Method of manufacturing a part made of composite material

A method for manufacturing a part formed of composite material including a thermoplastic or thermosetting matrix reinforced with fibers, the method comprising the steps of:

• winding or depositing pre-impregnated fibers about a mandrel so as to form a preform, the pre-impregnated fibers being pre-impregnated with a thermoplastic matrix or a thermosetting matrix and the mandrel being formed of a thermoplastic material or a thermosetting material;
• winding a heat-shrinkable film around the preform;
• polymerizing an intermediate product including the preform and the heat-shrinkable film at a temperature of polymerization of the thermoplastic material or the thermosetting material of the preform;
• and
• removing the heat-shrinkable film from the intermediate product so as to obtain a one-piece part including the composite material and the mandrel;
• wherein the mandrel includes a main tubular part with a first end and a second end and at least one forked part assembled to the first end of the main tubular part or to the second end of the main tubular part;
• further comprising a step of adding at least one reinforcement patch only around the at least one forked part before the step of winding or depositing pre-impregnated fibers around the mandrel.