Method for the manufacturing of a stiffened structural component made of composite material and structural component

A structural component made of composite material and comprising:

• a skin formed by a plurality of layers of composite material;
• a plurality of stiffening stringers made of composite material, fixed to the skin and oriented substantially parallel to a longitudinal direction of the structural component;
• and
• a plurality of stiffening ribs made of composite material, fixed to the skin and oriented transversally to the longitudinal direction of the structural component;
• the structural component having a plurality of sub-panels joined to one another and comprising, each, a sub-skin defined by first layers of said plurality of layers of composite material and at least one stringer and at least one rib which are fixed to an internal surface of the sub-skin;
• wherein each sub-skin has an external surface opposite to said internal surface;
• wherein the structural component comprises a continuous sub-wall defined by the union of the external surfaces of the sub-skins of the sub-panels joined to one another;
• wherein second layers of said plurality of layers of composite material are laminated onto the first layers so as to define a continuous external over-skin layered on said sub-wall;
• and
• wherein the skin is defined by the set of said sub-skin and said over-skin, and comprises the first layers and the second layers.

A method of manufacturing a structural component, the method including the steps of:

• a) laminating first layers of non-cured composite material onto a forming tool thus forming a sub-skin comprising a first surface in contact with the forming tool and a second surface opposite to the first surface;
• b) arranging at least one stiffening stringer made of pre-cured composite material on the second surface of the sub-skin along a longitudinal direction of the structural component;
• c) arranging at least one stiffening rib made of pre-cured composite material on the second surface of the sub-skin, along a transversal direction which is transversal to the longitudinal direction of the structural component;
• d) applying pre-set temperature and pressure to the assembly defined by the sub-skin, by the at least one stringer and by the at least one rib, so as to cure the composite material and determine the rigid and integral fixing of the stringer and of the rib to the second surface of the sub-skin, thus obtaining a sub-panel made of cured composite material;
• e) repeating steps a) to d) to obtain a plurality of sub-panels;
• f) arranging the obtained sub-panels onto a central support, so as to at least partially surround the central support and so that the second surface of each sub-skin faces towards the central support and the first surface of each sub-skin faces outwards;
• g) joining together pairs of laterally adjacent sub-panels at the respective sub-skins, so as to define a pre-component having a continuous external surface defined by the set of the first surfaces of the sub-skins of the jointed sub-panels;
• h) laminating second layers of non-cured composite material on the external surface of the pre-component, so as to define a continuous external over-skin onto the pre-component, and so as to define a skin, said skin consisting of said first layers and said second layers;
• and
• i) applying pre-set temperature and pressure to the assembly comprising the pre-component and the continuous external over-skin, so as to cure the composite material and determine the rigid and integral fixing of the second layers to the first layers.