Patent ID: 8388789

Claim:
A method of manufacturing an arcuate structural member of a fuselage frame of composite material uses tapes of resin pre-impregnated unidirectional fibers, the member includes a web lying in a radial plane and at least one radially outer cylindrical flange, the method comprising the steps of: providing an elongate, arcuate forming mandrel having a flat radial surface forming an angular edge with a radially outer, convex cylindrical surface; providing a plurality of promontory-shaped formations radiating outwardly with respect to the cylindrical surface; laying a plurality of layers of pre-impregnated composite material on the forming mandrel to form at least a first flat arcuate laminate, with a part of the laminate projecting radially outwardly beyond the angular edge; covering the mandrel, the laminate and the promontory formations with a membrane; applying a vacuum underneath the membrane, causing the membrane to urge the projecting part of the laminate against the cylindrical surface and against the promontory formations, whereby the projecting part, bent by the membrane, partially copies the shape of the cylindrical surface of the mandrel in the intermediate areas between the promontory formations, whereas these prevent or retard the contact of the projecting part with the cylindrical surface near the promontory formations; removing discrete portions of the projecting part near the promontory formations, obtaining peripheral cavities spaced apart from one another by flange lengths in the form of cylindrical segments.