Abstract: A sandwich panel for an aircraft turbojet nacelle includes an outer skin in contact with an air flow, an inner skin opposed to the outer skin, and an intermediate system comprising partitions connecting the inner and outer skins so as to form cells, the inner skin of at least one cell having at least one corrugation configured to allow the materials making up the sandwich panel to deform in the event of thermal variation.

Abstract: A method for manufacturing a fibrous tubular structure including lobes, in which fibers are draped/deposited on a mandrel having a shape corresponding to that of the fibrous structure, includes draping/deposition carried out such that at least one group of fibers has a same orientation with respect to the axis (A) of said fibrous structure, then, the fibers having been draped over an angular sector less than the total periphery of the mandrel, one of the ends of the fibrous structure is separated from the mandrel in order to allow the continuation of the draping on the same mandrel.

Abstract: The present disclosure relates to a cell structure for an acoustic attenuation device for a nacelle of an aircraft propulsion assembly. This cell structure includes lateral partitions forming channels that each extend between a first end and a second end and skin elements arranged so that each channel is at least partly closed at the first end thereof by at least one skin element. Each skin element is connected to a respective lateral partition and can move relative to the other lateral partitions. A continuous skin can be assembled on this cell structure so as to at least partly close the channels at the second end thereof and to thus form an acoustic attenuation device.

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 sandwich panel for an aircraft turbojet nacelle includes an outer skin in contact with an air flow, an inner skin opposed to the outer skin, and an intermediate system comprising partitions connecting the inner and outer skins so as to form cells, the inner skin of at least one cell having at least one corrugation configured to allow the materials making up the sandwich panel to deform in the event of thermal variation.

Abstract: A part for an aircraft turbojet engine nacelle is made of a composite material and includes at least one outer face (S1), a fibrous preform including fiber locks and having a surface(s) delimiting depressions between fiber locks, a covering material which at least partially covers the surface(s) of the fibrous preform and in particular the depressions, and a matrix which binds entirely the covering material and the fibrous preform. The covering material is a fibrous mat and the outer face (S1) is smooth. A method for manufacturing such a part includes manufacturing the fibrous preform, providing a fibrous mat, depositing the fibrous preform and fibrous mat in a mold, dispersing the matrix between the fibers of the preform and mat and consolidating the fibrous preform and mat.

Abstract: A panel for a nacelle of an aircraft propulsion assembly includes two skins and a cell structure provided with transverse partitions defining cells. The cell structure includes folds with at least one central part forming at least one part of at least one transverse partition and at least one peripheral part extending along at least one of the skins. A nacelle with such a panel is provided, as well as a method for manufacturing such a panel.

Abstract: The present disclosure relates to a cell structure for an acoustic attenuation device for a nacelle of an aircraft propulsion assembly. This cell structure includes lateral partitions forming channels that each extend between a first end and a second end and skin elements arranged so that each channel is at least partly closed at the first end thereof by at least one skin element. Each skin element is connected to a respective lateral partition and can move relative to the other lateral partitions. A continuous skin can be assembled on this cell structure so as to at least partly close the channels at the second end thereof and to thus form an acoustic attenuation device.

Abstract: A method for manufacturing a fibrous tubular structure including lobes, in which fibers are draped/deposited on a mandrel having a shape corresponding to that of the fibrous structure, includes draping/deposition carried out such that at least one group of fibers has a same orientation with respect to the axis (A) of said fibrous structure, then, the fibers having been draped over an angular sector less than the total periphery of the mandrel, one of the ends of the fibrous structure is separated from the mandrel in order to allow the continuation of the draping on the same mandrel.

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 part for an aircraft turbojet engine nacelle is made of a composite material and includes at least one outer face (S1), a fibrous preform including fiber locks and having a surface(s) delimiting depressions between fiber locks, a covering material which at least partially covers the surface(s) of the fibrous preform and in particular the depressions, and a matrix which binds entirely the covering material and the fibrous preform. The covering material is a fibrous mat and the outer face (S1) is smooth. A method for manufacturing such a part includes manufacturing the fibrous preform, providing a fibrous mat, depositing the fibrous preform and fibrous mat in a mold, dispersing the matrix between the fibers of the preform and mat and consolidating the fibrous preform and mat.