Abstract: A method of fabricating a gas turbine casing out of composite material of varying thickness, the method including making a strip-shaped fiber texture by three-dimensional weaving; winding the fiber texture as a plurality of superposed layers onto a mandrel of profile corresponding to the profile of the casing that is to be fabricated, so as to obtain a fiber preform of shape corresponding to the shape of the casing that is to be fabricated; and densifying the fiber preform with a matrix; wherein, before beginning to wind the fiber texture onto the mandrel, a reinforcing band of width smaller than the width of the fiber texture is placed on the mandrel in a zone that is to form a retention zone of the casing.

Abstract: A fibrous structure having the form of a band extending in a longitudinal direction (X) over a given length between a proximal part and a distal part and in a lateral direction (Y) over a given width between a first side edge and a second side edge, the fibrous structure having a three-dimensional or multilayer weave between a plurality of layers of warp yarns or strands extending longitudinally and a plurality of layers of weft yarns or strands extending laterally, wherein a first portion of the fibrous structure present between the proximal part and an intermediate part of the fibrous structure includes carbon fiber weft yarns or strands and wherein a second portion of the fibrous structure present between the intermediate part and the distal part includes glass fiber weft yarns or strands.

Abstract: A fibrous structure having the form of a band extending in a longitudinal direction (X) over a given length between a proximal part and a distal part and in a lateral direction (Y) over a given width between a first side edge and a second side edge, the fibrous structure having a three-dimensional or multilayer weave between a plurality of layers of warp yarns or strands extending longitudinally and a plurality of layers of weft yarns or strands extending laterally, wherein a first portion of the fibrous structure present between the proximal part and an intermediate part of the fibrous structure includes carbon fiber weft yarns or strands and wherein a second portion of the fibrous structure present between the intermediate part and the distal part includes glass fiber weft yarns or strands.

Abstract: A method of fabricating a gas turbine casing out of composite material of varying thickness, the method including making a strip-shaped fiber texture by three-dimensional weaving; winding the fiber texture as a plurality of superposed layers onto a mandrel of profile corresponding to the profile of the casing that is to be fabricated, so as to obtain a fiber preform of shape corresponding to the shape of the casing that is to be fabricated; and densifying the fiber preform with a matrix; wherein, before beginning to wind the fiber texture onto the mandrel, a reinforcing band of width smaller than the width of the fiber texture is placed on the mandrel in a zone that is to form a retention zone of the casing.

Abstract: A fiber preform for a hollow turbine engine vane, the preform including a main fiber structure obtained by three-dimensional weaving and including at least one main part, wherein the main part extends from a first link strip, includes a first main longitudinal portion forming a pressure side wall of an airfoil, an U-turn bend portion forming a leading edge or a trailing edge of the airfoil, a second main longitudinal portion facing the first main longitudinal portion and forming a suction side wall of the airfoil, and terminating at a second link strip. The first and second link strips are secured to each other and form a link portion of the main fiber structure. The main longitudinal portions are spaced apart so as to form a gap between the main longitudinal portions forming a hollow in the airfoil.

Abstract: A turbine or compressor stage for a turbine engine is provided. The stage includes a disk including a metal material configured to be coupled to a shaft of the turbine engine, an airfoil including a ceramic matrix composite material, and an interface part that is distinct from the airfoil and that is configured to be fastened to the disk and to fasten the airfoil. The interface part includes a ceramic or a ceramic matrix composite material.

Abstract: A turbine engine blade made of composite material including fiber reinforcement obtained by three dimensionally weaving yarns and densified with a matrix, the blade including an airfoil and a blade root forming a single part. The blade root includes two opposite lateral flanks that are substantially plane and that are clamped between two independent pads made of composite material, which pads are fastened against the lateral flanks of the blade root to form a blade root that is bulb-shaped.

Abstract: A turbine wheel in a turbine engine is provided. The wheel includes a disk having a plurality of blades with roots that are axially engaged and radially retained in longitudinal slots in the outer periphery of the disk, the blades having platforms that extend circumferentially end to end and that are radially facing longitudinal teeth of the disk that define the slots. Protection members for protecting the flanks of the slots and made out of sheet metal are mounted on the teeth of the disk and held thereon by co-operating shapes, the protection members bear radially against the platforms of the blades in order to oppose circumferential tilting of the blades, and at least partially close the radial gaps between the teeth and the platforms of the blades.

Abstract: A fiber preform for a hollow turbine engine vane, and a method of fabricating such a hollow vane are provided. The preform includes a first fiber structure including a main longitudinal portion for forming a pressure side wall of an airfoil; a second fiber structure including a main longitudinal portion for forming a suction side wall of the airfoil; each of the first and second fiber structures includes a first interlinking zone extending along the front edge of its main longitudinal portion, which first zones are integral with each other and form a first interlinking portion, and a second interlinking zone extending along the rear edge of its main longitudinal portion, the second zones being integral with each other and forming a second interlinking portion. The main longitudinal portions of the first and second fiber structures are dissociated so as to leave a gap between the main longitudinal portions forming an airfoil hollow.

