Method of forming a reinforced foam-filled composite stringer

• US 8,540,921 B2
• Filed: 11/25/2008
• Issued: 09/24/2013
• Est. Priority Date: 11/25/2008
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Senibi, Simon D., Van West, Barry P., Guzman, Juan Carlos, McCarville, Douglas A., Rotter, Daniel M.
• Primary Examiner(s): Johnson, Christina
• Assistant Examiner(s): SCHIFFMAN, BENJAMIN A
• Application Number:
  US12/277,483
• Publication Number:
  US 20100129589A1
• Time in Patent Office: 1,764 Days
• Field of Search: None
• US Class Current: 264/321
• CPC Class Codes: B32B 1/08 Tubular products
• CPC Class Codes: B32B 15/046 of foam
• CPC Class Codes: B32B 15/18 comprising iron or steel B32B15/011, B32B15/012 and B32B15/013 take precedence
• CPC Class Codes: B32B 15/20 comprising aluminium or copper B32B15/016 and B32B15/017 take precedence
• CPC Class Codes: B32B 2266/08 Closed cell foam
• CPC Class Codes: B32B 2307/558 Impact strength, toughness
• CPC Class Codes: B32B 2605/18 Aircraft
• CPC Class Codes: B32B 27/00 Layered products comprising a layer of synthetic resin fibrous or filamentary layer made of a synthetic resin B32B5/02; particulate layer made of a synthetic resin B32B5/16; foamed layer made of a synthetic resin B32B5/18
• CPC Class Codes: B32B 3/26 characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids foam layer B32B5/18; layer of synthetic resin characterised by fillers that create voids or cavities B32B27/205; characterised by an apertured layer
• CPC Class Codes: B32B 3/28 characterised by a layer comprising a deformed thin sheet , i.e. the layer having its entire thickness deformed out of the plane, e.g. corrugated, crumpled B32B29/08 takes precedence
• CPC Class Codes: B32B 5/18 characterised by features of a layer of foamed material
• CPC Class Codes: B32B 9/005 comprising one layer of ceramic material, e.g. porcelain, ceramic tile layered products with at least two ceramic layers composed mainly of ceramic B32B18/00
• CPC Class Codes: B32B 9/007 comprising carbon, e.g. graphite, composite carbon
• CPC Class Codes: B64C 1/064 Stringers; Longerons
• CPC Class Codes: Y10T 428/233 Foamed or expanded material encased
• CPC Class Codes: Y10T 428/24504 Component comprises a polymer [e.g., rubber, etc.]

Abstract

A method and apparatus for manufacturing a composite stringer. A composite material and foam are laid up onto a tool in the form of a stringer. The foam has a plurality of structural members within the foam. The plurality of structural members has a number of orientations to resist a number of loads. The composite material, the foam in the form of the stringer, and the plurality of structural members are cured to form the composite stringer.

Claims

1. A method for manufacturing a composite stringer, the method comprising:

placing a plurality of structural members within a foam, the plurality of structural members comprising at least one of a number of pins, a number of tubes, and a number of rods;

laying up a composite material and the foam with the plurality of structural members within the foam onto a tool in the form of a stringer, wherein the plurality of structural members has at least a first orientation and a second orientation, the first orientation and the second orientation being different from each other, the plurality of structural members configured to resist a number of loads on the stringer including at least compressive loads;

placing the foam and the composite material onto a skin ply such that the plurality of structural members within the foam do not substantially pierce the skin ply;

wherein the structural members extend from the skin ply to a first and a second wall of the composite stringer and wherein the structural members are positioned substantially within the foam; and

curing the composite material, the foam in the form of the stringer, and the plurality of structural members to form the composite stringer.

2. The method of claim 1 further comprising:

placing the plurality of structural members within the foam;

shaping the foam for the composite stringer with the plurality of structural members within the foam.

3. The method of claim 1, wherein the laying up step comprises:

laying up the composite material onto an inside mold line; and

placing the foam onto the composite material.

4. The method of claim 3, wherein the laying up step further comprises:

placing a skin ply over the foam and the composite material.

5. The method of claim 4 wherein the laying up step is performed using an outside mold line.

6. The method of claim 1, wherein the composite stringer has a shape selected from one of a trapezoid shape, a hat shape, a solid shape, and a hollow shape.

7. The method of claim 1, wherein the plurality of structural members is comprised of a material selected from one of aluminum, steel, carbon-reinforced material, graphite-reinforced material, titanium, a metal alloy, and a ceramic material.

8. The method of claim 1, wherein the plurality of structural members has a first density in a first area and a second density in a second area.

9. The method of claim 1, wherein the composite stringer is located in an aircraft.

10. The method of claim 1, wherein the first orientation and the second orientation are selected so as to be substantially normal to each other.

11. A method for forming a composite part, the method comprising:

laying up a composite material and a foam core onto a tool in a form of the composite part, the foam core having a plurality of structural members, wherein the plurality of structural members has at least a first orientation and a second orientation, the first orientation and the second orientation being different from each other, the plurality of structural members configured to resist a number of loads including at least compressive forces on the composite part, the plurality of structural members comprising at least one of a number of pins, a number of tubes, and a number of rods;

placing the foam core and the composite material onto a skin ply;

curing the composite material and the foam core in the form of the composite part such that the plurality of structural members do not substantially pierce the skin ply;

wherein the structural members extend from the skin ply to a first and a second wall of the composite part stringer and wherein the structural members are positioned substantially within the foam; and

forming the composite part with a channel in which the foam core is located.

12. The method of claim 11, wherein the laying up step comprises:

laying up the composite material onto an inside mold line; and

placing the foam core onto the composite material.

13. The method of claim 11, wherein the plurality of structural members has a first density in a first area and a second density in a second area, the first density and second density being different.

14. The method of claim 11, wherein the composite part is a composite stringer.

15. The method of claim 14, wherein the composite stringer has a shape selected from one of a trapezoid shape, a hat shape, a solid shape, and a hollow shape.

16. The method of claim 11, wherein the plurality of structural members is comprised of a material selected from one of aluminum, steel, carbon-reinforced material, graphite-reinforced material, titanium, a metal alloy, and a ceramic material.

17. The method of claim 11, wherein the first orientation and the second orientation are selected so as to be substantially normal to each other.

18. A method for manufacturing a plurality of composite stringers, the method comprising:

laying up composite material and foam with a plurality of z-pins within the foam onto a plurality of tools to form a plurality of composite stringers, wherein the plurality of z-pins has at least a first orientation, the plurality of z-pins configured to resist a number of loads including compressive loads on the composite stringers, and the plurality of z-pins comprising at least one of a number of pins, a number of tubes, and a number of rods;

placing the plurality of composite stringers on a single tool;

placing a skin ply over the plurality of composite stringers to form a structure;

wherein the plurality of z-pins extends from the skin ply to a first and a second wall of the composite stringers and wherein the structural members are positioned substantially within the foam; and

curing the structure such that the plurality of z-pins do not substantially extend past the first and the second wall of the composite stringer.