| 摘要 |
To manufacture an arcuate structural member (10) of a fuselage frame of composite material, tapes of resin pre-impregnated unidirectional fibres are used. The member (10) includes a web (11) lying in a radial plane and a radially outer cylindrical flange (12). Use is made of an elongate, arcuate forming mandrel (M1) having a flat radial surface (F) forming an angular edge (D) with a radially outer, convex cylindrical surface (S); and a series of promontories (P) radiating outwardly with respect to the cylindrical surface (S) are provided. A plurality of layers of pre-impregnated composite material are laid on the mandrel (M1) so as to form a first flat arcuate laminate (20'), with a part (20") of the laminate projecting radially outwardly beyond the angular edge (D). The mandrel (M1), the laminate (20') and the promontories (P) are covered with a membrane (E). A vacuum is then applied underneath the membrane, causing the membrane to urge the projecting part (20") of the laminate against the cylindrical surface (S) and against the promontories (P). In this way the projecting part, bent by the membrane, partially copies the shape of the cylindrical surface (S) of the mandrel in the intermediate areas between the promontories, whereas these prevent or retard the contact of the projecting part (20") with the cylindrical surface (S) near the promontories. Finally, discrete portions of the projecting part (20") near the promontories are removed, obtaining peripheral cavities (15) spaced apart from one another by flange lengths (22) in the form of cylindrical segments. |
