Abstract: The invention relates to a compaction assembly comprising a shaping mold (24) delimiting an upwardly open housing, capable of receiving a woven preform cut out beforehand (10a), and a vertically moveable compaction tool (128) and forming, with the shaping mold, (24), a compaction assembly for the preform placed beforehand in the housing. The compaction tool (128) includes at least one foot portion (128A). The compaction tool (128) comprises at least three separate compaction blocks (1281-1287). Application to the manufacturing of composite fan blades for a turbomachine.

Abstract: A fiber blank woven as a single piece by three-dimensional weaving to make a closed box-structure platform out of composite material for a turbine engine fan. In each plane of the fiber blank, a set of warp yarns interlinks layers of weft yarns in first, second, and third portions of the fiber blank, while leaving a closed non-interlinked zone separating the first and second portions over a fraction of the dimension of the fiber blank in the warp direction between an upstream non-interlinking limit and a downstream non-interlinking limit, and while leaving at least one open non-interlinked zone separating the second and third portions over a fraction of the dimension of the fiber blank in the warp direction from a non-interlinking limit to a downstream edge of the fiber blank. A method of fabricating a preform for the closed box-structure platform can use such a fiber blank.

Abstract: Compacting assembly comprising a shaper mold (24) defining an upwardly open housing suitable for receiving a woven preform (10a) that has previously been cut out, and a vertically movable compacting tool (128) that, together with the shaper mold (24), forms a compacting assembly for compacting said preform previously placed in the housing. The compacting tool (128) comprises at least a root portion (128A). The invention is applicable to fabricating turbine engine composite blades.

Abstract: In a fiber structure woven as a single piece by three-dimensional weaving, first warp yarns interlink layers of weft yarns in a first portion of the fiber structure adjacent to a non-interlinked zone and also weft yarns of a second portion of the fiber structure beyond the non-interlinked zone, and second warp yarns interlink layers of weft yarns of the second portion of the fiber structure adjacent to the non-interlinked zone and also layers of weft yarns of the first portion of the fiber structure beyond the non-interlinked zone, such that the paths of the first and second warp yarns cross in at least one transition zone extending within the fiber structure from the end of the non-interlinked zone, the transition zone extending in the warp direction over a distance greater than the pitch between adjacent warp columns.

Abstract: A method for cutting a preform usable for production of a turbomachine part and including a weaving of a plurality of threads, the threads including single threads that are visually identifiable, along a cutting contour calculated based on a preform model in which the threads have a reference arrangement, the method including: taking an image of the preform; processing the image to determine a deviation in an arrangement of the threads which are visually identifiable relative to the reference layout; correcting the cutting contour according to the deviation; and cutting the preform along the corrected cutting contour.

Abstract: A fiber preform is formed by a fiber structure woven by three-dimensional weaving with a plurality of layers of warp yarns interlinked by weft yarns of a plurality of layers of weft yarns, the fiber preform having a first portion and a second portion that extend one another in the weft direction and that are at an angle to each other. In the fold zone and in each weft plane of the fiber structure, two weft yarns situated in a region adjacent to an outside face of the fiber structure situated on the inside of the corner present paths that cross, so that less curvature is imposed on these yarns.

Abstract: In a fiber structure woven as a single piece by three-dimensional weaving, first weft yarns interlink layers of warp yarns in a first portion of the fiber structure adjacent to a non-interlinked zone and also warp yarns of a second portion of the fiber structure beyond the non-interlinked zone, and second weft yarns interlink layers of warp yarns of the second portion of the fiber structure adjacent to the non-interlinked zone and also layers of warp yarns of the first portion of the fiber structure beyond the non-interlinked zone, such that the paths of the first and second weft yarns cross in at least one transition zone extending within the fiber structure from the end of the non-interlinked zone, the transition zone extending in the weft direction over a distance greater than the pitch between adjacent warp columns.

Abstract: A fiber blank woven as a single piece by three-dimensional weaving to make a closed box-structure platform out of composite material for a turbine engine fan. In each plane of the fiber blank, a set of warp yarns interlinks layers of weft yarns in first, second, and third portions of the fiber blank, while leaving a closed non-interlinked zone separating the first and second portions over a fraction of the dimension of the fiber blank in the warp direction between an upstream non-interlinking limit and a downstream non-interlinking limit, and while leaving at least one open non-interlinked zone separating the second and third portions over a fraction of the dimension of the fiber blank in the warp direction from a non-interlinking limit to a downstream edge of the fiber blank. A method of fabricating a preform for the closed box-structure platform can use such a fiber blank.

Abstract: A fiber blank woven as a single piece by three-dimensional weaving to make a closed box-structure platform out of composite material for a turbine engine fan. In each plane of the fiber blank, a set of warp yarns interlinks layers of weft yarns in first, second, and third portions of the fiber blank, while leaving a closed non-interlinked zone separating the first and second portions over a fraction of the dimension of the fiber blank in the warp direction between an upstream non-interlinking limit and a downstream non-interlinking limit, and while leaving at least one open non-interlinked zone separating the second and third portions over a fraction of the dimension of the fiber blank in the warp direction from a non-interlinking limit to a downstream edge of the fiber blank. A method of fabricating a preform for the closed box-structure platform can use such a fiber blank.

Abstract: A fiber preform for a vane module of an intermediate casing of a turbine engine, the preform being obtained by three-dimensional weaving. The preform includes first longitudinal segment presenting opposite first and second ends and suitable for forming a first vane; a second longitudinal segment presenting first and second opposite ends and suitable for forming a second vane; and a first transverse segment connecting together the first and second longitudinal segments by their first ends, and suitable for forming a first transverse vane portion such as a flange or a platform.

