A method for the manufacture of a structural component made of composite material reinforced with stiffening stringers, defining, in use, at least part of an outer shell of a casing and comprising a skin and a plurality of stringers having a hollow section rigidly and integrally fixed to said skin, the method comprising the steps of:
- a) laminating a plurality of first layers of non-cured or pre-cured composite material onto an external surface of a cure tool to form said skin, so that a first face of said skin defining, in use, the internal surface of the structural component facing the internal environment of the casing is facing the external surface of the tool;
- b) laminating respective pluralities of second layers of composite material on longitudinal hollow expandable inserts, thereby forming the plurality of said stringers each having a longitudinal axis, so that each stringer is wound, at least partially, on an external surface of one respective hollow insert so as to define a longitudinal cavity of each stringer that is engaged by a relative hollow insert to obtain a plurality of reinforcing elements each defined by one said stringer wound on one said hollow insert;
- c) positioning each reinforcing element on a second face of the skin opposite to said first face and defining, in use, the external surface of the structural component facing the environment external to the casing, and so that the cavities of each stringer face towards said second face;
- d) holding each reinforcing element on the second face of the skin in a respective fixed position with respect to the tool;
- e) housing the tool, the skin and the reinforcing elements inside a vacuum bag;
- f) compacting together the first layers forming the skin with the second layers forming the stringers by applying vacuum inside the vacuum bag;
- g) housing, after step f), tool, skin and reinforcing elements in a further vacuum bag;
- h) sealing the further vacuum bag to delimit a vacuum chamber therein;
- i) applying preset temperature and pressure to the outside of the vacuum chamber, in order to cure the composite material and determine the rigid and integral attachment of the stringers to the second face of the skin;
- wherein the method further comprises the step of:
- n) wrapping, prior to step c), the vacuum bag around the skin laminated on the tool, said vacuum bag comprising a plurality of adjacent longitudinal pockets sealable in a fluid-tight manner between one another;
- wherein step c) of positioning comprises placing each reinforcing element inside a respective pocket, sequentially;
- wherein the housing of step (e) is achieved through the wrapping of step (n) and the positioning of step (c);
- wherein step f) of compacting is performed by sequentially applying the vacuum inside each pocket housing the respective reinforcing element;
- and wherein step d) of holding is carried out by means of the compaction referred to in step f).