Patent Description:
Off-line fiber placement techniques allow a composite skin to be formed independent of a vehicle on which the composite skin is subsequently applied. After forming, the composite skin is picked up, placed in position, and secured to the vehicle. Issues with the off-line fiber placement techniques include a criterion for an off-line layup surface used to form the composite skin to have a similar contour to the final skin, and there is a risk of wrinkles. Layup on contoured tools adds cost to layup machinery, adds costs to tooling, and increases a footprint used in manufacturing. Alternatively, a hot drape form can be used that adds verification complexity and has thickness limitations without incurring significant heating time.

<CIT>, according to its abstract, states that systems and methods are provided for designing composite parts. One embodiment is a method for fabricating a composite part. The method includes receiving a design that defines a stacking sequence for a composite charge comprising plies that have different fiber orientations, defining a splice zone within the design, modifying the design by splicing plies in a manner that accommodates ply slippage when the composite charge is formed to a contour, and fabricating a composite part based on the design that was modified.

According to the present disclosure, a method as defined in claim <NUM> and a manufacturing system as defined in claim <NUM> are provided. Further embodiments of the claimed invention are defined in the dependent claims. Although the invention is only defined by the claims, the below embodiments, examples, and aspects are present for aiding in understanding the background and advantages of the invention.

In one embodiment, a method for contour forming in a fiber placement system is provided herein. The method includes depositing a plurality of sliced layers on a stationary form to create a composite component. The plurality of sliced layers includes a plurality of hoop tows. One or more overlap splices are formed in each of the plurality of hoop tows. The method includes applying a layup heat to a plurality of target areas on the plurality of sliced layers during the depositing.

The plurality of target areas is spatially arranged to permit a slippage in the plurality of overlap splices. The method further includes draping the composite component on a curved tool with the plurality of hoop tows oriented perpendicular to an axis of curvature of the curved tool, and applying a curing heat to the composite component after the composite component has been contoured by the curved tool. The curing heat inhibits a further slippage in the plurality of overlap splices.

In one or more embodiments of the method, each of the plurality of overlap splices includes a first segment overlaid with a second segment, the second segment is inside of the plurality of target areas, and the first segment is outside of the plurality of target areas to permit the slippage.

In one or more embodiments of the method, each of the plurality of overlap splices includes a first segment overlaid with a second segment, and both the first segment and the second segment are outside of the plurality of target areas to permit the slippage.

In one or more embodiments of the method, each of the plurality of overlap splices includes an unexposed area in which a first segment is overlaid with a second segment, and the unexposed area is outside of the plurality of target areas to permit the slippage.

In one or more embodiments of the method, the plurality of target areas includes between the plurality of overlap splices, and between the plurality of overlap splices and a plurality of additional tows upon which the plurality of hoop tows is painted.

In one or more embodiments of the method, the plurality of sliced layers includes a plurality of additional tows that are oriented nonparallel to the plurality of hoop tows, each of the plurality of additional tows includes an unexposed area aligned with one or more of the plurality of overlap splices in the plurality of hoop tows, and the unexposed areas are outside of the plurality of target areas to permit shear in the plurality of additional tows when the composite component is draped on the curved tool.

In one or more embodiments of the method, the plurality of hoop tows is painted in a plurality of courses, and the plurality of overlap splices are offset from each other among the plurality of courses.

In one or more embodiments of the method, the plurality of hoop tows is disposed on two or more of the plurality of sliced layers.

In one or more embodiments of the method, the composite component is part of an aircraft.

In one or more embodiments of the method, the stationary form is approximately flat, and the curved tool has a radius from the axis of curvature in a range of approximately <NUM> inches to approximately <NUM> inches.

In one embodiment, a composite component formed by a method for contour forming in a fiber placement system is provided herein. The method includes depositing a plurality of sliced layers on a stationary form to create a composite component. The plurality of sliced layers includes a plurality of hoop tows. One or more overlap splices are formed in each of the plurality of hoop tows. The method includes applying a layup heat to a plurality of target areas on the plurality of sliced layers during the painting. The plurality of target areas is spatially arranged to permit a slippage in the plurality of overlap splices. The method further includes draping the composite component on a curved tool with the plurality of hoop tows oriented perpendicular to an axis of curvature of the curved tool, and applying a curing heat to the composite component after the composite component has been contoured by the curved tool. The curing heat inhibits a further slippage in the plurality of overlap splices.

In one embodiment, a manufacturing system is provided herein. The manufacturing system includes an automated-fiber-placement system, a curved tool, a pick-and-place machine, and an autoclave. The automated-fiber-placement system is configured to deposit a plurality of sliced layers on a stationary form to create a composite component. The plurality of sliced layers includes a plurality of hoop tows. One or more overlap splices are formed in each of the plurality of hoop tows. The automated-fiber-placement system is configured to apply a layup heat to a plurality of target areas on the plurality of sliced layers during the depositing. The plurality of target areas is spatially arranged to permit a slippage in the plurality of overlap splices.

