Composite structure with curvature through web and multiple flanges

Abstract

The present disclosure relates to a composite structure having a bend through a web and a plurality of flanges. Methods and apparatus are provided for forming a composite structure having bends in a web and a plurality of flanges of the composite structure. A flat uncured composite laminate is placed in contact with the forming surface of the mandrel. Pressure is applied to a portion of the flat uncured composite laminate over the bending region in the forming surface of the mandrel to form a curved laminate. The bent laminate and mandrel are placed into a forming assembly. The overhanging portion of the curved laminate is bent by a forming assembly into contact with the side of the mandrel to form a composite structure having bends in a web of the composite structure in contact with the forming surface of the mandrel and a plurality of flanges in contact with the side of the mandrel.

Description

Technical Field

[0001] The present disclosure relates generally to composite material manufacturing and, more particularly, to forming a composite material structure having a bend through a web and a plurality of flanges. Background Art

[0002] Composite materials are strong, lightweight materials produced by combining two or more functional components. For example, a composite material may include reinforcing fibers incorporated into a polymer resin matrix. The fibers may take the form of unidirectional tapes, woven fabrics or fabrics, or braids. The mechanical properties and other material properties of a composite material may be desirable for some implementations.

[0003] Composite fabrication uses different methods than metal working due to the different material properties. Due to complex shapes, especially those with bends or curves, some composite fabrication is done by hand. However, manually forming composite structures is undesirably time consuming.

[0004] Therefore, it is desirable to have a method and apparatus that takes into account at least some of the above-mentioned problems as well as other possible problems.It is desirable to have an automated method of forming a composite material structure having curvature in a manner that reduces wrinkles. Summary of the invention

[0005] Embodiments of the present disclosure provide a method for forming a composite structure having bends in a web and multiple flanges of the composite structure. A flat uncured composite laminate is placed in contact with a forming surface of a mandrel. Pressure is applied to a portion of the flat uncured composite laminate on a bend area in the forming surface of the mandrel to form a bent laminate. The flat uncured composite laminate includes a plurality of zero-degree plies that are discontinuous along corresponding lengths. The bent laminate and the mandrel are placed into a forming assembly. The overhanging portion of the bent laminate is bent by the forming assembly into contact with the side of the mandrel to form a composite structure having bends in the web of the composite structure in contact with the forming surface of the mandrel and in multiple flanges in contact with the side of the mandrel.

[0006] An embodiment of the present disclosure provides a forming system. The forming system comprises a mandrel, the mandrel comprising: a web surface having a bending area; and flange forming surfaces on both sides of the web surface, the flange forming surfaces being connected to the web surface through two angle forming edges.

[0007] An embodiment of the present disclosure provides a method for forming a composite structure having bends in a web and a plurality of flanges of the composite structure. A bent laminate including a plurality of composite plies on a mandrel is moved into a forming assembly, the bent laminate being in contact with a web surface of the mandrel and including an overhanging portion overhanging the mandrel, the web surface including a bending region, the bending region including a plurality of bends, the plurality of bends forming an angle between a first portion and a second portion of the web surface in a longitudinal direction of the mandrel. The bent laminate includes a plurality of zero-degree plies having cuts within a desired distance of each of the plurality of bends. The overhanging portion of the bent laminate is bent by a forming assembly into contact with a side of the mandrel to form a composite structure having bends in a web of the composite structure in contact with the forming surface of the mandrel and in a plurality of flanges in contact with the side of the mandrel.

[0008] The features and functions can be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments in which further details can be seen with reference to the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The novel features believed to be characteristic of the illustrative embodiments are set forth in the appended claims. However, the illustrative embodiments and their preferred modes of use, further objects and features thereof will be best understood by reference to the following detailed description of illustrative embodiments of the disclosure when read in conjunction with the accompanying drawings, in which:

[0010] Figure 1 is a diagram of an aircraft according to an illustrative embodiment;

[0011] Figure 2 is an illustration of a block diagram of a manufacturing environment according to an illustrative embodiment;

[0012] Figure 3 is an illustration of a flow chart of a method of forming a composite structure having a curvature according to an illustrative embodiment;

[0013] Figure 4 is a flow chart of a method of forming a composite structure having curvatures in a web and a plurality of flanges of the composite structure according to an illustrative embodiment;

[0014] Figure 5 is an illustration of an isometric view of a composite material structure having multiple bends according to an illustrative embodiment;

[0015] Figure 6 is an illustration of an isometric view of a mandrel having multiple bends in accordance with an illustrative embodiment;

[0016] Figure 7 is an illustration of an isometric view of a mandrel having multiple bends and a flat uncured composite feedstock according to an illustrative embodiment;

[0017] Figure 8 is an illustration of the underside of an overhanging portion of a flat, uncured composite feedstock on a mandrel having a plurality of bends in accordance with an illustrative embodiment;

[0018] Fig. 9 is an illustration of a side view of a presser foot in contact with a flat uncured composite feed material over a plurality of bends on a mandrel in accordance with an illustrative embodiment;

[0019] Fig.10 is an illustration of an isometric view of a shim in contact with a curved composite feedstock on a mandrel in accordance with an illustrative embodiment;

[0020] Fig.11 is an illustration of a curved composite feedstock on a mandrel being introduced into a forming assembly in accordance with an illustrative embodiment;

[0021] Fig.12 is a diagram of a pusher device of a forming assembly according to an illustrative embodiment;

[0022] Fig.13 is an illustration of a heater assembly of a forming assembly according to an illustrative embodiment;

[0023] Fig.14 is an illustration of an isometric view of a composite material structure having multiple bends according to an illustrative embodiment;

[0024] Fig.15A and Fig. 15B is a flow chart of a method of forming a composite structure having curvatures in a web and a plurality of flanges of the composite structure according to an illustrative embodiment;

[0025] Fig.16 is a flow chart of a method of forming a composite structure having curvatures in a web and a plurality of flanges of the composite structure according to an illustrative embodiment;

[0026] Fig.17 is an illustration of an aircraft manufacturing and service method in block diagram form according to an illustrative embodiment; and

[0027] Fig.18 is an illustration of an aircraft in block diagram form in which illustrative embodiments may be implemented. DETAILED DESCRIPTION

[0028] The illustrative examples recognize and take into account one or more considerations. The illustrative examples recognize and take into account that curvature exists in wing spars used for aerospace structures and drag reduction. The illustrative examples recognize and take into account that curvature presents manufacturing challenges for composite manufacturing. The illustrative examples recognize and take into account that some wing spars with curvature are manufactured in three or more parts.

[0029] The illustrative examples allow bending of an uncured composite feedstock without undesirable wrinkle formation in the raw composite feedstock. The illustrative examples provide methods and apparatus for forming a composite material structure having at least one curvature.

[0030] Now go to Figure 1 , an illustration of an aircraft is shown in accordance with an illustrative embodiment. Aircraft 100 has wing 102 and wing 104 attached to fuselage 106. Aircraft 100 includes engine 108 attached to wing 102 and engine 110 attached to wing 104.

[0031] Fuselage 106 has tail section 112 . Horizontal stabilizer 114 , horizontal stabilizer 116 , and vertical stabilizer 118 are attached to tail section 112 of fuselage 106 .

[0032] Aircraft 100 is an example of an aircraft that may have a composite material structure formed using an illustrative example. For example, a component of at least one of wing 102 or wing 104 may be formed using an illustrative example. In some illustrative examples, a wing spar of at least one of wing 102 or wing 104 may be formed using the illustrative examples.

[0033] Now go to Figure 2, an illustration of a block diagram of a manufacturing environment according to an illustrative embodiment is shown. A forming system 202 is present in the manufacturing environment 200. In some illustrative examples, the forming system 202 may be referred to as a composite forming system, a spar forming system, or a longitudinal composite forming system. The forming system 202 includes a mandrel 204. The mandrel 204 includes: a web surface 206 having a bending area 208; and flange forming surfaces 210 on both sides of the web surface 206. The flange forming surface 210 is connected to the web surface 206 by two corner forming edges (corner forming edge 212 and corner forming edge 214). The flange forming surface 210 includes a flange forming surface 216 connected to the web surface 206 by the corner forming edge 212. The flange forming surface 210 includes a flange forming surface 218 connected to the web surface 206 by the corner forming edge 214. Web surface 206, flange forming surface 216, and flange forming surface 218 form forming surface 230 of mandrel 204. Side 220 of mandrel 204 includes flange forming surface 210. Web surface 206 includes bend region 208 including a plurality of bends 209 forming angle 222 between a first portion 224 and a second portion 226 of web surface 206 in a longitudinal direction 228 of mandrel 204. In some illustrative examples, plurality of bends 209 includes more than one bend configured to form bend 268 in composite structure 298. In some other illustrative examples, plurality of bends 209 is a single bend configured to form bend 268 in composite structure 298.

[0034] In some illustrative examples, forming system 202 includes support brackets movably connected to flange forming surface 210 of mandrel 204: support bracket 236 and support bracket 232. Support bracket 236 is movably connected to flange forming surface 218. Support bracket 232 is movably connected to flange forming surface 216.

[0035] Support bracket 236 and support bracket 232 can be movably connected to flange forming surface 216 by at least one of active or passive connection. In some illustrative examples, support bracket (support bracket 236 and support bracket 232) is connected to flange forming surface 216 by vacuum cup, hydraulic device or other force. In some illustrative examples, support bracket (support bracket 236 and support bracket 232) is magnetically connected to flange forming surface 210. Magnetic connection can be passive or active. In some illustrative examples, support bracket 236 and support bracket 232 are movably connected to flange forming surface 216 by electromagnet, and the strength of the electromagnet varies based on the power provided. As shown in the figure, support bracket 236 is connected to flange forming surface 218 by magnet 238. As shown in the figure, support bracket 232 is connected to flange forming surface 216 by magnet 234.

