HIGH PULLOFF CAPABILITY HAT STRINGER

• US 20110139932A1
• Filed: 12/15/2009
• Published: 06/16/2011
• Est. Priority Date: 12/15/2009
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Brook, Kenneth L., Matheson, Donald P.
• Granted Patent: US 8,714,485 B2
• Time in Patent Office: Days
• US Class Current: 244/132
• CPC Class Codes: B29C 70/00 Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
• CPC Class Codes: B29D 99/0014 provided with ridges or ribs, e.g. joined ribs
• CPC Class Codes: B32B 2260/021 Fibrous or filamentary layer
• CPC Class Codes: B32B 2260/023 Two or more layers
• CPC Class Codes: B32B 2260/046 Synthetic resin
• CPC Class Codes: B32B 2262/106 Carbon fibres, e.g. graphite fibres
• CPC Class Codes: B32B 2605/18 Aircraft
• CPC Class Codes: B32B 2607/00 Walls, panels
• CPC Class Codes: B32B 3/02 characterised by features of form at particular places, e.g. in edge regions non-uniform thickness B32B3/263
• 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
• CPC Class Codes: B32B 7/05 the layers not being connected over the whole surface, e.g. discontinuous connection or patterned connection using interposed adhesives or bonding materials applied in spaced arrangements B32B7/14
• CPC Class Codes: B64C 1/064 Stringers; Longerons
• CPC Class Codes: B64C 3/182 Stringers, longerons
• CPC Class Codes: B64C 3/26 Construction, shape, or attachment of separate skins, e.g. panels
• CPC Class Codes: Y02T 50/40 Weight reduction
• CPC Class Codes: Y10T 29/49622 Vehicular structural member making
• CPC Class Codes: Y10T 428/2457 Parallel ribs and/or grooves
• CPC Class Codes: Y10T 428/24612 Composite web or sheet
• CPC Class Codes: Y10T 428/31511 Of epoxy ether

Abstract

A structure may comprise a skin member and a hat stringer. The hat stringer may include a base portion and first and second webs extending outwardly from the base portion. Each one of the first and second webs may be comprised of a wrap laminate having wrap plies and a cover laminate having cover plies. The first and second webs may be interconnected by a cap. The hat stringer and skin member may be co-cured.

Claims

1. A structure, comprising:

a skin member; and

a hat stringer, including;

a base portion;

a first web and a second web extending outwardly from the base portion, each one of the first and second webs being comprised of a wrap laminate having wrap plies and a cover laminate having cover plies; and

a cap interconnecting the first and second webs;

the hat stringer and skin member being co-cured.

2. The structure of claim 1 wherein:

the cover plies are substantially equal in quantity to the wrap plies.

3. The structure of claim 1 wherein the hat stringer further comprises:

a first noodle and a second noodle extending along the wrap laminate and cover laminate and being covered by a base laminate.

4. The structure of claim 1 further comprising:

a rib attached to at least one of the cap and the first and second webs.

5. The structure of claim 4 further comprising:

at least one bracket mounted to at least one of the first and second webs, the rib being fastened to the bracket.

6. The structure of claim 5 further comprising:

first and second brackets respectively mounted to the first and second webs; and

a fastener extending through the first and second webs and the first and second brackets.

7. The structure of claim 5 further comprising:

at least one fastener extending from a rib flange into one of the first and second brackets.

8. The structure of claim 4 further comprising:

a fastener extending from the rib into the cap.

9. The structure of claim 8 wherein the fastener is blind fastener.

10. The structure of claim 1 wherein:

the hat stringer and the skin member comprise a portion of at least one of the following;

a fuselage, a wing, a tail section.

11. A composite structure, comprising:

a skin member;

a hat stringer co-cured with the skin member and including;

a base portion;

a first web and a second web extending outwardly from the base portion, each one of the first and second webs being comprised of a wrap laminate having wrap plies and a cover laminate having cover plies in substantially equal quantity to the wrap plies;

a cap interconnecting the first and second webs; and

a first noodle and a second noodle extending along the wrap laminate and cover laminate;

first and second brackets respectively mounted to the first and second webs by a stud extending therethrough; and

a rib fastened to the first and second brackets.

12. The composite structure of claim 11 wherein:

the hat stringer and the skin member comprise a portion of at least one of the following;

a fuselage, a wing, a tail section.

13. A method of fabricating a hat stringer comprising the steps of:

forming a wrap laminate by laying up wrap plies about a removable mandrel;

forming a cover laminate by laying up cover plies on a cover mold;

forming a base laminate by laying up base plies on a base mold;

inserting the wrap laminate into the cover laminate;

placing a first noodle and a second noodle along the wrap laminate and cover laminate;

applying the base laminate to the wrap laminate and cover laminate such that the first and second noodles are captured between the wrap laminate, cover laminate and base laminate;

mounting the hat stringer to a skin member; and

co-curing the skin member, wrap laminate, cover laminate and base laminate.

14. The method of claim 13 wherein the step of forming the hat stringer further includes:

forming the cover laminate such that the quantity of wrap plies and cover plies are substantially equivalent.

15. The method of claim 13 wherein the step of forming the hat stringer further includes:

placing adhesive along the first and second noodles for bonding thereof to the wrap laminate, cover laminate and base laminate.

16. A method of assembling a structure, comprising the steps of:

mounting a hat stringer to a skin member, the hat stringer comprising a wrap laminate and a cover laminate respectively including wrap plies and cover plies in substantially equal quantity; and

attaching a rib to the hat stringer.

17. The method of claim 16 wherein the step of attaching the rib to the hat stringer comprises:

attaching the rib at least one of a web and a cap of the hat stringer.

18. The method of claim 17 wherein the step of attaching the rib to the hat stringer further includes:

mounting at least one bracket to the web;

fastening the rib to the bracket; and

fastening the bracket to the web.

19. The method of claim 18 wherein the step of fastening the bracket to the web comprises:

extending a stud through the web and bracket.

20. The method of claim 19 wherein the hat stringer comprises first and second webs, the method comprising the step of:

mounting first and second brackets to respective ones of the first and second webs; and

extending the stud through the first and second webs and the first and second brackets.

21. The method of claim 18 wherein the step of fastening the rib to the bracket comprises:

securing the rib flange to the bracket with a fastener.

22. The method of claim 16 wherein the step of attaching the rib to the hat stringer comprises:

extending a fastener from the rib into the cap.

23. The method of claim 22 wherein the fastener is a blind fastener.

24. The method of claim 22 further comprising the step

applying an EME resistant coating to the fastener.

25. A method of assembling a composite structure, comprising the steps of:

forming a hat stringer having first and second webs, including the steps of;

forming a wrap laminate by laying up wrap plies about a removable mandrel formed complementary to the cover mold;

forming a cover laminate by laying up cover plies on a cover mold such that the quantity of wrap plies and cover plies are substantially equivalent in the first and second webs;

forming a base laminate by laying up base plies on a base mold;

inserting the wrap laminate into the cover laminate;

placing a first noodle and a second noodle along the wrap laminate and cover laminate; and

adding the base laminate to the wrap laminate and cover laminate such that the first and second noodles are captured between the wrap laminate, cover laminate and base laminate;

mounting the hat stringer to a skin member;

co-curing the skin member, wrap laminate, cover laminate, base laminate and first and second noodles to form the composite structure;

mounting first and second brackets to respective ones of the first and second webs;

extending a stud through the first and second webs and the first and second brackets;

mounting a rib to the hat stringer;

extending at least one fastener from the rib into each one of the first and second brackets; and

applying an EME resistant coating to the stud and fasteners.