding-trimming system 1301 can be used to provide and maintain the desired architecture of the braided ply 1306. In these illustrative examples, the bonding-trimming system 1301 is used to perform adhesive welding and trimming prior to consolidation. However, in other illustrative examples, the bonding-trimming system 1301 can be used to adhesively weld and trim local ply features that are added to an integrated structure (e.g., a fuselage barrel section) that has undergone at least one consolidation process.

[0368] Figure 14 is an illustration of a cross-sectional view of a portion of the bonding-trimming mechanism 1300 according to an example embodiment. The view of the bonding-trimming mechanism 1300 is taken along line 14-14 in [[ ]]. Figure 13A and Figure 13B in [[ ]]. Figure 13B in [[ ]].

[0369] As depicted, the bond-trim system 1301 is secured to the support system 1302. The bond-trim system 1301 includes a bond welder 1400 and a trimmer 1402. The bond welder 1400 is positioned to assist in the laying of the thermoplastic tows along the surface 1304 to form a braided ply 1306 composed of thermoplastic laminae. The tow 1404 is an example of one of these thermoplastic tows supplied from a braiding ring or a braiding machine. The bond welder 1400 is resistively heated and helps bond the tow 1404 to the braided ply 1306.

[0370] The trimmer 1402 is used to trim the tow 1404. The trimmer 1402 can be, for example but not limited to, a laser trimmer. The conductive member 1308 is positioned between the tow 1404 and the braided ply 1306 to absorb the laser energy emitted by the trimmer 1402, thereby protecting the braided ply 1306. In these examples, the conductive member 1308 is thermally conductive.

[0371] Figures 3A to 14 The illustrations in do not imply physical or architectural limitations on the ways in which the illustrative embodiments can be implemented. Other components can be used in addition to or in place of the components shown. Some components can be optional.

[0372] Figures 3A to 14 The different components shown in can be Figures 1 to 2 illustrative examples of how the components shown in block form in are implemented as physical structures. Additionally, Figures 3A to 14 Some of the components in can be combined with Figures 1 to 2 the components in, used with Figures 1 to 2 the components in, or both.

[0373] Figure 15 is a flow chart of a process for forming a composite structure according to an example embodiment. Figure 15 The process 1500 shown in can be performed using, for example Figure 1 the system 113 described in to form the composite structure 101. In some examples, Figures 3A to 11D the consolidation mechanism 300 of is used to form the composite structure 101.

[0374] The process 1500 begins with constructing a stack that includes a bladder having a plurality of recessed portions, a plurality of partitions within the plurality of recessed portions, a plurality of overbraided thermoplastic members, a plurality of stringer bladders, and an overbraided thermoplastic skin, the stack being positioned between an internal tool and an external tool (operation 1502). The stack, the internal tool, and the external tool can be implemented in a manner similar to, for example Figure 1 the stack 112, the internal tool 108, and the external tool 110 in or Figures 3A to 8 the stack 306, the internal tool 304, and the external tool 308 in.

[0375] In some cases, with respect to operation 1502, the laminate is built component by component on the internal tool. Then the external tool is secured over the laminate. In other cases, the laminate is pre-built and then positioned on the internal tool before the external tool is positioned over the laminate.

[0376] Thereafter, the load restraint device is positioned around the external tool such that the internal tool, the laminate, the external tool, and the load restraint device form a consolidation mechanism (operation 1504). The consolidation mechanism is inductively heated to consolidate the plurality of overbraided thermoplastic members to the overbraided thermoplastic skin, thereby forming a composite structure (operation 1506), after which the process terminates. In particular, operation 1506 results in the formation of an integrated composite structure.

[0377] In some illustrative examples, operation 1506 can be performed by inductively heating a first smart sensor located between the internal tool and the laminate and a second smart sensor located between the external tool and the laminate to cause the plurality of overbraided thermoplastic members to consolidate to the overbraided thermoplastic skin. The process forms a plurality of fuselage stringers integrated with the circumferential skin. The plurality of overbraided thermoplastic members form the fuselage stringers, and the overbraided thermoplastic skin forms the circumferential skin, thereby forming a composite fuselage structure, such as Figure 1 the composite fuselage structure 102 in

[0378] Figure 16 is a flowchart of a process for building a laminate according to an example embodiment. The process 1600 shown in Figure 16 can be performed to build a laminate 112 such as described in Figure 1 or a laminate 306 such as described in Figures 3A to 8 In addition, the process 1600 can be used to implement Figure 15 operation 1502 in

[0379] The process 1600 begins with positioning a bladder around a first smart sensor that surrounds the internal tool (operation 1602). The bladder can be made of aluminum. In these illustrative examples, the first smart sensor surrounds the internal tool like a liner for the internal tool.

[0380] Thereafter, a plurality of septa are positioned within a plurality of recessed portions of the bladder (operation 1604). In these illustrative examples, each of the plurality of septa is made of a nickel-iron alloy. In one illustrative example, each of the plurality of septa is made of an Invar alloy (such as Invar alloy 52).

[0381] Then, a plurality of overwrapped braided thermoplastic members are positioned over the plurality of septa (operation 1606). In particular, each of the plurality of overwrapped braided thermoplastic members is positioned over and within a recessed portion of a corresponding one of the plurality of septa. Each of the plurality of overwrapped braided thermoplastic members has a shape similar to the shape of the septum. The septa help provide mechanical strength and stiffness during heating to help maintain the shape and smoothness of the plurality of overwrapped braided thermoplastic members.

[0382] Next, a plurality of stringer bags are positioned over the plurality of overwrapped braided thermoplastic members (operation 1608). Then, an overwrapped braided thermoplastic skin is positioned around the plurality of stringer bags and the plurality of overwrapped braided thermoplastic members such that the overwrapped braided thermoplastic skin contacts end sections of the plurality of overwrapped braided thermoplastic members. After induction consolidation, the overwrapped braided thermoplastic skin and the plurality of overwrapped braided thermoplastic members form a composite fuselage structure (operation 1610), after which the process terminates. During induction consolidation, the overwrapped braided thermoplastic skin is consolidated or integrated with the overwrapped braided thermoplastic members. The overwrapped braided thermoplastic skin forms the fuselage skin for the composite fuselage structure, and the overwrapped braided thermoplastic members form the fuselage stringers for the composite fuselage structure.

[0383] Figure 17 is a flowchart of a process for constructing a system including a consolidation mechanism according to an example embodiment. The process 1700 shown in Figure 17 can be performed to construct a system 103 including the consolidation mechanism 104 described in Figure 1 or a system 1000 including the consolidation mechanism 300 described in Figures 3A to 11D .

[0384] The process 1700 can begin with positioning a bag around a first intelligent sensor that surrounds an internal tool (operation 1702). The internal tool includes a plurality of induction coils embedded within the internal tool. The internal tool can be supported by a support structure. In these examples, the internal tool has a circumferential shape (e.g., a cylindrical or approximately cylindrical shape, a tapered cylindrical shape, a conical shape, etc.). In one illustrative example, the internal tool is shaped such that any given cross-section along the longitudinal axis of the internal tool has a substantially circular (circular or approximately circular) shape.

[0385] In operation 1702, the bag can be an aluminum bag having a plurality of recessed portions. The bag can be positioned around the first intelligent sensor to surround the first intelligent sensor and thereby surround the internal tool.

[0386] Position the separator within the recessed portion of the bladder (operation 1704). In operation 1704, the separator can be made of a nickel-iron alloy, such as Invar. Each separator is formed to substantially conform to or match the shape of the corresponding recessed portion of the bladder in which it is positioned. In one illustrative example, the recessed portion of the bladder, and thus the separator, has an upside-down hat shape.

