Compacted stringer packages

An illustrative embodiment of the present disclosure provides a method. A composite charge is placed over a forming and cure mandrel, a first radius filler, and a second radius filler. Mechanical pressure is applied to shape the composite charge to the forming and cure mandrel and a rigid base to form a stringer layup having a hat-shaped cross-section. Vacuum pressure is applied to the stringer layup to form a compacted stringer package.

BACKGROUND INFORMATION

The present disclosure relates generally to manufacturing and, in particular, to composite manufacturing. More particularly, the present disclosure relates to a method and apparatus for composite manufacturing with compacted stringer packages.

Aircraft generally include an airframe, which may be regarded as an underlying skeleton to which skins are attached to form a smooth aerodynamic outer surface. Stringers of various shapes may be used for stiffening fuselage sections and wing skins on aircraft. Composite materials are used in aircraft to decrease the weight of the aircraft. Modern aircraft may include both composite stringers and composite skins.

Conventionally, composite stringers are attached to a composite skin using fasteners, curing the composite stringers to the composite skin, or a combination of the two. In some conventional processes, composite stringers are assembled on a cure tool common to both the composite stringers and the composite skin.

The cure tool common to the composite stringers and the composite skin is large enough to form a portion of a fuselage. The cure tool may therefore have a large manufacturing footprint. The large manufacturing footprint limits the quantity of cure tools that fit within a manufacturing environment.

To assemble the composite stringers on the cure tool, a number of processes are performed, each of which has an associated performance time. Each stringer component is laid onto the cure tool and then compacted separately. Each process associated with assembling the composite stringers adds to an overall manufacturing time. Manufacturing time may limit a quantity of aircraft produced. Therefore, it would be desirable to have a method and apparatus that take into account at least some of the issues discussed above, as well as other possible issues.

SUMMARY

An illustrative embodiment of the present disclosure provides a method. A composite charge is placed over a forming and cure mandrel, a first radius filler, and a second radius filler. Mechanical pressure is applied to shape the composite charge to the forming and cure mandrel and a rigid base to form a stringer layup. Vacuum pressure is applied to the stringer layup to form a compacted stringer package having a hat-shaped cross-section.

Another illustrative embodiment of the present disclosure provides a method. A plurality of compacted stringer packages is formed, each comprising a composite charge having a hat-shaped cross-section, a first radius filler contacting the composite charge, a second radius filler contacting the composite charge, and a forming and cure mandrel positioned within a cap, a first web, and a second web of the hat-shaped cross-section. The plurality of compacted stringer packages is placed onto a cure tool.

A further illustrative embodiment of the present disclosure provides a compacted stringer package. The compacted stringer package comprises a composite charge, a first radius filler, a second radius filler, and a forming and cure mandrel. The composite charge has a hat-shaped cross-section. The first radius filler contacts the composite charge. The second radius filler contacts the composite charge. The forming and cure mandrel is positioned within a cap, a first web, and a second web of the hat-shaped cross-section.

DETAILED DESCRIPTION

The illustrative embodiments recognize and take into account one or more different considerations. For example, the illustrative embodiments recognize and take into account that composite materials are used in aircraft to decrease weight of the aircraft. This decreased weight improves performance features such as payload capacity and fuel efficiency. Further, composite materials provide longer service life for various components in an aircraft.

The illustrative embodiments recognize and take into account that composite materials may be tough, light-weight materials created by combining two or more functional components. For example, a composite material may include reinforcing fibers bound in a polymer resin matrix. The fibers may be unidirectional or may take the form of a woven cloth or fabric. The fibers and resins may be arranged and cured to form a composite structure.

The illustrative examples recognize and take into account that composite stringers may be attached to a composite skin using fasteners, curing the composite stringers to the composite skin, or by other desirable methods. The illustrative examples recognize and take into account that the fasteners add to the weight of the aircraft. The illustrative examples thus recognize and take into account that curing the composite stringers to the composite skin is a desirable attachment method.