The pick-and-place machine is configured to drape the composite component on a curved tool with the plurality of hoop tows oriented perpendicular to an axis of curvature of the curved tool. The autoclave is configured to apply a curing heat to the composite component after the composite component has been contoured by the curved tool. The curing heat inhibits a further slippage in the plurality of overlap splices.

In one or more embodiments of the manufacturing system, each of the plurality of overlap splices includes a first segment overlaid with a second segment, the second segment is inside of the plurality of target areas, and the first segment is outside of the plurality of target areas to permit the slippage.

In one or more embodiments of the manufacturing system, each of the plurality of overlap splices includes a first segment overlaid with a second segment, and both the first segment and the second segment are outside of the plurality of target areas to permit the slippage.

In one or more embodiments of the manufacturing system, each of the plurality of overlap splices includes an unexposed area in which a first segment is overlaid with a second segment, and the unexposed area is outside of the plurality of target areas to permit the slippage.

In one or more embodiments of the manufacturing system, the plurality of target areas includes between the plurality of overlap splices, and between the plurality of overlap splices and a plurality of additional tows upon which the plurality of hoop tows is painted.

In one or more embodiments of the manufacturing system, the plurality of sliced layers includes a plurality of additional tows that are oriented nonparallel to the plurality of hoop tows, each of the plurality of additional tows includes an unexposed area aligned with one or more of the plurality of overlap splices in the plurality of hoop tows, and the unexposed areas are outside of the plurality of target areas to permit shear in the plurality of additional tows when the composite component is draped on the curved tool.

In one or more embodiments of the manufacturing system, the plurality of hoop tows is painted in a plurality of courses, and the plurality of overlap splices are offset from each other among the plurality of courses.

In one or more embodiments of the manufacturing system, the plurality of hoop tows is disposed on two or more of the plurality of sliced layers.

In one or more embodiments of the manufacturing system, the composite component is part of an aircraft.

The above features and advantages, and other features and advantages of the present disclosure are readily apparent from the following detailed description of the best modes for carrying out the disclosure when taken in connection with the accompanying drawings.

This disclosure is susceptible of embodiments in many different forms. Representative embodiments of the disclosure are shown in the drawings and will herein be described in detail with the understanding that these embodiments are provided as an exemplification of the disclosed principles, not limitations of the broad aspects of the disclosure. To that extent, elements and limitations that are described, for example, in the Abstract, Background, Summary, and Detailed Description sections, but not explicitly set forth in the claims, should not be incorporated into the claims, singly or collectively, by implication, inference or otherwise.

For purposes of the present detailed description, unless specifically disclaimed, the singular includes the plural and vice versa. The words "and" and "or" shall be both conjunctive and disjunctive. The words "any" and "all" shall both mean "any and all", and the words "including," "containing," "comprising," "having," and the like shall each mean "including without limitation. " Moreover, words of approximation such as "about," "almost," "substantially," "approximately," and "generally," may be used herein in the sense of "at, near, or nearly at," or "within <NUM>-<NUM>% of," or "within acceptable manufacturing tolerances," or other logical combinations thereof. Referring to the drawings, wherein like reference numbers refer to like components.

Embodiments of the present disclosure include a method and/or a manufacturing system that addresses wrinkles in composite layups when draped into contoured locations. The method/system (or technique) produces fiber placement laminations off-line and subsequently contours the laminations with a curved tool, whereas conventional flat-to-curved contouring techniques could lead to buckling. The fiber placement laminations use tows to build a composite component (e.g., a skin or a pad-up). The technique utilizes targeted laser heating of the tows and an introduction of overlap splices in the tows. The overlap splices are introduced in areas of future high contour. The laser heating is controlled to avoid layup heating of the splices in the tows. Thereafter, the splices serve as slip planes during drape forming on a curved tool.

A "tow" is a continuous narrow strip of composite material and may be impregnated with a resin. A "tow" may also be referred to as "slit tow" because it is created by slitting a wide roll. An overlap splice exists where a start of a tow overlaps an end of another tow. In various embodiments, the overlap splices are introduced into the hoop tows with a second pass on top of a first pass during the manufacturing of the composite component. In other embodiments, the overlap splices are present in the hoop tows before the manufacturing of the composite component begins.

