Method of manufacturing curved composite structural elements

• US 20060249868A1
• Filed: 05/03/2005
• Published: 11/09/2006
• Est. Priority Date: 05/03/2005
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Friddell, Stephen Douglas, Modin, Andrew E., Harris, Christopher G., Brown, Todd A.
• Granted Patent: US 8,632,653 B2
• Time in Patent Office: Days
• US Class Current: 264/163
• CPC Class Codes: B29C 43/12 using bags surrounding the moulding material or using membranes contacting the moulding material
• CPC Class Codes: B29C 70/342 using isostatic pressure
• CPC Class Codes: B29C 70/382 Automated fiber placement [AFP]
• CPC Class Codes: B29C 70/386 Automated tape laying [ATL]
• CPC Class Codes: B29C 70/48 and impregnating the reinforcements in the closed mould, e.g. resin transfer moulding [RTM] , e.g. by vacuum
• CPC Class Codes: B29C 70/545 Perforating, cutting or machining during or after moulding
• CPC Class Codes: B29K 2063/00 Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2307/00 Use of elements other than metals as reinforcement
• CPC Class Codes: B29K 2309/10 Mica
• CPC Class Codes: B29L 2031/003 having a profiled transverse cross-section
• CPC Class Codes: B29L 2031/3082 Fuselages
• CPC Class Codes: B32B 38/0004 Cutting, tearing or severing, e.g. bursting; Cutter details cutting in general B26D; laminating combined with punching or perforating B32B38/04; removing all or part of the layers B32B38/10; cutting in combination with laying up and registration B32B38/185 takes precedence
• CPC Class Codes: B32B 38/04 Punching, slitting or perforating
• CPC Class Codes: B32B 38/1808 characterised by the laying up of the layers
• CPC Class Codes: B32B 38/1816 Cross feeding of one or more of the layers
• CPC Class Codes: B32B 38/1858 using vacuum
• CPC Class Codes: Y10T 156/1002 with permanent bending or reshaping or surface deformation of self sustaining lamina
• CPC Class Codes: Y10T 156/1051 by folding
• CPC Class Codes: Y10T 156/1067 Continuous longitudinal slitting
• CPC Class Codes: Y10T 156/1075 : of plural laminae from single stock and assembling to each other or to additional lamina
• CPC Class Codes: Y10T 156/108 : Flash, trim or excess removal

Abstract

A method of manufacturing curved composite structural elements can include fabricating a web ply in a flat curve over a removable substrate and laying up the ply on a curved web surface of a manufacturing tool. The method also can include laying up a diagonal ply with fibers oriented at +/−45° from the centerline of the web surface. The method further can include cutting a unidirectional composite tape into segments and laying up the tape segments to form a cross ply with a fiber orientation normal to the centerline of the web surface. One or both edges of the diagonal and cross plies may be folded over one or two sides of the manufacturing tool to form one or two flange surfaces. Additionally, a cap ply can be laid up on one or both flange surfaces using composite tape. The structural element layup can then be inspected and any excess composite material can be trimmed away.

Claims

1. A method of fabricating a composite curved ply, comprising the steps of:

placing a plurality of contiguously adjoined strips of a composite material in the shape of a planar arc to form a ply, wherein the composite material includes a plurality of fibers comprising a general fiber orientation, and the fiber orientation of each of the strips is substantially aligned along the full length of the planar arc; and

trimming an edge of the ply.

2. The method of claim 1, wherein each strip includes a slit cut from a composite unidirectional tape impregnated with a resin.

3. The method of claim 1, wherein each strip includes a strand of a composite tow impregnated with a resin.

4. The method of claim 1, further comprising placing the strips on a removable substrate material.

5. The method of claim 1, further comprising laying up the ply on a manufacturing tool, the manufacturing tool including a curved surface in the shape of the planar arc such that the fiber orientation is substantially aligned with a longitudinal centerline of the curved surface.

6. A method of manufacturing a composite curved structural element, comprising the steps of:

laying up a curved composite web ply including a composite material on a manufacturing tool, the manufacturing tool including a curved surface in the shape of a planar arc, wherein the composite material comprises a plurality of fibers including a general fiber orientation, and the fiber orientation of the web ply is substantially aligned with a longitudinal centerline of the curved surface; and

curing the web ply.

7. The method of claim 6, further comprising the step of removing a substrate material from the web ply subsequent to the web ply being laid up on the tool.

8. The method of claim 6, further comprising the step of laying up a cap ply including a composite tape on a cap surface of the manufacturing tool that intersects the curved surface forming a corner between the cap surface and the curved surface, wherein the composite tape comprises a plurality of tape fibers including a general tape fiber orientation, and the tape fiber orientation is substantially aligned with a longitudinal centerline of the cap surface, and a splice is formed along the corner where the cap ply meets the web ply.