The illustrative examples recognize and take into account that laying the composite material onto a large cure tool is a time limiting step. Laying the composite material is a layered process. The illustrative examples recognize and take into account that forming composite portions offline from the cure tool may reduce manufacturing time. For example, forming multiple composite stringers offline from the cure tool may reduce the manufacturing time.

The illustrative examples recognize and take into account that a fuselage of an aircraft has a contour. The illustrative examples recognize and take into account that the composite stringers have curvatures to match the contour of the fuselage.

The illustrative examples recognize and take into account that manufacturing tooling is stored when not in use. The illustrative examples thus recognize and take into account that increasing a quantity of manufacturing tools increases storage volume for the manufacturing tools.

The illustrative examples recognize and take into account that interchangeable parts and assembly line processing reduces storage volume. Further, the illustrative examples recognize and take into account that the interchangeable parts and the assembly line processing may reduce complexity of forming a structure. The illustrative examples recognize and take into account that substantially similar composite stringers, such as substantially straight composite stringer lay-ups, may be formed using an assembly line.

The illustrative examples further recognize and take into account that bending complex composite structures, such as the composite stringers, to contours may introduce wrinkles into the composite material. For example, the illustrative examples recognize and take into account that the wrinkles may be introduced into a composite stringer lay-up when forming the composite stringer lay-up to a complex contour of the cure tool. The illustrative examples recognize and take into account that the wrinkles affect the performance of the composite material. The illustrative examples recognize and take into account that the wrinkles may be undesirably difficult to detect.

The illustrative examples recognize and take into account that support is desirably provided to hollow portions of composite materials during curing. For example, rigid tooling or pressurized tooling, such as bladders, may be present in hollow portions of the composite materials during curing.

The illustrative examples recognize and take into account that eliminating any of additional curing steps, additional consolidation steps, or additional layup steps will reduce the manufacturing time. The illustrative examples thus recognize and take into account that consolidating multiple layers of the composite material simultaneously may reduce the manufacturing time. The illustrative examples further recognize and take into account that tooling, which serves multiple purposes, may reduce at least one of the manufacturing time or the manufacturing expense.

The illustrative examples recognize and take into account that in conventional fuselage manufacturing, a consolidated composite section having a hat-shaped cross-section may be placed into a cure tool. Once in the cure tool, any forming tooling still present is removed from the consolidated composite section. After removing the forming tooling, a curing mandrel or a curing bladder is placed into the consolidated composite section. After placing the curing mandrel or the curing bladder, a first radius filler and a second radius filler are positioned in the consolidated composite section. Conventionally, these steps are performed on the cure tool. The illustrative embodiments recognize and take into account that each subsequent step performed on the cure tool increases the amount of manufacturing time to form a component using the cure tool.

The illustrative examples recognize and take into account that forming a stringer onto the tool that holds the cavity shape during cure is not a current practice. The illustrative examples further recognize and take into account that incorporating the first radius filler and the second radius filler into the forming process is not a current process.

With reference now to the Figures and, in particular, with reference toFIG. 1, an illustration of an aircraft is depicted in which an illustrative embodiment may be implemented. In this illustrative example, aircraft100has wing102and wing104attached to body106. Aircraft100includes engine108attached to wing102and engine110attached to wing104.

Aircraft100is an example of an aircraft manufactured using compacted stringer packages in accordance with an illustrative embodiment. For example, body106may be manufactured using compacted stringer packages.FIG. 1depicts an exposed view of stiffeners120. Stiffeners120are examples of stringers manufactured using compacted stringer packages.

This illustration of aircraft100is provided for purposes of illustrating one environment in which the different illustrative embodiments may be implemented. The illustration of aircraft100inFIG. 1is not meant to imply architectural limitations as to the manner in which different illustrative embodiments may be implemented. For example, aircraft100is shown as a commercial passenger aircraft. The different illustrative embodiments may be applied to other types of aircraft, such as private passenger aircraft, a rotorcraft, and other suitable type of aircraft.