Referring to <FIG>, a schematic diagram of an example implementation of a manufacturing system <NUM> is shown in accordance with an exemplary embodiment. The manufacturing system <NUM> generally includes an automated-fiber-placement (AFP) system <NUM>, a stationary form <NUM>, a layup heat <NUM>, a pick-and-place machine <NUM>, a curved tool <NUM> that has an axis of curvature <NUM> and a radius <NUM>, and an autoclave <NUM> that generates a curing heat <NUM>. The automated-fiber-placement system <NUM> includes a fiber-placement machine <NUM>, a heater <NUM>, and a controller <NUM>. The manufacturing system <NUM> is generally operational to create an intermediate component <NUM> that includes a carrier <NUM> and a composite component <NUM>. By the end of the manufacturing process, the composite component <NUM> is separated from the carrier <NUM>.

The automated-fiber-placement system <NUM> is implemented as a moving machine that lays multiple narrow tows on the stationary form <NUM>. The automated-fiber-placement system <NUM> is configured to paint a plurality of sliced layers on the stationary form <NUM> to create the composite component <NUM>. The automated-fiber-placement system <NUM> is also configured to apply the layup heat <NUM> to a plurality of target areas on the sliced layers during the painting. The sliced layers include a plurality of hoop (e.g., direction of contour) tows. One or more overlap splices are formed in each of the hoop tows. The target areas are spatially arranged to permit a slippage in the overlap splices. A technique implemented by the automated-fiber-placement system <NUM> generally reduces a probability of wrinkle formation where the composite component <NUM> is contoured to a final shape.

The stationary form <NUM> is implemented as an approximately flat surface. The stationary form <NUM> is operational to provide a substantially horizontal surface onto which the tows are painted to create the composite component <NUM>.

The layup heat <NUM> is implemented as an optical beam (or signal). In various embodiments, the layup heat <NUM> is a laser beam controlled to be scanned in multiple (e.g., two) dimensions across the tows as the tows are being deposited on the stationary form <NUM>. The layup heat <NUM> warms a portion of the tows previously deposited and/or a portion of the tows being deposited just before, or as the tows pass by a compression roller of the fiber-placement machine <NUM>.

The pick-and-place machine <NUM> is implemented as a robotic manipulator. The pick-and-place machine <NUM> is configured to pick up the intermediate component <NUM> (that includes the composite component <NUM>) from the stationary form <NUM>, and drape (or place) the composite component <NUM> on the curved tool <NUM> with the hoop tows oriented perpendicular to the axis of curvature <NUM> of the curved tool <NUM>. During the pick-and-place activity, rather than having a neutral axis stack up from the inner layers to the outer layers, putting intermediate layers into compression, the overlap splices in the hoop tows allow the hoop tow layer(s) to slip under tension. The slippage effectively softens the pre-cure stiffness of such layers as the composite component <NUM> is bent by the curved tool <NUM>. In various embodiments, the sliced layers above and below the hoop tow layers may have some amount of give at the hoop tow/tow gaps.

The curved tool <NUM> is implemented as a curved surface at the radius <NUM> about the axis of curvature <NUM>. The curved tool <NUM> is configured to bend the flat composite component <NUM> into a contoured shape in response to the composite component <NUM> being pressed against the curved surface. The curved surface may be described for a dominant hoop curvature (e.g., a <NUM>-degree direction). The radius <NUM> of the curvature may be described in terms of a large radius (e.g., approximately <NUM> (<NUM> feet)) feetra medium radius (e.g., approximately <NUM> (<NUM> feet)), and/or a short radius (e.g., approximately <NUM> (<NUM> inches)) In various embodiments, the curved tool <NUM> may be representative of a door-surround sized area of a jet aircraft (e.g., a Boeing <NUM> aircraft, a Boeing <NUM> aircraft, etc.). In other embodiments, the curved tool <NUM> may be representative of a horizontal stabilizer loft area of the jet aircraft.

The autoclave <NUM> is implemented as a curing chamber. The autoclave <NUM> is configured to apply the curing heat <NUM> to the composite component <NUM> after the composite component <NUM> has been contoured by the curved tool <NUM>. The autoclave <NUM> may also be configured to cure the contoured composite component <NUM> under heat, vacuum and/or pressure. An inert atmosphere, such as nitrogen or carbon dioxide, may be provided inside the autoclave <NUM>.

The curing heat <NUM> is implemented as a controlled heat. The curing heat <NUM> may be generated by an electric heater, a steam heater, a gas heater, an externally fired heater, or the like. The curing heat <NUM> inhibits a further slippage in the overlap splices when the composite component <NUM> is subjected to external forces.

The fiber-placement machine <NUM> is implemented as a composite ply placement machine. The fiber-placement machine <NUM> is generally operational to paint (or deposit) multiple sliced layers of the tow onto the carrier <NUM>. The tow may be deposited in multiple layers. In various embodiments, the sliced layers may be created with the tows oriented at particular angles (e.g., +<NUM> degrees, <NUM> degrees, -<NUM> degrees, and <NUM> degrees) relative to a planned orientation of the composite component <NUM>. In other embodiments, the tows may be oriented at other angles (e.g., +<NUM> degrees, <NUM> degrees, -<NUM> degrees, and <NUM> degrees) relative to a planned orientation of the composite component <NUM>. Other angles and/or other numbers of the angles may be implemented to meet the design criteria of a particular application.