[0036] Support brackets 236 and support brackets 232 support overhanging portion 257 of flat, uncured composite laminate 240. Overhanging portion 257 is the portion of flat, uncured composite laminate 240 that is not in contact with mandrel 204 when flat, uncured composite laminate 240 is in contact with web surface 206. In some illustrative examples, overhanging portion 257 may be referred to as a cantilevered portion.

[0037] In some illustrative examples, flat uncured composite laminate 240 is transferred to mandrel 204 using vacuum cups 265. In some illustrative examples, vacuum cups 265 remain on flat uncured composite laminate 240 during forming against forming surface 230 of mandrel 204. In some illustrative examples, vacuum cups 265 remain on curved laminate 266 when plurality of flanges 293 are formed by forming assembly 276. In some illustrative examples, forming assembly 276 may be referred to as a composite forming assembly, a spar forming assembly, or a longitudinal composite forming assembly. Vacuum cups 265 help maintain tension in the composite laminate, flat uncured composite laminate 240, and curved laminate 266 during forming against forming surface 230. Thickness 267 of vacuum cups 265 moves the neutral axis of bending to the interface between flat uncured composite laminate 240 and vacuum cups 265.

[0038] While pressure 264 is applied by the presser foot 262, vacuum is applied to the flat, uncured composite laminate 240 to hold the flat, uncured composite laminate 240 on the vacuum chuck 265. The vacuum chuck 265 is configured such that applying vacuum to the flat, uncured composite laminate 240 pulls the neutral axis to the interface between the flat, uncured composite laminate 240 and the vacuum chuck 265. Applying vacuum to the flat, uncured composite laminate 240 keeps the flat, uncured composite laminate 240 taut during forming of the flat, uncured composite laminate 240 against the mandrel 204.

[0039] Pressure 264 is applied to flat, uncured composite laminate 240 on web surface 206 of mandrel 204 to bend flat, uncured composite laminate 240. In some illustrative examples, pressure 264 is applied locally to flat, uncured composite laminate 240 above bend region 208 in web surface 206 of mandrel 204. In some illustrative examples, forming system 202 includes presser foot 262 that is configured to apply pressure 264 locally above bend region 208 in web surface 206. Applying pressure 264 to flat, uncured composite laminate 240 may be referred to as a first forming operation. Bend 268 is formed in the first forming operation.

[0040] By applying pressure 264 to the flat uncured composite laminate 240 on the mandrel 204, the flat uncured composite laminate 240 is bent into a curved laminate 266 having a bend 268. The bend 268 matches the bend region 208 in the web surface 206. The curved laminate 266 has an overhanging portion 257 supported by the support brackets 232 and the support brackets 236. The bend 268 forms an angle between two portions of the composite structure 298 in the longitudinal direction 295. The bend 268 extends through the web 291 and the plurality of flanges 293.

[0041] The contact between the bent laminate 266 and the web surface 206 is maintained during the second forming operation. The contact between the bent laminate 266 and the web surface 206 is maintained by applying pressure to the bent laminate 266. In some illustrative examples, the forming system 202 includes a shim 270 having a curved portion 272, which is configured to maintain contact between the composite laminate (the bent laminate 266) and the web surface 206. The curved portion 272 has a curved region 274 that matches the curved region 208 of the mandrel 204. In some illustrative examples, a presser foot is used to maintain contact between the bent laminate 266 and the web surface 206.

[0042] The curved laminate 266 including the plurality of composite plies 242 moves over the mandrel 204 into the forming assembly 276. The curved laminate 266 contacts the web surface 206 of the mandrel 204. The curved laminate 266 includes an overhang portion 257 that overhangs the mandrel 204.

[0043] The forming assembly 276 bends 292 the overhanging portion 257 of the bent laminate 266 into contact with the side 220 of the mandrel 204 to form a composite structure 298. The composite structure 298 has a bend 268 in a web 291 of the composite structure 298 in contact with the forming surface 230 of the mandrel 204 and a plurality of flanges 293 in contact with the side 220 of the mandrel 204. The bent laminate 266 includes a plurality of zero degree plies 244 having cutouts 246 within a desired distance 252 of the bend 268.

[0044] Forming assembly 276 includes press 282 that applies pressure to curved laminate 266 on web surface 206. In some illustrative examples, press 282 is planar 296, and shim 270 is positioned between press 282 and curved laminate 266. In some illustrative examples, press 282 takes the form of a press foot that is adjustable to apply pressure to curved laminate 266 including bend 268.

[0045] Forming system 202 also includes a heater assembly 278 configured to heat bent laminate 266 to facilitate bend 292. In some illustrative examples, heater assembly 278 of forming assembly 276 is a non-contact heating method. In some illustrative examples, forming system 202 includes heater assembly 278 configured to locally apply forced air heating 283 to the composite material above bend region 208. In some illustrative examples, heater assembly 278 includes one of IR heating or induction heating.

[0046] In some illustrative examples, heater assembly 278 includes an upper heater 284 and a lower heater 286. In some illustrative examples, upper heater 284 heats the upper surface of curved laminate 266. In some illustrative examples, lower heater 286 heats below at least one overhang portion 257 of curved laminate 266.

[0047] In some illustrative examples, forming assembly 276 also includes heating plate 285. Heating plate 285 heats curved laminate 266 in the planar region. Heating plate 285 may be used to heat curved laminate 266 outside of bend 268.

[0048] A plurality of flanges 293 of composite structure 298 are formed by bending 292 overhanging portion 257 of bent laminate 266 onto flange forming surface 210 . In some illustrative examples, bending 292 overhanging portion 257 includes swinging 294 overhanging portion 257 down onto side 220 of mandrel 204 .

[0049] The push device 280 of the forming assembly 276 performs the bending 292 of the overhang portion 257. The push device 280 can be formed of any desired flexible or compressible material. The push device 280 includes a bend 290 that matches the bending area 208 of the mandrel 204. The push device 280 can also be referred to as a plurality of wigglers 287. The plurality of wigglers 287 have a bend 289 that matches the web surface 206 of the mandrel 204. The push device 280 is configured to form the bent laminate 266 downward to abut against the mandrel 204 without undesirably affecting the bent laminate 266. In some illustrative examples, the push device 280 takes the form of a bladder 288. The bladder 288 is a flexible bladder that is configured to bend the overhang portion 257 downward without undesirably affecting the bent laminate 266.

[0050] A plurality of composite plies 242 are laid on a layup tool to form a flat uncured composite laminate 240. A plurality of composite plies 242 include composite plies having any desired fiber orientation. The fiber orientation may be selected from 0 degrees, + / -45 degrees, 90 degrees, or any other desired fiber orientation. In some illustrative examples, a plurality of composite plies 242 include a plurality of fiber orientations. A plurality of composite plies 242 include a plurality of zero-degree plies 244. During layup, in the plurality of composite plies 242, a cut 246 is formed in the plurality of zero-degree plies 244 within a desired distance 252 of an expected position 260 of a bend 268.

[0051] In some illustrative examples, cutouts 246 extend across an entire width 249 of plurality of zero degree plies 244. When cutouts 246 extend across an entire width 249 of plurality of zero degree plies 244, plurality of zero degree plies 244 are discontinuous 248. In some illustrative examples, cutouts 246 are present only in regions of plurality of composite plies 242 where plurality of flanges 293 will be formed. In these illustrative examples, cutouts 246 are not present in web 291 of composite structure 298. In some illustrative examples, cutouts 246 are present in plurality of composite plies 242 in a staggered manner 250 through thickness 256. In some illustrative examples, cutouts 246 are located a plurality of distances 254 from intended locations 260.

[0052] Cuts 246 in plurality of zero degree plies 244 are staggered through thickness 256 of flat uncured composite laminate 240. Cuts 246 are staggered through thickness 256 such that consecutive zero degree plies in plurality of zero degree plies 244 overlap one another. In some illustrative examples, cuts 246 are staggered on either side of a bend in mandrel 204 such that consecutive zero degree plies in plurality of zero degree plies 244 overlap one another. Cuts 246 are staggered such that consecutive zero degree plies in plurality of zero degree plies 244 overlap one another even after gaps are formed in plurality of zero degree plies 244 during formation of bend 268 in web 291 and flange 293.

[0053] The staggered pattern 250 of the cuts 246 creates an overlap 299 of the plurality of zero degree plies 244. The overlap 299 of the plurality of zero degree plies 244 over the cuts 246 is configured such that loads are carried through the bend 268 in the composite structure 298. The overlap 299 of the plurality of zero degree plies 244 allows loads to be transferred from a cut in the cuts 246 to the next consecutive zero degree ply in the plurality of zero degree plies 244. The staggering of the cuts 246 allows loads to be carried through the bend 268 in the composite structure 298 having the cuts 246. The overlap 299 is configured such that after the gap 297 is formed in the plurality of zero degree plies 244 during bending, each consecutive zero degree ply in the plurality of zero degree plies 244 still overlaps.

[0054] Cuts 246 create cut fibers in each of plurality of zero degree plies 244. When cuts 246 are created in plurality of zero degree plies 244 during layup, the cut fibers in each zero degree ply will abut. In some illustrative examples, a cut in cuts 246 does not remove material from a corresponding zero degree ply in plurality of zero degree plies 244. The cuts sever the fibers in the corresponding zero degree ply so that the ply is discontinuous 248.