Turning now toFIG. 2, an illustration of a block diagram of a manufacturing environment is depicted in accordance with an illustrative embodiment. Components of aircraft100ofFIG. 1may be formed in manufacturing environment200. For example, stiffeners120ofFIG. 1of aircraft100are laid up in manufacturing environment200.

Compacted stringer package202is formed in manufacturing environment200. Compacted stringer package202comprises composite charge204having hat-shaped cross-section206, first radius filler207contacting composite charge204, second radius filler208contacting composite charge204, and forming and cure mandrel210positioned within cap212, first web213and second webs214of hat-shaped cross-section206. Cap212is positioned between first web213and second web214. First radius filler207and second radius filler208are positioned on either side of cap212.

In some illustrative examples, compacted stringer package202comprises inner ply216connecting first flange217and second flange218of hat-shaped cross-section206and contacting first radius filler207and second radius filler208. First flange217is connected to first web213. Second flange218is connected to second web214. First flange217and second flange218are on opposite sides of cap212.

Inner ply216is optional to compacted stringer package202. When present, inner ply216helps maintain the shape of compacted stringer package202. In some illustrative examples, inner ply216may be referred to as an “inner mold line” (IML) ply.

In some illustrative examples, compacted stringer package202comprises composite ply220wrapped around forming and cure mandrel210. Composite ply220is optional to compacted stringer package202. Composite ply220may also be referred to as a “wrap ply.” When present, composite ply220helps maintain the shape of compacted stringer package202.

Forming and cure mandrel210of compacted stringer package202comprises at least one of a collapsible mandrel, a dissolvable material, a solid mandrel, or an inflatable bladder. As used herein, the phrase “at least one of,” when used with a list of items, means different combinations of one or more of the listed items may be used, and only one of each item in the list may be needed. In other words, “at least one of” means any combination of items and number of items may be used from the list, but not all of the items in the list are required. The item may be a particular object, a thing, or a category.

For example, “at least one of item A, item B, or item C” may include, without limitation, item A, item A and item B, or item B. This example also may include item A, item B, and item C or item B and item C. Of course, any combination of these items may be present. In other examples, “at least one of” may be, for example, without limitation, 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.

In some illustrative examples, a collapsible mandrel includes foam portions and a rigid center. Collapsing the foam portions of the collapsible mandrel allows for removable of forming and cure mandrel210from the remainder of compacted stringer package202.

When forming and cure mandrel210includes an inflatable bladder, the inflatable bladder is formed of any desirable material. An inflatable bladder may be a polymeric material, metallic material, or any other desirable airtight material.

In some illustrative examples, forming and cure mandrel210of compacted stringer package202has curvature222in at least one of an X-Y axis, X-Z axis, or Y-Z axis. In some illustrative examples, curvature222is unique to forming and cure mandrel210. Curvature222is designed based on unique location224for compacted stringer package202on cure tool226.

Curvature222of forming and cure mandrel210imparts curvature228to compacted stringer package202. Curvature222in the Y-Z plane will be referred to as roll (twist), curvature222in the X-Z plane will be referred to as pitch, and curvature222in the X-Y plane will be referred to as yaw.

In some illustrative examples, forming and cure mandrel210remains in compacted stringer package202during curing of compacted stringer package202on cure tool226. In these illustrative examples, forming and cure mandrel210is configured to function as a curing bladder.

To form compacted stringer package202, composite charge204is placed over forming and cure mandrel210, first radius filler207, and second radius filler208. When composite ply220is present, composite charge204contacts composite ply220, first radius filler207, and second radius filler208. When composite ply220is not present, composite charge204contacts forming and cure mandrel210, first radius filler207, and second radius filler208.

