Method for manufacturing a hollow composite material part comprising internal stiffeners

Abstract

The invention relates to a method for manufacturing a composite part (10, 20) comprising steps consisting of: producing a fibrous preform (36) of the composite part; producing mandrels (31-34) from a molded soluble paste; forming a fibrous reinforcement (35) around each mandrel; inserting the assembled mandrels into the preform at a location of a cavity (3) to be formed in the composite part; inserting the preform incorporating the mandrels into a mold; injecting a resin into the mold to obtain the composite part, the resin diffusing into the preform and the fibrous reinforcements; demolding the composite part; forming a channel (38) in the composite part to reach the mandrels; and injecting a solvent into the channel to dissolve the mandrels, and form the cavity in the composite part, the fibrous reinforcements between the mandrels forming stiffeners in the cavity. Figure 4H