Method for manufacturing a vane comprising a reinforced cavity

A method for manufacturing a turbomachine vane made of composite material and having a cavity, the method comprising:

• producing a core having the shape of the cavity of the vane to be manufactured, said core comprising a reinforcing structure occupying only a portion of a volume of the core, the reinforcing structure having, at least in part, a lattice structure, the core further comprising a sealed envelope defining the outer surface of said core, the lattice structure consisting of a three-dimensional assembly of bars connecting inner walls of the envelope at a number of points, at least one bar of the three-dimensional assembly of bars extending from one of the inner walls of the envelope to an opposite inner wall of the envelope;
• forming a composite material skin around the core, the reinforcing structure comprising at least one support element joining two opposing inner walls of the envelope, and
• studying natural modes of vibration of the walls of the cavity in order to determine a location of anti-nodes of the natural modes of vibration, the support element being positioned at one or more of the anti-nodes of the natural modes of vibration of the walls of the cavity.