Wind turbine rotor blade components and methods of making same
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 composite beam for a wind turbine blade comprising:
a plurality of stacked preform layers, each of the plurality of stacked preform layers 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 of the plurality of stacked preform layers also including a carrier layer to which the multiple elongate strength rods are joined to form the preform layer;
wherein the carrier layer spaces adjacent strength rods a fixed distance apart to facilitate the flow of liquid bonding resin between adjacent strength rods of the preform layer to its joined carrier layer, the carrier layer being of a permeable material suitable to facilitate the flow of liquid bonding resin through the carrier layer; and
further comprising one or more layers of at least one of a fibrous woven material or a fibrous non-woven material stacked with the plurality of stacked preform layers.
2. The composite beam of claim 1 , including an absence of material between each strength rod, the absence of material comprising one or more spaces permitting flow of liquid bonding resin between adjacent strength members.
3. The composite beam of claim 1 , wherein the carrier layer includes at least one of: a non-woven material and a woven material.
4. The composite beam of claim 3 , wherein the at least one of non-woven material and a woven material are selected for their wettability and material compatibility with the elongate strength rods.
5. The composite beam of claim 1 , wherein the multiple elongate strength rods are joined to the carrier layer by an adhesive, the adhesive being an adhesive compatible with the liquid bonding resin.
6. The composite beam of claim 1 , wherein each elongate strength rod has a rectangular cross-section and each of the rectangular elongate strength rods includes rounded edges.
7. The composite beam of claim 6 , wherein the rounded edges of the strength rods define an edge radius of curvature.
8. The composite beam of claim 7 , wherein the edge radius is less than an upper limit of ¼ of the thickness of the rectangular strength rods.
9. The composite beam of claim 6 , wherein the rectangular cross sections of each of the strength rods are substantially the same size.
10. The composite beam of claim 1 , wherein the multiple elongate strength rods in the stacked preform layers are stacked in a brick pattern.
11. The composite beam of claim 1 , wherein the multiple elongate strength rods in the stacked preform layers are stacked in a column pattern.
12. The composite beam of claim 1 , wherein the multiple elongate strength rods in the stacked preform layers are stacked in a random pattern.
13. The composite beam of claim 1 , wherein the carrier layer and the one or more layers of fibrous woven or non-woven materials are constructed of the same materials.
14. The composite beam of claim 1 , wherein the carrier layer of the preform layer comprises at least one of a non-woven 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.
15. The composite beam of claim 1 , wherein the composite beam forms one or more of a spar cap, an I-beam, a shear web and other structural blade components of the wind turbine blade.
16. The composite beam of claim 1 , wherein the fibrous material is selected from one or more of: glass fabrics, meshes, fibers, yarns and/or rovings; carbon fabrics, meshes, fibers, yarns and/or rovings; graphite fabrics, meshes, fibers, yarns and/or rovings; basalt fabrics, meshes, fibers, yarns and/or rovings; and ceramic fabrics, meshes, fibers, yarns and/or rovings.
17. The composite beam of claim 1 , wherein the one or more preform layers stacked with the one or more layers of fibrous woven materials or non-woven materials are fixed by solidified liquid bonding resin to define the composite beam.
18. The composite beam of claim 1 , wherein the one or more layers of fibrous woven or non-woven materials are comprised of permeable materials suitable to facilitate permeation and penetration to permit flow of the liquid bonding resin through the one or more layers of fibrous woven or non-woven materials.
19. The composite beam of claim 2 , wherein the spaces between the elongate strength rods, the permeability of materials of the carrier layer and of the one or more fibrous woven or non-woven materials permit the liquid bonding resin to flow through the spaces through the carrier layer and through the fibrous woven or non-woven materials.