Aircraft structural components
View Patent ↗A structural component such as a wing skin for an aircraft is formed generally of a first composite fiber and matrix material exhibiting a first tensile modulus in respect of tensile stress and a first tolerance of strain resulting from such stress. One or more openings are provided in the component and the material of a portion of the component bounding the opening(s) is a second composite fiber and matrix material. The second material exhibits a second tensile modulus in respect of tensile stress that is smaller than the first tensile modulus of the first material and a second tolerance of strain resulting from such stress that is greater than the first tolerance of strain of the first material.
1. A structural component for an aircraft, said component having at least a locally longitudinally planar feature, the component comprised of a first composite fibre and matrix material exhibiting a first tensile modulus, wherein an opening is provided in the locally longitudinally planar feature of the component and the material of a portion of the component bounding the opening is a second composite fibre and matrix material exhibiting a second tensile modulus, said second tensile modulus is smaller than the first tensile modulus, wherein said first composite fibre and matrix material includes fibres of a first type and the second composite fibre and matrix material includes fibres of a second type, the fibres of the second type having a tensile modulus smaller than the tensile modulus of the fibres of the first type.
2. A structural component according to claim 1 , in which the second composite fibre and matrix material includes both fibres of the first type and fibres of the second type.
3. A structural component according to claim 1 , in which the second composite material includes a plurality of layers of fibres, and fibres of the second type are present in only some of the layers.
4. A structural component according to claim 1 , in which the second composite material includes fibres extending in a plurality of different directions and fibres of the second type all extend in the same direction.
5. A structural component according to claim 4 , in which substantially all the fibres of the first type extend in directions other than the direction in which the fibres of the second type extend.
6. A structural component according to claim 1 , in which the fibres of the first type are carbon fibres.
7. A structural component according to claim 1 , in which the fibres of the second type are glass fibres.
8. A structural component according to claim 1 , in which the second composite fibre and matrix material surrounds the opening.
9. A structural component according to claim 1 , in which the thickness of the portion of the component formed of the second composite fibre and matrix material is substantially the same as the thickness of the neighbouring portion of the component formed of the first composite fibre and matrix material.
10. A structural component according to claim 1 , in which the opening has an area greater than 10 4 mm2 and the second composite fibre and matrix material extends across a width greater than 400 mm.
11. A structural component according to claim 1 , in which the structural component is a lower wing skin and the opening is a manhole.
12. A structural component according to claim 11 , in which the second composite fibre and matrix material extends transversely outwardly from the manhole partway towards edges of the wing skin.
13. A structural component according to claim 11 , in which a plurality of manholes are provided, each bounded by the second composite fibre and matrix material.
14. An aircraft wing structure including a lower wing skin according to claim 11 .
15. An aircraft including a structural component according to claim 1 .
16. A lower lifting surface skin for an aircraft, comprised of:
first and second composite fibre and matrix materials, said materials exhibiting first and second tensile modulae, respectively, said second material tensile modulus is smaller than said first material tensile modulus, wherein said first material includes fibres of a first type and the second material includes fibres of a second type, the fibres of the second type having a tensile modulus smaller than the tensile modulus of the fibres of the first type; and
at least one opening is provided in the lower wing skin and, wherein a portion of the wing skin bounding the opening is said second composite fibre and matrix material.
17. A lower lifting surface skin according to claim 16 , in which the second composite fibre and matrix material includes both fibres of the first type and fibres of the second type.
18. A lower lifting surface skin according to claim 16 , in which the second material includes a plurality of layers of fibres, and fibres of the second type are present in only some of the layers.
19. A lower lifting surface skin according to claim 16 , in which the second material includes fibres extending in a plurality of different directions and fibres of the second type all extend in the same direction.
20. A lower lifting surface skin according to claim 19 , in which substantially all the fibres of the first type extend in directions other than the direction in which the fibres of the second type extend.
21. A lower lifting surface skin according to claim 16 , in which the fibres of the first type are carbon fibres.
22. A lower lifting surface skin according to claim 16 , in which the fibres of the second type are glass fibres.
23. A lower lifting surface skin according to claim 16 , in which the second composite fibre and matrix material surrounds the opening.
24. A lower lifting surface skin according to claim 16 , in which the thickness of the portion of the skin formed of the second composite fibre and matrix material is substantially the same as the thickness of the neighbouring portion of the skin formed of the first composite fibre and matrix material.
25. A lower lifting surface skin according to claim 16 , in which the opening has an area greater than 10 4 mm2 and the second composite fibre and matrix material extends across a width greater than 400 mm.
26. A lower lifting surface skin according to claim 16 , in which the lower lifting surface skin is a wing lower surface skin and said opening is a manhole in the wing lower surface skin.
27. A structural component according to claim 26 , in which the second composite fibre and matrix material extends transversely outwardly from the manhole partway towards edges of the wing lower surface skin.
28. A lower lifting surface skin according to claim 26 , in which a plurality of manholes are provided, each bounded by the second composite fibre and matrix material.