Curved composite frames and method of making the same

• US 9,096,305 B2
• Filed: 11/26/2012
• Issued: 08/04/2015
• Est. Priority Date: 04/17/2008
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Kehrl, David J., Johnson, Kent E., McCarville, Douglas A.
• Primary Examiner(s): Dinh, Tien
• Assistant Examiner(s): Green, Richard R
• Application Number:
  US13/684,988
• Publication Number:
  US 20130084434A1
• Time in Patent Office: 981 Days
• Field of Search: 244/117.R, 244/119, 244/131, 244/132
• US Class Current: 1/1
• 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 aircraft frame comprising a composite laminate comprising multiple plies that form a web and an outer chord such that:

the outer chord comprises a first tailored axial modulus and a cutout through which a stringer may extend;

at least one laminate ply in the multiple plies comprises continuous reinforcing fibers configured to extend an entire length of the curved aircraft frame substantially tangent to a hoop direction of the curved aircraft frame at substantially all points along a curvature of the curved aircraft frame;

a gauge of the outer chord comprises a first quantity of plies;

a first section of the web comprises a second tailored axial modulus and a first gauge of the web comprising a second quantity of plies;

a second section of the web comprises a third tailored axial modulus and a second gauge of the web comprising a third quantity of plies;

the first quantity of plies varies from the second quantity of plies and the third quantity of plies via at least one tow in at least one ply layer comprising a drop;

the second quantity of plies exceeds the third quantity of plies; and

the first tailored axial modulus, the second tailored axial modulus, and the third tailored axial modulus each differ with respect to each based upon a desired compression loading, radial stiffness, and shear load transfer capability desired for each of the outer chord, the first section of the web, and the second section of the web, such that at least one laminate ply in the multiple plies comprises substantially evenly displaced discontinuities.

2. The curved aircraft frame of claim 1, wherein the composite laminate comprises a one-piece, unitary construction and a cross section comprising at least one of a Z-shape and a J-shape, such that the Z shape comprises an inner chord comprising a fourth quantity of plies comprising a gauge of the inner chord, the fourth quantity of plies varying from:

the first quantity of plies, and the second quantity of plies.

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

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

the outer chord adapted to be fastened to an aircraft skin, the outer chord being integrally formed with the web and extending laterally outward from a second end of the web in a first direction being opposite to a second direction of lateral extension of the inner chord, and the first tailored axial modulus being based upon a desired fastener bearing.

4. The curved aircraft frame of claim 3, wherein at least certain of the multiple 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 curved aircraft frame of claim 1, wherein:

the plies each include a polymer matrix, and

the fibers include carbon fibers held within an epoxy matrix.

6. The curved aircraft frame of claim 1, further comprising the composite laminate being a vacuum formed multi-ply composite laminate.

7. The aircraft frame of claim 1, further comprising a pad-up configured with a tailored axial modulus based upon 0°

fibers being tangent to the hoop direction at substantially all points and laminate orientation percentages.

8. The curved aircraft frame of claim 1, further comprising:

the first section of the web comprising a pad-up, the pad-up being integrated within the web and comprising the first gauge of the web; and

each of the multiple plies comprising a same resin and a same fiber as every other ply in the multiple plies, and each ply formed as a pre-preg tow in the form of a slit tape.

9. An aircraft fuselage frame, configured as one-piece in a curved shape and comprising:

multiple ply layers;

a web comprising;

a first end;

a second end;

a first section;

a second section;

a first gauge comprising a first ply buildup; and

a first tailored axial modulus, such that the first section comprises a pad-up integrated within the web, the pad-up comprising a greater number of ply layers and a greater gauge than comprise the second section of the web;

an inner chord, on the first end of the web, comprising a second ply buildup and a second tailored axial modulus;

an outer chord, on the second end of the web, comprising a third ply buildup and a third tailored axial modulus; and

the web, the inner chord, and the outer chord being integrally formed and comprising laminated plies comprising fiber reinforced resin such that;

each of the first ply buildup, the second ply buildup, and the third ply buildup differ with respect to each other at least via at least one tow in at least one ply layer in the multiple ply layers comprising a drop; and

each of the first tailored axial modulus, the second tailored axial modulus, and the third tailored axial modulus differ with respect to each other based upon a desired compression loading, radial stiffness, and shear load transfer capability desired for each of the inner chord, the outer chord, and the web, such that at least one ply in the multiple ply layers comprises substantially evenly displaced discontinuities.

10. The aircraft fuselage frame of claim 9, wherein the outer chord is adapted to be fastened to a fuselage outer skin and the pad-up comprises a 0°

degree fiber content of 40-50%.

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

12. The aircraft fuselage frame of claim 9, wherein at least one of:

the web, the inner chord, and the outer chord comprise plies comprising continuous unidirectional reinforcing fibers configured to extend an entire length of the aircraft fuselage frame and that lie substantially tangent to a curvature of the frame.

