FIBROUS PREFORM OF A TURBOMACHINE BLADE MADE OF COMPOSITE MATERIAL WITH IN-BUILT PLATFORM, AND METHOD OF PRODUCING SAME

摘要

The invention relates to a method for producing a fibrous preform for the manufacture of a turbomachine blade made of composite material, the method involving using three-dimensional weaving to create a fibrous rough form (100) in a single piece with layers of longitudinal threads (c1 to c24) joined together by threads of layers of transverse threads (t1 to t24), and shaping the fibrous rough form to obtain a fibrous preform in a single piece having a part that forms the aerofoil preform and at least a part that forms a platform preform. During the course of the weaving process, the threads (c5 to c7) of a first group of longitudinal threads are led out from the fibrous rough form on the side of one of the lateral faces (110a) of the rough form to form a part (120) that corresponds to a preform of a blade platform, and threads (c3 and c4) of a second group of longitudinal threads are injected into the fibrous rough form with mutual criss-crossing between the threads of the first group and the threads of the second group. The invention also relates to a preform obtained using this method.