[0055] Forming bend 268 into flat uncured composite laminate 240 causes gaps 297 within plurality of zero degree plies 244 having cutouts 246. Gaps 297 will exist at cutouts 246 in plurality of zero degree plies 244. The size of gaps 297 in plurality of flanges 293 is different from the size of gaps 297 in web 291. Gaps 297 in web 291 will be smaller than gaps 297 in plurality of flanges 293. In some illustrative examples, the size of gaps 297 varies in longitudinal direction 295 of composite structure 298. In some illustrative examples, gaps 297 near a bend in mandrel 204 are larger than gaps 297 away from the bend. In some illustrative examples, when plurality of bends 209 includes two bends, gap 297 formed between the two bends is larger than gaps formed near the respective bends or outside bend region 208.

[0056] In some illustrative examples, gaps 297 in plurality of flanges 293 have a "scalloped" or triangular shape across plurality of flanges 293. The size of each gap of gaps 297 increases as it moves away from web 291 in a flange of plurality of flanges 293. The portion of the gap near a corresponding corner forming edge (e.g., corner forming edge 212 or corner forming edge 214) will be smaller than the portion of the same gap moving down the corresponding side of side 220 and away from web surface 206. In some illustrative examples, the increased gaps and positioning the neutral axis outside of flat uncured composite laminate 240 during bending result in uniform distribution of compressive loads on the fibers regardless of the fiber orientation through at least the bend during forming. In some illustrative examples, uniform distribution of compressive loads allows forming to be performed with reduced or no wrinkling.

[0057] The plurality of composite plies 242 are placed on the mandrel 204 as a flat uncured composite laminate 240. Pressure 264 is applied to the flat uncured composite laminate 240 on the mandrel 204 to shape the plurality of composite plies 242 against the web surface 206 and form a curved laminate 266 having a curvature 268.

[0058] Pressure 264 is applied to a portion 258 of the flat uncured composite laminate 240 above the bend region 208 in the forming surface 230 of the mandrel 204 to form a curved laminate 266. The flat uncured composite laminate 240 includes a plurality of zero degree plies 244 along respective length discontinuities 248.

[0059] The bent laminate 266 and the mandrel 204 are placed in a forming assembly 276. By the forming assembly 276, the overhanging portion 257 of the bent laminate 266 is bent to contact the side 220 of the mandrel 204 to form a composite structure 298. After the plurality of flanges 293 are formed, the composite structure 298 has a bend 268 in the web 291 of the composite structure 298 in contact with the forming surface 230 of the mandrel 204 and the plurality of flanges 293 in contact with the side 220 of the mandrel 204.

[0060] In some illustrative examples, applying pressure 264 includes locally applying downward pressure 264 over bend region 208 in forming surface 230 using presser foot 262. In some illustrative examples, bending 292 overhang portion 257 of bent laminate 266 includes swinging overhang portion 257 downward onto flange forming surface 210 of mandrel 204.

[0061] In some illustrative examples, bending 292 overhang portion 257 includes swinging 294 overhang portion 257 downward using biasing device 280 .

[0062] In some illustrative examples, placing flat uncured composite laminate 240 in contact with forming surface 230 includes placing flat uncured composite laminate 240 in contact with web surface 206 of mandrel 204 and in contact with support brackets 232, 236 that are movably connected to flange forming surface 210 of mandrel 204 on either side of web surface 206 of mandrel 204. Support brackets 232, 236 may include support brackets near bend region 208 of mandrel 204. After forming flat uncured composite laminate 240 on web surface 206, support brackets near bend region 208 may remain on either side of web surface 206. When bent laminate 266 on mandrel 204 is placed in forming assembly 276, support brackets attached at bend region 208 may remain on either side of web surface 206. In some illustrative examples, additional support brackets are present in the non-bending region of mandrel 204. In some illustrative examples, the additional support brackets outside of bending region 208 may be removed from mandrel 204 prior to placing bent laminate 266 and mandrel 204 into forming assembly 276.

[0063] In some illustrative examples, bending 292 overhanging portion 257 of bent laminate 266 pushes support brackets 232, 236 downwardly against flange forming surface 210 of mandrel 204. In some illustrative examples, while bending 292 overhanging portion 257 of bent laminate 266, forced air heating 283 is used to locally heat bent laminate 266 at bend 268.

[0064] Figure 2 The illustration of manufacturing environment 200 in FIG. 1 is not meant to imply physical or architectural limitations on the manner in which the illustrative embodiments may be implemented. Other components in addition to or in place of the components shown may be used. Some components may be unnecessary. In addition, these blocks are provided to illustrate some functional components. When implemented in the illustrative embodiments, one or more of these blocks may be combined, divided, or combined and divided into different blocks.

[0065] For example, additional support brackets other than support brackets 232 and support brackets 236 may be present in non-bending regions of mandrel 204. When bent laminate 266 on mandrel 204 is placed in forming assembly 276, support brackets 232 and support brackets 236 near bend region 208 may remain on both sides of web surface 206. In some illustrative examples, additional support brackets outside of bend region 208 may be removed from mandrel 204 before bent laminate 266 and mandrel 204 are placed in forming assembly 276.

[0066] Composite structure 298 is a composite structure having a channel formed between web 291 and plurality of flanges 293. In some illustrative examples, composite structure 298 is a composite structure having a C cross-sectional shape. In some illustrative examples, composite structure 298 is a composite structure having an L cross-sectional shape. In some illustrative examples, composite structure 298 is a composite spar.

[0067] Now go to Figure 3 , an illustration of a flow chart of a method of forming a composite material structure having a plurality of bends is shown according to an illustrative embodiment. The method 300 may be Figure 2 A method is performed in manufacturing environment 200 to form composite structure 298 using forming system 202 .

[0068] In method 300, a flat, uncured composite laminate 240 is formed in composite layup formation 302. In composite layup formation 302, a plurality of composite plies 242 are laid up to form flat, uncured composite laminate 240. In this illustrative example, flat, uncured composite laminate 240 includes a plurality of zero-degree plies 244 having cutouts 246. Cutouts 246 across plurality of zero-degree plies 244 allow flat, uncured composite laminate 240 to be shaped while reducing or preventing wrinkling.

[0069] After laying up the flat uncured composite laminate 240 in the composite material layup formation 302, the flat uncured composite laminate 240 is placed on the mandrel 204. After placing the flat uncured composite laminate 240 on the mandrel 204, a first forming 304 is performed. During the first forming 304, the flat uncured composite laminate 240 is formed into the web surface 206 having the bend region 208. The first forming 304 includes applying pressure to the flat uncured composite laminate 240 over the bend region 208 of the mandrel 204 to form the flat uncured composite laminate 240 into a curved laminate 266 having a bend 268. The bend 268 matches the bend region 208 in the mandrel 204. The first forming 304 is performed on the flat uncured composite laminate 240 to form a web portion.

[0070] After the first forming 304, the bent laminate 266 on the mandrel 204 is delivered to the forming assembly 276. A second forming 306 is performed to bend the bent laminate 266 onto the flange forming surface 210. The forming assembly 276 performs the second forming 306 on the bent laminate 266 to produce a composite structure 298. The composite structure 298 includes a web 291 having a bend 268 on the web surface 206 of the mandrel 204. The composite structure 298 also includes a plurality of flanges 293 in contact with the flange forming surface 210 of the mandrel 204. During the second forming 306, the forming assembly 276 swings the overhanging portion of the bent laminate 266 onto the flange forming surface 210 of the mandrel 204 to form the plurality of flanges 293.

[0071] Now go to Figure 4 , a flow chart showing a method of forming a composite structure having a curvature in a web and a plurality of flanges according to an illustrative embodiment. The method 400 may be performed to form Figure 1 The method 400 may be used to form a composite material structure of an aircraft 100. Figure 2 The composite structure 298. The method 400 may be used to perform Figure 3 The method 400 can be used to form a first forming 304 and a second forming 306. Figure 5 The composite structure 500. The method 400 may be used Figures 6 to 14 The method 400 may be performed on a spindle 600. Figures 7 to 14 The composite laminate 702 is performed.

[0072] Method 400 staggers cuts of a plurality of zero degree plies through the thickness of a flat uncured composite laminate as it is laid (operation 402). Method 400 arranges the cut fibers of a plurality of zero degree plies to be approximately parallel to the longitudinal axis of the mandrel while placing the flat uncured composite laminate onto a mandrel (operation 404). Method 400 forms a bend in a flat uncured composite laminate by creating gaps between the ends of the cut fibers of a plurality of zero degree plies while maintaining overlap between consecutive staggered cut zero degree plies of the plurality of zero degree plies (operation 406). The overlap between consecutive staggered cut zero degree plies allows for the transfer of loads to adjacent zero degree plies despite the presence of cuts in the plies. Method 400 evenly distributes compressive loads on the fibers of the flat uncured composite laminate regardless of the orientation of the fibers through at least the bend during formation (operation 408).

[0073] In some illustrative examples, a flat uncured composite laminate includes a plurality of composite plies, the plurality of composite plies including a plurality of zero-degree plies. In some illustrative examples, forming a bend includes forming a plurality of flanges of a composite structure by swinging an overhanging portion of a plurality of composite plies onto the side of a mandrel (operation 410). In some illustrative examples, swinging the overhanging portion of a plurality of composite plies includes swinging the overhanging portion downward using a capsule that matches the bend (operation 412). In some illustrative examples, the size of the gap between the ends of the cut fibers increases, thereby moving a flange of the plurality of flanges downward away from a web of the composite structure (operation 414). In some illustrative examples, the gap in the cut zero-degree plies has a triangular or "fan-shaped" shape, thereby moving the corresponding flange downward away from the web surface of the mandrel. In some illustrative examples, the size of the gap increases in the flange that moves in the direction of the plurality of flanges.

