Apparatus, system, and method for reinforcing composite structure

Patent metadata

Field	Value
Publication number	US-12491691-B2
Application number	US-202217718027-A
Country	US
Kind code	B2
Filing date	Apr 11, 2022
Priority date	Jun 2, 2021
Publication date	Dec 9, 2025
Grant date	Dec 9, 2025

Abstract

Disclosed herein are a repair apparatus, system, and method for structurally reinforcing an abnormal composite structural member. The repair is suited for reinforcing a cured composite structure that defines a strength tolerance and has an abnormality that reduces the structural strength relative to the strength tolerance of the cured composite. The structural reinforcement repairs the abnormality in the cured composite and provides the repair strength so that the repaired composite has a structural strength that meets or exceeds the strength tolerance. The structural reinforcement has a composite patch that is coupled to the cured composite over the abnormality and is covered by pressure-sensitive tape.

First claim

What is claimed is:

1 . A composite structure, comprising:
a structural member made of a cured composite, the cured composite comprising a cured-composite plurality of unidirectional fibers and defining a strength tolerance, the structural member comprising a solid laminate having an abnormality in the solid laminate, wherein the abnormality has a reduced strength relative to the strength tolerance of the cured composite; and a structural reinforcement coupled to the cured composite over the abnormality and having a repair strength, the structural reinforcement comprising:
a patch covering a predetermined area greater than the abnormality of the solid laminate and comprising:
a plurality of plies, wherein:
a first ply in the plurality of plies comprises a first-ply plurality of unidirectional fibers embedded in a matrix material and oriented in a first direction that is parallel to the cured-composite plurality of unidirectional fibers;
a second ply in the plurality of plies comprises a second-ply plurality of unidirectional fibers oriented in a second direction that is different than the first direction; and
the plurality of plies define a first side of the plurality of plies and a second side of the plurality of plies opposite the first side; and

a patch adhesive comprising an adhesive material that is on the first side of the plurality of plies, wherein the first side of the plurality of plies is adhesively bonded directly to the cured composite of the structural member via the patch adhesive; and

a pressure-sensitive tape comprising a metallic material and a tape adhesive, fixed to the metallic material, wherein the pressure-sensitive tape is fixed to and covers an entirety of the second side of the patch.

2 . The composite structure of claim 1 , wherein the repair strength of the structural reinforcement is equal to or exceeds the strength tolerance of the cured composite.

3 . The composite structure of claim 1 , wherein the patch further comprises an overlay portion that extends beyond an outer peripheral edge of the abnormality and about an entirety of the abnormality.

4 . The composite structure of claim 1 , wherein:
the predetermined area comprises a first area; the patch adhesive covers a second area; and the second area is not greater than the first area.

5 . The composite structure of claim 1 , wherein the first side of the plurality of plies is adhesively bonded directly to the solid laminate.

6 . The composite structure of claim 1 , wherein:
the cured composite is a sandwich panel, comprising a core interposed between a first sheet and a second sheet; and the first side of the plurality of plies is adhesively bonded directly to the first sheet.

7 . The composite structure of claim 6 , wherein:
the core comprises a honeycomb panel having elongated channels that are oriented orthogonally relative to the first sheet and the second sheet; and the honeycomb panel carries a shear load between the first sheet and the second sheet.

8 . The composite structure of claim 1 , wherein:
the repair strength is equal to a summation of a patch strength of the patch and a tape strength of the pressure-sensitive tape; and the patch strength is greater than the tape strength.

9 . The composite structure of claim 8 , wherein the repair strength is greater than the strength tolerance.

10 . The composite structure of claim 8 , wherein the patch strength is less than the repair strength.

11 . The composite structure of claim 1 , wherein:
the plurality of plies comprises a first ply and a second ply; and the tape adhesive contacts a first-ply edge of the first ply and a second-ply edge of the second ply.

12 . The composite structure of claim 1 , wherein:
the first direction is orthogonal to the second direction.

13 . The composite structure of claim 11 , wherein:
the first direction is 45° relative to the second direction.

14 . A method of repairing a composite structure, the method comprising:
applying a patch, comprising a plurality of plies comprising fibers embedded in a matrix material and a patch adhesive coupled to the plurality of plies, onto a first portion of a cured composite over and surrounding an abnormality in a solid laminate of the cured composite so that the plurality of plies is adhesively bonded directly to the first portion of the cured composite via the patch adhesive and the patch covers a predetermined area greater than the abnormality of the cured composite, wherein:
the cured composite comprises a cured-composite plurality of unidirectional fibers; and
the plurality of plies comprises:
a first ply, wherein the first ply comprises a first-ply plurality of unidirectional fibers embedded in a matrix material and oriented in a first direction that is parallel to the cured-composite plurality of unidirectional fibers; and
a second ply, wherein the second ply in the plurality of plies comprises a second-ply plurality of unidirectional fibers oriented in a second direction that is different than the first direction; and

applying a pressure-sensitive tape, comprising a metallic material and a tape adhesive fixed to the metallic material, over the patch and the cured composite such that the tape adhesive of the pressure-sensitive tape adheres to the patch and a second portion of the cured composite surrounding the first portion of the cured composite.

15 . The method of claim 14 , further comprising:
removing a coating layer of the cured composite surrounding the abnormality of the cured composite; prior to applying the patch and after removing the coating layer of the cured composite, abrading the first portion and the second portion of the cured composite to form an abraded portion of the cured composite; prior to applying the patch and after removing the coating layer, cleaning the abraded portion of the cured composite with a solvent to form a clean abraded portion of the cured composite; and wherein applying the patch comprises applying the patch onto the clean abraded portion of the cured composite.

16 . The method of claim 14 , wherein:
the patch further comprises a protective layer that covers and is releasably coupled to the patch adhesive; and the method further comprises removing the protective layer from the patch adhesive before applying the patch onto the cured composite.

17 . The method of claim 14 , further comprising, after applying the patch onto the cured composite, applying a vacuum bag over the patch and reducing a pressure within the vacuum bag.

18 . The method of claim 14 , wherein:
the patch has a patch curvature that is different from a composite curvature of the cured composite; and applying the patch onto the cured composite further comprises adjusting the patch curvature to complement the composite curvature.

19 . A structural reinforcement for repairing an abnormal surface of a composite structure, comprising:
a patch, having a patch strength and comprising:
a plurality of plies in a stacked arrangement, wherein:
a first ply of the plurality of plies is made of a fiber-reinforced polymeric material comprising a matrix material and a first-ply plurality of unidirectional fibers embedded in the matrix material and oriented in a first direction that is parallel to a cured-composite plurality of unidirectional fibers of the composite structure;
a second ply of the plurality of plies comprises a second-ply plurality of unidirectional fibers oriented in a second direction that is different than the first dir

Assignees

• Boeing Co

Inventors

• Staal Remmelt Andrew
• Edwards Glory C
• Smith Gregory J
• Register Justin H
• Fidgeon Ernie

Classifications

• B32B5/024

  Woven fabric · CPC title

• B32B15/14

  next to a fibrous or filamentary layer · CPC title

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• B29L2031/3076

  Aircrafts (blades, propellers B29L2031/08) · CPC title

• B32B5/263

  next to one or more woven fabric layers · CPC title