Composite structure and method for inspecting a pre-bond surface of a composite structure

Patent metadata

Field	Value
Publication number	US-10239304-B2
Application number	US-201715681799-A
Country	US
Kind code	B2
Filing date	Aug 21, 2017
Priority date	Mar 17, 2014
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A method for preparing a pre-bond surface of a composite structure includes the steps of: (1) separating a peel ply, co-cured with a composite substrate, from the composite substrate; and (2) transferring an identifiable marking agent from the peel ply to the composite substrate upon separation of the peel ply from the composite substrate. Residue of the peel ply, transferred from the peel ply to the composite substrate upon separation of the peel ply from the composite substrate, is layered on the identifiable marking agent.

First claim

What is claimed is:

1. A method for inspecting a pre-bond surface of a composite structure, said method comprising:
placing onto a composite substrate surface of a composite substrate a peel ply comprising a peel ply surface, said peel ply surface comprising an identifiable marking agent, said composite substrate comprising a resin, wherein said peel ply surface is in contact with said composite substrate surface;
co-curing said peel ply and said composite substrate;
removing said peel ply from said composite substrate to form a modified surface of said composite substrate; and
inspecting said composite substrate to determine whether said identifiable marking agent transferred to said modified surface,
wherein said identifiable marking agent is evidence of residue transferred from said peel ply to said composite substrate.

2. The method of claim 1 comprising:
ablating said modified surface to remove said identifiable marking agent and said residue; and
inspecting said modified surface after said ablating step for said identifiable marking agent.

3. The method of claim 1 comprising applying said identifiable marking agent onto said peel ply surface.

4. The method of claim 3 wherein said applying step comprises applying ink onto at least a portion of said peel ply surface.

5. The method of claim 1 comprising incorporating said identifiable marking agent into said peel ply surface.

6. The method of claim 5 wherein said incorporating step comprises weaving a plurality of tracer filaments into a fabric layer of said peel ply to define at least a portion of said peel ply surface.

7. A method for preparing a pre-bond surface of a composite structure, said method comprising:
separating a peel ply, co-cured with a composite substrate, from said composite substrate, wherein said composite substrate comprises a resin; and
transferring residue and an identifiable marking agent from said peel ply to said composite substrate upon separation of said peel ply from said composite substrate,
wherein said residue of said peel ply, transferred from said peel ply to said composite substrate upon separation of said peel ply from said composite substrate, is layered on said identifiable marking agent.

8. The method of claim 7 further comprising removing said identifiable marking agent from said composite substrate, wherein removal of said identifiable marking agent from said composite substrate concurrently removes said residue of said peel ply from said composite substrate.

9. The method of claim 8 wherein said removing step comprises ablating said composite substrate to a depth sufficient to remove substantially all of said identifiable marking agent from said composite substrate.

10. The method of claim 8 further comprising inspecting said composite substrate for said identifiable marking agent, wherein said identifiable marking agent visually indicates existence of said residue of said peel ply on said composite substrate.

11. The method of claim 7 further comprising applying said identifiable marking agent onto a peel ply surface of said peel ply before said peel ply is co-cured with said composite substrate.

12. The method of claim 11 wherein:
said identifiable marking agent comprises ink; and
said applying step comprises covering at least a portion of said peel ply surface with said ink.

13. The method of claim 12 wherein said ink comprises one of a polyester resin based ink and a nylon resin based ink.

14. The method of claim 12 wherein said ink comprises one of a light activated fluorescent ink and an ultraviolet light activated ink.

15. The method of claim 7 further comprising incorporating said identifiable marking agent into a peel ply surface of said peel ply before said peel ply is co-cured with said composite substrate.

16. The method of claim 15 wherein:
said identifiable marking agent comprises tracer filaments; and
said incorporating step comprises weaving said filaments into said peel ply to form at least a portion of said peel ply surface.

17. The method of claim 7 further comprising structurally modifying a composite substrate surface of said composite substrate upon separation of said peel ply from said composite substrate.

18. The method of claim 17 wherein said structurally modifying step comprises at least one of roughening said composite substrate surface, texturing said composite substrate surface, and chemically activating said composite substrate surface.

19. The method of claim 7 wherein:
said peel ply comprises a woven fabric; and
said residue of said peel ply comprises material particles of said woven fabric.

20. The method of claim 19 wherein:
said peel ply further comprises a layer of said identifiable marking agent located on said woven fabric; and
wherein said layer of said identifiable marking agent is positioned in contact with a composite substrate surface of said composite substrate when said peel ply and said composite structure are co-cured.

Assignees

• Boeing Co

Inventors

• Van Voast Peter J
• Belcher Marcus A

Classifications

• B32B2605/18

  Aircraft · CPC title

• B29C66/72141

  Fibres of continuous length · CPC title

• B29C66/7212

  characterised by the composition of the fibres · CPC title

• B29C66/73753

  the to-be-joined area of at least one of the parts to be joined being partially cured, i.e. partially cross-linked, partially vulcanized · CPC title

• B29C66/73161

  Roughness or rugosity · CPC title