The fiber-placement machine <NUM> may include, but is not limited to, a head, a compaction roller, a bulk reel of the composite ply, one or more guide rollers, and/or a drive mechanism for urging the compaction roller. The head of the fiber-placement machine <NUM> generally brings together a set of the tows. The set is then feed to the compaction roller. The compaction roller presses the tows onto the stationary form <NUM>.

The heater <NUM> is implemented as an optical heater. The heater <NUM> is configured to generate the optical signal that provides the layup heat <NUM>. In various embodiments, the heater <NUM> may be a continuous-wave laser modulated to achieve a specified pulse frequency. In some embodiments, the heater <NUM> may be a pulse laser that emits at a specified pulse frequency.

The controller <NUM> is implemented as a processor circuit (e.g., one or more microprocessors). The controller <NUM> may be configured to control application and scanning of the layup heat <NUM>. The controller <NUM> is operational to communicate with the heater <NUM> via the control lines <NUM>. Control of the layup heat <NUM> may include, but is not limited to, control over an optical power, a pulse frequency, and a spatial direction of the optical signal.

The control lines <NUM> are implemented as one or more electrical wires and/or busses. The control lines <NUM> are generally operational to provide bidirectional communication between the controller <NUM> and the heater <NUM>.

The intermediate component <NUM> is implemented as the composite component <NUM> residing on the carrier <NUM>. In various embodiments, the carrier <NUM> may be formed of thermoplastic materials, plexiglass, oil palm fiber (OPF) latex, or similar materials. The carrier <NUM> is removable from the composite component <NUM> near an end of the manufacturing process.

The composite component <NUM> is implemented as a structural part of a vehicle or an object. In various embodiments, the vehicle may be an aircraft, an automobile, a truck, a boat, or the like. The object may be a container, a covering, a shelter, or the like. The composite component <NUM> may be implemented as parts of other types vehicles or objects to meet a design criteria of a particular application.

In designs where the composite component <NUM> is implemented as a thick pad-up area, a baseline layup and drape may be performed with an initial thin composite component on the curved tool <NUM>. The carrier <NUM> may subsequently be removed. One or more additional thin composite components may be formed and draped on the initial composite component <NUM> at decreasing curvatures (e.g., increasing radii <NUM>). After the thin composite components have been joined together on the curved tool <NUM>, the resulting composite component <NUM> may be moved to the autoclave <NUM> for curing.

Referring to <FIG>, a schematic diagram of an example implementation of the heater <NUM> is shown in accordance with an exemplary embodiment. The heater <NUM> includes a laser <NUM> and a scan head <NUM>. A laser light <NUM> generated by the laser <NUM> is transferred to the scan head <NUM>. The scan head <NUM> is configured to spatially direct the laser light <NUM> to aim the layup heat <NUM> within the target area.

The laser <NUM> may implement an optical laser. The laser <NUM> is configured to generate the laser light <NUM> in response to controls received over the control lines <NUM>. The laser <NUM> may be implemented as a continuous-wave laser or a pulse laser.

The scan head <NUM> may implement a multidimensional (e.g., two-dimensional) optical scanner. The scan head <NUM> is configured to direct the laser light <NUM> to the sliced layer being deposited in response to control signals received from the control lines <NUM>.

The laser light <NUM> generally has a wavelength that is absorbed by and warms one or two sliced layers. In various embodiments, the wavelength may range from about <NUM> micrometers (µm) to about <NUM> (e.g., near infrared). In other embodiments, the wavelength may range from about <NUM> to about <NUM> (e.g., short-wavelength infrared). In some embodiments, the wavelength may range from about <NUM> to about <NUM> (e.g., mid-wavelength infrared). In still other embodiments, the wavelength may range from about <NUM> to about <NUM> (e.g., long-wavelength infrared). The wavelength may range from about <NUM> to about <NUM>,<NUM> (e.g., far infrared).

Referring to <FIG>, a schematic diagram of an example implementation of the scan head <NUM> is shown in accordance with an exemplary embodiment. The scan head <NUM> includes a first mirror <NUM> and a second mirror <NUM>. The first mirror <NUM> and the second mirror <NUM> are configured to rotate about different axes to provide the multidimensional scanning.

