Patent ID: 8562780

Claim:
A process for the production of a stiffened panel made of composite material, comprising: producing a panel ( 12 ) comprising fibers woven in a resin matrix; and stiffening said panel by installing a stiffener ( 14 ) on one surface of said panel ( 12 ), said stiffener ( 14 ) made of composite material, said stiffener ( 14 ) having a cross-section comprising a non-flat central part, having a convex surface, with caps on either side of said central part, said caps in contact with said panel and said central part being separated from said panel, said caps terminating in lateral edges ( 60 , 60 ′) running a length of said stiffener ( 14 ), wherein said producing and stiffening steps comprise the stages of depositing the fibers that constitute said panel on a rigid device ( 50 ), depositing said stiffener ( 14 ) by inserting a core ( 52 , 66 ) between said stiffener and the panel to thereby form a unit, covering the unit with a sealed wall connected to the rigid device ( 50 ) on a periphery of said panel, the sealed wall comprising i) a rigid counter-mold ( 54 ) placed in contact with the convex surface of said stiffener ( 14 ), lateral edges ( 58 , 58 ′) of the rigid counter-mold ( 54 ) not going beyond the lateral edges ( 60 , 60 ′) of said caps, ii) at least one band ( 62 ) covering zone(s) on said one surface of said panel ( 12 ) not covered by said stiffener ( 14 ), said at least one band ( 62 ) being rigid enough to transmit compression forces by allowing play between said at least one band ( 62 ) and said stiffener ( 14 ), and iii) a deposited seal ( 64 ) located between a lateral edge of said at least one band ( 62 ) and a corresponding lateral edge of said counter-mold ( 54 ), the seal ( 64 ) covering the lateral edges ( 60 , 60 ′) of said caps, said seal ( 64 ) having two states, a first malleable state during application of said seal ( 64 ) so that said seal ( 64 ) adapts to a profile of the lateral edges of the caps and a hardened state after the application and during a subsequent polymerization sufficient to ensure the transmission of compression forces in a manner that is essentially identical to the rigid counter-molds ( 54 ) and to the at least one band ( 62 ) so as not to generate a pressure gradient, and polymerizing the unit by subjecting the unit to pressure.