Structural mat for reinforcing a wind turbine blade structure, a wind turbine blade and a method for manufacturing a wind turbine blade

Abstract

The invention relates to a structural mat for reinforcing a wind turbine blade structure. The structural mat comprises two or more groups of bonded fibres, the fibres being bonded by a matrix substantially preventing relative movement of said fibres and wherein said groups are connected to each other by connection means limiting the relative movement of said groups. The invention further relates to a wind turbine blade and a method for manufacturing a wind turbine blade.

What is claimed is: 
     
         1 - 18 . (canceled) 
     
     
         19 . A method of manufacturing a wind turbine blade of generally hollow construction and formed from first and second opposing half-shells, the method comprising:
 constructing each half-shell from an inner skin and an outer skin;   locating at least one reinforcing structure on the outer skin so as to extend along the lengthwise direction of the blade, each of the at least one reinforcing structure comprising a stack of layers, each stack having a thickness which extends in a direction substantially perpendicular to a surface of the blade, each layer extending across a width of the respective stack, the width being perpendicular to the lengthwise direction of the blade and perpendicular to the thickness of the stack, and each layer comprising at least one pre-cured pultruded fibrous composite strip;   disposing within each half-shell core material on the outer skin so as to extend: (a) from the at least one elongate reinforcing structure towards a leading edge of the blade; and (b) from the at least one elongate reinforcing structure towards a trailing edge of the blade;   disposing the inner skin on upper surfaces of the at least one elongate reinforcing structure and the core material; and   disposing an elongate web so as to extend between the at least one reinforcing structure in the first half-shell and the at least one reinforcing structure in the second half-shell.   
     
     
         20 . A method of manufacturing a wind turbine blade of generally hollow construction and comprising first and second half-shells, the method comprising:
 disposing, in each of a first and second elongated half-mould, one or more fibre cloths for respective outer skins;   locating, in each of the first and second elongated half-moulds, at least one elongate reinforcing structure on the fibre cloths for the outer skins so as to extend along the lengthwise direction of the respective half-moulds, each of the at least one reinforcing structure comprising a stack of layers, each stack having a thickness which extends in a direction substantially perpendicular to a surface of the respective half-mould, each layer extending across a width of the respective stack, the width being perpendicular to the lengthwise direction of the respective half-mould and perpendicular to the thickness of the stack, and each layer comprising at least one pre-cured pultruded fibrous composite strip;   disposing within each of the respective half-moulds core material on the fiber cloths for the outer skin so as to extend: (a) from the at least one elongate reinforcing structure towards a leading edge of the respective half-mould; and (b) from the at least one elongate reinforcing structure towards a trailing edge of the respective half-mould;   disposing, in each of the first and second elongated half-moulds, on upper surfaces of the at least one reinforcing structure and the core material, one or more fibre cloths for respective inner skins;   supplying resin into the first and second half-moulds; and   subsequently curing the resin so as to form the first and second half-shells.   
     
     
         21 . The method of  claim 20 , further comprising:
 subsequently disposing an elongate web in one of the half-moulds; and   pivoting the first half-mould into a position above the second half-mould, so as for the elongate web to extend between the at least one reinforcing structure in the first half-shell and the at least one reinforcing structure in the second half-shell.   
     
     
         22 . A wind turbine blade of generally hollow construction, comprising:
 first and second opposing half-shells, each half-shell comprising:
 an inner skin; 
 an outer skin; 
 at least one reinforcing structure being located between the inner and outer skins, each of the at least one reinforcing structure extending along a lengthwise direction of the blade and comprising a stack of layers, each stack having a thickness which extends in a direction substantially perpendicular to a surface of the blade, each layer extending across a width of the respective stack, the width being perpendicular to the lengthwise direction of the blade and perpendicular to the thickness of the stack, and each layer comprising at least one pre-cured pultruded fibrous composite strip; and 
 core material disposed between the inner and outer skins and extending: (a) from the at least one reinforcing structure towards a leading edge of the blade; and (b) from the at least one reinforcing structure toward a trailing edge of the blade; and 
   an elongate web extending between the at least one reinforcing structure in the first half-shell and the at least one reinforcing structure in the second-half shell.   
     
     
         23 . The wind turbine blade of  claim 22 , wherein the at least one elongate reinforcing structure and the core material define abutment edges which are substantially perpendicular to the surface of the wind turbine blade. 
     
     
         24 . The wind turbine blade of  claim 22 , wherein the layers are of different lengths such that the thickness of the stack is tapered towards at least one end. 
     
     
         25 . The wind turbine blade of  claim 24 , wherein at least one of the two ends of each layer is chamfered. 
     
     
         26 . The wind turbine blade of  claim 22 , wherein each layer comprises a plurality of pultruded fibrous composite strips 
     
     
         27 . The wind turbine blade of  claim 26 , wherein the plurality of pultruded fibrous composite strips comprises a parallel configuration of strips within the layers. 
     
     
         28 . The wind turbine blade of  claim 27 , wherein the longitudinal inner edges of the strips within each layer of the stack are staggered with respect to the inner longitudinal edges of the strips within the or each adjacent layer. 
     
     
         29 . The wind turbine blade of  claim 28 , wherein the plurality of pultruded fibrous composite strips comprises a plurality of strips arranged end to end. 
     
     
         30 . The wind turbine blade of  claim 22 , wherein the pultruded fibrous composite strips are formed from fibers selected from: natural fibers; metal fibers; mineral fibers; cellulose-based fibers; polymer fibers; glass fibers; aramid fibers; and/or carbon fibers.