[0387] Then position the overwrapped braided thermoplastic member over the separator (operation 1706). In operation 1706, the overwrapped braided thermoplastic member is formed to substantially conform to or match the separator. Thereafter, position the stringer bladder over the plurality of overwrapped braided thermoplastic members (operation 1708). The stringer bladder is formed to nest within the recessed portion or open space defined by the overwrapped braided thermoplastic members. In these illustrative examples, these stringer bladders can be made of aluminum.

[0388] The stringer bladder is surrounded by an overwrapped braided thermoplastic skin such that the bladder, separator, overwrapped braided thermoplastic member, stringer bladder, and overwrapped braided thermoplastic skin together form a laminate (operation 1710). In operation 1710, the overwrapped braided thermoplastic skin contacts at least a portion of the overwrapped braided thermoplastic member. These portions can be the flange sections of the overwrapped braided thermoplastic member.

[0389] Then, position a second smart sensor around the overwrapped braided thermoplastic skin (operation 1712). Position an external tool around the second smart sensor to form a consolidation mechanism (operation 1714). Similar to the internal tool, the external tool includes a plurality of induction coils embedded within the external tool. Then use a load restraint device to secure the external tool, laminate, and internal tool (operation 1716).

[0390] Insert a pressurized tube through the bladder and the stringer bladder (operation 1718), after which the process terminates. As an illustrative example, one pressurized tube can be inserted through a channel in the bladder, while multiple other pressurized tubes can be inserted through the stringer bladders (e.g., one pressurized tube per stringer bladder). Thus, the consolidation mechanism includes the internal tool, laminate, external tool, load restraint device, and pressurized tube. In other illustrative examples, the pressurized tube can be considered separate from the consolidation mechanism.

[0391] Thereafter, connect a first induction coil embedded in the internal tool and a second induction coil embedded in the external tool via a connector device (operation 1720). These connector devices can take the form of, for example, a knife switch connector. Cover the ends of the laminate with plugs (operation 1722). Position and secure the plugs using an end tool (operation 1724), after which the process terminates.

[0392] Figure 18is a flowchart of a process for constructing a system to form a composite airframe structure according to an example embodiment. The process Figure 18 shown in Figure 1 can be executed to construct the

[0393] system 113 described in Figure 17 . The process 1800 can begin with constructing a consolidation mechanism (operation 1802). Operation 1802 can be performed using, for example, the process 1700 in Figure 17 . For example, the consolidation mechanism constructed in operation 1802 includes an internal tool embedded with a first induction coil, an external tool embedded with a second induction coil, a first intelligent sensor, a second intelligent sensor, and a laminate positioned between the first intelligent sensor and the second intelligent sensor, the laminate including a plurality of overbraided thermoplastic members and an overbraided thermoplastic skin.

[0394] Next, the consolidation mechanism is inductively heated using the first induction coil, the second induction coil, the first intelligent sensor, and the second intelligent sensor to consolidate the overbraided thermoplastic skin with the plurality of overbraided thermoplastic members to form a composite airframe structure (operation 1804), after which the process terminates.

[0395] Figure 19 is a flowchart of a process for inductively consolidating an overbraided thermoplastic skin with overbraided thermoplastic members to form a composite airframe structure according to an example embodiment. Figure 19 The method 1900 shown can be executed to inductively consolidate, for example, the Figure 2 overbraided thermoplastic skin 210 with the overbraided thermoplastic members 206. Additionally, the process 1900 can be implemented using the system 103, which includes a consolidation mechanism 104 that includes a laminate 112, as described in Figures 1 to 2 .

[0396] The process 1900 begins by connecting a first induction coil embedded in an internal tool of the consolidation mechanism to a second induction coil embedded in an external tool of the consolidation mechanism (operation 1902). Operation 1902 can be performed using a connector device such as the Figure 1 connector device 107 in

[0397] Thereafter, a selected amount of pressure is applied to the bladder in the consolidation mechanism (operation 1904). For example, in operation 1904, a pressurization system can be connected to the bladder and an inert gas can be used to apply pressure. In one illustrative example, the pressurization system pressurization tube is positioned within the bladder or positioned to extend through a passage in the bladder. The pressurization system can use an inert gas to apply pressure. In operation 1904, the amount of pressure applied can be small (e.g., about 15 psi).

[0398] The first induction coil and the second induction coil are energized to heat the first smart sensor and the second smart sensor in the consolidation mechanism, thereby heating the thermoplastic material in the consolidation mechanism within a selected tolerance of a selected temperature (operation 1906). The selected temperature can be, for example, a temperature above 350 degrees Fahrenheit. In operation 1906, the thermoplastic material can be a laminated overwrapped braided thermoplastic skin and an overwrapped braided thermoplastic member that will respectively form the fuselage skin and the fuselage stringer of the composite fuselage structure.

[0399] Pressure is applied via the bladder and the stringer bladder (operation 1908). Operation 1908 can be performed by applying a pressure of about 250 psi, for example, using a pressurization system to help smooth the thermoplastic material. Operation 1908 is the step where the overwrapped braided thermoplastic skin is inductively consolidated to the overwrapped braided thermoplastic member and the composite fuselage structure is formed. The composite fuselage structure can be, for example, a fuselage barrel section. Then, the temperature of the thermoplastic material is reduced (operation 1910). When the temperature has reached below a selected threshold, the pressure is reduced (operation 1912). For example, in operation 1912, once the temperature has dropped below about 300 degrees Fahrenheit, the pressure can be reduced to about 15 psi.

[0400] Thereafter, the composite fuselage structure is unloaded (operation 1914). A vacuum is applied to the bladder to create a gap between the composite fuselage structure and the internal tool of the consolidation mechanism (operation 1916). The external tool of the consolidation mechanism is removed, allowing the composite fuselage structure to be removed from the internal tool (operation 1918), after which the process terminates.

[0401] In other illustrative examples, process 1900 includes additional operations to customize the composite fuselage structure once the composite fuselage structure has been removed from the internal tool. For example, cuts can be added to the composite fuselage structure, and other components can be added to the composite fuselage structure. In one illustrative example, windows, strips, and cuts are added. In other examples, induction bonding or induction welding techniques are used to add the fuselage and window frames. Induction bonding or induction welding can also be used to add components such as but not limited to shear tie members, system brackets, antenna stiffeners, access panel stiffeners, other types of components, or combinations thereof to the composite fuselage structure.

[0402] Figure 20 is a flowchart for forming a composite structure according to an example embodiment. The process Figure 20 shown in 2000 can be executed to form a composite structure such as the composite structure 101 in Figure 1 .

[0403] The process 2000 begins by holding an internal tool, a laminate, and an external tool together in place using a load restraint device (operation 2002). The bladder and the plurality of stringer bladders in the laminate are pressurized to cause inflation of the bladder and the plurality of bladders, thereby pushing the overbraided thermoplastic skin and the plurality of overbraided thermoplastic members together (operation 2004).

[0404] Thereafter, the overbraided thermoplastic skin and the plurality of overbraided thermoplastic members are co-consolidated in the laminate while pressurizing the bladder and the plurality of stringer bladders to form a composite structure (operation 2006), after which the process terminates. The pressurization provided in operation 2004 ensures that the co-consolidation of the overbraided thermoplastic skin and the plurality of overbraided thermoplastic members occurs uniformly and smoothly.

[0405] Figure 21 is a flowchart for forming a composite fuselage structure according to an example embodiment. The process Figure 21 shown in 2100 can be executed to form a composite structure such as the composite structure 101 in Figure 1 .

