Tubular members integrated to form a structure

• US 7,063,763 B2
• Filed: 02/13/2003
• Issued: 06/20/2006
• Est. Priority Date: 01/21/2000
• Status: Expired due to Fees

• Current Assignee: Chapman W. Cullen Jr
• Original Assignee: Chapman W. Cullen Jr
• Inventors: Chapman, W. Cullen Jr.
• Primary Examiner(s): Aftergut, Jeff H.
• Application Number:
  US10/366,606
• Publication Number:
  US 20030173460A1
• Time in Patent Office: 1,223 Days
• Field of Search: 156/169, 156/173, 156/175, 156/185
• US Class Current: 156/175
• CPC Class Codes: B29C 53/60 using internal forming surfaces, e.g. mandrels
• CPC Class Codes: B29C 53/821 Mandrels especially adapted for winding and joining
• CPC Class Codes: B29C 53/822 Single use mandrels, e.g. destructible, becoming part of the wound articles B29C53/825 takes precedence
• CPC Class Codes: B29C 70/32 on a rotating mould, former or core
• CPC Class Codes: B29D 24/004 the structure having vertical or oblique ribs
• CPC Class Codes: B29L 2031/3076 Aircrafts blades, propellers B29L2031/08
• CPC Class Codes: B64C 1/06 Frames; Stringers; Longerons ; Fuselage sections
• CPC Class Codes: B64C 2001/0072 from composite materials
• CPC Class Codes: Y02T 50/40 Weight reduction

Abstract

Integrally stiffened and formed, load carrying structures comprising a plurality of elongated thin-walled tubes placed co-extensively in a complementary side-by-side fashion which together form a hollow structure having a desired external contour. Integral skins forming the external and internal surfaces of the structure cooperatively therewith. The structure can be formed with an underlying internal support member spanning the interior of the load carrying structure, thereby connecting opposite sides of the structure together. Also, each of the tubes are wound with fibers in controlled orientations generally paralleling the direction of the loads applied to the tubes to optimize the strength to weight ratio of the tubes.

Claims

1. A method of forming a load carrying shell, comprising:

rotating a mandrel having a contoured shape to form the load carrying shell;

winding fibers around the mandrel to form an inner skin of the load carrying shell;

placing fiber wound triangular tubes in side-by-side relationship on the inner skin, where at least one of the fiber wound triangular tubes is adapted to couple to another load carrying structure;

winding fibers around the fiber wound triangular tubes to form an outer skin of the load carrying shell;

forming a fiber wound plug having an inner end and an outer end;

inserting the inner end of the fiber wound plug to another end of the at least one fiber wound triangular tube; and

inserting the outer end of the plug to the another load carrying structure adapted to receive the outer end of the plug.

2. The method according to claim 1, further including:

bonding the inner skin, fiber wound triangular tubes, and outer skin together.

3. The method according to claim 1, further including:

bonding concurrently the fibers of the fiber wound triangular tubes, inner skin, and the outer skin together.

4. The method according to claim 2, further including:

removing the mandrel.

5. The method according to claim 1, further comprising:

placing the load carrying shell into a mold; and

heating the mold to bond the inner skin, fiber wound triangular tubes, and the outer skin together.

6. The method according to claim 1, further comprising:

placing the load carrying shell into a mold; and

pressurizing the mold to bond the inner skin, fiber wound triangular tubes, and the outer skin together.

7. The method according to claim 1, where the load carrying shell is an airfoil having a rounded leading edge that tapers to form a trailing edge.

8. The method according to claim 1, where the load carrying shell is an airplane fuselage.

9. The method according to claim 1, where the fiber wound triangular tubes taper in along the longitudinal direction to one end of the tubes.

10. The method according to claim 9, where the load carrying shell is a wing for an airplane.

11. The method according to claim 1, where a portion of the fiber wound triangular tubes has one side that is round, where the round sides of the fiber wound triangular tubes are faced outwardly to provide a curved surface.

12. The method according to claim 1, where the winding of fibers over the curved surface of the fiber wound triangular tubes form the outer skin that is curved.

13. The method according to claim 1, further including:

forming another load carrying shell; and

coupling the load carrying shell to another load carrying shell.

14. The method according to claim 1, further including:

inserting a pin through the predetermined fiber wound triangular tube and the plug to couple the plug to the predetermined fiber wound triangular tube.

15. The method according to claim 1, where the step of placing the fiber wound triangular tubes is done to assemble multiple layers of the tubes, and further including:

removing selected portions of the tubes to form a keeper; and

inserting the keeper into lugs formed in another load carrying section to couple the load carrying section to another load carrying section.

16. A method for forming a load carrying structure, comprising:

winding fibers to form an inner skin of a load carrying structure;

placing fiber wound triangular tubes in side-by-side relationship on the inner skin to assemble multiple layers of the tubes;

winding fibers over the filament wound triangular tubes to form an outer skin of the load carrying structure;

removing selected portions of the tubes to form a keeper; and

inserting the keeper into lugs formed in another load carrying section to couple the load carrying section to another load carrying section.

17. The method according to claim 16, where the fibers have a triangular cross-section.

18. The method according to claim 16, further applying metal matrix to the fibers.

19. The method according to claim 16, where the fibers are pre-impregnated with matrix material.

20. The method according to claim 19, where the matrix material is a metal matrix.

21. The method according to claim 18, further including bonding the metal matrix to the fibers by heating the metal matrix.

22. The method according to claim 16, further including plating the outer skin of the load carrying structure with an aluminum outer skin.

23. The method according to claim 16, further including monitoring the structural integrity of the load carrying structure.

24. The method according to claim 16, further including aligning the fibers along the direction of the local stress on the load carrying structure.

25. The method according to claim 16, where the step of winding the fibers to form the inner skin is done by winding the fibers over a mandrel that is adapted to rotate about an axis.

26. The method according to claim 25, further including:

removing at least a portion of the mandrels in the fiber wound triangular tubes.

27. The method according to claim 25, where the mandrel is an insulating material.

28. The method according to claim 25, further including:

dissolving the mandrel to remove the mandrel.

29. The method according to claim 16, where each of the filament wound triangular tube is wound with fibers aligned in predetermined directions to carry the stress on that filament wound triangular tube.

30. The method according to claim 16, further including bonding the inner skin, filament wound triangular tubes, and the outer skin together.

31. The method according to claim 30, further including coloring the load carrying structure during the bonding process.

32. The method according to claim 16, further including:

sucking outside air through the fiber wound triangular tubes to minimize turbulence as the load carrying structure passes through the outside air.

33. The method according to claim 16, where one end of the load carrying structure is open, and further including:

enclosing the open end of the load carrying structure with a fairing.

34. The method according to claim 33, further including:

inserting a structural insert through the triangular tube along a predetermined location along the longitudinal axis of the triangular tube to provide structure reinforcement.

35. The method according to claim 16, further including:

incorporating an internal support member to support the inner skin of the load carrying structure.