Multilayer woven fibrous structure including a hollow tubular part, production method thereof and composite part comprising same

A method of making a structure woven as a single piece by multilayer weaving and including at least one hollow portion that is longitudinally partitioned, the method comprising:

• weaving warp yarns of a first set of layers of warp yarns with weft yarns including at least some that are inserted in layers of warp yarns of the first set of layers of warp yarns while being taken over a distance that is greater than a length of the first set of layers of warp yarns measured in a weft direction to have weft yarn end portions available that extend beyond a zone of weaving;
• weaving warp yarns of a second set of layers of warp yarns with weft yarns including at least some that are inserted in layers of warp yarns of the second set of layers of warp yarns while being taken over a distance that is greater than a length of the second set of layers of warp yarns measured in the weft direction to have weft yarn end portions available that extend beyond the zone of weaving, the first and second sets of layers of warp yarns being arranged one above another and being interlinked over a fraction only of their width in the weft direction;
• returning the weft yarn end portions so as to weave the weft yarn end portions with warp yarns by reinserting the weft yarn end portions in layers of warp yarns;
• and
• forming the partitioned hollow portion by looping the first and second sets of layers of warp yarns back onto themselves and applying traction to the ends of the reinserted weft yarns, the hollow portion being entirely defined by a multilayer woven wall including a plurality of layers of yarns interlinked by weaving throughout a thickness of the wall.