[0406] The process 2100 begins by inflating the bladder and the plurality of stringer bladders in the laminate to place fibers in the overbraided thermoplastic skin and the plurality of overbraided thermoplastic members under tension (operation 2102). Operation 2102 can be performed, for example, by pressurizing the bladder and the plurality of stringer bladders. In some examples, the bladder and the stringer bladders are pressurized using a pressurization tube through which an inert gas flows. The pressurization tube can be inflated by adding an inert gas, which can cause inflation of the bladder and the stringer bladders.

[0407] The laminate is heated to melt the overbraided thermoplastic skin and the plurality of overbraided thermoplastic members (operation 2104). Operation 2104 can be performed using induction-based intelligent sensor heating. The overbraided thermoplastic skin and the plurality of overbraided thermoplastic members are then joined together while melting the overbraided thermoplastic skin and the plurality of overbraided thermoplastic members (operation 2106). The laminate is cooled so that the overbraided thermoplastic skin and the plurality of overbraided thermoplastic members form an integrated structure, i.e., a composite fuselage structure (operation 2108), after which the process terminates.

[0408] Figure 22 is a flowchart for forming a composite structure according to an example embodiment. The process Figure 22 shown in 2200 can be executed to form, for example,Figure 1 The composite structure of the composite structure 101 in

[0409] Process 2200 begins with constructing a laminate including a plurality of overbraided thermoplastic members and an overbraided thermoplastic skin (operation 2202). The laminate is placed between an inner tool and an outer tool (operation 2204). A load restraint device is used to hold the inner tool, the laminate, and the outer tool together in place, where the inner tool, the laminate, the outer tool, and the load restraint device form a consolidation mechanism (operation 2206). The consolidation mechanism is heated to form a composite structure (operation 2208), after which the process terminates.

[0410] Figure 23 is a diagram of a process for forming a composite structure according to an example embodiment. The process 2300 shown in Figure 23 can be executed to form, for example, Figure 1 the composite structure of the composite structure 101 in

[0411] Process 2300 may include forming a plurality of consolidated overbraided thermoplastic preforms (operation 2302). The plurality of consolidated overbraided thermoplastic preforms may include a plurality of overbraided thermoplastic members and an overbraided thermoplastic skin. Additionally, process 2300 includes co - consolidating the plurality of consolidated overbraided thermoplastic preforms in a circumferentially constrained circumferential laminate (operation 2304). During co - consolidation, the fibers of the plurality of consolidated overbraided thermoplastic preforms are tensioned (operation 2306).

[0412] In process 2300, operation 2304 is performed without using an autoclave. In operation 2304, a bladder is used to resist an external load restraint device and provide the pressure typically provided by an autoclave. Additionally, in operation 2304, induction coils and intelligent sensors are used to provide the heat typically provided by an autoclave.

[0413] Figure 24 is a diagram of a process for forming a composite structure according to an example embodiment. The process 2400 shown in Figure 24 can be executed to form, for example, Figure 1 the composite structure of the composite structure 101 in

[0414] Process 2400 begins with inflating a plurality of stringer bladders in a laminate, thereby applying a force against a plurality of overbraided thermoplastic members and an overbraided thermoplastic skin (operation 2402). Operation 2402 can be performed by heating the plurality of stringer bladders and pressurizing the plurality of stringer bladders with an inert gas flowing from a plurality of pressurized tubes into the plurality of stringer bladders. The inflation of the plurality of stringer bladders tensions the plurality of overbraided thermoplastic members and helps resist compressive loads on the plurality of overbraided thermoplastic members.

[0415] During inflation of multiple stringer bags, a dielectric material confinement laminate (operation 2404) is constrained via a dielectric material embedded within a non-dielectric material. Operation 2404 can be performed by pressing the laminate against an external tool that includes the dielectric material. The dielectric material is a ceramic material, and the non-dielectric material can be the multiple induction coils used for heating in operation 2402. During inflation of multiple stringer bags, the non-dielectric material is constrained via the dielectric material (operation 2406).

[0416] Figure 25 is a flowchart of a process for bonding and trimming a thermoplastic tow according to an example embodiment. Figure 25 The method shown in can be used to bond and trim a thermoplastic tow that ultimately forms Figure 2 the overbraided thermoplastic skin 210 and the overbraided thermoplastic member 206 in.

[0417] Process 2500 begins by laying a thermoplastic tow received from a braiding loop on top of a braided structure on a surface, with a portion of the thermoplastic tow received on top of a conductive member (operation 2502). The thermoplastic tow can be an overbraided thermoplastic tow. The surface can be formed by at least one of a tool surface, a septum, a bladder, a stringer bladder, a partially formed braided ply, a preform, an integrated composite structure, or some other type of surface. The braided structure can be, for example, a braided ply of overbraided thermoplastic material, a partially formed braided ply, a preform, an integrated structure made of overbraided thermoplastic material, or some other type of braided structure. In operation 2502, the thermoplastic tow can be positioned on top of the braided structure formed on the surface. The conductive member in operation 2502 can be referred to as a "boot".

[0418] The thermoplastic tow is then adhesively welded to the braided structure using an adhesive welder secured to a support ring (operation 2504). In operation 2504, the adhesive welder is resistively heated to ensure that the thermoplastic tow is uniformly bonded to the braided structure. A portion of the thermoplastic tow is trimmed so as to trim the thermoplastic tow received on top of the braided structure (operation 2506), after which the process terminates. In operation 2506, laser energy is applied to the portion of the thermoplastic tow supported by the conductive member to trim the thermoplastic tow. The conductive member absorbs the laser energy to protect the braided structure beneath the conductive member.

[0419] Figure 26 is a flowchart of a process for bonding and trimming a thermoplastic tow according to an example embodiment. Figure 26 The process shown in can be used to bond and trim a thermoplastic tow that ultimately forms Figure 2 the overbraided thermoplastic skin 210 and the overbraided thermoplastic member 206 in.

[0420] Process 2600 begins with laying a thermoplastic tow received from a braiding system on top of a braided structure on a surface (operation 2602). The received thermoplastic tow is adhesively welded to the braided structure (operation 2604). The thermoplastic tow is trimmed by applying laser energy to a portion of the received thermoplastic tow (operation 2606), after which the process terminates.

[0421] Example embodiments of the present disclosure may be described in the context of an aircraft manufacturing and maintenance method 2700 as shown in Figure 27 and an aircraft 2800 as shown in Figure 28 . First, turning to Figure 27 , an illustration of an aircraft manufacturing and maintenance method is depicted in accordance with an illustrative embodiment. During pre-production, aircraft manufacturing and maintenance method 2700 may include Figure 28 specification and design 2702 and material procurement 2704 of aircraft 2800 in

[0422] . During production, component and sub-component manufacturing 2706 and system integration 2708 of aircraft 2800 in Figure 28 occur. Thereafter, aircraft 2800 in Figure 28 may undergo certification and delivery 2710 for service entry 2712. When in customer service 2712, aircraft 2800 in Figure 28 is scheduled for routine maintenance and repair 2714, which may include modification, reconfiguration, refurbishment, and other maintenance or repair.

[0423] Each process of aircraft manufacturing and maintenance method 2700 may be performed or implemented by a system integrator, a third party, and / or an operator. In these examples, the operator may be a customer. For the purposes of this specification, a system integrator may include, but is not limited to, any number of aircraft manufacturers and prime system subcontractors; a third party may include, but is not limited to, any number of suppliers, subcontractors, and vendors; and an operator may be an airline, a leasing company, a military entity, a maintenance organization, etc.

