Systems and methods for compacting composite components

A method for compacting a component using a compaction tool, the compaction tool comprising a first tool defining a first tool portion and a second tool defining a second tool portion, the method comprising:

• positioning at least a portion of the component between the first tool portion and the second tool portion;
• positioning a sandwich structure between the first tool portion and the portion of the component, the sandwich structure comprising a thermally expandable material and a rigid shell, wherein the rigid shell maintains its shape when subjected to elevated temperatures and pressures, wherein the thermally expandable material is positioned between the first tool portion and the rigid shell, the rigid shell is positioned between the thermally expandable material and the component such that the rigid shell is configured to contact the component, and wherein the rigid shell is shaped complimentary to an inner surface of the component;
• and
• compacting the component by subjecting the thermally expandable material to elevated temperatures and pressures while the sandwich structure is between the first tool portion and the portion of the component such that the thermally expandable material expands to apply a force on the rigid shell, which causes the rigid shell to be pushed towards the portion of the component and causes the rigid shell to contact and apply a force on the portion of the component so as to compact the portion of the component between the rigid shell and the second tool portion.