Curved stiffener for a turbine engine nacelle and method for producing such a stiffener

Patent metadata

Field	Value
Publication number	US-12479568-B2
Application number	US-202218552829-A
Country	US
Kind code	B2
Filing date	Apr 8, 2022
Priority date	Apr 12, 2021
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

Curved stiffener for a turbomachine cowl composed of a resin-impregnated fibrous reinforcement, including a stack of a plurality of layers of fibers stacked along the thickness direction and extending on the entire width of the fibrous reinforcement, each layer of fibers having a plurality of fibers parallel to each other extending along a direction inclined relative to the length direction, the fibers of two consecutive layers of fibers along the thickness direction have directions inclined relative to each other, and the layers of fibers are sewn together by sewing threads extending along the length direction, the fibrous reinforcement includes a layer of reinforcing fibers having a plurality of fibers parallel to each other extending along the length direction, the layer of reinforcing fibers extending at least on the central part, over a width smaller than the width of the fibrous reinforcement.

First claim

The invention claimed is:

1 . A curved stiffener for a turbomachine cowl composed of a resin-impregnated fibrous reinforcement,
the stiffener comprising a ring portion shaped head, two ring portion shaped feet concentric with the head and having a radius greater than a radius of the head, and two inclined portions, each connecting one of the feet to a lateral side of the head, the fibrous reinforcement extending along a length direction, a width direction and a thickness direction, the dimension of the fibrous reinforcement along the length direction being greater than the dimension of the fibrous reinforcement along the width direction, and the dimension of the fibrous reinforcement along the thickness direction being the smallest of the dimensions of the fibrous reinforcement, the fibrous reinforcement having a central portion configured to form the head, two end portions disposed on either side of the central portion and configured to form the feet, two connecting portions connecting the central portion to the end portions and configured to form the inclined portions, the fibrous reinforcement comprising a stack of a plurality of layers of fibers stacked along the thickness direction and extending on the entire width of the fibrous reinforcement, each layer of fibers having a plurality of fibers parallel to each other extending along a direction inclined relative to the length direction, the fibers of two consecutive layers of fibers along the thickness direction have directions inclined relative to each other, and the layers of fibers are sewn together by sewing threads extending along the length direction, wherein the fibrous reinforcement comprises a layer of reinforcing fibers sewn with the layers of fibers by the sewing threads having a plurality of fibers parallel to each other extending along the length direction, the layer of reinforcing fibers extending at least on the central part, over a width smaller than the width of the fibrous reinforcement.

2 . The stiffener according to claim 1 wherein the layer of reinforcing fibers extends on part of the connecting portions.

3 . The stiffener according to claim 1 , wherein the layer of reinforcing fibers is disposed on the plurality of layers of fibers at one end of the fibrous reinforcement along the thickness direction.

4 . The stiffener according to claim 1 , comprising at least one additional layer of reinforcing fibers disposed in the stack of the layers of fibers.

5 . The stiffener according to claim 1 , comprising chain stitch seams disposed at the ends of the fibrous reinforcement along the width direction.

6 . The stiffener according to claim 1 , wherein the layers of fibers and the layers of reinforcing fibers are sewn together by knit-type stitches.

7 . The stiffener according to claim 1 , wherein the tension of the sewing threads is lower in the connecting portions than the tension of the sewing threads in the central portion.

8 . The stiffener according to claim 1 , wherein a distribution of sewing stitches in the central portion is denser than a distribution of sewing stitches in the connecting portions.

9 . The stiffener according to claim 1 , wherein the sewing threads sewn on the end portions and the connecting portions have an excess length.

10 . A nacelle comprising a stiffener according to claim 1 .

11 . An aircraft engine comprising a nacelle according to claim 10 .

12 . A method for manufacturing a curved stiffener according to claim 1 comprising:
a sewing step in which the fibrous reinforcement is formed by sewing together the plurality of layers of fibers and the layer(s) of reinforcing fibers,
a draping step in which the fibrous reinforcement is disposed on a stiffener mold,
an impregnation step in which the fibrous reinforcement disposed on the stiffener mold is impregnated with resin,
a polymerization step in which the resin impregnated in the fibrous reinforcement is solidified.

Assignees

• Safran Nacelles

Inventors

• Provost Benjamin
• Lorrillard Julien
• Desjoyeaux Bertrand Léon Marie
• Parant Pierre

Classifications

• B64C2001/0072

  from composite materials · CPC title

• B29C70/30

  Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core · CPC title

• B29C70/24

  oriented in at least three directions forming a three-dimensional [3D] structure · CPC title

• B29D99/0007

  having a variable cross-section · CPC title

• B32B3/18

  characterised by an internal layer formed of separate pieces of material {which are juxtaposed side-by-side (B32B5/02 takes precedence)} · CPC title