[0424] Now referring to Figure 28 , an illustration of an aircraft in which illustrative embodiments may be implemented is described. In this example, aircraft 2800 is produced by aircraft manufacturing and maintenance method 2700 in Figure 27 and may include an airframe 2802 having a plurality of systems 2804 and an interior 2806. Examples of systems 2804 include one or more of a propulsion system 2808, an electrical system 2810, a hydraulic system 2812, and an environmental system 2814. Any number of other systems may be included. Although an aerospace example is shown, different illustrative embodiments may be applied to other industries, such as the automotive industry.

[0425] During at least one stage of the aircraft manufacturing and repair method 2700 in Figure 27 , the devices and methods implemented herein can be employed, and in particular, Figures 1 to 2 the system 103 of Figures 1 to 2 can be used to form the composite structure 101 during any one stage of the aircraft manufacturing and repair method 2700. For example, but not limited to, Figures 1 to 2 the system 103 of Figure 28 can be used to form at least a part of the airframe 2802 of the aircraft 2800 in

[0426] In one illustrative example, the parts or sub-assemblies produced in the parts and sub-assembly manufacturing 2706 in Figure 27 can be manufactured or produced in a manner similar to the parts or sub-assemblies produced when the aircraft 2800 is in Figure 27 service 2712 in Figure 27 As another example, during the production stage, for example, during the parts and sub-assembly manufacturing 2706 and system integration 2708 in Figure 27 , one or more device embodiments, method embodiments, or combinations thereof can be used. When the aircraft 2800 is in service 2712 and / or during the maintenance and repair 2714 in

[0427] Using multiple different illustrative embodiments can substantially accelerate the assembly of the aircraft 2800 and / or reduce its cost.

[0428] In some alternative implementations of the example embodiments, one or more of the functions labeled in the boxes may not occur in the order labeled in the figure. For example, in some cases, depending on the functions involved, two consecutively shown boxes may be executed substantially simultaneously, or these boxes may sometimes be executed in the reverse order. In addition, other boxes may be added in addition to the boxes shown in the flowchart or block diagram.

[0429] As used herein, the phrase "at least one of" when used in conjunction with a list of items means that different combinations of one or more of the listed items may be used and only one of the items in the list may be required. The items can be specific objects, things, steps, operations, processes, or categories. In other words, "at least one of" means that any combination or number of items in the list may be used, but not all of the items in the list may be required. For example, without limitation, "at least one of item A, item B, or item C" or "at least one of item A, item B, and item C" can refer to item A; item A and item B; item B; item A, item B, and item C; item B and item C; or item A and item C. In some cases, "at least one of item A, item B, or item C" or "at least one of item A, item B, and item C" can represent, but is not limited to, two of item A, one of item B, and ten of item C; four of item B and seven of item C; or some other suitable combination.

[0430] The present disclosure also provides the following clauses, which relate to:

[0431] 1. A method for forming a composite structure 101, the method comprising:

[0432] Constructing 2202 a laminate 112 comprising a plurality of overbraided thermoplastic members 206 and an overbraided thermoplastic skin 210;

[0433] Placing 2204 the laminate 112 between an inner tool 108 and an outer tool 110;

[0434] Using a load restraint device 117 to hold 2206 the inner tool 108, the laminate 112, and the outer tool 110 together in place, the inner tool 108, the laminate 112, the outer tool 110, and the load restraint device 117 forming a consolidation mechanism 104; and

[0435] Heating 2208 the consolidation mechanism 104 to form the composite structure 101.

[0436] 2. The method of clause 1, wherein constructing 2202 the laminate 112 comprises:

[0437] Constructing the laminate 112 comprising a bladder 202, a plurality of partitions 204, a plurality of overbraided thermoplastic members 206, a plurality of stringer bladders 208, and an overbraided thermoplastic skin 210, the bladder 202 having a plurality of recessed portions 216, the plurality of partitions 204 nested within the plurality of recessed portions 216.

[0438] 3. The method according to clause 1 or 2, wherein heating the consolidation mechanism 104 includes:

[0439] Inductively heating the consolidation mechanism 104 to consolidate the plurality of overbraided thermoplastic members 206 with the overbraided thermoplastic skin 210, thereby forming an integrated composite structure 101.

[0440] 4. The method according to clause 3, wherein heating the consolidation mechanism 104 includes:

[0441] Inductively heating a first smart sensor 114 located between the internal tool 108 and the laminate 112 and a second smart sensor 115 located between the external tool 110 and the laminate 112 to consolidate the plurality of overbraided thermoplastic members 206 to the overbraided thermoplastic skin 210.

[0442] 5. The method according to any one of clauses 1 to 4, the method further comprising:

[0443] Passing a plurality of pressure tubes 238 through a plurality of stringer pockets 208.

[0444] 6. The method according to clause 5, the method further comprising:

[0445] Using a plurality of plugs 106 located at the ends of the laminate 112 to fix 1722 the plurality of pressure tubes 238 within the plurality of stringer pockets 208.

[0446] 7. The method according to any one of clauses 1 to 6, wherein constructing the laminate 112 includes:

[0447] Positioning 1602 a first smart sensor 114 around the internal tool 108, wherein the internal tool 108 is supported by a support structure 116; and

[0448] Positioning 1702 a pocket 202 around the first smart sensor 114.

[0449] 8. The method according to clause 7, wherein constructing 2202 the laminate 112 further includes:

[0450] Positioning 1604 a plurality of partitions 204 within a plurality of recessed portions 216 of the pocket 202, wherein each of the plurality of partitions 204 is made of a nickel-iron alloy.

[0451] 9. The method according to clause 8, wherein constructing 2202 the laminate 112 further includes:

[0452] Position the plurality of overwrapped braided thermoplastic members 206 on top of the plurality of partitions 204, wherein the shape of the overwrapped braided thermoplastic member among the plurality of overwrapped braided thermoplastic members 206 is substantially similar to the shape of the corresponding partition among the plurality of partitions 204 on which the overwrapped braided thermoplastic member is positioned above.

[0453] 10. The method according to clause 9, wherein constructing 2202 the laminate 112 further comprises;

[0454] Position the plurality of stringer bags 208 on top of the plurality of overwrapped braided thermoplastic members 206; and

[0455] Place 1610 the overwrapped braided thermoplastic skin 210 around the plurality of stringer bags 208 and the plurality of overwrapped braided thermoplastic members 206 to complete the laminate 112, wherein the overwrapped braided thermoplastic skin 210 contacts the end sections of the plurality of overwrapped braided thermoplastic members 206.

[0456] 11. The method according to clause 10, the method further comprising:

[0457] Position 1712 the second intelligent sensor 115 around the overwrapped braided thermoplastic skin 210; and

[0458] Position 1714 the external tool 110 around the second intelligent sensor 115, wherein the internal tool 108, the first intelligent sensor 114, the laminate 112, the second intelligent sensor 115 and the external tool 110 together form at least a part of the consolidation mechanism 104.

[0459] 12. The method according to any one of clauses 1 to 11, the method further comprising:

[0460] Use a plurality of plugs 106 to plug 1722 the first end 126 and the second end 128 of the laminate 112, wherein the first plug 1006 among the plurality of plugs 106 used at the first end 126 of the laminate 112 and the second plug 1008 among the plurality of plugs 106 used at the second end 128 of the laminate 112 both include plug portions 1100, 1106, thermal insulation layers 1102, 1108 and sensor connectors 1104, 1110.

[0461] 13. The method according to clause 12, the method further comprising:

[0462] Fix 1724 the end tool 105 to the plurality of plugs 106 to prepare for consolidating the plurality of overwrapped braided thermoplastic members 206 to the overwrapped braided thermoplastic skin 210.

