Tooling apparatus and method for double-vacuum-bag degassing of a composite layup

A tooling apparatus for manufacturing a composite structure, comprising:

• a rigid outer plate supported in spaced relation above a layup plate, the layup plate configured to receive a tool side of a composite layup;
• a tubular inner vacuum bag defining an inner vacuum chamber and configured to be positioned between the rigid outer plate and a bag side of the composite layup;
• an outer vacuum bag sealing the composite layup and tubular inner vacuum bag to the layup plate, the outer vacuum bag and the tubular inner vacuum bag collectively defining an outer vacuum chamber containing the composite layup and the tubular inner vacuum bag;
• an outer bag vacuum source fluidly coupled to the outer vacuum bag and configured to apply an outer bag vacuum pressure on the outer vacuum chamber;
• an inner bag vacuum source fluidly coupled to the tubular inner vacuum bag and configured to apply an inner bag vacuum pressure on the inner vacuum chamber during application of the outer bag vacuum pressure on the outer vacuum chamber;
• and
• the rigid outer plate separating the outer vacuum bag from at least one of the tubular inner vacuum bag and the composite layup at locations where the tubular inner vacuum bag applies compaction pressure to the bag side of the composite layup.

A tooling apparatus for manufacturing a composite structure, comprising:

• a clamshell mold having a mold lower half and a mold upper half configured to respectively receive a lower skin layup and an upper skin layup and an internal element layup extending between a bag side of the lower skin layup and a bag side of the upper skin layup;
• a pair of tubular inner vacuum bags each defining an inner vacuum chamber and supported on a bag carrier and positioned between the lower skin layup and the upper skin layup and located on opposite sides of the internal element layup;
• an outer vacuum bag covering at least a portion of the clamshell mold such that the outer vacuum bag and the pair of tubular inner vacuum bags collectively define an outer vacuum chamber containing the lower skin layup, the upper skin layup, and the internal element layup;
• an outer bag vacuum source fluidly coupled to the outer vacuum bag and controlling an outer bag vacuum pressure within the outer vacuum chamber;
• and
• an inner bag vacuum source fluidly coupled to the tubular inner vacuum bags and controlling an inner bag vacuum pressure within the inner vacuum chamber.

A method of manufacturing a composite structure, comprising:

• supporting a tool side of a composite layup on a rigid outer tool;
• positioning a tubular inner vacuum bag against a bag side of the composite layup, the tubular inner vacuum bag having an interior defining an inner vacuum chamber;
• covering, using an outer vacuum bag, at least a portion of the rigid outer tool such that the outer vacuum bag and the tubular inner vacuum bag collectively define an outer vacuum chamber containing the composite layup;
• applying an outer bag vacuum pressure to the outer vacuum chamber while applying an inner bag vacuum pressure to the inner vacuum chamber, the inner bag vacuum pressure being no less than the outer bag vacuum pressure;
• and
• drawing gas from the composite layup and out of the outer vacuum bag while applying the outer bag vacuum pressure and the inner bag vacuum pressure, the rigid outer tool separating the outer vacuum bag from at least one of the tubular inner vacuum bag and the composite layup at locations where the tubular inner vacuum bag applies compaction pressure to the bag side of the composite layup.