Abstract: A tubular structure having lobes is produced as a single piece over at least two lobes. Circumferential fibres of the structure have a constant orientation with respect to the longitudinal axis (A) of the structure in any plane (P) transverse to the longitudinal axis. The structure is obtained by weaving or by filament winding.

Abstract: A method for manufacturing a preform has a non-developable end shape having, about a longitudinal axis (A), an end overall radius of curvature (R2), and, in at least a longitudinal section, curved segments forming bending radii linking straight segments. The method includes a step of depositing successive layers giving the preform an initial substantially rotational shape having, about the longitudinal axis (A), an initial overall radius of curvature, then a step of deploying the preform by increasing the initial overall radius of curvature until the end overall radius of curvature is reached (R2), in order to close the bending radii of the curved segments.

Abstract: A method for manufacturing a preform has a non-developable end shape having, about a longitudinal axis (A), an end overall radius of curvature (R2), and, in at least a longitudinal section, curved segments forming bending radii linking straight segments. The method includes a step of depositing successive layers giving the preform an initial substantially rotational shape having, about the longitudinal axis (A), an initial overall radius of curvature, then a step of deploying the preform by increasing the initial overall radius of curvature until the end overall radius of curvature is reached (R2), in order to close the bending radii of the curved segments.

Abstract: A method for manufacturing a preform has a non-developable end shape having, about a longitudinal axis (A), an end overall radius of curvature (R2), and, in at least a longitudinal section, curved segments forming bending radii linking straight segments. The method includes a step of depositing successive layers giving the preform an initial substantially rotational shape having, about the longitudinal axis (A), an initial overall radius of curvature, then a step of deploying the preform by increasing the initial overall radius of curvature until the end overall radius of curvature is reached (R2), in order to close the bending radii of the curved segments.

Abstract: A tubular structure having lobes is produced as a single piece over at least two lobes. Circumferential fibres of the structure have a constant orientation with respect to the longitudinal axis (A) of the structure in any plane (P) transverse to the longitudinal axis. The structure is obtained by weaving or by filament winding.

Abstract: A method for manufacturing a preform has a non-developable end shape having, about a longitudinal axis (A), an end overall radius of curvature (R2), and, in at least a longitudinal section, curved segments forming bending radii linking straight segments. The method includes a step of depositing successive layers giving the preform an initial substantially rotational shape having, about the longitudinal axis (A), an initial overall radius of curvature, then a step of deploying the preform by increasing the initial overall radius of curvature until the end overall radius of curvature is reached (R2), in order to close the bending radii of the curved segments.

Abstract: The present disclosure relates to a preform that includes layers of textile reinforcements that are arranged in a mold by an automatic placement head and are connected to each other, and which can be dry or pre-impregnated, in order to form a part made of composite materials after curing of an impregnating resin. The part includes a folding produced by conformation of the preform after the placement of the layers of textile reinforcements. At the folding, there are spacings between at least some of the layers of textile reinforcements.