Systems and methods for locally curing composite structures
A system for locally curing a composite structure includes a constraining container including a cover and having an interior volume. The cover is configured to enclose a portion of a composite structure. The system includes a retainer configured to hold the cover against the composite structure. The system included an expandable medium configured to be disposed within the interior volume of the cover between the walls and the composite structure.
1 . A method comprising:
enclosing a portion of a composite structure and an initial volume of an expandable medium within an interior volume formed by a constraining container and the composite structure;
holding at least a portion of the constraining container against the composite structure;
producing a predetermined change in at least one of an internal cellular structure or a chemical state of the expandable medium thereby expanding the expandable medium disposed within the interior volume formed by the constraining container and the composite structure toward a predetermined volume that is greater than the interior volume and applying positive pressure to the composite structure; and
curing the composite structure under the positive pressure.
2 . The method of claim 1 , further comprising moving the cover relative to the composite structure.
3 . The method of claim 1 , wherein:
the composite structure comprises a plurality of composite layers; and
at least a portion of the plurality of composite layers is uncured or partially cured.
4 . The method of claim 3 , wherein at least one of the plurality of composite layers is a composite patch configured to repair a portion of a composite surface of the composite structure.
5 . The method of claim 1 , further comprising selectively varying the interior volume formed by the constraining container and the composite structure.
6 . The method of claim 1 , further comprising:
applying a casting between the expandable medium and a composite surface of the composite structure; and
hardening the casting.
7 . The method of claim 1 , further comprising supporting at least the portion of the composite structure on a base of the constraining container.
8 . The method of claim 7 , further comprising coupling a cover of the constraining container to the base.
9 . The method of claim 1 , further comprising increasing a temperature of the expandable medium to at least an activation temperature.
10 . The method of claim 8 , wherein the cover is thermally reflective.
11 . The method of claim 8 , wherein the cover comprises a plurality of walls.
12 . The method of claim 11 , further comprising moving at least one wall of the plurality of walls to modify the interior volume of the cover.
13 . The method of claim 1 , wherein a cover of the constraining container comprises an overlay that is flexible and non-expandable.
14 . The method of claim 1 , wherein a cover of the constraining container is held against the composite structure by a retainer.
15 . The method of claim 14 , wherein the retainer comprises at least one clamp.
16 . The method of claim 1 , wherein the composite structure comprises polymer materials and fiber reinforcement materials.
17 . The method of claim 1 , wherein the curing the composite structure comprises heating the composite structure.
18 . A method comprising:
enclosing a portion of a composite structure and an initial volume of an expandable medium within an interior volume formed by a constraining container and the composite structure, wherein the composite structure comprises a plurality of composite layers, and wherein and at least composite layer of the plurality of composite layers is uncured or partially cured;
holding at least a portion of the constraining container against the composite structure;
producing a predetermined change in at least one of an internal cellular structure or a chemical state of the expandable medium thereby expanding the expandable medium disposed within the interior volume formed by the constraining container and the composite structure toward a predetermined volume that is greater than the interior volume and applying positive pressure to the composite structure;
selectively varying the interior volume formed by the constraining container and the composite structure thereby controlling the positive pressure to the composite structure; and
curing the composite structure under the positive pressure.
19 . The method of claim 18 , wherein the curing the composite structure comprises heating the composite structure.
20 . The method of claim 1 , wherein producing the predetermined change in at least one of the internal cellular structure or the chemical state of the expandable medium comprises heating the expandable medium.