13. The aircraft fuselage frame of claim 9, wherein each of:

the web, the inner chord and the outer chord comprise plies comprising continuous unidirectional reinforcing fibers configured to extend an entire length of the aircraft fuselage frame and that lie substantially tangent to a curvature of the frame, and at least one ply buildup comprises a partial ply.

14. The aircraft fuselage frame of claim 9, such that the laminate comprises:

unitary construction, and a cross section shape being at least one of;

of a Z, and a J.

15. The aircraft fuselage frame of claim 9, further comprising the pad-up configured with a tailored axial modulus based upon 0°

fibers being tangent to a hoop direction of the aircraft fuselage frame at substantially all points and laminate orientation percentages.

16. The aircraft fuselage frame of claim 9, wherein the outer chord comprises a cutout section configured to accommodate a stringer.

17. The aircraft fuselage frame of claim 9, wherein the laminated plies comprise a layup of fiber reinforced resin plies such that a quantity of the fiber reinforced resin plies varies along a length of the laminated plies.

18. A curved composite fuselage frame, comprising:

a one-piece, multi-ply laminate comprising a cross section comprising;

a web;

an inner chord, and

an outer chord comprising a cutout through which a stringer may extend, the outer chord configured as an integrated shear tie fastenable to a skin on a fuselage, the inner and outer chords being respectively positioned on opposite ends of the web and extending outwardly from the web in opposite directions, such that the multi-ply laminate comprises fiber reinforced resin plies configured to extend an entire length of the curved composite fuselage frame such that a quantity of the fiber reinforced resin plies varies-along a length of the one-piece, multi-ply laminate via at least one tow in at least one ply comprising a drop; and

such that a respective gauge for each of;

the web, the inner chord, and the outer chord each comprise a unique ply buildup and a uniquely tailored axial modulus based upon a desired compression loading, radial stiffness, and shear load transfer capability for each of the web, the inner chord, and the outer chord; and

the web comprising a pad-up comprising a first section of the web, the first section being integrated within the web and comprising more ply layers and a greater gauge than comprise a second section of the web, such that at least one ply in the multi-ply laminate comprises substantially evenly displaced discontinuities.

19. The curved composite fuselage frame of claim 18, further comprising the cross section comprising a shape substantially being one of:

a Z, and a J, and the tailored axial modulus of the outer chord being based upon a desired fastener bearing.

20. The composite fuselage frame of claim 18, wherein each of:

the web, the inner chord and the outer chord comprise plies comprising continuous unidirectional reinforcing fibers that lie substantially tangent to a curvature of the frame and at least one ply buildup comprises a partial ply.

21. The curved composite fuselage frame of claim 18, such that at least certain plies extend substantially continuously through the web, the inner chord and the outer chord in the direction of a curvature of the frame.

22. The curved composite fuselage frame of claim 18, further comprising the pad-up configured with a tailored axial modulus based upon laminate orientation percentages.

23. A composite frame for an aircraft fuselage, the composite frame being one-piece and comprising:

a multi-ply composite laminate, each ply comprising an angular fiber orientation relative to an adjacent ply, defining;

a web, an inner chord, and an outer chord, configured as an integrated shear tie to connect the composite frame to an outer skin on the aircraft fuselage;

the outer chord configured to extend laterally upward from a first end of the web, and comprise a first tailored axial modulus and a cutout through which a stringer may extend;

the inner chord configured to extend laterally outward from a second end of the web in a direction opposite of that of the outer chord, and comprise a second tailored axial modulus;

the web comprising a pad-up comprising a first section of the web, the first section being integrated within the web and comprising more ply layers and a different gauge than comprise a second section of the web, such that the first section comprises a third tailored axial modulus, and the second section comprises a fourth tailored axial modulus; and

each of;

the web, the inner chord, and the outer chord comprising plies comprising continuous reinforcing fibers, such that a gauge of the web, a gauge of the inner chord, and a gauge of the outer chord each comprise a respective unique quantity of ply layers;

at least certain of the plies comprise reinforcing fibers oriented substantially tangent to a curvature of the frame substantially along an entire length of the curvature, and at least one tow in at least one ply comprising a drop;

such that the first tailored axial modulus, the second tailored axial modulus, the third tailored axial modulus, and the fourth tailored axial modulus each differ from one another based upon a desired compression loading, radial stiffness, and shear load transfer capability for each of the first section, the second section, the inner chord, and the outer chord, such that at least one ply in the multi-ply laminate comprises substantially evenly displaced discontinuities.

24. The composite frame of claim 23, such that 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.

25. The composite frame of claim 23, such that the web, inner chord, and outer chord comprise a shape substantially of at least one of:

a Z, and a J.