Methods and apparatus to increase fire resistance and fracture toughness of a composite structure

Patent metadata

Field	Value
Publication number	US-10710348-B2
Application number	US-201715660376-A
Country	US
Kind code	B2
Filing date	Jul 26, 2017
Priority date	Jul 26, 2017
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

Abstract

Methods and apparatus to increase fire resistance and fracture toughness of a composite structure are described. An example apparatus includes a composite structure formed by an innermost ply and a fire-resistant ply including a first additive to increase a flammability resistance of the structure, where the fire-resistant ply is an inner ply of the composite structure.

First claim

What is claimed is:

1. A multi-ply composite fuselage comprising:
an innermost ply forming an inner skin of the multi-ply composite fuselage;
an outermost ply forming an outer skin of the multi-ply composite fuselage; and
a single fire-resistant ply located between the innermost ply and the outermost ply, the single fire-resistant ply including an epoxy-based resin and a first additive mixed evenly throughout the epoxy-based resin, the first additive to increase a flammability resistance of the multi-ply composite fuselage, wherein the single fire-resistant ply is the only ply of the multi-ply composite fuselage that includes the first additive, and wherein no ply of the multi-ply composite fuselage other than the single fire-resistant ply includes a fire-retardant additive.

2. The multi-ply composite fuselage as defined in claim 1 , wherein the single fire-resistant ply is positioned within an innermost 50% of plies of the multi-ply composite fuselage.

3. The multi-ply composite fuselage as defined in claim 1 , wherein the single fire-resistant ply is positioned within an innermost 33% of plies of the multi-ply composite fuselage.

4. The multi-ply composite fuselage as defined in claim 1 , wherein the single fire-resistant ply is positioned within an outermost 33% of plies of the multi-ply composite fuselage.

5. The multi-ply composite fuselage as defined in claim 1 , wherein the innermost ply is oriented at a first angle, and wherein an adjacent ply of the multi-ply composite fuselage positioned in contact with the innermost ply is oriented at a second angle.

6. The multi-ply composite fuselage as defined in claim 1 , wherein the innermost ply has a first thickness and the single fire-resistant ply has a second thickness less than the first thickness.

7. The multi-ply composite fuselage as defined in claim 1 , further comprising an additional ply located between the innermost ply and the outermost ply, the single fire-resistant ply having a first flammability resistance, the additional ply having a second flammability resistance that is less than the first flammability resistance.

8. The multi-ply composite fuselage as defined in claim 1 , wherein the single fire-resistant ply further includes a second additive mixed evenly throughout the epoxy-based resin, the second additive to increase a fracture toughness of the multi-ply composite fuselage.

9. The multi-ply composite fuselage as defined in claim 1 , wherein the single fire-resistant ply further includes a second additive mixed evenly throughout the epoxy-based resin, the second additive to char upon contact with a flame to form a protective layer, the second additive being a thermoplastic.

10. The multi-ply composite fuselage as defined in claim 1 , wherein the innermost ply is a first fabric composite ply, the outermost ply is a second fabric composite ply, and the single fire-resistant ply is a tape composite ply.

11. The multi-ply composite fuselage as defined in claim 1 , wherein the single fire-resistant ply further includes a second additive mixed evenly throughout the epoxy-based resin, and a third additive mixed evenly throughout the epoxy-based resin, the second additive being a charring thermoplastic, the second additive to increase a fracture toughness of the multi-ply composite fuselage, the third additive to promote char in the second additive.

12. The multi-ply composite fuselage as defined in claim 11 , wherein the single fire-resistant ply is adjacent the innermost ply.

13. The multi-ply composite fuselage as defined in claim 12 , further comprising an additional ply that does not include any of the first, second or third additives, the additional ply being located between the single fire-resistant ply and the outermost ply and further being located adjacent the single fire-resistant ply, the single fire-resistant ply having a first flammability resistance, the additional ply having a second flammability resistance that is less than the first flammability resistance.

14. A multi-ply composite fuselage comprising:
an innermost ply forming an inner skin of the multi-ply composite fuselage;
an outermost ply forming an outer skin of the multi-ply composite fuselage; and
a single fire-resistant ply formed by an epoxy-based resin, a first additive mixed evenly throughout the epoxy-based resin, and a second additive mixed evenly throughout the epoxy-based resin, the first additive to reduce a flammability of the multi-ply composite fuselage, the second additive to increase a fracture toughness of the multi-ply composite fuselage, wherein the single fire-resistant ply is the only ply of the multi-ply composite fuselage that includes the first additive, and wherein no ply of the multi-ply composite fuselage other than the single fire-resistant ply includes a fire-retardant additive.

15. The multi-ply composite fuselage as defined in claim 14 , wherein the first additive is an organic fire retardant, an inorganic fire retardant, or an inorganic-organic hybrid fire retardant.

16. The multi-ply composite fuselage as defined in claim 14 , wherein the second additive is a charring thermoplastic.

17. The multi-ply composite fuselage as defined in claim 14 , wherein the single fire-resistant ply is further formed by a third additive mixed evenly throughout the epoxy-based resin, the third additive to promote char in the second additive.

18. The multi-ply composite fuselage as defined in claim 17 , wherein at least two of the first additive, the second additive, and the third additive are combined into an agent.

19. The multi-ply composite fuselage as defined in claim 14 , wherein the second additive is at least one of a nanotube, a nanoparticle, a film, a veil, a mesh, toughening particles, or a filamentous material.

20. The multi-ply composite fuselage as defined in claim 14 , wherein the single fire-resistant ply of the multi-ply composite fuselage is positioned closer to the innermost ply of the multi-ply composite fuselage than the outermost ply of the multi-ply composite fuselage.

Assignees

• Boeing Co

Inventors

• Bauer Andrew L
• Rogalski Mark E

Classifications

• B64C2001/0072

  from composite materials · CPC title

• B32B27/06 Primary

  as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08)} · CPC title

• B32B5/26

  another layer {next to it} also being fibrous or filamentary {(relative arrangement of fibres or filaments of different layers B32B5/12)} · CPC title

• B32B27/18 Primary

  characterised by the use of special additives · CPC title

• B32B5/12 Primary

  characterised by the relative arrangement of fibres or filaments of {different layers, e.g. the fibres or filaments being parallel or perpendicular to each other} · CPC title