US-12623767-B2 - Aircraft structural component and a method of fabricating an aircraft structural component

US12623767B2US 12623767 B2US12623767 B2US 12623767B2US-12623767-B2

Abstract

An aircraft structural component includes a flange having a non-planar side and a web having a first end extending from the non-planar side of the flange and a second end distal from the first end and from the non-planar side of the flange wherein the web has a non-planar shape that deviates from a plane normal to the non-planar side of the flange and extending in a longitudinal direction of the aircraft structural component, so that a deviation of the non-planar shape of the web from the plane increases with distance along the web in a direction from one of the first and second ends to the other of the first and second ends, and so that the deviation extends over at least 10 cm of a length of the aircraft structural component.

Inventors

Stuart BRYANT
Thomas Barnett

Assignees

AIRBUS OPERATIONS LIMITED

Dates

Publication Date: 20260512
Application Date: 20231114
Priority Date: 20221118

Claims (17)

1 . An aircraft structural component, comprising: a flange having a non-planar side; and a web comprising: a first end, which extends from the non-planar side of the flange; a second end, which is distal from the first end and from the non-planar side of the flange; and a non-planar shape that deviates from a plane, which is normal to the non-planar side of the flange and extends in a longitudinal direction of the aircraft structural component; wherein the non-planar shape defines at least one sine wave that has an amplitude and a wavelength; wherein the wavelength is at least 20 centimeters (cm); wherein a deviation of the non-planar shape of the web from the plane increases with distance along the web in a direction from the first end to the second end; and wherein the deviation of the non-planar shape of the web from the plane extends over at least 10 cm of a length of the aircraft structural component.
2 . The aircraft structural component of claim 1 , wherein the non-planar shape of the web deviates from the plane by a constantly increasing amount along the length of the aircraft structural component from a first point along the length of the aircraft structural component to a second point along the length of the aircraft structural component.
3 . The aircraft structural component of claim 1 , wherein the first end of the web and the second end of the web are of equal length.
4 . The aircraft structural component of claim 1 , wherein the non-planar shape of the web deviates from the plane by a constantly increasing amount with distance along the web in a direction from the first end to the second end.
5 . The aircraft structural component of claim 1 , wherein the web is made from a fiber composite material.
6 . The aircraft structural component of claim 1 , wherein the deviation is zero at the first end of the web.
7 . The aircraft structural component of claim 1 , wherein the aircraft structural component is a stringer.
8 . The aircraft structural component of claim 1 , wherein at least one portion of the web is perpendicular to the flange.
9 . The aircraft structural component of claim 8 , wherein at least one of the at least one portion of the web is located at a longitudinal end of the web.
10 . The aircraft structural component of claim 8 , wherein at least one of the at least one portion of the web is located part way along a length of the web.
11 . An aircraft structural assembly, comprising: the aircraft structural component of claim 1 ; and a skin section affixed to the flange of the aircraft structural component.
12 . An aircraft comprising the aircraft structural assembly of claim 11 .
13 . A method of fabricating an aircraft structural component for an aircraft, the method comprising: providing a flange having a non-planar side; and providing a web comprising: a first end, which extends from the non-planar side of the flange; a second end, which is distal from the first end and from the non-planar side of the flange; and a non-planar shape that deviates from a plane, which is normal to the non-planar side of the flange and extends in a longitudinal direction of the aircraft structural component; wherein a deviation of the non-planar shape of the web from the plane increases with distance along the web in a direction from the first end to the second end, a magnitude of the deviation from the plane increasing as a function of distance along a height of the web, from the first end to the second end; wherein the deviation of the non-planar shape of the web from the plane extends over at least 10 cm of a length of the component; wherein the providing the web comprises use of a tool with a non-planar profile to impart the non-planar shape to the web when material to define the web is laid on the tool; wherein the non-planar profile of the tool is such that the material to define the web, when laid on the tool, defines at least one sine wave that has an amplitude and a wavelength; and wherein the wavelength is at least 20 centimeters (cm).
14 . The method of claim 13 , wherein the material to define the web is rectangular.
15 . The method of claim 13 , comprising curing the web when the web is on the tool.
16 . The method of claim 13 , wherein the deviation is chosen according to one or more parameters, the one or more parameters comprising any one or more of: a final length of the aircraft structural component; a required radius of the non-planar side of the flange; a required distance from the first end to the second end of the web; a required configuration of the aircraft structural component in the aircraft; and an intended function of the aircraft structural component in the aircraft.
17 . The method of claim 13 , wherein the aircraft structural component is a stringer.