After placing composite charge204, mechanical pressure is applied to shape composite charge204to forming and cure mandrel210and rigid base230to form stringer layup232. Vacuum pressure is applied to stringer layup232to form compacted stringer package202having hat-shaped cross-section234.

In some illustrative examples, components of a resulting compacted stringer package202, such as composite charge204, are ambient temperature while at least one of the mechanical pressure and the vacuum pressure is applied. In other illustrative examples, composite charge204or another component of compacted stringer package202may be heated while at least one of the mechanical pressure or the vacuum pressure is applied.

Hat-shaped cross-section234comprises cap212first web213, and second web214, one on each side of cap, shaped by forming and cure mandrel210, and first flange217and second flange218, shaped by rigid base230. When inner ply216is present, hat-shaped cross-section234further comprises bottom236connecting first flange217and second flange218and extending underneath cap212and first web213and second web214. The vacuum pressure is supplied using vacuum forming equipment237. Vacuum forming equipment237may include at least one of a vacuum bag, a number of seals, tubing, and a vacuum source.

Compacted stringer package202is uncured but substantially rigid. Compacted stringer package202is rigid enough for transporting within manufacturing environment200. In some illustrative examples, the mechanical pressure and the vacuum pressure are applied substantially simultaneously.

When composite ply220is present, composite ply220is wrapped around forming and cure mandrel210prior to placing composite charge204over forming and cure mandrel210, first radius filler207, and second radius filler208such that at least one of applying mechanical pressure to shape composite charge204or applying vacuum pressure to stringer layup232adheres composite charge204to composite ply220. When composite ply220is present, composite ply220has a trapezoidal cross-section formed by the cross-section of forming and cure mandrel210.

When inner ply216is present, inner ply216is placed onto rigid base230. First radius filler207and second radius filler208are placed onto inner ply216on rigid base230. Forming and cure mandrel210is placed onto inner ply216prior to placing composite charge204over forming and cure mandrel210.

Compacted stringer package202is then placed into cure tool226. After curing compacted stringer package202, forming and cure mandrel210is removed from compacted stringer package202.

The mechanical pressure is applied using mechanical shaping tool240. Mechanical shaping tool240may take any desirable configuration. In one illustrative example, applying the mechanical pressure comprises pressing composite charge204using plurality of mechanical fingers242by sliding plurality of mechanical fingers242across composite charge204.

Compacted stringer package202is one of plurality of compacted stringer packages244. To form a composite structure, such as a portion of body106ofFIG. 1, plurality of compacted stringer packages244is formed, each comprising a composite charge having a hat-shaped cross-section, a first radius filler contacting the composite charge, a second radius filler contacting the composite charge, and a forming and cure mandrel positioned within a cap, a first web, and a second web of the hat-shaped cross-section. Plurality of compacted stringer packages244is placed onto cure tool226.

Plurality of compacted stringer packages244includes any quantity of compacted stringer packages. Although not depicted, plurality of compacted stringer packages244includes a respective composite charge having a hat-shaped cross-section, a first radius filler contacting the composite charge, a second radius filler contacting the composite charge, and a forming and cure mandrel positioned within a cap, a first web, and a second web of the hat-shaped cross-section for each respective compacted stringer package of plurality of compacted stringer packages244.

In some illustrative examples, each of plurality of compacted stringer packages244has a curvature complementary to a unique location on cure tool226. When each of plurality of compacted stringer packages244has a curvature complementary to a unique location, each of plurality of compacted stringer packages244has its own respective forming and cure mandrel and its own respective rigid base.

In these illustrative examples, forming plurality of compacted stringer packages244comprises placing a plurality of composite charges each over a respective forming and cure mandrel, a respective first radius filler, and a respective second radius filler. Each respective forming and cure mandrel has a complementary curvature to a respective rigid base.

For example, respective forming and cure mandrels for each of plurality of compacted stringer packages244are not depicted. Additionally, optional plies, inner ply216and composite ply220, are both depicted inFIG. 2. In some illustrative examples, one or both of inner ply216and composite ply220are not present.