[0463] 14. The method according to any one of clauses 1 to 13, the method further comprising:

[0464] During the consolidation of the plurality of overbraided thermoplastic members 206 to the overbraided thermoplastic skin 210, pressurizing the bladder 202 and the plurality of stringer bladders 208 in the laminate 112 to substantially the same pressure.

[0465] 15. The method according to any one of clauses 1 to 14, the method further comprising:

[0466] During the consolidation of the plurality of overbraided thermoplastic members 206 to the overbraided thermoplastic skin 210, providing mechanical strength and stiffness to the plurality of overbraided thermoplastic members 206 via a plurality of partitions 204 in the laminate 112.

[0467] 16. A part of an aircraft composite barrel section 102 assembled by the method according to any one of clauses 1 to 15.

[0468] 17. A method for forming a composite fuselage structure 102, the method comprising:

[0469] Inflating 2102 the bladder 202 and the plurality of stringer bladders 208 in the laminate 112 to place the fibers in the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206 under tension;

[0470] Heating 2104 the laminate 112 to melt the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206; and

[0471] While the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206 are melted, joining 2106 the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206; and

[0472] Cooling 2108 the laminate 112 such that the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206 form an integrated structure, namely the composite fuselage structure 102.

[0473] 18. A composite fuselage structure 102 assembled by the method according to clause 17.

[0474] 19. A device, the device comprising:

[0475] An internal tool 108;

[0476] A first intelligent sensor 114 positioned around the internal tool 108;

[0477] Laminated layer 112, which is positioned around the first intelligent sensor 114, and the laminated layer 112 includes a plurality of overbraided thermoplastic members 206 and an overbraided thermoplastic skin 210;

[0478] A second intelligent sensor 115, which is positioned around the laminated layer 112;

[0479] An external tool 110, which is positioned around the second intelligent sensor 115; and

[0480] A load restraint device 117, which is used to hold the internal tool 108, the first intelligent sensor 114, the laminated layer 112, the second intelligent sensor 115, and the external tool 110 in place.

[0481] 20. The device according to clause 19, wherein the laminated layer 112 further includes:

[0482] A plurality of partition plates 204, and each of the plurality of partition plates 204 provides a clearly defined surface and stiffness for the corresponding overbraided thermoplastic member among the plurality of overbraided thermoplastic members 206.

[0483] 21. The device according to clause 19 or 20, further including:

[0484] A plurality of pressure tubes 238, which extend through a plurality of stringer pockets 208 in the laminated layer 112; and

[0485] A pressure tube 240, which extends through a pocket 202 in the laminated layer 112.

[0486] 22. Using the device according to any one of clauses 19 to 21 to form an aircraft composite barrel section 102.

[0487] 23. A method for forming a composite structure 101, the method including:

[0488] Using a load restraint device 117 to hold the internal tool 108, the laminated layer 112, and the external tool 110 together in place;

[0489] Pressurizing the pocket 202 and the plurality of stringer pockets 208 in the laminated layer 112 to cause the pocket 202 and the plurality of stringer pockets 208 to expand, so as to push the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206 in the laminated layer 112 together; and

[0490] While the bladder 202 and the plurality of stringer bladders 208 are being pressurized, co-consolidate 2006 the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206 to form the composite structure 101.

[0491] 24. The method of clause 23, wherein co-consolidating 2006 the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206 comprises:

[0492] Inductively heating the first smart sensors 114 and the second smart sensors 114 in the laminate 112 to melt the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206, thereby joining the overbraided thermoplastic skin 210 and the plurality of overbraided thermoplastic members 206 together.

[0493] 25. The method of clause 24, wherein inductively heating the first smart sensors 114 and the second smart sensors 114 comprises:

[0494] Generating magnetic energy using a first induction coil 118 embedded in the internal tool 108 and a second induction coil 120 embedded in the external tool 110; and

[0495] Converting the magnetic energy into heat energy using the first smart sensors 114 and the second smart sensors 114.

[0496] 26. The method of any one of clauses 23 to 25, wherein pressurizing 2004 the bladder 202 and the plurality of stringer bladders 208 in the laminate 112 comprises:

[0497] Pressurizing the plurality of stringer bladders 208 using an inert gas within a plurality of pressure tubes 238 extending through the plurality of stringer bladders 208.

[0498] 27. The method of any one of clauses 23 to 26, wherein pressurizing 2004 the bladder 202 and the plurality of stringer bladders 208 in the laminate 112 comprises:

[0499] Pressurizing the bladder 202 using an inert gas within a pressure tube extending through the bladder 202.

[0500] 28. The method of any one of clauses 23 to 27, the method further comprising:

[0501] During inductive heating, supporting each of the plurality of overbraided thermoplastic members 206 using a well-defined surface provided by a corresponding one of a plurality of partitions 204 in the laminate 112.

[0502] 29. The method according to any one of clauses 23 to 28, the method further comprising:

[0503] Cooling the laminate 112 of 2108 such that the overwrapped braided thermoplastic skin 210 and the plurality of overwrapped braided thermoplastic members 206 joined together form a single integrated composite structure 101.

[0504] 30. The method according to any one of clauses 23 to 29, the method further comprising:

[0505] Using a plurality of plugs to fix 1722 the first end 126 and the second end 128 of the laminate 112 to prevent longitudinal expansion of the bladder 202 or the plurality of stringer bladders 208 during induction heating.

[0506] 31. The method according to any one of clauses 23 to 30, the method further comprising:

[0507] Constructing 2202, 2204 the laminate 112 over the internal tool 108;

[0508] Fixing 2204 the external tool 110 around the laminate 112; and

[0509] While the laminate 112 is constructed over the internal tool 108 and the external tool 110 is fixed around the laminate 112, compressively loading 2206 the internal tool 108.

[0510] 32. A part of an aircraft composite barrel section 102 assembled by the method according to any one of clauses 23 to 31

[0511] 33. An apparatus, the apparatus comprising:

[0512] A bladder 202 having a plurality of recessed portions 212;

[0513] A plurality of partitions 204 positioned within the plurality of recessed portions 212;

[0514] A plurality of overwrapped braided thermoplastic members 206 positioned over the plurality of partitions 204;

[0515] A plurality of stringer bladders 208 positioned over the plurality of overwrapped braided thermoplastic members 206; and

[0516] An overwrapped braided thermoplastic skin 210 positioned over the plurality of stringer bladders 208 and the plurality of overwrapped braided thermoplastic members 206.

[0517] 34. The device according to clause 33, wherein the partitions among the plurality of partitions 204 are made of a nickel-iron alloy.

[0518] 35. The device according to clause 34, wherein the nickel-iron alloy is an Invar alloy containing approximately 40% to approximately 43% nickel.

[0519] 36. The device according to any one of clauses 33 to 35, wherein the plurality of partitions 204 have a first coefficient of thermal expansion 227 that is closer to the second coefficient of thermal expansion 237 of the plurality of overwrapped braided thermoplastic members 206.

[0520] 37. The device according to any one of clauses 33 to 36, wherein the bladder 202, the plurality of partitions 204, the plurality of overwrapped braided thermoplastic members 206, the plurality of longitudinal beam bladders 208, and the overwrapped braided thermoplastic skin 210 form a laminate 112.

[0521] 38. The device according to clause 37, wherein the laminate 112 is positioned between a first smart sensor 114 lined with an internal tool 108 and a second smart sensor 114 lined with an external tool 110, and wherein the overwrapped braided thermoplastic skin 210 is consolidated with the plurality of overwrapped braided thermoplastic members 206 via the first smart sensor 114 and the second smart sensor 114 by induction heating.

