CURVED COMPOSITE FRAMES AND METHOD OF MAKING THE SAME

• US 20110097554A1
• Filed: 05/10/2010
• Published: 04/28/2011
• Est. Priority Date: 04/17/2008
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Johnson, Kent E., Kehrl, David J., McCarville, Douglas A.
• Granted Patent: US 8,349,105 B2
• Time in Patent Office: Days
• US Class Current: 428/174
• CPC Class Codes: B29C 70/207 arranged in parallel planes of fibres crossing at substantial angles
• 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 99/0003 Producing profiled members, e.g. beams
• CPC Class Codes: B29L 2031/3082 Fuselages
• CPC Class Codes: B64C 1/061 Frames
• CPC Class Codes: B64C 1/064 Stringers; Longerons
• CPC Class Codes: B64C 2001/0072 from composite materials
• CPC Class Codes: Y02T 50/40 Weight reduction
• CPC Class Codes: Y10T 29/49622 Vehicular structural member making
• CPC Class Codes: Y10T 29/49801 Shaping fiber or fibered material
• CPC Class Codes: Y10T 29/49826 Assembling or joining
• CPC Class Codes: Y10T 428/24628 Nonplanar uniform thickness material

Abstract

A curved composite aircraft frame comprises a multi-ply composite laminate having a generally Z-shaped cross section. At least certain of the laminate plies include unidirectional reinforcing fibers that are substantially tangent at substantially all points along the curvature of the frame.

Claims

1. A curved composite aircraft frame, comprising:

a multi-ply composite laminate wherein at least certain of the laminate plies include unidirectional reinforcing fibers that are substantially tangent at substantially all points along the curvature of the frame.

2. The frame of claim 1, wherein the laminate is of a one-piece, unitary construction and has a cross section in the shape of one of a Z and a J.

3. The frame of claim 1, wherein the laminate includes:

a web,

an inner chord integrally formed with the web and extending laterally outward from one end of the web,

an outer chord adapted to be fastened to a aircraft outer skin, the outer chord being integrally formed with the web and extending laterally outward from the other end of the web in a direction opposite of that of the inner chord.

4. The frame of claim 3, wherein the at least certain plies extend substantially continuously through the web, the inner chord and the outer chord in the direction of the curvature of the frame.

5. The frame of claim 1, wherein:

the plies each include a polymer matrix, and

the fibers include carbon fibers held within the epoxy matrix.

6. The frame of claim 1, wherein each of the plies has a fiber orientation that is aligned within a polar coordinate reference system defining the curvature of the frame.

7. A curved, one-piece aircraft fuselage frame, comprising:

a web having first and second ends;

an inner chord on the first end of the web; and

an outer chord on the second end of the web,

the web, inner chord and outer chord being integrally formed of laminated plies of fiber reinforced resin and having a cross section generally in the shape of one of a Z and a J.

8. The frame of claim 7, wherein the outer chord is adapted to be fastened to a fuselage outer skin.

9. The frame of claim 7, wherein at least certain of the plies extend substantially continuously through the web, the inner chord and the outer chord.

10. The frame of claim 7, wherein at least one of the web, the inner chord and the outer chord include plies having unidirectional reinforcing fibers that lie substantially tangent to the curvature of the frame.

11. The frame of claim 7, wherein each of the web, the inner chord and the outer chord includes plies having unidirectional reinforcing fibers that lie substantially tangent to the curvature of the frame.

12. The frame of claim 7, wherein each of the web, the inner chord and the outer chord includes plies having unidirectional reinforcing fibers that lie substantially tangent to radial coordinates in a polar coordinate system defining the curvature of the frame.

13. The frame of claim 7, wherein the web includes a pad-up section of ply doublers for reinforcing the web.

14. A curved composite fuselage frame having an integrated shear tie, comprising:

a one-piece, multi-ply laminate having a cross section defining a web, an inner chord and an outer chord adapted to be fastened to a skin on the fuselage, the inner and outer chords being respectively positioned on opposite ends of the web and extending outwardly from the web in opposite directions.

15. The frame of claim 14, wherein the laminate has a cross section substantially in the shape of one of a Z and a J.

16. The frame of claim 14, wherein each of the web, the inner chord and the outer chord includes unidirectional reinforcing fibers that are substantially tangent at substantially all points along the curvature of the frame.

17. A method of fabricating a curved, one-piece composite frame for an aircraft fuselage, comprising:

assembling a layup of fiber reinforced resin plies using a polar coordinate system defining the curvature of the frame, including orienting unidirectional reinforcing fibers in at least certain of the plies substantially tangent to the curvature of the frame; and

forming the layup into a shape including a web, an inner chord and an outer chord.

18. The method of claim 17, wherein orienting the unidirectional reinforcing fibers substantially tangent to the curvature of the frame is performed using a computer controlled automatic fiber placement machine.

19. The method of claim 17, wherein forming the layup includes bending edges of the layup over a tool.

20. A method of fabricating a curved composite fuselage frame, comprising:

assembling a layup of composite plies each having unidirectional reinforcing fibers, including arranging at least certain of the plies such that their reinforcing fibers are substantially tangent at substantially all points along the curvature of the frame; and

forming the layup on a curved tool into a cross sectional shape having a web, and oppositely extending chords respectively on opposite ends of the web.

21. The method of claim 20, wherein arranging certain of the plies is performed using a computer controlled automatic fiber placement machine.

22. The method of claim 20, wherein assembling the plies is performed using a polar coordinate reference system that defines the curvature of the frame.

23. The method of claim 20, wherein forming the layup is performed by bending edges of the layup over a tool.

24. A method of fabricating a curved one-piece frame for an aircraft having an integrated shear tie, comprising:

defining the curvature of the frame using a polar coordinate reference system;

assembling a composite layup, including—

laying up multiple plies of composite material including resin reinforced with unidirectional fibers, each of the plies having an angular fiber orientation, and

using the polar coordinate reference system to orient each of the plies relative to the curvature of the frame as the plies are being laid up, including using a computer controlled automatic fiber placement machine to laydown composite fibers on the tool such that the fibers are substantially tangent to the curvature of the frame at substantially all points along the curvature;

placing the layup on a tool having first, second and third tool surfaces;

vacuum bag forming the layup on the tool, including drawing the layup down onto the first tool surface to form a inner chord, drawing the layup down on the second surface to form an outer chord, and drawing the layup down on the third surface to form a web connecting the inner and outer chords; and

curing the formed layup.

25. A one-piece composite frame for an aircraft fuselage having an integrated shear tie connecting the frame to an outer skin on the fuselage, comprising:

a multi-ply composite laminate having a substantially Z-shaped cross section defining a web, an inner chord and an outer chord, the outer chord being adapted to be fastened to the skin and extending laterally upward from one end of the web, the inner chord extending laterally outward from the other end of the web in a direction opposite of that of the outer chord,

each of the web, the inner chord and the outer chord including plies having unidirectional reinforcing fibers oriented within a polar coordinate reference system defining the curvature of the frame,

at least certain of the plies including reinforcing fibers oriented substantially tangent to the frame curvature substantially along the entire length of the curvature.