As another example, although not depicted inFIG. 2, manufacturing environment200may include a number of carriers, a number of shuttles, or other composite ply movement and placement equipment. As used herein, “a number of” is one or more items. For example, “a number of carriers” is one or more carriers. In some illustrative examples, at least one of composite charge204, composite ply220, inner ply216, first radius filler207, or second radius filler208may be moved and placed using equipment. In other illustrative examples, at least one of composite charge204, composite ply220, inner ply216, first radius filler207, or second radius filler208may be moved or placed by hand.

As yet another example, although not depicted inFIG. 2, manufacturing environment200may include movement equipment for moving compacted stringer package202. In some illustrative examples, the movement equipment may move and place compacted stringer package202onto cure tool226. In other illustrative examples, compacted stringer package202may be placed onto cure tool226by hand.

As a further example, although not depicted inFIG. 2, heating equipment may be present in manufacturing environment200. In some illustrative examples, stringer layup232is heated while the vacuum pressure is applied to stringer layup232to form compacted stringer package202having hat-shaped cross-section234. Heat may be applied using any desirable form of heating equipment. Heating of stringer layup232causes the composite material in stringer layup232to become more pliable than at room temperature. By heating stringer layup232while forming compacted stringer package202, fewer inconsistencies may be present in compacted stringer package202.

Turning now toFIG. 3, an illustration of a mechanical shaping tool in a manufacturing environment is depicted in accordance with an illustrative embodiment. Mechanical shaping tool300in manufacturing environment302is a physical implementation of mechanical shaping tool240ofFIG. 2.

Mechanical shaping tool300includes plurality of mechanical fingers304that slide across composite charge305on rigid base306. Mechanical fingers304may have any desirable shape and be actuated by any desirable force. As depicted, composite charge305and forming and cure mandrel308are present between rigid base306and vacuum bag310. Forming and cure mandrel308is present to shape composite charge305on rigid base306.

Turning now toFIG. 4, an illustration of a stringer layup in a mechanical shaping tool is depicted in accordance with an illustrative embodiment. View400is an illustration of mechanical shaping tool300while compacting stringer layup402. Stringer layup402includes composite charge404, first radius filler405, second radius filler406, wrap ply408, and inner ply410. Although both wrap ply408and inner ply410are present in stringer layup402, wrap ply408and inner ply410are both optional.

As depicted, plurality of mechanical fingers304slide across composite charge404on rigid base306. Plurality of mechanical fingers304applies mechanical pressure to composite charge404to shape and compact composite charge404.

Vacuum pressure is applied to stringer layup402under vacuum bag412. The vacuum pressure and the mechanical pressure may be substantially simultaneously applied. In some illustrative examples, the vacuum pressure may remain on stringer layup402longer than the mechanical pressure.

The illustrations of mechanical shaping tool300inFIGS. 3 and 4are not meant to imply physical or architectural limitations to the manner in which an illustrative embodiment may be implemented. Mechanical shaping tool300is only one physical implementation of mechanical shaping tool240ofFIG. 2. For example, mechanical shaping tool300may have any desirable number and shape of mechanical fingers.

In some illustrative examples, cap forming portion414of mechanical shaping tool300may have a different shape. In some illustrative examples, mechanical shaping tool240may include a diaphragm or inflatable bladder to apply the mechanical pressure to stringer layup402.

Turning now toFIG. 5, an illustration of components of a composite stringer package prior to compacting is depicted in accordance with an illustrative embodiment. Composite charge500is a physical implementation of composite charge204ofFIG. 2. Composite charge500is placed over forming and cure mandrel502, first radius filler503, and second radius filler504. Forming and cure mandrel502is a physical implementation of forming and cure mandrel210ofFIG. 2. First radius filler503and second radius filler504are physical implementations of first radius filler207and second radius filler208ofFIG. 2.