[0074] In some illustrative examples, forming the bend further includes applying pressure on a portion of the flat, uncured composite laminate above the bend region in the mandrel to form a bend in a web of the composite structure, and wherein a gap in the web of the composite structure is smaller than gaps in the plurality of flanges of the composite structure (operation 416). In some illustrative examples, the bend is formed in the web before forming the bend in the flanges.

[0075] In some illustrative examples, method 400 heats the plurality of composite plies to a forming temperature prior to forming the plurality of flanges (operation 418). In some illustrative examples, the heating system heats the plurality of composite plies using a heating plate in the non-bending region. In some illustrative examples, the heating system includes at least one non-contact heating method.

[0076] In some illustrative examples, method 400 locally heats the plurality of composite plies over the bend region of the mandrel using one of forced air heating, infrared heating, or induction heating while bending the overhang portion (operation 420 ).

[0077] Now go to Figure 5 , shows an isometric view of a composite material structure having multiple bends according to an illustrative embodiment. The composite material structure 500 is Figure 2 and Figure 3 The composite structure 500 may be a physical realization of the composite structure 298. Figure 1 Components of an aircraft 100 .

[0078] Composite structure 500 includes web 502, flange 504, and flange 506. Web 502 has bend 508 and bend 510. Bend 508 introduces an angle between web portion 512 and web portion 514. Bend 510 introduces an angle between web portion 514 and web portion 516.

[0079] Bend 508 or bend 510 may use a bending region of the mandrel (e.g. Figure 6 In some illustrative examples, composite structure 500 may be formed on a mandrel having two bending regions (a first bending region forming bend 508 and a second bending region forming bend 510). Figures 6 to 14 The illustrative example in FIG. 6 shows a single bend region, bend region 613 , but any desired number of bend regions may be present in a mandrel to form a composite structure having multiple bends.

[0080] In addition, each bend region of the mandrel may include any desired number of bends. For example, bend 508 may be formed by a bend region of the mandrel that includes only one bend. In other illustrative examples, bend 508 may be formed by a bend region of the mandrel that includes more than one bend. Bend region 613 is a physical realization of a bend region having more than one bend to form a single bend in a composite structure. Similarly, bend 510 is formed by a bend region of the mandrel that includes only one bend. In other illustrative examples, bend 510 may be formed by a bend region of the mandrel that includes more than one bend.

[0081] Now go to Figure 6 , shows an isometric view of a mandrel having multiple bends in accordance with an illustrative embodiment. Mandrel 600 is Figure 2 and Figure 3 The mandrel 600 can be used to form a physical implementation of the mandrel 204. Figure 1 The mandrel 600 can be used to form a composite component of the aircraft 100. Figure 5 Bend 508 or bend 510 in composite structure 500 .

[0082] Mandrel 600 includes web surface 602 and side surface 604. Side surface 604 includes flange forming surface 606. Flange forming surface 606 is on both sides of web surface 602. Flange forming surface 606 is connected to web surface 602 by two corner forming edges, corner forming edge 608 and corner forming edge 610.

[0083] Web surface 602 has bend 612 and bend 614. Bend 612 and bend 614 cause an angle change in web surface 602. Bend 612 and bend 614 may be used to form a bend in a composite structure, such as bend 508 or bend 510 in composite structure 500. Bend 612 and bend 614 cause an angle change between first portion 616 and second portion 618 of web surface 602. In some illustrative examples, bend 612, bend 614, and the area between bend 612 and bend 614 may be referred to as bend area 613.

[0084] The web surface 602 and the flange forming surface 606 form a forming surface 620. By applying pressure to the composite laminate on the mandrel 600, the composite laminate is formed against the forming surface 620.

[0085] In this illustrative example, bend 612 and bend 614 are multiple bends that are used together to form a single bend in a composite material structure. In some other illustrative examples not shown, a single bend may be used to form a bend in a composite material structure.

[0086] Now go to Figure 7 , shows an isometric view of a mandrel with multiple bends and a flat uncured composite feedstock in accordance with an illustrative embodiment. View 700 is a view of mandrel 600 and a composite laminate 702 to be formed on mandrel 600. Composite laminate 702 includes a flat uncured composite laminate 701.

[0087] A support bracket 704 is movably connected to the flange forming surface 606 of the mandrel 600. The support bracket 704 is present to support the overhanging portion of the composite laminate 702 on the mandrel 600 during transfer into the forming machine.

[0088] As shown, the support brackets 704 include support brackets 706 outside of the bends 612 and 614 and support brackets 708 near the bends 612 and 614. The support brackets 704 are movably connected to the mandrel 600 to provide for removal of the support brackets 704. The support brackets 704 are movably connected to the mandrel 600 so that during the flange forming operation, at least one of the support brackets 704 can be moved downwardly by swinging the composite laminate 702 onto the flange forming surface 606 of the mandrel 600.

[0089] The flat uncured composite laminate 701 is placed in contact with the forming surface 620 of the mandrel 600. In this illustrative example, the flat uncured composite laminate 701 is placed in contact with the web surface 602 of the mandrel 600. In some illustrative examples, placing the flat uncured composite laminate 701 in contact with the forming surface 620 includes placing the flat uncured composite laminate 701 in contact with the web surface 602 of the mandrel 600 and in contact with a support bracket 704 that is movably connected to a flange forming surface 606 of the mandrel 600 on both sides of the web surface 602 of the mandrel 600.

[0090] When the flat uncured composite laminate 701 is initially placed on the mandrel 600, the flat uncured composite laminate 701 spans the mandrel 600. The flat uncured composite laminate 701 is not in contact with the bends 612 and 614 until pressure is applied to the flat uncured composite laminate 701 over the bends 612 and 614.

[0091] The flat uncured composite laminate 701 resides on the vacuum chuck 710. The vacuum chuck 710 helps maintain tension in the composite laminate 702 during forming against the forming surface 620. The thickness of the vacuum chuck 710 moves the neutral axis of bending to the interface between the composite laminate 702 and the vacuum chuck 710.

[0092] Now go to Figure 8 , shows an illustration of the underside of an overhanging portion of a flat uncured composite feedstock on a mandrel having a plurality of bends in accordance with an illustrative embodiment. In view 800, a composite laminate 702 has been placed on the mandrel 600. In view 800, the overhanging portion 802 of the composite laminate 702 is supported by a support bracket 704 that is movably connected to the flange forming surface 606. A vacuum is applied to the flat uncured composite laminate 702 to hold the flat uncured composite laminate 702 on a vacuum chuck 710.

[0093] Now go to Fig. 9 , shows a side view of a presser foot in contact with a flat uncured composite feedstock over a plurality of bends of a mandrel in accordance with an illustrative embodiment. View 900 is a view of forming bends 904 into composite laminate 702 to form a curved laminate 906. View 900 is a view of Figure 3 A view of the first forming 304.

[0094] In view 900, pressure is applied to a portion of the composite laminate 702 over the bends 612 and 614 in the web surface 602 of the mandrel 600 to form a curved laminate 906 having a bend 904. As shown, applying pressure includes locally applying downward pressure over the portion of the composite laminate 702 over the bends 612 and 614 in the forming surface 620 of the mandrel 600 using a presser foot 902.

[0095] While pressure is applied by the presser foot 902, a vacuum is applied to the composite laminate 701 to hold the composite laminate 701 on the vacuum chuck 710. The vacuum chuck 710 is configured such that the application of vacuum to the composite laminate 701 pulls the neutral axis to the interface between the composite laminate 701 and the vacuum chuck 710. The application of vacuum to the composite laminate 701 maintains tension on the composite laminate 701 during forming of the composite laminate 701 against the mandrel 600.

[0096] Although pressure is applied directly above bend region 613 in view 900, in other examples not shown, additional forces may be applied in other areas of composite laminate 701. In some illustrative examples, an optional constant or variable distributed force may be applied to composite laminate 701 outside of bend region 613.

[0097] Now go to Fig.10 , is an illustration of an isometric view of a shim in contact with a curved composite feedstock on a mandrel in accordance with an illustrative embodiment. View 1000 is a view of composite laminate 702 in the form of curved laminate 906. Curved laminate 906 includes bend 904.

[0098] A first forming operation has been performed on the composite laminate 702 to form the bend 904 in the portion of the composite laminate 702 above the web surface 620 of the mandrel 600. A shim 1002 has been positioned above the bent laminate 906. The shim 1002 has a bent portion 1004 with a kink to maintain contact between the bent laminate 906 and the forming surface 620 of the mandrel 600 during bending of the bent laminate 906 in a second forming operation.

[0099] The shim 1002 is one illustrative example of maintaining contact between the bent laminate 906 and the forming surface 620 of the mandrel 600. In other illustrative examples, a plurality of separate presser feet may be used to maintain contact between the bent laminate 906 and the forming surface 620 of the mandrel 600. In some illustrative examples, the presser foot is a forming component (e.g., Figure 2 forming component 276).

[0100] Now go to Fig.11, shows an illustration of a curved composite feedstock on a mandrel being introduced into a forming assembly in accordance with an illustrative embodiment. In view 1100, composite laminate 702 in the form of curved laminate 906 is present on mandrel 600. Curved laminate 906 on mandrel 600 is positioned to be placed in forming assembly 1102. Forming assembly 1102 includes a pusher 1104. Pusher 1104 may also be referred to as a "wobbler."

