Processes for repairing complex laminated composites

Patent metadata

Field	Value
Publication number	US-9849640-B2
Application number	US-201213433106-A
Country	US
Kind code	B2
Filing date	Mar 28, 2012
Priority date	Mar 28, 2012
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

Complex laminated composites may be repaired by removal of individual damaged plies through peeling in order to exploit the weaker interlaminar properties of these composites. Upon removal of the individual damaged plies through peeling, replacement plies may be added to restore the laminated composite. In addition, when damage extends through the thickness of a laminated composite, a plug may be used to allow plies to be replaced while maintaining contour within the repair region. A caul plate also may be used to stiffen and maintain the contour of a repair region while peeling and removing plies from the repair region.

First claim

The invention claimed is:

1. A method for repairing a laminated composite, the method comprising:
mapping dimensions and arrangement of a plurality of plies forming the laminated composite;
defining a repair region by identifying at least one of the plurality of plies that is damaged;
scoring the one or more damaged plies before peeling occurs, wherein fibers within the one or more damaged plies are taken hold of to begin peeling and removing the one or more damaged plies, wherein the scoring is performed in such a way that the one or more damaged plies are not completely cut through;
peeling and removing the one or more damaged plies from the repair region,
wherein each of the one or more damaged plies is separately peeled and removed; and

adding at least one replacement ply to the repair region,
wherein the number of replacement plies added is at least equal to the number of damaged plies that are separately peeled and removed so as to preserve ply drops within the laminated composite, and
wherein the number of replacement plies match ply for ply the damaged plies that have been separately peeled and removed.

2. The method of claim 1 wherein each of the one or more damaged plies to be peeled and removed is separately scored before peeling.

3. The method of claim 1 further comprising:
creating a repair patch; and
aligning and bonding the repair patch within the repair region.

4. The method of claim 3 , the step of creating the repair patch further comprising:
forming a first layer that matches the mapped dimensions and arrangement of the plurality of plies forming the laminated composite;
forming at least one additional layer that matches the mapped dimensions and arrangement of the plurality of plies forming the laminated composite; and
aligning the first layer with the at least one additional layer.

5. The method of claim 1 wherein the at least one replacement ply is added in an overlapping manner.

6. The method of claim 1 wherein the number of replacement plies added is greater than the number of damaged plies that are separately peeled and removed.

7. The method of claim 1 wherein additional replacement plies are added to each side of the repair region to further strengthen the repair region.

Assignees

• Whitworth Denver R
• Nottorf Eric W
• Cribb Iii Vance N
• Jitariu Dumitru
• Bell Helicopter Textron Inc

Inventors

• Whitworth Denver R
• Nottorf Eric W
• Cribb Iii Vance N
• Jitariu Dumitru

Classifications

• B32B37/14

  characterised by the properties of the layers · CPC title

• B29C2073/264

  for cutting out or grooving the area to be repaired · CPC title

• B32B38/10 Primary

  Removing layers, or parts of layers, mechanically or chemically · CPC title

• B29C73/26

  for mechanical pretreatment · CPC title

• B32B17/04

  bonded with or embedded in a plastic substance · CPC title