Abstract: A method for cutting a preform usable for production of a turbomachine part and including a weaving of a plurality of threads, the threads including single threads that are visually identifiable, along a cutting contour calculated based on a preform model in which the threads have a reference arrangement, the method including: taking an image of the preform; processing the image to determine a deviation in an arrangement of the threads which are visually identifiable relative to the reference layout; correcting the cutting contour according to the deviation; and cutting the preform along the corrected cutting contour.

Abstract: A fiber structure includes a blank portion formed as a single part by three-dimensional weaving between a first plurality of yarn layers and a second plurality of yarn layers, the blank portion corresponding to all or part of a fiber reinforcement preform for a part made of composite material. Outside the blank portion, the fiber structure includes one or more two-dimensional fabric layers, each two-dimensional fabric layer grouping together the yarns of a single layer belonging to at least the first plurality of yarn layers and situated outside the blank portion.

Abstract: A method for cutting a preform usable for production of a turbomachine part and including a weaving of a plurality of threads, the threads including single threads that are visually identifiable, along a cutting contour calculated based on a preform model in which the threads have a reference arrangement, the method including: taking an image of the preform; processing the image to determine a deviation in an arrangement of the threads which are visually identifiable relative to the reference layout; correcting the cutting contour according to the deviation; and cutting the preform along the corrected cutting contour.

Abstract: A method for forming a preform for a hollow turbomachine component is provided. The method includes positioning a sheet made of woven fibers on a base equipped with a longitudinal impression; positioning a mandrel in the longitudinal impression to clamp the sheet between the base and the mandrel, the mandrel having a thickness that increases between a proximal end and a distal end; locking the distal end of the mandrel into position; placing a proximal block resting on the base; forming two flaps of the sheet around the flanks of the mandrel; resting two lateral blocks on the base on either side of the mandrel; locking the lateral blocks into position to form an assembly; drying the assembly to form a preform including a flat base, from which two flaps extend perpendicularly; and adjusting the flaps to the dimensions of the mandrel by trimming excess material.

Abstract: A method designing a part made of 3D woven composite material, performed by a computer, the method including: obtaining shape data representing an outside surface of the part; for each point of a set of points of the outside surface, determining a distance between the point and a projection of the point onto a target surface, the projection being along a predetermined projection direction; determining a structure of a 3D woven preform as a function of the determined distances; and obtaining projection data specifying a projection direction as a function of a position of a point on the outside surface of the part, wherein the projection direction that is used for at least some of the points of the set of points is determined during the determining a distance, as a function of the projection and as a function of the position of the point.

Abstract: A method of making a fiber preform, and the preform, for fabricating a turbine engine blade out of composite material, the method including: making a single-piece fiber blank by three-dimensional weaving with layers of longitudinal yarns interlinked by yarns of layers of transverse yarns; and shaping the fiber blank to obtain a single-piece fiber preform including a portion forming an airfoil preform and at least one portion forming a platform preform. During weaving, yarns of a first group of longitudinal yarns are extracted from the fiber blank beside one of side faces of the blank to form a portion corresponding to a blade platform preform, and yarns of a second group of longitudinal yarns are inserted into the fiber blank with mutual crossing of the yarns of the first group and the yarns of the second group.

Abstract: In a fiber structure woven as a single piece by three-dimensional weaving, first warp yarns interlink layers of weft yarns in a first portion of the fiber structure adjacent to a non-interlinked zone and also weft yarns of a second portion of the fiber structure beyond the non-interlinked zone, and second warp yarns interlink layers of weft yarns of the second portion of the fiber structure adjacent to the non-interlinked zone and also layers of weft yarns of the first portion of the fiber structure beyond the non-interlinked zone, such that the paths of the first and second warp yarns cross in at least one transition zone extending within the fiber structure from the end of the non-interlinked zone, the transition zone extending in the warp direction over a distance greater than the pitch between adjacent warp columns.

Abstract: A reinforcing part of ?-shaped section made out of composite material, and a method of making the part, the method including: making a first set of layers of interlinked yarns by three-dimensional weaving to form a first fiber blank portion to form a base preform; making a second set of layers of interlinked yarns by three-dimensional weaving to form a second fiber blank portion to form a stiffener preform, yarns of the second set being interlinked with yarns of the first set by weaving over a central interlinked strip that flares towards side edges of the first fiber blank portion in a zone corresponding to the step of the base; shaping the two fiber blank portions to obtain a single-piece fiber preform having a portion forming a base preform and a portion forming a stiffener preform; and depositing a resin in the fiber preform to form a matrix.

Abstract: A fiber preform of ?-shaped section, the preform including a base with a first face and an opposite second face, legs extending from the second face, and a fiber structure woven as a single piece by three-dimensional weaving with a plurality of layers of warp or weft yarns linked interlinked by weft or warp yarns in a plurality of layers of weft or warp yarns. In each plane of the preform, the weft or warp yarns of a first group of weft or warp yarns extend continuously through the base between two opposite edges thereof, and weft or warp yarns of a second group of weft or warp yarns extend continuously from an end of one of the legs to an end of the other leg, passing via the base, with the yarns of the first group and the yarns of the second group presenting two mutual crossings.

Abstract: The invention relates to a compaction assembly comprising a shaping mold (24) delimiting an upwardly open housing, capable of receiving a woven preform cut out beforehand (10a), and a vertically moveable compaction tool (128) and forming, with the shaping mold, (24), a compaction assembly for said preform placed beforehand in the housing. The compaction tool (128) includes at least one foot portion (128A). The compaction tool (128) comprises at least three separate compaction blocks (1281-1287). Application to the manufacturing of composite fan blades for a turbomachine.