Methods and systems for fabricating composite stiffeners with a rigid/malleable SMP apparatus

摘要

A method and apparatus for fabricating a composite part with a shape memory polymer (SMP) apparatus usable as both a rigid tool and as a bladder. The SMP apparatus may be heated until malleable, shaped, and then cooled in a desired rigid tool configuration. The composite material may be applied onto the SMP apparatus and then placed into a rigid external mold and heated to composite cure temperatures at which the SMP apparatus is malleable. In some embodiments, an impermeable sheet of material may also be placed over portions of the composite material to compress it against the SMP apparatus. A pressure differential may be induced which urges the SMP apparatus to compress the composite material against the rigid external mold. When the composite material is cured, the pressure differential may be equalized and/or reversed and the malleable SMP apparatus may be removed from within the composite part.

主权项

1. A method of fabricating a composite part, the method comprising:
applying composite material onto at least a portion of a shape memory polymer (SMP) apparatus; placing the composite material and SMP apparatus into a cavity within a rigid molding tool, such that at least a portion of the composite material rests against the rigid molding tool; placing an impermeable sheet of material over the composite material and SMP apparatus; sealing the impermeable sheet of material to at least one of the rigid molding tool and the SMP apparatus; heating the composite material to a composite material cure temperature; triggering the SMP apparatus to change in modulus from a rigid state to a malleable state; inducing a pressure differential sufficient to drive the impermeable sheet of material and the SMP apparatus, in the malleable state, toward the composite material, thereby compressing at least a portion of the composite material against the rigid molding tool during curing of the composite material into the composite part; removing the impermeable sheet of material from the rigid molding tool after the composite material is cured into the composite part; and removing the SMP apparatus from within the composite part.