Description

TECHNICAL FIELD The disclosure herein relates to aircraft structural components, such as stringers, and to methods of fabricating aircraft structural components. BACKGROUND In an aircraft, a curved shape is desirable for aerodynamic and weight saving purposes in some parts such as the wings or the fuselage. These parts normally comprise a skin at the surface. The skin is curved to accommodate or provide the required shape. The curved skin requires structural supports to be attached to it in order to have the structural rigidity suitable to withstand the severe demands of the operating conditions of the aircraft, such as the pressure in the cabin or the lift forces on the wing. The structural supports are thus subject to strict quality requirements. It is desirable to provide aircraft parts with tight curvature. Doing so will reduce the design constrains and permit, for example, aircraft design closely inspired by natural shapes. Such aircraft parts in turn require structural supports with the desired curvature while complying with the property criteria for application in aircraft. SUMMARY A first aspect of the disclosure herein provides an aircraft structural component, comprising: a flange having a non-planar side; and a web having a first end, which extends from the non-planar side of the flange, and a second end, which is distal from the first end and from the non-planar side of the flange; wherein the web has a non-planar shape that deviates from a plane, which is normal to the non-planar side of the flange and extends in a longitudinal direction of the component, so that a deviation of the non-planar shape of the web from the plane increases with distance along the web in a direction from one of the first and second ends to the other of the first and second ends, and so that the deviation extends over at least 10 cm of a length of the component. Introducing the deviation into the web of the component deliberately allows the tailoring of the deviation to the application desired for each individual component. This may improve the mechanical properties of the component, such as the ability of the component to sufficiently support another element, such as an aircraft skin, in use. It may additionally or alternatively better enable the component to have acceptable dimensions or uniformity with other like components. In the absence of such a deliberate and controlled deviation, one or more wrinkles may be formed upon forming of the web from a sheet material and thereafter bending the sheet material to form the component. This is due to the difference in length of the arcs at the inner and outer radii of curvature of the web, which result in excess material that needs to be accommodated. This is especially a problem where components are required to be bent to take their webs considerably out of a flat plane, i.e., have a small radius of curvature at one or other end of the web. Optionally, the non-planar side of the flange is a curved side, or a substantially curved side such as a plurality of flat surfaces arranged to approximate an arc. Optionally, the non-planar side of the flange is a concave side, or a substantially concave side such as a plurality of flat surfaces arranged to approximate a concavity. In such concave arrangements, the deviation of the non-planar shape of the web from the plane increases with distance along the web in a direction from the first end to the second end. Optionally, the non-planar shape of the web deviates from the plane by a constantly increasing amount along the length of the aircraft structural component from a first point along the length of the aircraft structural component to a second point along the length of the aircraft structural component. The deviation may, for example, reach one or plural maximums at respective points along the length of the component. There may, for example, be only a single maximum deviation at an approximately halfway point along the length of the component, so that the web forms a bow-like shape, or plural maximum deviations at two respective points along the length, so that the web forms an S-like shape. The non-constant size of the deviation along the length of the component enables the accommodation of excess material generated by forming the web from a rectangular piece of material while requiring the web to follow the non-planar shape of the flange, without incurring wrinkles in the web. Optionally, the first end of the web and the second end of the web are of equal length. This permits the web to be provided from a rectangular piece of material as a way of simplifying the manufacturing process. This in turn may provide cost benefits and increased flexibility of tooling equipment, as the material is usable easily to form differently shaped final components. Optionally, the non-planar shape of the web deviates from the plane by a constantly increasing amount with distance along the web in the direction from the first end to the second end