Repair concept comprising pre-impregnated pinned foam core for sandwich structural components

Patent metadata

Field	Value
Publication number	US-10611102-B2
Application number	US-201715602358-A
Country	US
Kind code	B2
Filing date	May 23, 2017
Priority date	May 25, 2016
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

A method for repairing a sandwich composite structure comprising a pinned foam core. In the sub-region in which the pinned foam core is damaged, the at least one upper or lower cover layer is removed as far as the pinned foam. The pinned foam core is removed. A pinned replacement foam core is inserted, the pinned replacement foam core being impregnated with a resin. An upper or lower replacement cover layer is applied. The pinned replacement foam core and optionally the upper or lower replacement cover layer are cured.

First claim

The invention claimed is:

1. A method for repairing a sandwich composite structure comprising a pinned foam core between at least one upper and at least one lower cover layer, in which the pinned foam core is damaged in a sub-region of the sandwich composite structure, comprising the following steps in the following sequence:
a) removing the at least one upper or lower cover layer as far as the pinned foam core in the sub-region in which the pinned foam core of the sandwich composite structure is damaged;
b) removing the pinned foam core in the sub-region in which the pinned foam core of the sandwich composite structure is damaged;
c) inserting a pinned replacement foam core, corresponding in size to the removed pinned foam core of step b), in the sub-region in which the pinned foam core was removed in step b), the pinned replacement foam core being impregnated at least with a resin;
d) applying an upper or lower replacement cover layer in the region in which one was removed in step a),
wherein the pinned replacement foam core and optionally the upper or lower replacement cover layer are cured.

2. The method for repairing a sandwich composite structure of claim 1 , wherein the pinned replacement foam core and the upper or lower replacement cover layer are cured together.

3. The method for repairing a sandwich composite structure of claim 1 , wherein, before step c), in the sub-region in which the pinned foam core was removed in step b), a binder is applied to the remaining pinned foam core remaining in this sub-region.

4. The method for repairing a sandwich composite structure of claim 1 , wherein, before step c), in the sub-region in which the pinned foam core was removed in step b), a binder is applied to the remaining lower cover layer remaining in this sub-region.

5. The method for repairing a sandwich composite structure of claim 1 , wherein, before step c), in the sub-region in which the pinned foam core was removed in step b), a binder is applied to the remaining upper cover layer remaining in this sub-region.

6. The method for repairing a sandwich composite structure of claim 1 , wherein, after step c), a binder is applied in the region of the upper cover layer in which this layer was removed.

7. The method for repairing a sandwich composite structure of claim 1 , wherein, after step c), a binder is applied in the region of the lower cover layer in which this layer was removed.

8. A repaired sandwich composite structure, manufactured by a method comprising the following steps in the following sequence:
a) removing the at least one upper or lower cover layer as far as the pinned foam core in the sub-region in which the pinned foam core of the sandwich composite structure is damaged;
b) removing the pinned foam core in the sub-region in which the pinned foam core of the sandwich composite structure is damaged;
c) inserting a pinned replacement foam core, corresponding in size to the removed pinned foam core of step b), in the sub-region in which the pinned foam core was removed in step b), the pinned replacement foam core being impregnated at least with a resin;
d) applying an upper or lower replacement cover layer in the region in which one was removed in step a),
wherein the pinned replacement foam core and optionally the upper or lower replacement cover layer are cured.

9. The method for repairing a sandwich composite structure of claim 1 , wherein before step c) the replacement foam core is vacuum-bagged.

10. The method for repairing a sandwich composite structure of claim 9 , wherein before step c) the replacement foam core is stored at a temperature of less than 10° C.

11. The method for repairing a sandwich composite structure of claim 1 , wherein before step c) the replacement foam core is stored at a temperature of less than 10° C.

12. The repaired sandwich composite structure of claim 8 , wherein before step c) the replacement foam core is vacuum-bagged.

13. The repaired sandwich composite structure of claim 12 , wherein before step c) the replacement foam core is stored at a temperature of less than 10° C.

14. The repaired sandwich composite structure of claim 8 , wherein before step c) the replacement foam core is stored at a temperature of less than 10° C.

Assignees

• Airbus Operations Gmbh

Inventors

• Sayeh Mohamed-Mourad
• Karrasch Tobias

Classifications

• B29C70/086

  and with one or more layers of pure plastics material, e.g. foam layers (applying a non-preformed coating, e.g. a gel-coat, B29C37/0025; with foam blocks B29C70/86) · CPC title

• B29C73/04 Primary

  using preformed elements · CPC title

• B29L2009/00

  Layered products · CPC title

• B29C69/001

  a shaping technique combined with cutting, e.g. in parts or slices combined with rearranging and joining the cut parts (for reinforced material B29C70/545; B29C49/4278, B29C51/268 take precedence) · CPC title

• B29K2105/04

  cellular or porous · CPC title