Insert for forming an end connection in a uni-axial composite material
View Patent ↗An insert for forming an end connection in a uni-axial composite material, and an end connection comprising at least one insert, is disclosed. The insert comprises a sleeve which comprises a plurality of fibers having a multi-axial arrangement. At least a portion of the interior surface of the sleeve comprises a thread formation. A method of forming an end connection in a uni-axial composite material is also disclosed. The method comprises providing a sleeve comprising a plurality of fibers having a multi-axial arrangement and providing a thread formation on at least a portion of the interior surface of the sleeve. The sleeve is positioned and secured within the uni-axial composite material.
1. An end connection comprising:
a uni-axial composite material; and
at least one insert for forming an end connection in the uni-axial composite material, the at least one insert comprising a sleeve, wherein the sleeve comprises a plurality of fibres having a multi-axial arrangement, wherein at least a portion of the interior surface of the sleeve comprises a thread formation, the at least one insert being embedded within the uni-axial composite material.
2. The end connection according to claim 1 wherein the sleeve comprises at least one layer of multi-axial fibre fabric.
3. The end connection according to claim 2 wherein the sleeve comprises a plurality of layers of multi-axial fibre fabric.
4. The end connection according to claim 2 wherein the sleeve further comprises at least one helically wound fibre layer.
5. The end connection according to claim 4 wherein the sleeve comprises a plurality of helically wound fibre layers.
6. The end connection according to claim 4 wherein the or each helically wound fibre layer overlies a layer of multi-axial fibre fabric.
7. The end connection according to claim 6 wherein the fibres of the or each helically wound fibre layer are substantially aligned with a path defined by crests of the thread formation.
8. The end connection according to claim 1 wherein the sleeve comprises a fibre reinforced plastic.
9. The end connection according to claim 8 wherein the sleeve comprises a filament wound fibre composite tube.
10. The end connection according to claim 9 wherein the winding angle of 90% of the fibres is substantially equal to ±θ, where θ is the thread angle of the thread formation.
11. The end connection according to claim 1 wherein the fibres are embedded within a cured resin matrix.
12. The end connection according to claim 1 wherein the thread formation is integrally formed with the sleeve.
13. The end connection according to claim 12 , wherein the thread formation is a cut thread formation.
14. The end connection according to claim 1 further comprising a helical thread insert located within the thread formation.
15. A wind turbine blade comprising
a plurality of inserts embedded within a root of the wind turbine blade, each insert comprising a sleeve, wherein the sleeve comprises a plurality of fibres having a multi-axial arrangement, wherein at least a portion of the interior surface of the sleeve comprises a thread formation.
16. The blade according to claim 15 , further comprising a helical thread insert located within the thread formation and remains in situ during operation.
17. The blade according to claim 15 , wherein the sleeve comprises at least one layer of multi-axial fibre fabric.
18. The blade according to claim 17 , wherein the sleeve comprises a plurality of layers of multi-axial fibre fabric.
19. The blade according to claim 17 , wherein the sleeve further comprises at least one helically wound fibre layer.
20. The blade according to claim 19 , wherein the sleeve comprises a plurality of helically wound fibre layers.
21. The blade according to claim 19 , wherein the or each helically wound fibre layer overlies a layer of multi-axial fibre fabric.
22. The blade according to claim 21 , wherein the fibres of the or each helically wound fibre layer are substantially aligned with a path defined by crests of the thread formation.
23. The blade according to claim 15 , wherein the sleeve comprises a fibre reinforced plastic.
24. The blade according to claim 23 , wherein the sleeve comprises a filament wound fibre composite tube.
25. The blade according to claim 24 , wherein the winding angle of 90% of the fibres is substantially equal to ±θ, where θ is the thread angle of the thread formation.
26. The blade according to claim 15 , wherein the fibres are embedded within a cured resin matrix.
27. The blade according to claim 15 , wherein the thread formation is integrally formed with the sleeve.
28. The blade according to claim 27 , wherein the thread formation is a cut thread formation.