METHOD FOR PRODUCING CONTOURED COMPOSITE STRUCTURES AND STRUCTURES PRODUCED THEREBY

• US 20090263618A1
• Filed: 03/02/2009
• Published: 10/22/2009
• Est. Priority Date: 04/17/2008
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: McCarville, Douglas A., Guzman, Juan C., Sweetin, Joseph L.
• Granted Patent: US 8,932,423 B2
• Time in Patent Office: Days
• US Class Current: 428/113
• CPC Class Codes: B29C 70/304 In-plane lamination by juxtaposing or interleaving of plies, e.g. scarf joining
• CPC Class Codes: B29C 70/38 Automated lay-up, e.g. using robots, laying filaments according to predetermined patterns application heads for tyres B29D30/28
• CPC Class Codes: B29D 99/0007 having a variable cross-section
• CPC Class Codes: B29L 2031/3082 Fuselages
• CPC Class Codes: Y10T 156/1002 with permanent bending or reshaping or surface deformation of self sustaining lamina
• CPC Class Codes: Y10T 156/1026 with slitting or removal of material at reshaping area prior to reshaping
• CPC Class Codes: Y10T 156/1028 by bending, drawing or stretch forming sheet to assume shape of configured lamina while in contact therewith
• CPC Class Codes: Y10T 156/1031 with preshaping of lamina
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing
• CPC Class Codes: Y10T 156/108 Flash, trim or excess removal
• CPC Class Codes: Y10T 428/24124 Fibers

Abstract

A contoured composite structure is fabricated by laying up a composite charge that includes at least one ply formed by uni-directional fiber pre-preg ply segments having substantially constant widths. The ply segments are placed in side-by-side, overlapping relationship with their longitudinal centerlines aligned in a polar orientation related to the contour of the structure. The charge is formed into the shape of the structure and cured.

Claims

1. A method of fabricating a contoured composite structure, comprising:

laying up a composite charge, including laying up at least one ply of uni-directional fiber pre-preg ply segments having substantially constant widths, including placing the ply segments in side-by-side, overlapping relationship and aligning longitudinal centerlines of the ply segments in a polar orientation related to the contour of the structure;

forming the composite charge substantially into the shape of the structure; and

curing the shaped charge.

2. The method of claim 1, wherein placing the ply segments in side-by-side relationship includes maintaining a substantially constant amount of overlap between the ply segments as the ply segments are being placed.

3. The method of claim 1, wherein laying up the ply includes cutting the ply segments from a length of composite tape.

4. The method of claim 3, wherein cutting the tape includes cutting the length of tape at an angle generally matching the contour of the structure.

5. The method of claim 1, wherein gaps are created between adjacent ones of the ply segments due to the polar orientation of the ply segments, and laying up the ply further includes substantially minimizing the gaps.

6. The method of claim 1, further comprising trimming edges of the ply segments to generally match the contour of the structure.

7. The method of claim 1, wherein placing the ply segments and aligning the centerlines is performed by an automatically controlled tape application head.

8. The method of claim 1, wherein laying up the ply includes producing the ply segments by cutting segments from a length of composite fiber tape.

9. A contoured composite structure fabricated by the method of claim 1.

10. A method of fabricating a contoured composite structure, comprising:

producing a composite charge using an automatically controlled tape placement head, including using the head to place each of a plurality of substantially constant width prepreg tape segments in side-by-side, overlapping relationship on a substrate and to align the tape segments in a polar orientation related to the contour of the structure;

forming the charge substantially into the shape of the structure; and

curing the shaped charge.

11. The method of claim 10, wherein using the head to place the ply segments include moving the head across a substrate and cutting a length of composite tape into segments.

12. The method of claim 11, wherein cutting the length of tape includes cutting the length of tape at an angle generally matching the contour of the structure.

13. The method of claim 10, wherein using the head to align the tape segments includes aligning the longitudinal centerlines of the tape segments along radial coordinates in a polar coordinate system.

14. The method of claim 10, wherein using the head to place the tape segments includes using the head to maintain a substantially constant amount of overlap between the tape segments as the tape segments are being placed.

15. The method of claim 10, wherein gaps are created between adjacent ones of the tape segments due to the polar orientation of the tape segments, and using the head to place the tape segments includes substantially minimizing the gaps.

16. The method of claim 10, further comprising trimming edges of the tape segments to generally match the contour of the structure.

17. A contoured composite structure fabricated by the method of claim 10.

24. A composite frame section for a vehicle formed by the method of claim 10.

18. A method of forming a contoured composite frame section, comprising:

forming a flat stack of fiber reinforced, pre-preg plies, including individually placing substantially constant width composite fiber tape segments in side-by-side, overlapping relationship and in a polar orientation related to the contour of the structure;

forming a first leg of the frame section; and

,

compacting and curing the formed stack.

19. The method of claim 18 wherein forming the first leg of the frame section is performed by bending the stack along a first edge of the stack.

20. The method of claim 19, further comprising:

forming a second leg of the frame section by bending the stack along a second edge of the stack.

21. The method of claim 18, wherein individually placing the tape segments includes trimming ends of the tape segments to generally match the contour of the structure.

22. The method of claim 18, wherein:

individually placing the fiber segments is performed using an automatically controlled tape placement head, and

using the head to individually place the tape segments includes aligning the longitudinal centerlines of the tape segments along radial coordinates in a polar coordinate system.

23. The method of claim 18, wherein using the head to individually place the tape segments includes maintaining a substantially constant amount of overlap between the tape segments as the tape segments are being placed.

25. A method of fabricating a multi-leg curved composite frame section for an aircraft, comprising:

forming a frame section by

using an automatic fiber tape placement machine to form a flat stack of composite plies, including forming at least certain of the plies by automatically placing segments of constant width unidirectional fiber pre-preg tape in side-by-side overlapping relationship along the length of the stack in which the longitudinal centerlines of the tape segments are generally aligned with radial coordinates in a polar coordinate system defining the curvature of the frame section, and forming other of the plies by automatically placing pre-preg unidirectional tape along the length of the stack,

forming spaced apart cut-outs in the flat stack along a first edge of the flat stack,

forming a first leg of the frame section by using drape forming to bend a second edge of the flat stack over a tool,

forming a second leg of the frame section by using hot drape forming to bend the first edge of the flat stack over a tool;

placing the frame section on a tool;

vacuum bagging the frame section and the tool; and

,

compacting and curing the frame section.