Low cost structural fabrication that resists catastrophic failure under rapid thermal loading

• US 6,450,450 B1
• Filed: 11/06/2000
• Issued: 09/17/2002
• Est. Priority Date: 11/06/2000
• Status: Expired due to Term

• Current Assignee: The Boeing Co., The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Stickler, Patrick B., MacDonald, Frank D., Warren, Ryon C., Chuang, Chun-Hua Kathy
• Primary Examiner(s): Carone, Michael J.
• Assistant Examiner(s): Semunegus, Lulit
• Application Number:
  US09/709,784
• Time in Patent Office: 680 Days
• Field of Search: 244/126, 244/133, 244/129.6
• US Class Current: 244/126
• CPC Class Codes: B29C 70/24 oriented in at least three directions forming a three dimensional structure
• CPC Class Codes: B29K 2995/0017 Heat stable
• CPC Class Codes: B29L 2031/3097 Cosmonautical vehicles; Rockets
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12

Abstract

Provided is a fabrication that is simple to make and cost effective in optimizing performance for moderately extended high velocity missions of high performance airborne vehicles. To counter rapid thermal loading while providing a relatively low cost structure, a laminate, in a preferred embodiment an intermediate modulus carbon fiber laminated as fabric layers in a resin matrix, is stitched through with glass fiber material. This laminate is then cured and formed as a section of skin of a supersonic missile, enabling extended supersonic operation, nominally some minutes after the laminate'"'"'s T_g has been reached or exceeded. Additionally, an airframe and airframe members constructed in accordance with a preferred embodiment of the present invention are disclosed. Compared to existing materials, it reduces cost and weight, increases thermal stability, and maximizes internal payload.

Claims

1. A structural member that accommodates high rate thermal and G-force loading for a time beyond that moment at which the glass transition temperature, T_g, of at least one constituent of said member is reached, comprising:

a composite material having a T_g, and three dimensions, wherein one of said three dimensions, termed thickness, is much smaller than either of the other two said three dimensions; and

a material compatible with said composite material and suitable for use with a device for penetrating said thickness of said composite material such that said thickness has pass throughs across said thickness,

wherein said pass throughs are occupied by stitching said material compatible with said composite material through said pass throughs,

wherein multiple layers of said composite material, comprising a lamination, may be penetrated by said stitching of said layers, and

wherein said pass throughs provide the member with pathways for outgassing of at least some of its constituent compounds during high rate thermal loading of the member, and

wherein said T_g of said composite material is to be at least attained in the normal operation of an apparatus constructed with said member.

2. The member of claim 1 wherein said T_g of said composite material is greater than 0°

F.

3. The member of claim 1 wherein said T_g of said composite material is greater than 200°

F.

4. The member of claim 1 wherein said T_g of said composite material is greater than 550°

F.

5. The member of claim 1 wherein said composite material consists essentially of layers of carbon fibers in a plastic matrix.

6. The member of claim 5 wherein said carbon fiber is IM7 and said plastic matrix is a resin.

7. The member of claim 1 wherein said material compatible with said composite material is a glass fiber.

8. A method of fabricating a structural member which accommodates high rate thermal and G-force loading for a time beyond that moment at which the glass transition temperature, T_g, of at least one constituent of said member is reached, wherein said member is provided with pathways for outgassing of at least some of its constituent compounds during high rate thermal and G-force loading of said member, comprising:

providing a composite material having a glass transition temperature, T_g, and three dimensions,

wherein one of said three dimensions, termed thickness, is much smaller than either of the other two said three dimensions; and

providing a material compatible with said composite material and suitable for use with a device for penetrating said thickness of said composite material;

perforating said thickness of said composite material with said device for penetrating thus creating pass throughs in said composite material; and

inserting in said pass throughs said material compatible with said composite material,

wherein said material compatible with said composite material provides reinforcing stitches across said thickness of said composite material.