Abstract: A fiber preform for a hollow turbine engine vane, the preform including a main fiber structure obtained by three-dimensional weaving and including at least one main part, wherein the main part extends from a first link strip, includes a first main longitudinal portion forming a pressure side wall of an airfoil, an U-turn bend portion forming a leading edge or a trailing edge of the airfoil, a second main longitudinal portion facing the first main longitudinal portion and forming a suction side wall of the airfoil, and terminating at a second link strip. The first and second link strips are secured to each other and form a link portion of the main fiber structure. The main longitudinal portions are spaced apart so as to form a gap between the main longitudinal portions forming a hollow in the airfoil.

Abstract: A turbine engine turbine blade of ceramic matrix composite. The root of the blade includes a single densified fiber preform including at least one recess made by machining, each point of the root of the blade being situated at a distance from a free surface of the root that is no greater than twice the maximum penetration distance into the preform of densification gas for densifying the preform, and the distal portion of the root of the blade includes a distal wall that is continuous and in a single piece.

Abstract: A turbine engine blade made of composite material including fiber reinforcement obtained by three dimensionally weaving yarns and densified with a matrix, the blade including an airfoil and a blade root forming a single part. The blade root includes two opposite lateral flanks that are substantially plane and that are clamped between two independent pads made of composite material, which pads are fastened against the lateral flanks of the blade root to form a blade root that is bulb-shaped.

Abstract: A turbine or compressor stage suitable for being included in airplane turbojets. According to the invention, the stage comprises a disk (30) configured to be coupled to a shaft of the turbine engine, and at least one airfoil (20), the disk (30) comprising a metal material, the airfoil (20) comprising a ceramic matrix composite material, and the stage further including an interface part (40) that is distinct from the airfoil (20) and that is configured to be fastened to the disk (30) and to fasten said at least one airfoil (20), said interface part (40) comprising a ceramic or a ceramic matrix composite material.

Abstract: The invention relates to a turbine wheel in a turbine engine, the wheel comprising a disk having a plurality of blades with roots that are axially engaged and radially retained in longitudinal slots in the outer periphery of the disk, the blades having platforms that extend circumferentially end to end and that are radially facing longitudinal teeth of the disk that define the slots. Protection members for protecting the flanks of the slots and made out of sheet metal are mounted on the teeth of the disk and held thereon by co-operating shapes, the protection members including means for bearing radially against the platforms of the blades in order to oppose circumferential tilting of the blades, and they also include means for at least partially closing the radial gaps between the teeth and the platforms of the blades.

Abstract: A blade made of composite material including an airfoil formed of filaments or fibers, optionally woven, impregnated with a heat-curable resin, with an intrados wall and an extrados wall between the leading edge and the trailing edge; and a device for damping the vibrations incorporated in one or other of the intrados and extrados walls is disclosed. The damping device is formed of at least one layer made of viscoelastic material and a layer made of rigid material, these layers being superposed. The layer made of rigid material includes a first zone and a second zone. The layer made of viscoelastic material is interposed between the airfoil and the first zone of the rigid layer, and the second zone of the rigid layer is attached to the wall of the airfoil without interposition of viscoelastic material.

Abstract: A turbine engine turbine blade of ceramic matrix composite. The root of the blade includes a single densified fiber preform including at least one recess made by machining, each point of the root of the blade being situated at a distance from a free surface of the root that is no greater than twice the maximum penetration distance into the preform of densification gas for densifying the preform, and the distal portion of the root of the blade includes a distal wall that is continuous and in a single piece.

Abstract: A rotor disk for a fan in a turbomachine is disclosed. The disk includes in its perimeter a plurality of essentially axial grooves for the installation and retention of vane roots having hooks at their downstream ends, and deformable regions formed by cavities being situated at the downstream end of the grooves in attachment flanges for inter-vane platforms to absorb the stresses between the disk and the vane roots.

Abstract: A rotor wheel of a turbine engine includes a plurality of CMC blades each having a first portion constituting a blade airfoil and root and made as a single piece with a second portion forming an outer platform. The blades are held under twisting prestress by mutual engagement via contact zones between the outer platforms of adjacent blades, and the contact zones that are situated on opposite sides of the outer platform of a blade are defined by at least one insert that is integrated in the outer platform and that is, for example, made of a carbon-based material.

Abstract: A twin fan turbomachine with two contrarotating fans, one upstream and one downstream, driven by two contrarotating coaxial shafts each of which connects one fan impeller to at least one low-pressure turbine impeller located downstream, the downstream fan impeller being connected by its downstream part to its drive shaft.

Abstract: The present invention relates to a blade made of composite, comprising a vane formed of woven filaments impregnated with a thermosetting resin with a protective element in the region of the leading edge of the vane comprising a part in the form of a rigid strip, said strip being secured to the vane. The blade is characterized in that at least one layer of a viscoelastic material is at least partially interposed between said rigid strip and the vane so as to form, with the protective element, a means of damping the vibrations of the vane.