The first mirror <NUM> is generally operational to redirect the laser light <NUM> from the laser <NUM> to the second mirror <NUM>. The second mirror <NUM> may be operational to redirect the laser light <NUM> from the first mirror <NUM> onto the composite component <NUM>. The laser light <NUM> generally provides the layup heat <NUM> to a heated area <NUM> on an exposed surface of the composite component <NUM>. Rotational movement of the first mirror <NUM> and the second mirror <NUM> provide spatial movement of the heated area <NUM>. While the laser light <NUM> is active, the heated area <NUM> may be scanned through multiple targeted areas to heat the tows being deposited by the fiber-placement machine <NUM>. The laser light <NUM> is extinguished while the scan head <NUM> points into multiple unexposed (or non-heated) areas (e.g., the splices in the hoop tows).

Referring to <FIG>, a side view schematic diagram of an example implementation of a restart drive roller <NUM> is shown in accordance with an exemplary embodiment. The restart drive roller <NUM> is a mechanism inside the head of the fiber-placement machine <NUM> that is a component of a tow add subsystem. The restart drive roller <NUM> includes a driven textured shaft and operates with a series of (typically pneumatic) actuated roller clamps.

Referring to <FIG>, an end view schematic diagram of an example implementation of the restart drive roller <NUM> and multiple roller clamps 152a-152n is shown in accordance with an exemplary embodiment. Each tow 202a-202n being painted has a dedicated roller clamp 152a-152n. When actuated, the roller clamps 152a-152n press the tows 202a-202n against the shaft of the restart drive roller <NUM>, which subsequently drives the material toward an exit of the head. Once the tows 202a-202n have achieved a predetermined amount of laydown and adequate tack exists between the tows 202a-202n and the substrate, the roller clamps 152a-152n disengage, and the material may be feed based on tension.

Referring to <FIG>, an enlarged partial sectional view schematic diagram of an example fabrication of an intermediate component <NUM> is shown in accordance with an exemplary embodiment. The intermediate component <NUM> includes the carrier <NUM> and the composite component <NUM>. The carrier <NUM> is generally disposed on the stationary form <NUM>. The automated-fiber-placement system <NUM> paints the sliced layers onto the carrier <NUM> thereby building up the composite component <NUM> layer by layer.

A first side <NUM> (e.g., a bottom side as illustrated) of the composite component <NUM> adjoins the carrier <NUM>. A second side <NUM> (e.g., a top side as illustrated) of the composite component <NUM> faces away from the first side <NUM>. The composite component <NUM> includes multiple sliced layers of tows 208a-214b. The various tows 208a-214b are aligned in multiple (e.g., <NUM> to <NUM>) directions.

In the example embodiment, the tows 208a-208c are aligned at +<NUM> degrees relative to the axis of curvature <NUM>. The tows 210a-210b are aligned at zero degrees relative to the axis of curvature <NUM>. The tows 212a-212b are aligned at -<NUM> degrees relative to the axis of curvature <NUM>. The hoop tows 214a-214b are aligned at <NUM> degrees relative to the axis of curvature <NUM>.

An initial +<NUM>-degree tow 208a is formed on the carrier <NUM>. An initial <NUM>-degree tow 210a is formed on the +<NUM>-degree tow 208a. An initial -<NUM>-degree tow 212a is formed on the <NUM>-degree tow 210a. An initial <NUM>-degree hoop tow 214a is formed on the <NUM>-degree tow 210a. The sequence of tows is generally repeated with a subsequent +<NUM>-degree tow 208b, a <NUM>-degree tow 210b, a -<NUM>-degree tow 212b, a <NUM>-degree hoop tow 214b, and another +<NUM>-degree tow 208c. Other sequences and/or numbers of the sliced layers may be implemented to meet the design criteria of a particular application.

Multiple (e.g., two illustrated) overlap splices 220a-220b are created in the hoop tows 214a-214b in the direction of curvature. Each hoop tow 214a-214b includes one or more of the overlap splices 220a-220b. The overlap splices 220a-220b are formed where first layups 216a-216b are overlaid with second layups 218a-218b of the respective hoop tows 214a-214b. The overlaid regions are referred to as first segments 222a-222b (e.g., the lower segments as illustrated) and second segments 224a-224b (e.g., the upper segments as illustrated). The overlap splices 220a-220b in different sliced layers may be spatially staggered relative to each other.

The first segments 222a-222b are shown as dashed lines. The dashed lines generally highlight where the layup heat <NUM> is absent during the lamination of the tows 208a-214b. The layup heat <NUM> is absent between the first segments 222a-222b and the second segments 224a-224b to prevent the tackiness from being established inside the overlap splices 220a-220b. The layup heat <NUM> may also be absent between adjacent overlap splices 220a-220b within the same sliced layers.