As depicted, composite ply506is wrapped around forming and cure mandrel502. Composite ply506is a physical implementation of composite ply220ofFIG. 2. By placing composite charge500over forming and cure mandrel502, composite charge500is positioned such that composite charge500contacts composite ply506.

Inner ply508is positioned on rigid base510. Inner ply508is a physical implementation of inner ply216ofFIG. 2. Rigid base510is a physical implementation of rigid base230ofFIG. 2.

InFIG. 5, mechanical pressure and vacuum pressure have not yet been applied. InFIG. 5, the components are not compacted.

Turning now toFIG. 6, an illustration of a compacted stringer package is depicted in accordance with an illustrative embodiment. Compacted stringer package600is a compacted structure formed of components shown inFIG. 5.

Compacted stringer package600includes composite charge500, forming and cure mandrel502, first radius filler503, second radius filler504, composite ply506, and inner ply508. Compacted stringer package600is sufficiently rigid to transport compacted stringer package600without rigid base510. Compacted stringer package600may be picked up as a whole and placed into a cure tool (not depicted) as a whole.

Turning now toFIG. 7, an illustration of components of a composite stringer package prior to compacting is depicted in accordance with an illustrative embodiment. Composite charge700is a physical implementation of composite charge204ofFIG. 2. Composite charge700is placed over forming and cure mandrel702, first radius filler703, and second radius filler704. Forming and cure mandrel702is a physical implementation of forming and cure mandrel210ofFIG. 2. First radius filler703and second radius filler704are a physical implementation of first radius filler207and second radius filler208ofFIG. 2.

As depicted, composite ply706is wrapped around forming and cure mandrel702. Composite ply706is a physical implementation of composite ply220ofFIG. 2. By placing composite charge700over forming and cure mandrel702, composite charge700is positioned such that composite charge700contacts composite ply706.

First radius filler703, second radius filler704, and a portion of composite ply706each contact rigid base708. Rigid base708is a physical implementation of rigid base230ofFIG. 2.

InFIG. 7, mechanical pressure and vacuum pressure have not yet been applied. InFIG. 7, the components are not compacted.

Turning now toFIG. 8, an illustration of a compacted stringer package is depicted in accordance with an illustrative embodiment. Compacted stringer package800is a compacted structure formed of components shown inFIG. 7.

Compacted stringer package800includes composite charge700, forming and cure mandrel702, first radius filler703, second radius filler704, and composite ply706. Compacted stringer package800is sufficiently rigid to transport compacted stringer package800without rigid base708. Compacted stringer package800may be picked up as a whole and placed into a cure tool (not depicted) as a whole.

Turning now toFIG. 9, an illustration of components of a composite stringer package prior to compacting is depicted in accordance with an illustrative embodiment. Composite charge900is a physical implementation of composite charge204ofFIG. 2. Composite charge900is placed over forming and cure mandrel902, first radius filler903, and second radius filler904. Forming and cure mandrel902is a physical implementation of forming and cure mandrel210ofFIG. 2. First radius filler903and second radius filler904are physical implementations of first radius filler207and second radius filler208ofFIG. 2.

As depicted, inner ply906is positioned on rigid base908. Inner ply906is a physical implementation of inner ply216ofFIG. 2. Rigid base908is a physical implementation of rigid base230ofFIG. 2.

InFIG. 9, mechanical pressure and vacuum pressure have not yet been applied. InFIG. 9, the components are not compacted.

Turning now toFIG. 10, an illustration of a compacted stringer package is depicted in accordance with an illustrative embodiment. Compacted stringer package1000is a compacted structure formed of components shown inFIG. 9.

Compacted stringer package1000includes composite charge900, forming and cure mandrel902, first radius filler903, second radius filler904, and inner ply906. Compacted stringer package1000is sufficiently rigid to transport compacted stringer package1000without rigid base908. Compacted stringer package1000may be picked up as a whole and placed into a cure tool (not depicted) as a whole.