[0522] 39. The device according to clause 38, wherein the internal tool 108 is embedded with a first induction coil 118, and the external tool 110 is embedded with a second induction coil 120.

[0523] 40. The device according to any one of clauses 37 to 39, the device further comprising:

[0524] A plurality of plugs 106 for plugging a first end 126 and a second end 128 of the laminate 112.

[0525] 41. The device according to clause 40, wherein a first plug 1006 among the plurality of plugs 106 and a second plug 1008 among the plurality of plugs 106 each comprise:

[0526] Plug portions 1100, 1106, and a pressure tube 1112 extends from the plurality of longitudinal beam bladders 208 into the plug portions;

[0527] Thermal insulation layers 1102, 1108; and

[0528] Sensor connectors 1104, 1110.

[0529] 42. The apparatus according to clause 41, wherein the sensor connectors 1104, 1110 are water-cooled.

[0530] 43. The apparatus according to any one of clauses 37 to 42, the apparatus further comprising:

[0531] A plurality of pressurized tubes 238 extending through the plurality of stringer bags 208.

[0532] 44. A method of forming an aircraft composite barrel section 102 using the apparatus according to clause 33.

[0533] 45. A system 103, the system comprising:

[0534] An internal tool 108 including a dielectric material and embedded with a first induction coil 118;

[0535] An external tool 110 including the dielectric material, the external tool 110 being embedded with a second induction coil 120 and being shaped and sized to surround the internal tool 108;

[0536] A first intelligent sensor 114 lining the internal tool 108; and

[0537] A second intelligent sensor 114 lining the external tool 110,

[0538] wherein when the first induction coil 118 and the second induction coil 120 are used to inductively heat a laminate 112 positioned between the internal tool 108 and the external tool 110, both the first intelligent sensor 114 and the second intelligent sensor 114 contribute to heat distribution and ensure thermal uniformity.

[0539] 46. A method of forming a composite fuselage structure 102 using the system 103 according to clause 45.

[0540] 47. A system 103, the system comprising:

[0541] An internal tool 108;

[0542] A first intelligent sensor 114 positioned around the internal tool 108;

[0543] A laminate 112 positioned around the first intelligent sensor 114, the laminate 112 comprising:

[0544] A bag 202 having a plurality of recessed portions 212;

[0545] A plurality of partition plates 204, the plurality of partition plates being positioned within the plurality of recessed portions 212;

[0546] A plurality of overwrapped braided thermoplastic members 206, the plurality of overwrapped braided thermoplastic members being positioned on the plurality of partition plates 204;

[0547] A plurality of stringer bags 208, the plurality of stringer bags being positioned in contact with the plurality of overwrapped braided thermoplastic members 206; and

[0548] An overwrapped braided thermoplastic skin 210, the overwrapped braided thermoplastic skin being positioned on the plurality of stringer bags 208 and the plurality of overwrapped braided thermoplastic members 206 such that each of the plurality of stringer bags 208 is sandwiched between the overwrapped braided thermoplastic skin 210 and a corresponding one of the plurality of overwrapped braided thermoplastic members;

[0549] A second intelligent sensor 115, the second intelligent sensor being positioned around the laminate 112; and

[0550] An external tool 110, the external tool being positioned around the second intelligent sensor 115.

[0551] 48. The system 103 of clause 47, the system further comprising:

[0552] A plurality of plugs 106, the plurality of plugs being for covering a first end 126 and a second end 128 of the laminate 112.

[0553] 49. The system 103 of clause 48, wherein the internal tool 108 is embedded with a first induction coil 118, and the external tool 110 is embedded with a second induction coil 120, and the system further comprises:

[0554] A plurality of connector devices 107, the plurality of connector devices being for connecting the first induction coil 118 and the second induction coil 120.

[0555] 50. The system 103 of clause 48 or 49, the system further comprising:

[0556] An end tool 105, the end tool being for positioning and fixing the plurality of plugs 106.

[0557] 51. A method of forming an aircraft composite barrel section 102 using the system 103 of clause 47.

[0558] 52. A method of forming a composite structure 101, the method comprising:

[0559] Inflate a plurality of stringer bags 208 in the laminate 112 to apply a force against the plurality of overbraided thermoplastic members 206 and the overbraided thermoplastic skin 210;

[0560] During inflation of the plurality of stringer bags 208, constrain the laminate 112 via a dielectric material embedded within a non - dielectric material; and

[0561] During inflation of the plurality of stringer bags 208, constrain the non - dielectric material via the dielectric material.

[0562] 53. The method of clause 52, the method further comprising:

[0563] Construct the laminate 112 including the bladder 202, the plurality of stringer bags 208, the plurality of overbraided thermoplastic members 206, and the overbraided thermoplastic skin 210; and

[0564] Position the laminate 112 between an internal tool 108 and an external tool 110, both the internal tool and the external tool including the dielectric material and the non - dielectric material.

[0565] 54. The method of clause 52 or 53, wherein inflating the plurality of stringer bags 208 in the laminate 112 comprises:

[0566] Heating the plurality of stringer bags 208.

[0567] 55. The method of any one of clauses 52 to 54, wherein inflating the plurality of stringer bags 208 in the laminate 112 comprises:

[0568] Pressurizing the plurality of stringer bags 208 via an inert gas flowing from a plurality of pressurized tubes into the plurality of stringer bags 208.

[0569] 56. The method of any one of clauses 52 to 55, wherein constraining the laminate 112 comprises:

[0570] Pressing the laminate 112 against an external tool 110 including the dielectric material, wherein the dielectric material is a ceramic material and the non - dielectric material embedded within the dielectric material is a plurality of induction coils.

[0571] 57. The method of any one of clauses 52 to 56, wherein inflating the plurality of stringer bags 208 in the laminate 112 comprises:

[0572] Inflating the plurality of stringer bags 208 to tension the plurality of overbraided thermoplastic members 206 via the inflation.

[0573] The method according to any one of clauses 52 to 57, wherein expanding the plurality of stringer bags 208 in the laminate 112 includes:

[0574] Resisting a compressive load on the plurality of overbraided thermoplastic members 206 by expansion of the plurality of stringer bags 208.

[0575] A portion of an aircraft composite barrel section 102 assembled by the method according to any one of clauses 52 to 58.

[0576] A method for forming a composite structure 101, the method comprising:

[0577] Co - consolidating 2304 a plurality of consolidated overbraided thermoplastic preforms 206, 210 in a circumferentially constrained circumferential laminate 112; and

[0578] During co - consolidation, tensioning 2306 the fibers of the plurality of consolidated overbraided thermoplastic preforms 206, 210.

[0579] The method according to clause 60, wherein co - consolidating 2304 the plurality of consolidated overbraided thermoplastic preforms 206, 210 includes:

[0580] Heating the circumferential laminate 112 to co - consolidate the plurality of consolidated overbraided thermoplastic preforms 206, 210.

[0581] The method according to clause 61, wherein heating the circumferential laminate 112 includes:

[0582] Inductively heating the circumferential laminate 112 to co - consolidate the plurality of consolidated overbraided thermoplastic preforms 206, 210.

[0583] The method according to any one of clauses 60 to 62, wherein co - consolidating 2304 the plurality of consolidated overbraided thermoplastic preforms 206, 210 includes:

[0584] Using a plurality of induction coils and a plurality of intelligent sensors to heat the circumferential laminate 112 to co - consolidate the plurality of consolidated overbraided thermoplastic preforms 206, 210.