9. A panel that accommodates high rate thermal and G-force loading for a moderate period beyond that moment at which constituent parts of said panel'"'"'s glass transition temperature, T_g, is reached, comprising:

composite material having a glass transition temperature, T_g, and three dimensions,

wherein one of said three dimensions, termed thickness, is much smaller than either of the other two said three dimensions; and

a material compatible with said composite material and suitable for use with a device for penetrating said thickness of said composite material such that said thickness has pass throughs therein,

wherein said pass throughs are occupied by stitching said material compatible with said composite material through said pass throughs,

wherein multiple layers of said composite material, comprising a lamination, may be penetrated by said stitching of said layers, and

wherein said pass throughs provide the panel with pathways for outgassing of at least some of its constituent compounds during high thermal loading of the panel, and

wherein said T_g of said constituent parts of said panel is at least attained during normal operation of an apparatus constructed with said member.

10. The panel of claim 9 wherein said T_g of said composite material is greater than 0°

F.

11. The panel of claim 9 wherein said T_g of said composite material is greater than 200°

F.

12. The panel of claim 9 wherein said T_g of said composite material is greater than 550°

F.

13. The panel of claim 9 wherein said composite material consists essentially of layers of a carbon fiber in a plastic matrix.

14. The panel of claim 13 wherein said carbon fiber is IM7 and said plastic matrix is a resin.

15. The panel of claim 9 wherein said material compatible with said composite material is a glass fiber.

16. An airframe, having constituent parts, that accommodates high rate thermal and G-force loading for a time beyond that moment at which at least some constituent parts of said airframe'"'"'s glass transition temperature, T_g, is reached, comprising:

a composite material having a T_g and three dimensions,

wherein one of said three dimensions, termed thickness, is much smaller than either of the other two said three dimensions; and

a material compatible with said composite material and suitable for use with a device for penetrating said thickness of said composite material such that said thickness has pass throughs therein,

wherein said pass throughs are occupied by stitching said material compatible with said composite material through said pass throughs,

wherein multiple layers of said composite material, comprising a lamination, may be penetrated by said stitching of said layers, and

wherein said pass throughs provide the airframe with pathways for outgassing of at least some of its constituent compounds during high rate thermal loading of the airframe, and

wherein said T_g of said at least some constituent parts of the airframe is at least attained during normal operation of the airframe.

17. The airframe of claim 16 wherein said T_g of said composite material is greater than 0°

F.

18. The airframe of claim 16 wherein said T_g of said composite material is greater than 200°

F.

19. The airframe of claim 16 wherein said T_g of said composite material is greater than 550°

F.

20. The airframe of claim 16 wherein said composite material consists essentially of layers of a carbon fiber in a plastic matrix.

21. The airframe of claim 20 wherein said carbon fiber is IM7 and said plastic matrix is a resin.

22. The airframe of claim 16 wherein said material compatible with said composite material is glass fiber.

23. A high speed vehicle, having constituent parts, that accommodates high rate thermal and G-force loading for a time beyond that moment at which at least some constituent parts of said high speed vehicle'"'"'s glass transition temperature, T_g, is reached, comprising:

a composite material having a T_g and three dimensions,

wherein one of said three dimensions, termed thickness, is much smaller than either of the other two said three dimensions; and

a material compatible with said composite material and suitable for use with a device for penetrating said thickness of said composite material such that said thickness has pass throughs therein,

wherein said pass throughs are occupied by stitching said material compatible with said composite material through said pass throughs,

wherein multiple layers of said composite material, comprising a lamination, may be penetrated by said stitching of said layers, and

wherein said pass throughs provide the airframe with pathways for outgassing of at least some of its constituent compounds during high rate thermal loading of the airframe, and

wherein said T_g of said at least some constituents of the airframe is at least attained during normal operation of the airframe.

24. The high speed vehicle of claim 23 wherein said T_g of said composite material is greater than 0°

F.

25. The high speed vehicle of claim 23 wherein said T_g of said composite material is greater than 200°

F.

26. The high speed vehicle of claim 23 wherein said T_g of said composite material is greater than 550°

F.

27. The high speed vehicle of claim 23 wherein said composite material consists essentially of layers of a carbon fiber in a plastic matrix.

28. The high-speed vehicle of claim 27 wherein said carbon fiber is IM7 and said plastic matrix is a resin.

29. The high speed vehicle of claim 23 wherein said material compatible with said composite material is glass fiber.

30. The high-speed vehicle of claim 23 in which said high-speed vehicle is a missile.

31. The high-speed vehicle of claim 23 in which said high-speed vehicle is an aircraft.

32. The high-speed vehicle of claim 23 in which said high-speed vehicle is a vehicle suitable for operation in outer space.