Turning now toFIG. 11, an illustration of a compacted stringer package placed onto a cure tool is depicted in accordance with an illustrative embodiment. In view1100, compacted stringer package1102is placed into hollow1104of cure tool1106. Hollow1104is a unique location of cure tool1106. Compacted stringer package1102is designed to fit within hollow1104. Compacted stringer package1102is complementary to any curvatures of hollow1104.

After placing all desired compacted stringer packages onto cure tool1106, a composite skin is placed over the compacted stringer packages. The composite skin and desired compacted stringer packages will then be co-cured on cure tool1106.

Although compacted stringer package1102has a layup similar to compacted stringer package600ofFIG. 6, compacted stringer package1102may have any desirable layup. For example, compacted stringer package1102may have a layup like compacted stringer package800ofFIG. 8. In another example, compacted stringer package1102has a layup like compacted stringer package1000ofFIG. 10.

Turning now toFIG. 12, an illustration of a perspective view of a compacted stringer package having complex contours is depicted in accordance with an illustrative embodiment. View1200is a perspective view of compacted stringer package600ofFIG. 6. Compacted stringer package600is a physical implementation of compacted stringer package202ofFIG. 2. In view1200, complex curvature of compacted stringer package600is visible.

Compacted stringer package600may have a number of complex contours along its length. The contours of compacted stringer package600may be constant or varying. As depicted, compacted stringer package600has curvatures in the X-Y plane and curvatures in the X-Z plane. Compacted stringer package600is also twisted. Compacted stringer package600may be twisted at a constant or varying angle θ.

Turning now toFIGS. 13 and 14, illustrations of cross-sectional views of a compacted stringer package having complex contours are depicted in accordance with an illustrative embodiment. Twists of compacted stringer package600within Y-Z plane are depicted inFIGS. 13 and 14.

Turning now toFIG. 15, an illustration of a top view of a compacted stringer package having complex contours is depicted in accordance with an illustrative embodiment. View1500is a top view of compacted stringer package600depicting curvature in the X-Y plane.

Turning now toFIG. 16, an illustration of a side view of a compacted stringer package having complex contours is depicted in accordance with an illustrative embodiment. View1600is a side view of compacted stringer package600depicting curvature in the X-Z plane.

The different components shown inFIGS. 1 and 3-16may be combined with components inFIG. 2, used with components inFIG. 2, or a combination of the two. Additionally, some of the components inFIGS. 1 and 3-16may be illustrative examples of how components shown in block form inFIG. 2can be implemented as physical structures.

Turning now toFIG. 17, an illustration of a flowchart of a method for forming a compacted stringer package is depicted in accordance with an illustrative embodiment. Method1700may be used to form any of compacted stringer package202ofFIG. 2, compacted stringer package600ofFIGS. 6 and 12-16, compacted stringer package800ofFIG. 8, or compacted stringer package1000ofFIG. 10.

Method1700places a composite charge over a forming and cure mandrel, a first radius filler, and a second radius filler (operation1702). Method1700applies mechanical pressure to shape the composite charge to the forming and cure mandrel and a rigid base to form a stringer layup (operation1704). In some illustrative examples, applying the mechanical pressure comprises pressing the composite charge using a plurality of mechanical fingers by sliding the plurality of mechanical fingers across the composite charge.

Method1700applies vacuum pressure to the stringer layup to form a compacted stringer package having a hat-shaped cross-section (operation1706). In some illustrative examples, the mechanical pressure and the vacuum pressure are applied substantially simultaneously. Afterwards, the process terminates.

In some illustrative examples, the hat-shaped cross-section comprises a cap, a first web, and a second web, shaped by the forming and cure mandrel. In some illustrative examples, the hat-shaped cross-section further comprises a first flange, and a second flange, shaped by the rigid base. In some illustrative examples, the hat-shaped cross-section further comprises a bottom connecting a first flange and a second flange and extending underneath the cap, the first web, and the second web.

