Wind turbine rotor blade components and methods of making same
View Patent ↗Structural preform layers of multiple rigid unidirectional strength elements or rods are constructed and arranged for use in fabricating load-bearing support structures and reinforcements of wind turbine blades. Individual preform layers include multiple elongate unidirectional strength elements or rods arranged in a single layer along a longitudinal axis of the preform layer. Each preform layer includes one or more fibrous carrier layers to which the multiple strength elements or rods are joined and arranged in the single layer. Each strength element or rod is longitudinally oriented and adjacent to other elements or rods. Individual strength elements or rods include a mass of substantially straight unidirectional structural fibers embedded within a matrix resin such that the elements or rods have a substantially uniform distribution of fibers and high degree of fiber collimation. The relative straightness of the fibers and fiber collimation provide strength elements or rods and the preform layers with high rigidity and significant compression strength.
1. A structural element for a wind turbine blade comprising:
a composite beam configured to extend along at least a portion of an airfoil of the wind turbine blade;
the composite beam including a preform layer, the preform layer including multiple elongate strength rods arranged longitudinally relative to one another in a single layer, each strength rod being disposed adjacent to and spaced from at least one adjacent strength rod;
each strength rod including multiple unidirectional, substantially straight collimated structural fibers fixed in a solidified matrix resin so that each strength rod is rigid and defines a finished geometry including a selected length and width and a selected profile;
the preform layer including at least one carrier layer to which the multiple strength rods are joined by an adhesive applied to at least one of the carrier layer and the strength rods;
wherein the carrier layer locates adjacent strength rods a fixed distance apart and the fixed distance permits the flow of liquid bonding resin between adjacent strength rods of a preform layer to its joined carrier layer;
wherein the carrier layer of the preform layer includes one or more permeable materials suitable to facilitate permeation and penetration to permit flow of liquid bonding resin through the carrier layer.
2. The structural element of claim 1 , wherein at least one end portion of the perform layer terminates in a tapered end zone, the tapering being at a selected rate of taper.
3. The structural element of claim 1 , including an absence of material between each strength rod, the absence of material permitting flow of liquid bonding resin between adjacent strength members.
4. The structural element of claim 1 , wherein the carrier layer includes at least one of: a nonwoven material and a woven material.
5. The structural element of claim 1 , wherein the at least one of a nonwoven material and a woven material is selected for its wettability and material compatibility.
6. The structural element of claim 1 , wherein an adhesive compatible with the liquid bonding resin joins the carrier layer and the multiple strength rods.
7. The structural element of claim 1 , wherein the adhesive applied to at least one of the carrier layer and the strength rods includes a layer of adhesive to join the strength rods to the carrier layer.
8. The structural element of claim 1 , wherein the carrier layer of the perform layer comprises at least one of a nonwoven material and a woven material having one or more of substantially unidirectional: multiple fibers, multiple yarns and multiple rovings disposed at a substantially transverse orientation relative to the longitudinal axis of the strength rods.
9. The structural element of claim 1 , wherein the structural element comprises one or more of a spar cap, an I-beam, a shear web and other structural blade components of the wind turbine blade.