The layup heat <NUM> may be absent in specific areas between other sliced layers. In various embodiments, the layup heat <NUM> may be absent from areas between the first segments 222a-222b and the corresponding -<NUM>-degree tows 212a-212b (e.g., below the overlap splices 220a-220b as illustrated). The laser light <NUM> may also be switched off in areas between the second segments 224a-224b and the corresponding +<NUM>-degree tows 208b-208c (e.g., above the overlap splices 220a-220b as illustrated).

Referring to <FIG>, an enlarged partial sectional view schematic diagram of an example curving of the intermediate component <NUM> is shown in accordance with an exemplary embodiment. After the intermediate component <NUM> has been fabricated on the stationary form <NUM>, the pick-and-place machine <NUM> may pick the intermediate component <NUM> off of the stationary form <NUM>, rotate the intermediate component <NUM> such that the second side <NUM> is facing the curved tool <NUM>, and place the intermediate component <NUM> onto the curved tool <NUM>. <FIG> generally shows the intermediate component <NUM> rotated clockwise relative to <FIG> such that the left side of <FIG> is now on the right side of <FIG>.

A pressure <NUM> may be applied to the intermediate component <NUM> to press the second side <NUM> of the composite component <NUM> against a contoured surface of the curved tool <NUM>. As the intermediate component <NUM> is draped onto the contoured surface of the curved tool <NUM>, the overlap splices 220a-220b in the hoop tows 214a-214b slip to compensate for the different arc lengths. The slippage is generally illustrated by arrows 226a-226b.

Estimated slip calculations for different numbers of slip layers (or plies), different numbers of hoop tows 214a-214b, different total thicknesses, and different numbers of overlap splices 220a-220b per layer is provided in Table I as follows:.

Referring to <FIG>, a schematic plan diagram of an example implementation of a composite component 200a is shown in accordance with an exemplary embodiment. The composite component 200a may be representative of the composite component <NUM>. A hoop layer 234a of the hoop tows 214a arranged in multiple courses 230a-230f is illustrated. Each course 230a-230f includes multiple tows 202a-202n. The courses 230a-230f may be deposited in a common direction.

Corresponding pairs of the courses 230a-230f form the overlap splices 220a-220c. For example, a start of the course 230b overlaps an end of the course 230a to form the overlap splice 220a. A start of the course 230d overlaps an end of the course 230c to form the overlap splice 220b, and so on. Some of the overlap splices, such as 220a and 220c, may be spatially aligned with each other in a planar surface of the hoop layer 234a. Some of the overlap splices, such as 230b, may be spatially staggered relative to other overlap splices, such as 230a.

During deposition of the hoop layer 234a on a substrate layer (e.g., a previously deposited layer of the -<NUM>-degree tows 212a-212n), the layup heat <NUM> may be applied in multiple target areas <NUM> to provide tackiness between the hoop layer 234a and the substrate layer. The target areas <NUM> generally cover the areas (or regions) outside of the overlap splices 220a-220c. Each overlap splice 220a-220c resides in a corresponding unexposed area <NUM> that is outside of the target areas <NUM>. The unexposed areas <NUM> are not subject to the layup heat <NUM> from the heater <NUM>. Therefore, the unexposed areas <NUM> do not acquire the tackiness between the overlapping courses 230a-230f. As the composite component 200a is draped onto the curved tool <NUM>, the lack of tackiness in the overlap splices 220a-220c allows the overlapping courses 230a-230f to slip relative to each other along the direction of the curvature.

Referring to <FIG>, a schematic plan diagram of an example implementation of another composite component 200b is shown in accordance with an exemplary embodiment. The composite component 200b may be representative of the composite components <NUM> and/or 200a. The hoop layer 234a of the hoop tows 214a with the multiple courses 230a-230f is illustrated. Each course 230a-230f includes multiple tows 202a-202n.

Adjacent courses 230a-230f may be deposited in opposite directions 154a-154b. For example, the courses 230a-230b may be deposited in a first direction 154a. The courses 230c-230d may be deposited in a second direction 154b. The courses 230e-230f may be deposited in the first direction 154a.

Referring to <FIG>, a schematic plan diagram of an example implementation of still another composite component 200c is shown in accordance with an exemplary embodiment. The composite component 200c may be representative of the composite components <NUM>, 200a and/or 200b. The hoop layer 234a of the hoop tows 214a organized in the multiple courses 230a-230f is illustrated. Each course 230a-230f includes multiple tows 202a-202n. Every other course 230a-230f is deposited in opposite directions 154a-154b.

The target areas <NUM> receiving the layup heat <NUM> may be controlled while the additional layer 234b is being formed to avoid warming the hoop layer 234a (and optionally the additional layer 234b) where the additional layer 234b crosses the overlap splices 220a-220c. Other portions of the additional layer 234b are inside the target areas <NUM> to obtain the tackiness between the additional layer 234b and the hoop layer 234a. In the example, the tows 208b in the additional layer 234b are shown in the unexposed areas <NUM> corresponding to the overlap splices 220b-220c in the hoop layer 234a. The absence of the tackiness between the hoop layer 234a and the additional layer 234b around the overlap splices 220a-220c generally reduces shear of the additional tows 208b when the overlap splices 220a-220c are stretched by the curved tool <NUM>. The reduced shear may avoid buckling of the additional tows 208b.

