Method of fabricating aircraft fuselage structure

A method of fabricating an aircraft fuselage structure comprising a plurality of ring-shaped members disposed coaxially and spaced axially from each other with substantially parallel orientation relative to each other, a plurality of stringers extending axially of the ring-shaped members in parallel spaced disposition circumferentially of the ring-shaped members which are U-shaped in cross section and have a hollow interior opening in an axial direction to thereby fixedly connect the ring-shaped members with each other so as to form a framework, thereby preventing deformation thereof during assembling and curing of the fuselage and an outer skin of a prepeg material secured to an outer surface of the framework to cover the same;

• said method comprising the steps of:
• preparing a plurality of ring-shaped members of a fiber-reinforced laminated material, each provided with a plurality of recesses around the outer peripheral surface thereof at positions spaced apart in the circumferential direction thereof;
• preparing a plurality of stringers of a fiber-reinforced laminated material, each consisting of a plate member and a convex part on the plate member, said convex part corresponding in shape to each of said recesses;
• arranging said ring-shaped members coaxially at spaced apart dispositions with substantially parallel orientation relative to each other and with the recesses of all the ring-shaped members in axial alignment;
• inserting into the ring-shaped members a silicone bag having open opposite ends and annular and longitudinal grooves which accommodate the ring-shaped members and the stringers to fixedly mount the ring-shaped members on the outer surface of the bag;
• placing said stringers on said silicone bag with the convex part of each stringer fitted in, and passing through, a set of axially aligned recesses of the ring-shaped members, to form a framework of the ring-shaped members and the stringers;
• inserting a laminating jig into the bag to support said framework from within the bag and to form an assembly of the laminating jig, the bag, the ring-shaped members and the stringers;
• fitting said assembly on a rotatable winding jig;
• winding a fiber-reinforced prepeg around the outer surface of said assembly by rotating the winding jig, so as to form a layer of the prepeg around said assembly;
• setting the layer of the prepeg;
• removing said assembly from the winding jig;
• removing the laminating jig from the assembly;
• subjecting the assembly to bagging and curing steps;
• and
• removing the bag to obtain the fuselage structure.