[0101] Now go to Fig.12 , shows an illustration of a push device of a forming assembly according to an illustrative embodiment. In view 1200, a push device 1104 of the forming assembly 1102 is visible. In this illustrative example, the push device 1104 takes the form of a flexible bladder. The push device 1104 may also be referred to as an oscillator. The push device 1104 may be formed of any desired flexible or compressible material. The push device 1104 is configured to form the composite laminate 702 downwardly against the mandrel 600 without undesirably affecting the composite laminate 702.

[0102] The push device 1104 will apply downward pressure on the overhanging portion of the composite laminate 701 on one side of the mandrel 600. Although not visible in view 1200, a second push device may apply downward pressure on a second overhanging portion of the composite laminate 701 on the opposite side of the mandrel 600. The push device 1104 and the second push device will follow the contour of the composite laminate 701 including the curved web.

[0103] Now go to Fig.13 , shows an illustration of a heater assembly of a forming assembly according to an illustrative embodiment. Heater assembly 1302 of forming assembly 1102 is visible in view 1300. In this illustrative example, heater assembly 1302 includes forced air heater 1304 and forced air heater 1306. Forced air heater 1304 is positioned to heat the upper portion of composite laminate 702. Forced air heater 1306 is positioned to heat the underside of composite laminate 702. In other illustrative examples, heater assembly 1302 can take a form other than a forced air heater. In some illustrative examples, heater assembly 1302 includes at least one of forced air heating, radiant heating, infrared heating, induction heating, or other non-contact heating.

[0104] Heater assembly 1302 is positioned in forming assembly 1102 to heat the portion of composite laminate 702 having bend 904. In some illustrative examples, heater assembly 1302 also includes a heating plate to heat the planar portion of the composite laminate.

[0105] Now go to Fig.14, shows an isometric view of a composite material structure having multiple bends in accordance with an illustrative embodiment. Figures 11 to 13 In the forming assembly 1102, a second forming operation is performed to form the composite laminate 702 into a composite structure 1402. The composite structure 1402 on the mandrel 600 leaves Figures 11 to 13 14. The formed assembly 1102 is shown in FIG. 1400. In view 1400, a web 1408 having a bend region 1404 and a plurality of flanges 1406 are visible. The bend region 1404 includes a bend 1410, a bend 1412, and a portion of the web 1408 between the bend 1410 and the bend 1412.

[0106] Composite structure 1402 is a composite structure having a channel formed between web 1408 and plurality of flanges 1406. In some illustrative examples, composite structure 1402 is a composite structure having a C cross-sectional shape. In some illustrative examples, composite structure 1402 is a composite structure having an L cross-sectional shape.

[0107] Now go to Fig.15A and Fig. 15B , a flow chart showing a method of forming a composite structure having curvatures in a web and a plurality of flanges according to an illustrative embodiment. The method 1500 may be performed to form Figure 1 The method 1500 may be used to form a composite material structure of an aircraft 100. Figure 2 The composite structure 298. The method 1500 may be used to perform Figure 3 The first forming 304 and the second forming 306 of the method 1500 can be used to form Figure 5 The composite structure 500. The method 1500 may be used Figures 6 to 14 The method 1500 may be performed on the spindle 600. Figures 7 to 14 The composite laminate 702 is performed.

[0108] A flat uncured composite laminate is placed in contact with a forming surface of a mandrel (operation 1502). Pressure is applied to a portion of the flat uncured composite laminate above the bend region in the forming surface of the mandrel to form a bent laminate (operation 1504). The bent laminate and mandrel are placed into a forming assembly (operation 1506). An overhanging portion of the bent laminate is bent by the forming assembly into contact with a side of the mandrel to form a composite structure having a bend in a web of the composite structure in contact with the forming surface of the mandrel and a plurality of flanges in contact with the side of the mandrel (operation 1508). Thereafter, method 1500 ends.

[0109] In some illustrative examples, method 1500 lays up a plurality of composite plies including a plurality of zero degree plies (operation 1510). In some illustrative embodiments, method 1500 cuts each of the plurality of zero degree plies during layup. In some illustrative examples, method 1500 cuts each of the plurality of zero degree plies in an area that will become a plurality of flanges in a composite structure. In some illustrative examples, method 1500 cuts each of the plurality of zero degree plies within a desired distance of an expected location of each bend in a bend area to form a flat uncured composite laminate (operation 1512). In some illustrative examples, method 1500 cuts each of the plurality of zero degree plies across a width of each of the plurality of zero degree plies within a desired distance of an expected location of a bend to form a flat uncured composite laminate.

[0110] In some illustrative examples, cutting each zero degree ply includes cutting the zero degree plies of the plurality of zero degree plies in a staggered manner through the thickness of the flat uncured composite laminate, operation 1514. By cutting the plurality of zero degree plies in a staggered manner, mechanical properties are not undesirably affected in the area of ​​the cuts.

[0111] In some illustrative examples, cutting each zero degree ply includes cutting a zero degree ply in the plurality of zero degree plies at a plurality of distances from the expected location of each bend in the bend region (operation 1516). The plurality of distances distributes the effect of the cut over a larger distance. The plurality of distances exists so that mechanical properties are not undesirably affected in the region of the cut.

[0112] In some illustrative examples, placing the flat uncured composite laminate in contact with the forming surface includes placing the flat uncured composite laminate in contact with the web surface of the mandrel and in contact with a support bracket that is movably connected to the flange forming surface of the mandrel on both sides of the web surface of the mandrel (operation 1518). In some illustrative examples, the support bracket can be movably connected to the flange forming surface by magnetic connection to the flange forming surface. In some illustrative examples, the support bracket is present on the side of the bend of the mandrel. In some illustrative examples, an additional support bracket can be movably connected to the flange forming surface outside the bend.

[0113] In some illustrative examples, applying pressure includes locally applying downward pressure using a presser foot over a portion of the flat, uncured composite laminate over the bend region of the forming surface (operation 1520). In some illustrative examples, the presser foot may gradually apply pressure to the composite laminate over the bend in the mandrel.

[0114] In some illustrative examples, method 1500 applies a vacuum to the flat uncured composite laminate while applying pressure to hold the flat uncured composite laminate on a vacuum chuck (operation 1521). The thickness of the vacuum chuck moves the neutral axis of bending to the interface between the composite laminate and the vacuum chuck.

[0115] In some illustrative examples, bending the overhang portion of the bent laminate includes swinging the overhang portion downward onto the flange forming surface of the mandrel (operation 1522). In some illustrative examples, swinging the overhang portion includes swinging the overhang portion downward using a flexible bladder (operation 1524). In some illustrative examples, bending the overhang portion of the bent laminate pushes a support bracket downward on the flange forming surface of the mandrel (operation 1526). In some illustrative examples, the support bracket that pushes downward may be present near the bend. In some illustrative examples, before bending the overhang portion downward, additional support brackets outside the bend may be removed from the flange forming surface.

[0116] In some illustrative examples, method 1500 locally heats the bent laminate at the bend using forced air heating while bending the overhanging portion of the bent laminate (operation 1528). In other illustrative examples, method 1500 locally heats the bent laminate at the bend using other non-contact methods such as IR heating or induction heating. In some illustrative examples, method 1500 uses a heating plate to heat the bent laminate in an area outside the bend.

[0117] In some illustrative examples, method 1500 applies pressure to the bent laminate using a shim having a bend with a bend area to maintain contact between the bent laminate and the forming surface during bending (operation 1530). In these illustrative examples, the shim may provide equal application of pressure from a flat presser foot to the bent laminate having the bend. In some illustrative examples, method 1500 applies pressure to the bent laminate using a presser foot to maintain contact between the bent laminate and the web surface during bending.

[0118] Now go to Fig.16 , a flow chart of a method of forming a composite structure having a curvature in a web and a plurality of flanges according to an illustrative embodiment. The method 1600 may be performed to form Figure 1 The method 1600 may be used to form a composite material structure of an aircraft 100. Figure 2 The composite structure 298. The method 1600 may be used to perform Figure 3 The first forming 304 and the second forming 306 of the method 1600 can be used to form Figure 5 The composite structure 500. The method 1600 may be used Figures 6 to 14 The method 1600 may be performed on the spindle 600. Figures 7 to 14 The composite laminate 702 is performed.

[0119] Method 1600 moves a bent laminate including a plurality of composite plies on a mandrel into a forming assembly, the bent laminate in contact with a web surface of the mandrel and including an overhanging portion overhanging the mandrel, the web surface including a bend region, the bend region including a plurality of bends, the plurality of bends forming an angle between a first portion and a second portion of the web surface in a longitudinal direction of the mandrel (operation 1602). Method 1600 bends the overhanging portion of the bent laminate into contact with a side of the mandrel by the forming assembly to form a composite structure having bends in a web of the composite structure in contact with the forming surface of the mandrel and a plurality of flanges in contact with the side of the mandrel, the bent laminate including a plurality of zero-degree plies having a cutout within a desired distance of each of the plurality of bends (operation 1604).

[0120] In some illustrative examples, method 1600 lays up the plurality of composite plies on a layup tool (operation 1606). In some illustrative examples, method 1600 forms a cut into a zero-degree ply of the plurality of zero-degree plies within a desired distance of an expected location of each bend in the plurality of bends in the plurality of composite plies during layup (operation 1608).

[0121] In some illustrative examples, method 1600 places the plurality of composite plies as a flat, uncured composite laminate onto a mandrel (operation 1610). In some illustrative examples, method 1600 applies pressure to the flat, uncured composite laminate on the mandrel to form the plurality of composite plies against the web surface and form a curved laminate having a curvature (operation 1612).