Referring to <FIG>, a schematic plan diagram of an example implementation of yet another composite component 200d is shown in accordance with an exemplary embodiment. The composite component 200d may be representative of the composite components <NUM>, 200a, 200b, and/or 200c. The hoop layer 234a of the hoop tows 214a and the additional layer 234b of additional tows 208b is illustrated. The hoop layer 234a may include the overlap splices 220a-220c. The additional layer 234b may include additional overlap splices 220d-220n. The additional layer 234b may be deposited in a third direction 154c.

The target areas <NUM>/unexposed areas <NUM> may be controlled to avoid warming the additional layer 234b over the overlap splices 220a-220c in the hoop layer 234a. The target areas <NUM>/unexposed areas <NUM> may also be controlled to avoid warming the overlap splices 220d-220n formed in the additional layer 234b. Therefore, the overlap splices 220d-220n may also slip when the composite component 200d is draped on the curved tool <NUM>. In various embodiments, the overlap splices 220d-220n may help accommodate complex contours that curve in multiple dimensions.

Referring to <FIG>, a schematic front view diagram of an example implementation of a fuselage section <NUM> of a vehicle or object <NUM> is shown in accordance with an exemplary embodiment. In the example, the vehicle/object <NUM> may be an aircraft. The fuselage section <NUM> include multiple (e.g., <NUM>) stabilizer loft areas 174a-174d. A radius of curvature may approach <NUM> inches throughout the stabilizer loft areas 174a-174d. Other radii of curvature may be implemented to meet the design criteria of a particular application.

Referring to <FIG>, a schematic perspective diagram of an example portion of the fuselage section <NUM> of the vehicle/object <NUM> is shown in accordance with an exemplary embodiment. Composite components 200e-<NUM> may be mounted in the stabilizer loft areas 174a-174d. Each composite component 200e-<NUM> may be representative of the composite components <NUM>, 200a, 200b, 200c, and/or 200d. In various embodiments, the composite components 200e-<NUM> may be thicker than the surrounding composite panels to accommodate higher localized stresses. The overlap splices 220a-220n in the composite components 200e-<NUM> generally allow for the formation of fewer wrinkles when the composite components 200e-<NUM> are bent on the curved tool <NUM>.

Referring to <FIG>, a schematic cross-section diagram of an example slice through the composite component <NUM> is shown in accordance with an exemplary embodiment. A thickness of the composite component <NUM> generally varies from many (e.g., <NUM>) layers (or plies P) to several (e.g., <NUM>) layers. The layers may include the various tows 208a-208n, 210a-210n, 212a-212n, and 214a-214n. Cover layers 232a-232b may be included around the tows 208a-214n.

In the example, the composite component <NUM> has multiple layers of the hoop tows 214a-214n. A pattern of the layers may be interleaved in the example. In some embodiments, various layers may be repeated on adjoining layers. In other embodiments, the pattern of the layers may be symmetrical. In other embodiments, the pattern of the layers may be asymmetrical. Other numbers of layers and/or other patterns of the layers may be implemented to meet the design criteria of a particular application.

Referring to <FIG>, an enlarged partial sectional view schematic diagram of an example composite component 200i is shown in accordance with an exemplary embodiment. The composite component 200i may be representative of various embodiments of the composite components <NUM>-<NUM>. The composite component 200i includes two types of layers, multiple <NUM>-degree tows 210a-210e and multiple hoop tows 214a-<NUM>.

In the example embodiment, multiple (e.g., eight illustrated) overlap splices are created in the hoop tows 214a-<NUM> and are aligned in the direction of the curvature. Each hoop tow 214a-<NUM> includes one or more of the overlap splices configured to slip in the same direction. The overlap splices in different sliced layers may be spatially staggered relative to each other. Some of the hoop tows 214a-<NUM> may form adjoining layers (e.g., 214a-214b, 214d-214e, and 214f-<NUM>). Other hoop tows 214a-<NUM> (e.g., 214c) may be surrounded by the <NUM>-degree tows 210a-210e (e.g., 210b-210c). Other sequences of tows, other numbers of the different types of tows, and/or other total numbers of the tows may be implemented to meet a design criteria of a particular application.