9. The method of claim 6, further comprising the step of laying up a diagonal ply over the curved surface.

10. The method of claim 6, further comprising the step of laying up a cross ply over the curved surface.

11. The method of claim 6, further comprising the step of sealing a composite curved structural element layup including the web ply on the manufacturing tool within a vacuum bag to remove trapped air from beneath and within the composite material.

12. The method of claim 6, further comprising the step of transferring a composite curved structural element layup including the web ply onto a second curved manufacturing tool having a shape of an opposite surface of the layup.

13. The method of claim 6, further comprising the step of inspecting a composite curved structural element layup including the web ply for defects.

14. The method of claim 6, further comprising the step of trimming a composite curved structural element layup including the web ply to remove excess material.

15. A method of manufacturing a composite curved structural element, comprising the steps of:

laying up a diagonal ply including a composite material on a manufacturing tool, the manufacturing tool including a curved surface in the shape of a planar arc, wherein the composite material comprises a plurality of fibers including a first fiber orientation and a second fiber orientation, and the first and second fiber orientations of the diagonal ply form angles with a tangent of a longitudinal centerline of the curved surface that are approximately constant at all points along the longitudinal centerline; and

curing the diagonal ply.

16. The method of claim 15, wherein the first and second fiber orientations are substantially perpendicular to each other, and the first and second fiber orientations of the diagonal ply form approximate 45-degree angles with a tangent of a longitudinal centerline of the curved surface at all points along the longitudinal centerline.

17. The method of claim 15, wherein the first and second fiber orientations of the diagonal ply form approximate 60-degree angles with a tangent of a longitudinal centerline of the curved surface at all points along the longitudinal centerline.

18. The method of claim 15, wherein the composite material comprises a dry form composite fabric.

19. The method of claim 15, wherein the composite material comprises a prepreg composite fabric impregnated with a resin.

20. The method of claim 15, wherein the composite material comprises a composite tape impregnated with a resin.

21. The method of claim 15, further comprising the steps of:

adhering an inner edge of the diagonal ply on an inner cap surface of the manufacturing tool, wherein the inner cap surface intersects the curved surface;

folding the diagonal ply over the curved surface of the manufacturing tool in order to form an inner corner between the inner cap surface and the curved surface; and

uniformly spreading the diagonal ply over the curved surface so as to avoid wrinkles in the composite material on the inner cap surface and on the curved surface.

22. The method of claim 15, further comprising the step of folding an outer edge of the diagonal ply over an outer cap surface of the manufacturing tool that intersects the curved surface in order to form an outer corner between the outer cap surface and the curved surface, so as to avoid wrinkles in the composite material on the outer cap surface.

23. The method of claim 15, further comprising the step of laying up a cross ply over the curved surface.

24. A method of manufacturing a composite curved structural element, comprising the steps of:

cutting a segment of a composite tape, wherein the composite tape includes a plurality of tape fibers having a general tape fiber orientation; and

laying up a cross ply including the tape segment on a manufacturing tool, the manufacturing tool including a curved surface in the shape of a planar arc, wherein the tape fiber orientation substantially forms a right angle with a tangent of a longitudinal centerline of the curved surface at all points along the longitudinal centerline.

25. The method of claim 24, further comprising the step of cutting the tape segment into a trapezoidal shape such that when laid up on the curved surface of the manufacturing tool a pair of nonparallel sides of the tape segment substantially forms right angles with the longitudinal centerline of the curved surface.

26. The method of claim 24, further comprising the step of cutting the tape segment into a modified funnel shape such that when laid up on the curved surface of the manufacturing tool a center pair of nonparallel sides of a center portion of the tape segment substantially forms right angles with the longitudinal centerline of the curved surface and an edge pair of parallel sides of an edge portion of the tape segment substantially forms right angles with a longitudinal cap centerline of a cap surface of the manufacturing tool, wherein the cap surface intersects the curved surface.

27. The method of claim 24, further comprising the steps of:

adhering an inner edge of the cross ply on an inner cap surface of the manufacturing tool, wherein the inner cap surface intersects the curved surface;

folding the cross ply over the curved surface of the manufacturing tool in order to form an inner corner between the inner cap surface and the curved surface; and

uniformly spreading the cross ply over the curved surface so as to avoid wrinkles in the composite material on the inner cap surface and on the curved surface, wherein the tape fiber orientation of the cross ply forms an approximate right angle with a tangent of a longitudinal centerline of the curved surface at all points along the longitudinal centerline.

28. The method of claim 24, further comprising the step of folding an outer edge of the cross ply over an outer cap surface of the manufacturing tool that intersects the curved surface in order to form an outer corner between the outer cap surface and the curved surface, so as to avoid wrinkles in the composite material on the outer cap surface.