[0122] As used herein, the phrase "at least one of...", when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one of each item in the list may be required. For example, "at least one of item A, item B, or item C" may include, but is not limited to: item A; item A and item B; or item B. This example may also include: item A, item B, and item C; or item B and item C. Of course, there may be any combination of these items. In other examples, "at least one of..." may be, for example, but 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 other suitable combinations. The item may be a specific object, thing, or category. In other words, "at least one of..." means that any combination of items and numbers of items in the list may be used, but not all items in the list are required.

[0123] As used herein, "plurality" when used with reference to items means one or more items.

[0124] The flowcharts and block diagrams in the different described embodiments illustrate the architecture, functionality, and operation of some possible implementations of the devices and methods in the illustrative embodiments. In this regard, each box in the flowchart or block diagram may represent at least one of the following: a module; a segment; a function; or a part of an operation or step.

[0125] In some alternative implementations of the illustrative embodiments, one or more functions indicated in the frame may not occur in the order indicated in the figure. For example, in some cases, two frames shown in succession may be performed substantially simultaneously, or the frames may sometimes be performed in reverse order, depending on the functions involved. In addition, in addition to the frames shown in the flow chart or block diagram, other frames may be added. Some frames may be optional. For example, operation 1510 to operation 1530 may be optional. For example, operation 1606 to operation 1612 may be optional.

[0126] You can Fig.17 Aircraft manufacturing and service method 1700 and the like are shown in Fig.18 Illustrative embodiments of the present disclosure are described in the context of aircraft 1800 as shown. Fig.17 , shows an illustration of an aircraft manufacturing and service method in block diagram form according to an illustrative embodiment. During pre-production, aircraft manufacturing and service method 1700 may include Fig.18 Specification and design 1702 of the aircraft 1800 and material procurement 1704.

[0127] During production, component and subassembly manufacturing 1706 and system integration 1708 of the aircraft 1800 occurs. Thereafter, the aircraft 1800 may be certified and delivered 1710 for placement into service 1712. When placed into service 1712 by a customer, the aircraft 1800 is scheduled for routine maintenance and repair 1714, which may include modification, reconfiguration, refurbishment, or other maintenance and service.

[0128] Each process of aircraft manufacturing and service method 1700 may be performed or carried out by a system integrator, a third party, and / or an operator. In these examples, the operator may be a customer. For purposes of this specification, a system integrator may include, but is not limited to, any number of aircraft manufacturers and major system subcontractors; a third party may include, but is not limited to, any number of vendors, subcontractors, and suppliers; an operator may be an airline, a leasing company, a military entity, a service organization, etc.

[0129] Reference now Fig.18, shows a diagram of an aircraft in block diagram form in which an illustrative embodiment may be implemented. In this example, aircraft 1800 is Fig.17 Aircraft manufacturing and service method 1700 is produced and may include airframe 1802 having multiple systems 1804 and interior 1806. Examples of systems 1804 include one or more of propulsion system 1808, electrical system 1810, hydraulic system 1812, and environmental system 1814. Any number of other systems may be included.

[0130] Apparatus and methods embodied herein may be employed during at least one of the stages of aircraft manufacturing and service method 1700. One or more illustrative embodiments may be used in Fig.17 The components and subassemblies are manufactured or used during at least one of manufacturing 1706 , system integration 1708 , service 1712 , or maintenance and repair 1714 .

[0131] The illustrative examples provide methods and apparatus for producing a composite material structure having at least one bend. The illustrative examples can be used to manufacture a composite material structure having multiple bends. In the illustrative examples, discontinuous zero-degree plies relieve tension during flange formation.

[0132] In illustrative examples, an uncured composite laminate is placed on a bent web and support bracket of a mandrel. A flat feedstock is bent to shape the web surface before forming the flange. Pressure is applied to the web surface during forming. In some illustrative examples, a forming bladder matches the bend. In some illustrative examples, pressure is gradually applied to bend / stretch the laminate into shape without wrinkling. The illustrative examples are conducted at room temperature.

[0133] The cut zero-degree plies are located in the desired portion of the stack for the bend. During the first forming process, a bend is formed in the flat laminate. In illustrative examples, at least a portion of the zero-degree plies in the composite laminate are cut in a staggered pattern. In some illustrative examples, the cuts of the zero-degree plies extend across the entire width of the corresponding zero-degree plies, including the portion where multiple flanges will be formed and across the web. In some illustrative examples, the cuts are only present in multiple flanges of the corresponding zero-degree plies. In some illustrative examples, at least one zero-degree ply in the stack is not cut to prevent the laminate from overstretching.

[0134] In some illustrative examples, a web shim is placed on the bent laminate to evenly distribute the compressive load at least through the bend. In some illustrative examples, the web shim is formed to fill the gap between the bent web surface and the flat web pressure application of the forming assembly. In some illustrative examples, the web shim is matched to the bend. The web shim holds the web of the composite laminate in place during forming. In other illustrative examples, a presser foot may be used.

[0135] The bent laminate on the mandrel is moved into a forming assembly. The forming assembly has a push device that matches the bend of the mandrel. In some illustrative examples, the push device takes the form of a bladder that matches the bend of the mandrel. In some illustrative examples, some support brackets are removed before forming the plurality of flanges in the forming machine.

[0136] In some illustrative examples, the bent laminate is heated to a forming temperature using a hot plate for the non-bending region. In some illustrative examples, the bending region of the laminate is heated by a non-contact method such as forced air heaters, IR heating, or induction heating.

[0137] In some illustrative examples, during the second forming operation, non-contact heaters are directed at the top and bottom surfaces of the composite laminate. In some illustrative examples, non-contact heaters are directed at the top and bottom surfaces of the composite laminate and they move together as the plurality of flanges are formed. The top heater has an attachment that spreads heat across the bend forming area.

[0138] In these illustrative examples, the nozzle of the forced air heater is aimed at the bend area of ​​the composite laminate.A non-contact heater (eg, a forced air heater) may be attached to a moving portion of the forming assembly so that the heater is continuously aimed at the portion of the composite laminate being formed.

[0139] In an illustrative example, a flange portion of a composite structure is formed by a forming assembly utilizing oscillation. A support bracket is used to support the composite laminate during secondary forming and transfer to a forming machine.

[0140] The support bracket can be held to the mandrel using any desired removable method. In some illustrative examples, a strong magnet is used to hold the support bracket to the mandrel, and the support bracket slides down the side of the mandrel as the forming laminate continues to support the laminate during the forming process.

[0141] In some illustrative examples, the longer support brackets under the bending area remain in place and are slid down the side of the mandrel by the laminate during forming. In some illustrative examples, the support brackets under the non-bending area are removed and a hot plate is slid under the laminate to heat the material to forming temperature.

[0142] Illustrative, non-exclusive examples of inventive subject matter according to the present disclosure are described in the following enumerated paragraphs:

[0143] A1. A method (1500) of forming a composite structure (298, 1402) having bends (268, 1404) in a web (291, 1408) and a plurality of flanges (293) of the composite structure (298, 1402), the method (1500) comprising:

[0144] placing (1502) a flat uncured composite laminate (240, 701) in contact with a forming surface (230, 620) of a mandrel (204, 600);

[0145] applying (1504) pressure (264) to a portion (258) of the flat uncured composite laminate (240, 701) above the bend region (208, 613) in the forming surface (230, 620) of the mandrel (204, 600) to form a curved laminate (266, 906), the flat uncured composite laminate (240, 701) comprising a plurality of zero degree plies (244) that are discontinuous (248) along respective lengths;

[0146] placing (1506) the curved laminate (266, 906) and the mandrel (204, 600) into a forming assembly (276); and

[0147] The overhanging portion (257, 802) of the bent laminate (266, 906) is bent (1508) by the forming assembly (276) to contact the side (220, 604) of the mandrel (204, 600) to form the composite structure (298, 1402), the composite structure (298, 1402) having the bend (268) in a web (291) of the composite structure (298, 1402) in contact with the forming surface (230, 620) of the mandrel (204, 600) and a plurality of flanges (293) in contact with the side (220, 604) of the mandrel (204, 600).

[0148] A2. The method (1500) of paragraph A1, wherein applying pressure (264) comprises: using a presser foot (262, 902) to locally apply (1520) pressure (264) downward over the portion of the flat, uncured composite laminate (240, 701) above the bend region (208, 613) of the forming surface (230, 620), and

[0149] The method also includes applying (1521) a vacuum to the flat uncured composite laminate (240, 701) while applying pressure to hold the flat uncured composite laminate (240, 701) on the vacuum chuck (265, 710).

[0150] A3. The method (1500) of paragraph A1, wherein bending the overhanging portion (257, 802) of the bent laminate (266, 906) comprises swinging (1522) the overhanging portion (257, 802) downward onto a flange forming surface (210, 606) of the mandrel (204, 600).

[0151] A4. The method (1500) according to paragraph A3, wherein causing the overhang portion (257, 802) to swing includes: using a pushing device (280, 1104) to cause the overhang portion (257, 802) to swing downward (1524).

[0152] A5. The method (1500) of paragraph A1, wherein placing the flat, uncured composite laminate (240, 701) in contact with the forming surface (230, 620) comprises placing (1518) the flat, uncured composite laminate (240, 701) in contact with the web surface (206, 602) of the mandrel (204, 600) and in contact with a support bracket (232, 236, 704), the support bracket being movably connected to a flange forming surface (210, 606) of the mandrel (204, 600) on both sides of the web surface (206, 602) of the mandrel (204, 600).

[0153] A6. The method (1500) of paragraph A5, wherein bending the overhanging portion (257, 802) of the curved laminate (266, 906) pushes the support bracket (232, 236, 704) downwardly on the flange forming surface (210, 606) of the mandrel (204, 600) (1526).

