Wind turbine blade comprising metal filaments and carbon fibres and a method of manufacturing thereof
Wind turbine blade has a longitudinal direction and includes a shell structure made of a fiber-reinforced polymer material including a polymer matrix and reinforcement material comprising a plurality of carbon fiber layers embedded in the polymer matrix. At least a portion of the shell structure is formed of a laminate 6 comprising at least one metal filament layer 15, 18 comprising metal filaments and being sandwiched between two carbon fiber layers 16, 16; 17, 18 comprising carbon fibers only. The carbon fiber layers are arranged contiguously with the metal filament layer.
1. A wind turbine blade having a longitudinal direction and including a shell structure made of a fibre-reinforced polymer material including a polymer matrix and reinforcement material comprising a plurality of carbon fibre layers embedded in the polymer matrix characterised in that at least a portion of the shell structure is formed of a laminate comprising:
at least one metal filament layer comprising metal filaments, a first side, and a second opposite side; and
a plurality of carbon fibre layers, each carbon fibre layer comprising carbon fibres only and the carbon fibre layers being arranged on top of each other,
wherein the carbon fibre layers abutting the metal filament layer are positioned on the first side of the metal filament layer and on the opposite second side of the metal filament layer.
2. The blade according to claim 1 , wherein the metal filament layer is a reinforcement layer.
3. The blade according to claim 1 , wherein the metal filaments are arranged substantially unidirectional.
4. The blade according to claim 1 , wherein the metal filaments are arranged substantially in the longitudinal direction of the wind turbine blade.
5. The blade according to claim 1 , wherein the carbon fibres constitute at least 70%, 75%, 80%, 85%, or 90% by volume of the reinforcement material of the laminate.
6. The blade according to claim 1 , wherein the laminate comprises two or more mutually interspaced metal filament layers.
7. The blade according to claim 1 , wherein the at least one metal filament layer comprises metal filaments only.
8. The blade according to claim 1 , wherein the at least one metal filament layer comprises both metal filaments and non-metal fibres.
9. The blade according to claim 1 , wherein the metal filament layer comprises at least one metal filament mat.
10. The blade according to claim 9 , wherein the metal filaments of the metal filament mat are arranged in bundles.
11. The blade according to claim 10 , wherein the metal filaments of the metal filament mat are arranged in bundles, comprising at least three filaments.
12. The blade according to claim 11 , wherein the metal filaments of the metal filament mat are arranged in bundles, comprising at least 7, 12, 24 or 36 filaments.
13. The blade according to claim 1 , wherein at least 50%, 60%, 70%, 80%, 90% or 100% of the metal filaments are arranged substantially parallel to each other.
14. The blade according to claim 1 , wherein the portion of the shell structure formed by the laminate is a longitudinally extending reinforcement section comprising a plurality of non-metal fibre layers.
15. The blade according to claim 1 , wherein 50%, 60%, 70%, 80%, 90% or 100% of the metal filaments of the laminate are arranged substantially in the longitudinal direction of the blade.
16. A method of manufacturing a shell structure part of a wind turbine blade, the shell structure part being made of a fibre-reinforced polymer material including a polymer matrix and a fibre-reinforcement material comprising a plurality of carbon fibre layer embedded in the polymer matrix, the method comprising the steps of:
A providing a first mould part having a longitudinal direction and comprising a first forming surface with a contour defining at least a portion of an outer surface of the shell structure part;
B arranging the fibre-reinforcement material in the first mould part so that at least in a longitudinal portion thereof at least one metal filament layer comprising metal filaments is sandwiched between carbon fibre layers comprising only carbon fibres, the carbon fibre layers abutting the metal filament layer;
C providing a second mould part and sealing the second mould part to the first mould part so as to provide a mould cavity between the first and the second mould part;
D providing resin in the mould cavity simultaneously with step B, and/or subsequently to step C; and
E curing or allowing the resin to cure in order to form the shell structure part.
17. The method according to claim 16 , wherein the at least one metal filament layer comprises only metal filaments, the metal filament preferably being arranged in a metal filament mat.
18. The method of claim 16 , further comprising evacuating the mould cavity after step C and before step D.