[0585] The method according to any one of clauses 60 to 63, wherein co - consolidating 2304 the plurality of consolidated overbraided thermoplastic preforms 206, 210 includes:

[0586] Expanding a plurality of stringer bags 208 and bags 202 in the circumferential laminate 112, thereby applying a force against the plurality of consolidated overbraided thermoplastic preforms 206, 210.

[0587] 65. The method according to clause 64, wherein inflating the plurality of stringer bladders 208 and the bladder 202 comprises:

[0588] Pressurizing the plurality of stringer bladders 208 and the bladder 202 in the circumferential laminate 112 with an inert gas.

[0589] 66. A part of an aircraft composite barrel section 102 assembled by the method according to any one of clauses 60 to 65.

[0590] 67. A tow bonding and trimming device, the tow bonding and trimming device comprising:

[0591] A bonding-trimming system 1301 for bonding and trimming a thermoplastic tow 1404 into a braided structure 1306; and

[0592] A support system 1302 to which the bonding-trimming system 1301 is attached, the support system 1302 being sized and shaped to operably position the bonding-trimming system 1301 relative to a cylindrical thermoplastic laminate 306.

[0593] 68. The tow bonding and trimming device according to clause 67, wherein the support system 1302 comprises:

[0594] A support ring 1303 sized and shaped to completely surround a circumferential surface 1304, wherein the bonding-trimming system 1301 is fixed to the support ring 1303.

[0595] 69. The tow bonding and trimming device according to clause 67 or 68, wherein the bonding-trimming system 1301 comprises:

[0596] A bonding welder 1400 fixed to a part of the support system 1302, wherein the bonding welder 1400 is resistance heated.

[0597] 70. The tow bonding and trimming device according to any one of clauses 67 to 69, wherein the bonding-trimming system 1301 comprises:

[0598] A trimmer 1402 fixed to a part of the support system 1302, wherein the trimmer 1402 uses laser energy to trim the thermoplastic tow 1404.

[0599] 71. The tow bonding and trimming device according to clause 70, the tow bonding and trimming device further comprising:

[0600] A conductive member 1308, the conductive member being positioned between the braided structure 1306 and the thermoplastic tow 1404.

[0601] 72. The tow bonding and trimming apparatus according to clause 71, wherein the cross-sectional shape of the conductive member 1308 is wedge-shaped.

[0602] 73. The tow bonding and trimming apparatus according to clause 71 or 72, wherein the conductive member 1308 is thermally conductive and is used to absorb laser energy emitted by the trimmer 1402 to protect the braided structure 1306.

[0603] 74. The tow bonding and trimming apparatus according to any one of clauses 71 to 73, wherein the thermoplastic tow 1404 is received from a braiding loop and the thermoplastic tow 1404 passes over the conductive member 1308.

[0604] 75. The tow bonding and trimming apparatus according to any one of clauses 67 to 74, wherein the support system 1302 travels together with the braiding loop that supplies the thermoplastic tow 1404.

[0605] 76. The tow bonding and trimming apparatus according to any one of clauses 67 to 76, wherein the bonding-trimming system 1301 is one of a plurality of bonding-trimming systems distributed along the support system 1302.

[0606] 77. The tow bonding and trimming apparatus according to any one of clauses 67 to 76, wherein the braided structure 1306 includes a plurality of thermoplastic sheets that wrap continuous thermoplastic composite fibers.

[0607] 78. A method for bonding and trimming a thermoplastic tow 1404, the method comprising:

[0608] Laying 2502 the thermoplastic tow 1404 received from a braiding system on top of the braided structure 1306 on a surface 1304; and

[0609] Bonding and welding 2504 the thermoplastic tow 1404 to the braided structure 1306; and

[0610] Trimming 2506 a portion of the thermoplastic tow 1404, thereby trimming the thermoplastic tow 1404 received on top of the braided structure 1306.

[0611] 79. The method according to clause 78, the method further comprising:

[0612] Receiving a portion of the thermoplastic tow 1404 on top of a conductive member 1308 positioned between the braided structure 1306 and the thermoplastic tow 1404.

[0613] 80. The method according to clause 78 or 79, wherein the adhesive welding 2504 of the thermoplastic tow 1404 comprises:

[0614] Adhesively welding the thermoplastic tow 1404 to the braided structure 1306 using an adhesive welder 1400 fixed to a support ring 1303.

[0615] 81. The method according to any one of clauses 78 to 80, wherein the adhesive welding 2504 of the thermoplastic tow 1404 comprises:

[0616] Adhesively welding the thermoplastic tow 1404 to the braided structure 1306 using an adhesive welder 1400 fixed to a support ring 1303 surrounding the surface 1304, wherein the adhesive welder 1400 is resistance heated.

[0617] 82. The method according to any one of clauses 78 to 81, the method further comprising:

[0618] Supporting the portion of the thermoplastic tow 1404 by a conducting member 1308.

[0619] 83. The method according to clause 82, wherein trimming 2506 the portion of the thermoplastic tow 1404 comprises:

[0620] Applying laser energy to the portion of the thermoplastic tow 1404 supported by the conducting member 1308.

[0621] 84. The method according to clause 83, wherein applying the laser energy comprises:

[0622] When trimming the thermoplastic tow 1404, using the conducting member 1308 to absorb the laser energy to protect the braided structure 1306.

[0623] 85. The method according to any one of clauses 78 to 84, wherein laying 2502 the thermoplastic tow 1404 comprises:

[0624] Laying the thermoplastic tow 1404 on the surface 1304, the surface 1304 being formed by at least one of a tool surface 1304, a spacer 502, a bladder 400, a stringer bladder 702, a partially formed braided ply 1306, a preform 800, 600 or an integrated composite structure 101.

[0625] 86. The method according to any one of clauses 78 to 85, wherein laying 2502 the thermoplastic tow 1404 comprises:

[0626] Lay the thermoplastic tow 1404 to add local features to the braided structure 1306.

[0627] 87. A part of an aircraft composite barrel section 102 assembled by the method according to any one of clauses 78 to 86.

[0628] 88. A method for bonding and trimming a thermoplastic tow 1404, the method comprising:

[0629] Laying 2602 the thermoplastic tow 1404 received from a braiding system on top of a braided structure 1306 on a surface 1304; and

[0630] Bonding and welding 2604 the thermoplastic tow 1404 received from the braiding system to the braided structure 1306; and

[0631] Trimming 2606 the thermoplastic tow 1404 by applying laser energy to a portion of the thermoplastic tow 1404.

[0632] 89. The method according to clause 88, the method further comprising:

[0633] Supporting the portion of the thermoplastic tow 1404 by a conducting member 1308.

[0634] 90. The method according to clause 88 or 89, wherein trimming 2606 the thermoplastic tow 1404 comprises:

[0635] Applying the laser energy to the portion of the thermoplastic tow 1404 supported by the conducting member 1308.

[0636] 91. A part of an aircraft composite barrel section 102 assembled by the method according to clause 88.

[0637] 92. A bonding-trimming mechanism, the bonding-trimming mechanism comprising:

[0638] A support ring 1303, the size and shape of the support ring 1303 being designed to completely surround a circumferential surface 1304;

[0639] A bonding-trimming system 1301, the bonding-trimming system 1301 being fixed to the support ring 1303 for bonding a thermoplastic tow 1404 to a braided structure 1306, wherein the bonding-trimming system 1301 comprises:

[0640] A bonding welder 1400, the bonding welder 1400 being fixed to a part of the support ring 1303, wherein the bonding welder 1400 is resistance heated; and

[0641] Trimmer 1402, which is fixed to a part of the support ring 1303, wherein the trimmer 1402 uses laser energy to trim the thermoplastic tow 1404; and

[0642] Conduction member 1308, which is positioned between the braided structure 1306 and the thermoplastic tow 1404.