[0154] A7. The method (1500) according to paragraph A1 further comprising:

[0155] laying (1510) a plurality of composite plies (242) including the plurality of zero degree plies (244); and

[0156] Each zero degree ply of the plurality of zero degree plies (244) is cut (1512) across a width (249) of each zero degree ply within a desired distance (252) of an expected position (260) of each bend (209, 612, 614) of the bend region (208, 613) to form the flat uncured composite laminate (240, 701).

[0157] A8. The method (1500) of paragraph A7, wherein cutting each zero-degree ply comprises cutting (1514) zero-degree plies of the plurality of zero-degree plies (244) in a staggered manner (250) through the thickness (256) of the flat, uncured composite laminate (240, 701).

[0158] A9. The method (1500) described in paragraph A7, wherein cutting each zero-degree board layer comprises cutting (1516) a zero-degree layer of the multiple zero-degree layer sheets (244) at multiple distances (254) from the expected position (260) of each bend (209, 612, 614) of the bending region (208, 613).

[0159] A10. The method (1500) according to paragraph A1 further comprising:

[0160] The bent laminate (266, 906) is locally heated (1528) at the bend region (208, 613) using forced air heating (283, 1302) while the overhanging portion (257, 802) of the bent laminate (266, 906) is bent.

[0161] A11. The method (1500) according to paragraph A1 further comprising:

[0162] A shim (270, 1002) having a curved portion (272) with a bending area (274) is used to apply (1530) pressure (264) to the curved laminate (266, 906) to maintain contact between the curved laminate (266, 906) and the forming surface (230, 620) during bending.

[0163] B1. A forming system (202), the forming system comprising:

[0164] A mandrel (204, 600) comprises: a web surface (206, 602) having a bending area (208, 613); and flange forming surfaces (210, 606) on both sides of the web surface (206, 602), the flange forming surfaces (210, 606) being connected to the web surface (206, 602) by two corner forming edges (212, 214).

[0165] B2. The forming system (202) according to paragraph B1, further comprising:

[0166] A support bracket (232, 236, 704) is movably connected to the flange forming surface (210, 606) of the mandrel (204, 600).

[0167] B3. The forming system (202) of paragraph B2, wherein the support bracket (232, 236, 704) is magnetically connected to the flange forming surface (210, 606).

[0168] B4. The forming system (202) according to paragraph B1, further comprising:

[0169] A pressure foot (262, 902) is configured to locally apply pressure (264) over a bend region (208, 613) in the web surface (206, 602).

[0170] B5. The forming system (202) according to paragraph B1, further comprising:

[0171] A heater assembly (278, 1302) is configured to locally apply forced air heating (283) to the composite material above the bend region (208, 613).

[0172] B6. The forming system (202) according to paragraph B1, further comprising:

[0173] A plurality of oscillators (287, 1104) having curved portions (289) that mate with a web surface (206, 602) of the mandrel (204, 600).

[0174] B7 The forming system (202) according to paragraph B1, further comprising:

[0175] A shim (270, 1002) having a curved portion (272, 1004) is configured to maintain contact between a composite laminate (240, 701) and the web surface (206, 602).

[0176] B8. A forming system (202) according to paragraph B1, wherein the web surface (206, 602) includes the bending area (208, 613), the bending area includes a plurality of bends (209, 612, 614), and the plurality of bends form an angle (222) between a first portion (224, 616) and a second portion (226, 618) of the web surface (206, 602) in the longitudinal direction (228) of the mandrel (204, 600).

[0177] C1. A method (1600) of forming a composite structure (298, 1402) having bends (268) in a web (291) and a plurality of flanges (293) of the composite structure (298, 1402), the method comprising:

[0178] A bent laminate (266, 906) including a plurality of composite plies (242) on a mandrel (204, 600) is moved (1602) into a forming assembly (276), the bent laminate (266, 906) being in contact with a web surface (206, 602) of the mandrel (204, 600) and including an overhang (257, 802) overhanging the mandrel (204, 600), the The web surface (206, 602) includes a bend region (208, 613), the bend region including a plurality of bends (209, 612, 614), the plurality of bends forming an angle (222) between a first portion (224, 616) and a second portion (226, 618) of the web surface (206, 602) in a longitudinal direction (228) of the mandrel (204, 600); and

[0179] The overhanging portion (257, 802) of the bent laminate (266, 906) is bent (1604) by the forming assembly (276) to contact the side (220, 604) of the mandrel (204, 600) to form the composite structure (298, 1402), wherein the composite structure (298, 1402) is disposed on a web surface (206, 220, 604) of the composite structure (298, 1402) that contacts the mandrel (204, 600). A laminate (266, 906) having a bend (268, 1404) in a web (291, 1408) in contact with a side (220, 604) of the mandrel (204, 600) and a plurality of flanges (293, 1406) in contact with the side (220, 604) of the mandrel (204, 600), the bent laminate (266, 906) comprising a plurality of zero-degree plies (244) having cutouts (246) within a desired distance (252) of each of the plurality of bends (209, 612, 614).

[0180] C2. The method (1600) according to paragraph C1, further comprising:

[0181] laying up (1606) the plurality of composite plies (242) on a layup tool, the plurality of composite plies (242) including the plurality of zero degree plies (244); and

[0182] The cut (246) is formed (1608) into a zero degree ply of the plurality of composite plies (242) during layup within a desired distance (252) of an expected location (260) of each bend in the plurality of bends (209, 612, 614).

[0183] C3. The method (1600) according to paragraph C2 further comprising:

[0184] placing (1610) the plurality of composite plies (242) as a flat uncured composite laminate (240, 701) onto the mandrel (204, 600); and

[0185] A pressure (264) is applied (1612) to the flat uncured composite laminate (240, 701) on the mandrel (204, 600) to shape the plurality of composite plies (242) against the web surface (206, 602) and form the curved laminate (266, 906) having the curvature (268).

[0186] D1. A method (400) of forming a bend (268) in a composite material structure (298, 1402), the method comprising:

[0187] When laying down a flat uncured composite laminate (240), staggering (402) cuts (246) of a plurality of zero degree plies (244) through a thickness (256) of the flat uncured composite laminate (240);

[0188] while placing the flat uncured composite laminate (240) onto a mandrel (204, 600), arranging (404) chopped fibers of the plurality of zero degree plies (244) substantially parallel to a longitudinal axis of the mandrel (204, 600);

[0189] forming (406) the bend (268) in the flat uncured composite laminate (240) by creating gaps (297) between ends of the cut fibers in the plurality of zero degree plies (244) while maintaining an overlap (299) between successive staggered cut zero degree plies; and

[0190] Compressive loads are evenly distributed (408) across fibers of the plurality of composite plies (242) regardless of fiber orientation through at least the bend (268) during formation.

[0191] D2. A method (400) according to paragraph D1, wherein the flat uncured composite laminate (240) includes a plurality of composite plies (242), the plurality of composite plies (242) including the plurality of zero-degree plies (244), and wherein forming the bend (268) includes: forming (410) a plurality of flanges (293) of the composite structure (298) by swinging overhanging portions (257) of the plurality of composite plies (242) onto the side (220) of the mandrel (204).

[0192] D3. The method (400) of paragraph D2, wherein causing the overhanging portion (257) of the plurality of composite plies (242) to swing downward (412) the overhanging portion (257) using a bladder (288) that matches the bend (268).

[0193] D4. The method (400) of paragraph D2, wherein the size of the gap between the ends of the cut fibers increases (414), thereby causing a flange of the plurality of flanges (293) to move downward away from the web (291) of the composite structure (298).

[0194] D5. The method (400) of paragraph D4, wherein forming the bend (268) further comprises applying (416) pressure on a portion of the flat, uncured composite laminate (240) above the bending region (208) in the mandrel (204) to form the bend (268) in the web (291) of the composite structure (298), and wherein the gap (297) in the web (291) of the composite structure (298) is smaller than the gap (297) in the plurality of flanges (293) of the composite structure (298).

[0195] D6. The method (400) according to paragraph D2, further comprising:

[0196] Prior to forming the plurality of flanges (293), the plurality of composite plies (242) are heated (418) to a forming temperature.

[0197] D7. The method (400) according to paragraph D6, further comprising:

[0198] While bending the overhang portion (257), the plurality of composite plies (242) are locally heated (420) over the bend region (208) of the mandrel (204) using one of forced air heating, infrared heating, or induction heating.

[0199] Descriptions of different illustrative embodiments have been given for purposes of illustration and description, and these descriptions are not intended to be exhaustive or limited to the embodiments of the disclosed forms. Many modifications and variations are apparent to those of ordinary skill in the art. In addition, different illustrative embodiments may provide different features compared to other illustrative embodiments. One or more selected embodiments are selected and described in order to best explain the principles of the embodiments, practical applications, and to enable other persons of ordinary skill in the art to understand the disclosure of various embodiments with various modifications suitable for the intended specific use.

[0200] CROSS-REFERENCE TO RELATED APPLICATIONS

[0201] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 590,272, filed on October 13, 2023, entitled "COMPOLYTES STRUCTURE WITH CURVED THROUGH WEB AND MULTIPLE FLANGES," the entire contents of which are incorporated herein by reference.

