Methods for manufacturing an i-stringer of an aircraft and devices for use in such methods

• US 9,475,569 B2
• Filed: 10/29/2013
• Issued: 10/25/2016
• Est. Priority Date: 10/29/2013
• Status: Active Grant

• Current Assignee: Gulfstream Aerospace Corporation (General Dynamics Corporation)
• Original Assignee: Gulfstream Aerospace Corporation (General Dynamics Corporation)
• Inventors: Aitken, Charles, Autry, Brenden
• Primary Examiner(s): Chang, Richard
• Application Number:
  US14/066,376
• Publication Number:
  US 20150246718A1
• Time in Patent Office: 1,092 Days
• US Class Current: 1/1
• CPC Class Codes: B29C 33/405 Elastomers, e.g. rubber B29C33/50 takes precedence
• CPC Class Codes: B29C 70/222 the structure being shaped to form a three dimensional configuration
• CPC Class Codes: B29C 70/42 for producing articles of definite length, i.e. discrete articles
• CPC Class Codes: B29C 70/44 using isostatic pressure, e.g. pressure difference-moulding, vacuum bag-moulding, autoclave-moulding or expanding rubber-moulding
• CPC Class Codes: B29C 70/50 for producing articles of indefinite length, e.g. prepregs, sheet moulding compounds [SMC] or cross moulding compounds [XMC]
• CPC Class Codes: B29C 70/504 using rollers or pressure bands for corrugating B29C53/22
• CPC Class Codes: B29C 70/54 Component parts, details or accessories; Auxiliary operations , e.g. feeding or storage of prepregs or SMC after impregnation or during ageing
• CPC Class Codes: B29C 70/865 completely encapsulated
• CPC Class Codes: B29D 99/0007 having a variable cross-section
• CPC Class Codes: B29D 99/001 Producing wall or panel-like structures, e.g. for hulls, fuselages, or buildings articles with hollow walls B29D24/00
• CPC Class Codes: B29L 2031/3076 Aircrafts blades, propellers B29L2031/08
• CPC Class Codes: B64C 1/064 Stringers; Longerons
• CPC Class Codes: B64C 1/26 Attaching the wing or tail units or stabilising surfaces
• CPC Class Codes: B64C 2001/0072 from composite materials
• CPC Class Codes: B64C 3/182 Stringers, longerons
• CPC Class Codes: B64F 5/10 Manufacturing or assembling aircraft, e.g. jigs therefor
• CPC Class Codes: Y02T 50/40 Weight reduction
• CPC Class Codes: Y10T 29/49622 Vehicular structural member making
• CPC Class Codes: Y10T 29/53 Means to assemble or disassemble

Abstract

Methods for manufacturing a reinforced composite structure for an aircraft and devices used in such methods are provided. A method includes advancing a composite material layout through a cap-forming device. The advancing results in a preformed cap section, a first length of the layout and a second length of the layout. The layout is removed from the cap-forming device and the preformed cap section of the layout is arranged within a cavity of a flexible mandrel with a foot portion of the first length and a foot portion of the second length remaining outside the cavity of the flexible mandrel. The foot portion of the first length and the foot portion of the second length contact a skin structure. The layout is heated and pressurized using the flexible mandrel to cure the layout and form the reinforced composite structure affixed to the skin structure.

Claims

1. A method for manufacturing a reinforced composite structure for an aircraft, the method comprising the steps of:

forming a composite material layout by arranging a first composite material ply overlying a second composite material ply and positioning a pre-cured cap insert on the first composite material ply;

advancing the composite material layout through a cap-forming device, wherein the advancing results in a preformed cap section, a first length of the composite material layout and a second length of the composite material layout;

removing the composite material layout from the cap-forming device;

arranging the preformed cap section of the composite material layout within a cavity of a flexible mandrel with a foot portion of the first length and a foot portion of the second length remaining outside the cavity of the flexible mandrel;

contacting the foot portion of the first length and the foot portion of the second length with a skin structure; and

heating and pressurizing the composite material layout using the flexible mandrel to cure the composite material layout and form the reinforced composite structure affixed to the skin structure.

2. The method of claim 1, further comprising forming the composite material layout by arranging the first composite material ply overlying the second composite material ply such that the first composite material ply is offset from the second composite material ply, wherein forming the composite material layout is performed before advancing.

3. The method of claim 2, wherein forming comprises overlapping the first composite material ply and the second material ply so that the first composite material ply is about 6.35 mm (¼

inch) to about 12.7 mm (½

inch) offset from the second material ply.

4. The method of claim 1, further comprising forming the composite material layout by arranging the first composite material ply overlying the second composite material ply, wherein the first composite material ply and the second composite material ply have tapered ends, wherein forming the composite material layout is performed before advancing.

5. The method of claim 1, wherein positioning the pre-cured cap insert comprises positioning the pre-cured cap insert comprising a unidirectional carbon fiber-reinforced material.

6. The method of claim 1, wherein arranging comprises arranging the preformed cap section of the composite material layout within a cap cavity section of the flexible mandrel before contacting and arranging a web portion of the first length and a web portion of the second length of the composite material layout in a web cavity section of the flexible mandrel before contacting.

7. The method of claim 1, wherein, before contacting, placing the flexible mandrel, with the composite material layout, in an inflexible support structure.

8. The method of claim 1, wherein advancing comprises advancing the composite material layout through the cap-forming device such that the cap-forming device causes the first composite material ply and the second composite material ply to envelope the pre-cured cap insert and contact each other at a contact area.

9. The method of claim 8, further comprising applying heat at the contact area.

10. The method of claim 8, wherein the cap-forming device comprises a vertical wheel and wherein advancing the composite material layout through the cap-forming device comprises urging the vertical wheel against the pre-cured cap insert while lengths of the composite material layout are pulled away from the pre-cured cap insert.

11. The method of claim 8, wherein advancing comprises advancing the first composite material ply and the second composite material ply between two pinching wheels that cause the first composite material ply and the second composite material ply to envelope the pre-cured cap insert and contact each other at a contact area.

12. The method of claim 11, wherein advancing the first composite material ply and the second composite material ply between two pinching wheels comprises advancing the first composite material ply and the second composite material ply between two pinching wheels that urge the first composite material ply and the second composite material ply to physically contact each other at the contact area that has a width of about 6.35 mm (about ¼

inch).

13. The method of claim 1, further comprising applying a film adhesive between the pre-cured cap insert and the second composite material ply.

14. The method of claim 1, further comprising, before contacting the foot portion of the first length and the foot portion of the second length with the skin structure, inserting a web-wedge insert at ends of the composite material layout.