[0643] 93. The bonding-trimming mechanism according to clause 92, wherein the cross-sectional shape of the conduction member 1308 is wedge-shaped and is thermally conductive to absorb the laser energy emitted by the trimmer 1402, thereby protecting the braided structure 1306 during trimming of the thermoplastic tow 1404.

[0644] 94. The bonding-trimming mechanism according to clause 93, wherein the bonding-trimming system 1301 is one of a plurality of bonding-trimming systems 1301 distributed along the support ring 1303.

[0645] 95. The bonding-trimming mechanism according to any one of clauses 92 to 94, wherein the braided structure 1306 includes a plurality of thermoplastic sheets covering and braiding continuous thermoplastic composite fibers.

[0646] 96. The bonding-trimming mechanism according to any one of clauses 92 to 95, wherein the surface 1304 is formed by at least one of a tool surface 1304, a partition 502, a bladder 400, a stringer bladder 702, a partially formed braided ply 1306, a preform 800, 600, or an integrated composite structure 101.

[0647] For purposes of illustration and description, descriptions of different example embodiments have been presented and are not intended to be exhaustive or limited to the disclosed forms of the embodiments. Many modifications and variations are obvious to those of ordinary skill in the art. Additionally, different example embodiments may provide different features compared to other desired embodiments. The selection and description of the selected one or more embodiments are intended to best explain the principles of the embodiments, practical applications, and to enable other ordinary skill in the art to understand the disclosure of the various embodiments with various modifications suitable for the particular uses contemplated.

Claims

1. A method for forming a composite structure (101), the method comprising: Constructing (2202) a laminate (112) including a plurality of overbraided thermoplastic members (206) and an overbraided thermoplastic skin (210); Placing (2204) the laminate (112) between an internal tool (108) and an external tool (110); Using a load restraint device (117) to hold (2206) the internal tool (108), the laminate (112), and the external tool (110) together in place, the internal tool (108), the laminate (112), the external tool (110), and the load restraint device (117) forming a consolidation mechanism (104); And Heating (2208) the consolidation mechanism (104) to form the composite structure (101); The method further comprises: Using a plurality of plugs (106) to plug (1722) a first end (126) and a second end (128) of the laminate (112), wherein a first plug (1006) among the plurality of plugs (106) used at the first end (126) of the laminate (112) and a second plug (1008) among the plurality of plugs (106) used at the second end (128) of the laminate (112) each include a plug portion (1100, 1106), a thermal insulation layer (1102, 1108), and a sensor connector (1104, 1110).

2. The method according to claim 1, wherein, Constructing (2202) the laminate (112) includes: Constructing the laminate (112) including a bladder (202), a plurality of partitions (204), a plurality of overbraided thermoplastic members (206), a plurality of stringer bladders (208), and an overbraided thermoplastic skin (210), the bladder (202) having a plurality of recessed portions (216), and the plurality of partitions (204) being nested within the plurality of recessed portions (216).

3. The method according to claim 1 or 2, wherein Heating (2208) the consolidation mechanism (104) includes: Inductively heating the consolidation mechanism (104) to consolidate the plurality of overbraided thermoplastic members (206) with the overbraided thermoplastic skin (210), thereby forming an integrated composite structure (101).

4. The method according to claim 1 or 2, the method further comprising: Passing a plurality of pressure tubes (238) through the plurality of stringer bladders (208).

5. The method according to claim 1 or 2, wherein Constructing the laminate (112) includes: Positioning a first intelligent sensor (114) around the internal tool (108), wherein the internal tool (108) is supported by a support structure (116); and Positioning the bladder (202) around the first intelligent sensor (114).

6. The method according to claim 1 or 2, the method further comprising: During consolidating the plurality of overbraided thermoplastic members (206) to the overbraided thermoplastic skin (210), pressurizing the bladder (202) and the plurality of stringer bladders (208) in the laminate (112) to substantially the same pressure.

7. The method according to claim 1 or 2, the method further comprising: During consolidating the plurality of overbraided thermoplastic members (206) to the overbraided thermoplastic skin (210), providing mechanical strength and stiffness to the plurality of overbraided thermoplastic members (206) via a plurality of partitions (204) in the laminate (112).

8. An apparatus for forming a composite structure (101), the apparatus comprising: An internal tool (108); A first smart sensor (114) positioned around the internal tool (108); A laminate (112) positioned around the first smart sensor (114), the laminate (112) comprising a plurality of overbraided thermoplastic members (206) and an overbraided thermoplastic skin (210); A second smart sensor (115) positioned around the laminate (112); An external tool (110) positioned around the second smart sensor (115); A load restraint device (117) for holding the internal tool (108), the first smart sensor (114), the laminate (112), the second smart sensor (115) and the external tool (110) in place; And A plurality of plugs (106) for covering a first end (126) and a second end (128) of the laminate (112), wherein a first plug (1006) of the plurality of plugs (106) used at the first end (126) of the laminate (112) and a second plug (1008) of the plurality of plugs (106) used at the second end (128) of the laminate (112) each comprise a plug portion (1100, 1106), a thermal insulation layer (1102, 1108) and a sensor connector (1104, 1110).

9. The apparatus according to claim 8, wherein, The laminate (112) further comprises: A plurality of partitions (204), each of the plurality of partitions (204) providing a well - defined surface and stiffness for a corresponding one of the plurality of overbraided thermoplastic members (206).

10. The apparatus according to claim 8 or 9, the apparatus further comprising: A plurality of first pressure tubes (238) extending through a plurality of stringer pockets (208) in the laminate (112); And A second pressure tube (240) extending through a pocket (202) in the laminate (112).

11. A system (103) for forming a composite structure (101), the system comprising: An internal tool (108); A first smart sensor (114) positioned around the internal tool (108); A laminate (112) positioned around the first smart sensor (114), the laminate (112) comprising: A pocket (202) having a plurality of recessed portions (212); A plurality of partitions (204), the plurality of partitions being positioned within the plurality of recessed portions (212); A plurality of overwrapped braided thermoplastic members (206), the plurality of overwrapped braided thermoplastic members being positioned on top of the plurality of partitions (204); A plurality of stringer bags (208), the plurality of stringer bags being positioned in contact with the plurality of overwrapped braided thermoplastic members (206); and An overwrapped braided thermoplastic skin (210), the overwrapped braided thermoplastic skin being positioned on top of the plurality of stringer bags (208) and the plurality of overwrapped braided thermoplastic members (206) such that each of the plurality of stringer bags (208) is sandwiched between the overwrapped braided thermoplastic skin (210) and a corresponding one of the plurality of overwrapped braided thermoplastic members (206); A second intelligent sensor (115), the second intelligent sensor being positioned around the laminate (112); An external tool (110), the external tool being positioned around the second intelligent sensor (115); and A plurality of plugs (106) for covering a first end (126) and a second end (128) of the laminate (112), wherein a first plug (1006) of the plurality of plugs (106) used at the first end (126) of the laminate (112) and a second plug (1008) of the plurality of plugs (106) used at the second end (128) of the laminate (112) each include a plug portion (1100, 1106), a thermal insulation layer (1102, 1108), and a sensor connector (1104, 1110).

12. The system (103) according to claim 11, wherein, The internal tool (108) is embedded with a first induction coil (118), and the external tool (110) is embedded with a second induction coil (120), and the system further includes: A plurality of connector devices (107) for connecting the first induction coil (118) and the second induction coil (120).

13. The system (103) according to claim 11 or 12, the system further including: An end tool (105) for positioning and fixing the plurality of plugs (106).

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