Turning now toFIG. 18, an illustration of a flowchart of a method for manufacturing using a plurality of compacted stringer packages is depicted in accordance with an illustrative embodiment. Method1800may be performed using at least one of compacted stringer package202ofFIG. 2, compacted stringer package600ofFIGS. 6 and 12-16, compacted stringer package800ofFIG. 8, or compacted stringer package1000ofFIG. 10.

Method1800forms a plurality of compacted stringer packages each comprising a composite charge having a hat-shaped cross-section, a first radius filler contacting the composite charge, a second radius filler contacting the composite charge, and a forming and cure mandrel positioned within a cap, a first web, and a second web of the hat-shaped cross-section (operation1802). In some illustrative examples, forming the plurality of compacted stringer packages comprises placing a plurality of composite charges each over a respective forming and cure mandrel, a respective first radius filler, and a respective second radius filler, applying mechanical pressure to shape each of the plurality of composite charges to the respective forming and cure mandrel and a respective rigid base to form stringer layups, and applying vacuum pressure to the stringer layups to form the plurality of compacted stringer packages each having the hat-shaped cross-section. In some of these illustrative examples, each respective forming and cure mandrel has a complementary curvature to a respective rigid base.

Method1800places the plurality of compacted stringer packages onto a cure tool (operation1804). Afterwards, the process terminates. In some illustrative examples, each of the plurality of compacted stringer packages has a curvature complementary to a unique location on the cure tool. In some illustrative examples, one compacted stringer package is placed onto the cure tool at a time. In other illustrative examples, multiple compacted stringer packages are placed onto the cure tool at substantially the same time.

In some illustrative examples, the plurality of compacted stringer packages are placed onto the cure tool by a number of human operators. In other illustrative examples, the plurality of compacted stringer packages are placed onto the cure tool by a number of robots using automation.

In some illustrative examples, method1700ofFIG. 17further comprises wrapping a composite ply around the forming and cure mandrel prior to placing the composite charge over the forming and cure mandrel, the first radius filler, and the second radius filler, such that at least one of applying the mechanical pressure to shape the composite charge or applying the vacuum pressure to the stringer layup adheres the composite charge to the composite ply. In some illustrative examples, method1700further comprises placing an inner ply onto the rigid base, placing the first radius filler and the second radius filler onto the inner ply on the rigid base, and placing the forming and cure mandrel onto the inner ply prior to placing the composite charge over the forming and cure mandrel.

In some illustrative examples, method1700further comprises removing the compacted stringer package from the rigid base, and placing the compacted stringer package into a cure tool. In an illustrative example, method1700additionally further comprises removing the forming and cure mandrel from the compacted stringer package. In yet another illustrative example, method1800ofFIG. 18further comprises removing a respective forming and cure mandrel from each of the plurality of compacted stringer packages.

The illustrative examples provide methods and apparatus for composite manufacturing with stringers having hat-shaped cross-sections. The illustrative examples form compacted stringer packages having hat-shaped cross-sections.

In the illustrative examples, a finger former device may be used to form pre-preg hat-shaped stringers directly onto the bladder/mandrel that provides the inside geometry of the stringer. Also included in the forming is the radius filler (noodle) that interfaces with the skin. These components create a package of the stringer, the bladder/mandrel, and the noodle that is ready for installation. The finger-forming technology allows the stringer package to be formed to engineering contour, so that the stringer will not bend (and wrinkle) during installation.

By assembling the stringer package on a feeder-line, the illustrative examples remove significant flow time in the critical path of a fuselage build. By forming to a contour, the stringer inspection can take place at the forming station rather than on the cure tool.

The illustrative examples allow flexibility to use automation in the stringer fabrication feeder-line and stringer installation line. It also moves significant work out of the critical flow path. Thus, the illustrative examples reduce composite fabrication flow time and allow process automation.