Referring to <FIG>, a flow diagram of an example implementation of a method <NUM> for contour forming in a fiber placement system is shown in accordance with an exemplary embodiment. The method (or process) <NUM> may be implemented by the manufacturing system <NUM>. The method generally includes a step <NUM>, a step <NUM>, a step <NUM>, a step <NUM>, a step <NUM>, a step <NUM>, a step <NUM>, a step <NUM>, a step <NUM>, a step <NUM>, a step <NUM>, and a step <NUM>. The sequence of steps is shown as a representative example. Other step orders may be implemented to meet the criteria of a particular application.

In the step <NUM>, the carrier <NUM> may be placed on the stationary form <NUM>. Multiple sliced layers 234a-234b are painted on the carrier <NUM> (on the stationary form <NUM>) by the automated-fiber-placement system <NUM> to create the composite component <NUM> in the step <NUM>. The sliced layers 234a-234b include multiple hoop tows 214a-214n. One or more overlap splices 220a-220n are formed in each of the plurality of hoop tows 214a-214n. As the hoop tows 214a-214n are being deposited, the layup heat <NUM> is applied in the step <NUM> to multiple target areas <NUM> on the sliced layers during the painting. The target areas <NUM> are spatially arranged to permit a slippage in the overlap splices 220a-220d when the composite component <NUM> is draped on the curved tool <NUM>.

A check is performed in the step <NUM> to determine if more courses should be laid. If more courses are to be deposited, the method <NUM> returns to the step <NUM> to paint the additional courses. If the specified courses in a current layer have already been deposited, the method <NUM> continues with the step <NUM>.

A check is performed in the step <NUM> to determine if more layers should be added. If more layers are specified, the method <NUM> returns to the step <NUM> to paint the additional layers. If the layers have already been deposited, the method <NUM> continues with the step <NUM>.

In the step <NUM>, the pick-and-place machine <NUM> drapes the composite component <NUM> on the curved tool <NUM> with the hoop tows 214a-214n oriented perpendicular to the axis of curvature <NUM> of the curved tool <NUM>. The pressure <NUM> is applied to the carrier <NUM> to conform the composite component <NUM> to the contours of the curved tool <NUM>. The carrier <NUM> is removed from the composite component <NUM> in the step <NUM>. The cover layers 232a-232b may be applied in the step <NUM> to continue fabrication of the composite component <NUM>. The cover layers 232a-232b generally provided for protection, for example lightning strike protection and/or ultraviolet light protection.

An application of cure bagging materials may be performed in the step <NUM> to protect the composite component <NUM> during a subsequent cure. The curved composite component <NUM> is subsequently moved into the autoclave <NUM>. While in the autoclave <NUM>, the curing heat <NUM> is applied to the composite component <NUM> in the step <NUM> (after the composite component has been contoured by the curved tool <NUM>). The curing heat <NUM> inhibits a further slippage in the overlap splices 220a-220n. In the step <NUM>, the composite component <NUM> is shaped to specified dimensions. In the step <NUM>, the finished composite component <NUM> may be installed on the vehicle/object <NUM>.

Embodiments of the present disclosure may result in a reduction in tooling cost for pick and place since contoured forms are replaced by the flat stationary form <NUM>. The layer stack up with overlap splicing generally improves drapability of the flat intermediate components <NUM>. A head pressure of the automated-fiber-placement system <NUM> on subsequent tows may impact the available slippage. Therefore, a head pressure during open laydown may be reduced, a hardness of the roller may be tailored and/or less-ideally segmented rollers may be utilized in the fabrication. A tensioning on the tows may be reduced in the area of the adjacent plies to impact available slippage. In some situations, a temperature of the materials may also be adjusted to control the slippage during the laydown. Subsequent laydown course directions may be tailored to avoid roll-over wraps. In various embodiments, the processing may be done in a "fish scale" method in order to prevent fold-over tows and/or lift-off tows. The method and/or system may result in cost saving and/or weight savings.

Claim 1:
A method (<NUM>) for contour forming in a fiber-placement system, the method comprising:
depositing (<NUM>) a plurality of sliced layers on a stationary form to create a composite component, wherein the plurality of sliced layers includes a plurality of hoop tows, and one or more overlap splices are formed in each of the plurality of hoop tows;
applying (<NUM>) a layup heat to a plurality of target areas on the plurality of sliced layers during the depositing, wherein the plurality of target areas is spatially arranged to permit a slippage in the plurality of overlap splices when the composite component is draped on a curved tool;
draping (<NUM>) the composite component on the curved tool with the plurality of hoop tows oriented perpendicular to an axis of curvature of the curved tool; and
applying (<NUM>) a curing heat to the composite component after the composite component has been bent into a contoured shape by the curved tool, wherein the curing heat inhibits a further slippage in the plurality of overlap splices;
wherein each of the plurality of overlap splices includes a non-heated area in which a first segment is overlaid with a second segment, and the non-heated area is outside of the plurality of target areas to permit the slippage.