Method of repairing a core stiffened structure

Patent metadata

Field	Value
Publication number	US-9849656-B2
Application number	US-201414512837-A
Country	US
Kind code	B2
Filing date	Oct 13, 2014
Priority date	Oct 13, 2014
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A method of repairing a core stiffened structure, including removing a damaged portion of the core stiffened structure; bonding a shelf onto a first core member; bonding a second core member to a shelf; and securing a skin patch over the second core member.

First claim

The invention claimed is:

1. A method of repairing a rotor blade, the method comprising:
removing a damaged portion of the rotor blade to provide a first core member within a cavity of the rotor blade;
installing an uncured composite shelf onto the first core member in the cavity;
bonding the uncured composite shelf onto the first core member with an adhesive;
concurrently curing the uncured composite shelf and the adhesive to form a cured composite shelf bonded to the first core member;
bonding a second core member having a plurality of cells to the cured composite shelf;
depositing a foam mixture into a cell of the second core member;
allowing the foam mixture to expand and fill the plurality of cells in the second core member so as to form an expanded foam;
trimming the expanded foam; and
securing a skin patch over the second core member;
wherein the cured composite shelf provides a shear transfer medium between the first core member and the second core member.

2. The method according to claim 1 , wherein the step of removing the damaged portion includes removing a skin portion and a damaged core portion.

3. The method according to claim 1 , wherein the step of bonding the uncured composite shelf onto the first core member includes locating the adhesive approximate to a lower surface of the uncured composite shelf and an upper surface network of the first core member.

4. The method according to claim 1 , further comprising: curing the skin patch.

5. The method according to claim 1 , wherein the step of bonding the second core member to the cured composite shelf also includes depositing a foam mixture into a space between outer cell members of the second core member and adjacent cells walls of the first core member.

6. The method according to claim 1 , wherein the skin patch is a composite member.

7. The method according to claim 1 , wherein the uncured composite shelf is an uncured composite layup.

8. The method according to claim 1 , wherein the step of bonding the second core member to the cured composite shelf also includes applying a foam mixture into a space between outer cell members of the second core member and adjacent cells walls of the first core member.

9. The method according to claim 1 , wherein the step of bonding the second core member to the cured composite shelf also includes applying a paste adhesive into a space between outer cell members of the second core member and adjacent cells walls of the first core member.

10. The method according to claim 1 , wherein the step of bonding the second core member to the cured composite shelf includes applying a film adhesive between the second core member and an upper surface of the cured composite shelf.

11. The method according to claim 1 , wherein the step of bonding the second core member to the cured composite shelf includes applying a foam adhesive between the second core member and an upper surface of the cured composite shelf.

Assignees

• Bell Helicopter Textron Inc

Inventors

• Wardlaw Robert
• Modrzejewski Brian S
• Mueller Byron
• Cribb Iii Vance N

Classifications

• B29L2031/082

  Blades, e.g. for helicopters · CPC title

• B32B2305/024

  Honeycomb · CPC title

• B64C27/473

  Constructional features · CPC title

• B29C44/18

  Filling preformed cavities {(B29C44/1204 takes precedence)} · CPC title

• B29L2031/608

  Honeycomb structures · CPC title