Claims

1. A method (1500) of forming a composite material structure (298, 1402) having bends (268, 1404) in a web (291, 1408) and a plurality of flanges (293) of the composite material structure (298, 1402), the method (1500) comprising: placing (1502) a flat uncured composite laminate (240, 701) in contact with a forming surface (230, 620) of a mandrel (204, 600); applying (1504) pressure (264) to a portion (258) of the flat uncured composite laminate (240, 701) above the bend region (208, 613) in the forming surface (230, 620) of the mandrel (204, 600) to form a curved laminate (266, 906), the flat uncured composite laminate (240, 701) comprising a plurality of zero degree plies (244) that are discontinuous (248) along respective lengths; placing (1506) the curved laminate (266, 906) and the mandrel (204, 600) into a forming assembly (276); and The overhanging portion (257, 802) of the bent laminate (266, 906) is bent (1508) by the forming assembly (276) to contact the side (220, 604) of the mandrel (204, 600) to form the composite structure (298, 1402), the composite structure (298, 1402) having the bend (268) in a web (291) of the composite structure (298, 1402) in contact with the forming surface (230, 620) of the mandrel (204, 600) and a plurality of flanges (293) in contact with the side (220, 604) of the mandrel (204, 600).

2. The method (1500) of claim 1, wherein: Applying pressure (264) includes: using a presser foot (262, 902) to locally apply (1520) pressure (264) downwardly over the portion of the flat uncured composite laminate (240, 701) above the bend region (208, 613) of the forming surface (230, 620), and The method also includes applying (1521) a vacuum to the flat uncured composite laminate (240, 701) while applying pressure to hold the flat uncured composite laminate (240, 701) on the vacuum chuck (265, 710).

3. The method (1500) of claim 1, wherein: Bending the overhanging portion (257, 802) of the bent laminate (266, 906) includes swinging the overhanging portion (257, 802) downwardly (1522) onto the flange forming surface (210, 606) of the mandrel (204, 600).

4. The method (1500) of claim 3, wherein: Swinging the overhang portion (257, 802) includes: using a pushing device (280, 1104) to swing the overhang portion (257, 802) downward (1524).

5. The method (1500) according to any one of claims 1 to 4, wherein: Placing the flat uncured composite laminate (240, 701) in contact with the forming surface (230, 620) includes placing (1518) the flat uncured composite laminate (240, 701) in contact with the web surface (206, 602) of the mandrel (204, 600) and in contact with a support bracket (232, 236, 704), the support bracket being movably connected to a flange forming surface (210, 606) of the mandrel (204, 600) on both sides of the web surface (206, 602) of the mandrel (204, 600).

6. The method (1500) of claim 5, wherein: Bending the overhanging portion (257, 802) of the bent laminate (266, 906) pushes the support bracket (232, 236, 704) downwardly on the flange forming surface (210, 606) of the mandrel (204, 600) (1526).

7. The method (1500) according to any one of claims 1 to 4, further comprising: laying (1510) a plurality of composite plies (242) including the plurality of zero degree plies (244); and Each zero degree ply of the plurality of zero degree plies (244) is cut (1512) across a width (249) of each zero degree ply within a desired distance (252) of an expected position (260) of each bend (209, 612, 614) of the bend region (208, 613) to form the flat uncured composite laminate (240, 701).

8. The method (1500) of claim 7, wherein: Cutting each zero degree ply includes: cutting (1514) zero degree plies of the plurality of zero degree plies (244) in a staggered manner (250) through a thickness (256) of the flat uncured composite laminate (240, 701); or Wherein, cutting each zero-degree board layer includes: cutting (1516) zero-degree plies among the multiple zero-degree plies (244) at multiple distances (254) from the expected position (260) of each bend (209, 612, 614) of the bending area (208, 613).

9. The method (1500) according to any one of claims 1 to 4, further comprising: locally heating (1528) the bent laminate (266, 906) at the bend region (208, 613) using forced air heating (283, 1302) while bending the overhanging portion (257, 802) of the bent laminate (266, 906); and / or A shim (270, 1002) having a curved portion (272) with a bending area (274) is used to apply (1530) pressure (264) to the curved laminate (266, 906) to maintain contact between the curved laminate (266, 906) and the forming surface (230, 620) during bending.

10. A forming system (202), the forming system comprising: A mandrel (204, 600) comprises: a web surface (206, 602) having a bending area (208, 613); and flange forming surfaces (210, 606) on both sides of the web surface (206, 602), the flange forming surfaces (210, 606) being connected to the web surface (206, 602) by two corner forming edges (212, 214).

11. The forming system (202) according to claim 10, further comprising: a support bracket (232, 236, 704) movably connected to the flange forming surface (210, 606) of the mandrel (204, 600); a pressure foot (262, 902) configured to locally apply pressure (264) over a bend region (208, 613) in the web surface (206, 602); a heater assembly (278, 1302) configured to locally apply forced air heating (283) to the composite material above the bend region (208, 613); a plurality of oscillators (287, 1104) having a curved portion (289) that matches a web surface (206, 602) of the mandrel (204, 600); and / or A shim (270, 1002) having a curved portion (272, 1004) is configured to maintain contact between a composite laminate (240, 701) and the web surface (206, 602).

12. The forming system (202) according to claim 10 or 11, wherein: The web surface (206, 602) includes the bending region (208, 613), the bending region including a plurality of bends (209, 612, 614), the plurality of bends forming an angle (222) between a first portion (224, 616) and a second portion (226, 618) of the web surface (206, 602) in a longitudinal direction (228) of the mandrel (204, 600).

13. A method (1600) of forming a composite structure (298, 1402) having bends (268) in a web (291) and a plurality of flanges (293) of the composite structure (298, 1402), the method comprising: A bent laminate (266, 906) including a plurality of composite plies (242) on a mandrel (204, 600) is moved (1602) into a forming assembly (276), the bent laminate (266, 906) being in contact with a web surface (206, 602) of the mandrel (204, 600) and including an overhang (257, 802) overhanging the mandrel (204, 600), the The web surface (206, 602) includes a bend region (208, 613), the bend region including a plurality of bends (209, 612, 614), the plurality of bends forming an angle (222) between a first portion (224, 616) and a second portion (226, 618) of the web surface (206, 602) in a longitudinal direction (228) of the mandrel (204, 600); and The overhanging portion (257, 802) of the bent laminate (266, 906) is bent (1604) by the forming assembly (276) to contact the side (220, 604) of the mandrel (204, 600) to form the composite structure (298, 1402), wherein the composite structure (298, 1402) is disposed on a web surface (206, 220, 604) of the composite structure (298, 1402) that contacts the mandrel (204, 600). A laminate (266, 906) having a bend (268, 1404) in a web (291, 1408) in contact with a side (220, 604) of the mandrel (204, 600) and a plurality of flanges (293, 1406) in contact with the side (220, 604) of the mandrel (204, 600), the bent laminate (266, 906) comprising a plurality of zero-degree plies (244) having cutouts (246) within a desired distance (252) of each of the plurality of bends (209, 612, 614).

14. The method (1600) of claim 13, further comprising: laying up (1606) the plurality of composite plies (242) on a layup tool, the plurality of composite plies (242) including the plurality of zero degree plies (244); and The cut (246) is formed (1608) into a zero degree ply of the plurality of composite plies (242) during layup within a desired distance (252) of an expected location (260) of each bend in the plurality of bends (209, 612, 614).

15. The method (1600) of claim 14, further comprising: placing (1610) the plurality of composite plies (242) as a flat uncured composite laminate (240, 701) onto the mandrel (204, 600); and A pressure (264) is applied (1612) to the flat uncured composite laminate (240, 701) on the mandrel (204, 600) to shape the plurality of composite plies (242) against the web surface (206, 602) and form the curved laminate (266, 906) having the curvature (268).

16. A method (400) of forming a bend (268) in a composite material structure (298, 1402), the method comprising: When laying down a flat uncured composite laminate (240), staggering (402) cuts (246) of a plurality of zero degree plies (244) through a thickness (256) of the flat uncured composite laminate (240); while placing the flat uncured composite laminate (240) onto a mandrel (204, 600), arranging (404) chopped fibers of the plurality of zero degree plies (244) substantially parallel to a longitudinal axis of the mandrel (204, 600); forming (406) the bend (268) in the flat uncured composite laminate (240) by creating gaps (297) between ends of the cut fibers in the plurality of zero degree plies (244) while maintaining an overlap (299) between successive staggered cut zero degree plies; and Compressive loads are evenly distributed (408) across fibers of the plurality of composite plies (242) regardless of fiber orientation through at least the bend (268) during formation.

17. The method (400) of claim 16, wherein: The flat uncured composite laminate (240) includes a plurality of composite plies (242), the plurality of composite plies (242) including the plurality of zero-degree plies (244), and wherein forming the bend (268) includes forming (410) a plurality of flanges (293) of the composite structure (298) by swinging overhanging portions (257) of the plurality of composite plies (242) onto the side (220) of the mandrel (204).

18. The method (400) of claim 17, wherein: Oscillating the overhanging portion (257) of the plurality of composite plies (242) includes: using a bladder (288) that matches the bend (268) to oscillate the overhanging portion (257) downward (412); or wherein the size of the gaps between the ends of the cut fibers increases (414) thereby causing flanges of the plurality of flanges (293) to move downwardly away from the web (291) of the composite structure (298).

19. The method (400) of claim 18, wherein: Forming the bend (268) also includes: applying (416) pressure on a portion of the flat uncured composite laminate (240) above the bending region (208) in the mandrel (204) to form the bend (268) in the web (291) of the composite structure (298), and wherein the gap (297) in the web (291) of the composite structure (298) is smaller than the gap (297) in the multiple flanges (293) of the composite structure (298).

20. The method (400) of claim 17, further comprising: Prior to forming the plurality of flanges (293), the plurality of composite plies (242) are heated (418) to a forming temperature.

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