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 method for assembling a structural element for a wind turbine blade comprising the steps of:
providing a composite beam including two or more preform layers, each preform layer including multiple elongate strength rods which are arranged longitudinally relative to one another in a single layer, and wherein each strength rod is positioned 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;
providing, for each preform layer, a carrier layer and joining the multiple elongate strength rods to the carrier layer 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, the fixed distance permitting the flow of liquid bonding resin between adjacent strength rods of a preform layer to its joined carrier layer; and
wherein the carrier layer includes one or more permeable materials suitable to facilitate permeation and penetration to permit flow of liquid bonding resin between stacked preform layers;
stacking each preform layer with one or more other preform layers;
causing liquid bonding resin to flow between adjacent strength rods and through the carrier layer to which the strength rods are joined and to adjacent stacked preform layers; and
solidifying the liquid bonding resin to fix the stacked preform layers to form the structural element.
2. The method of claim 1 , further comprising:
stacking each preform layer with one or more other preform layers;
causing liquid bonding resin to flow between adjacent strength rods and through the carrier layer to which the strength rods are joined and to adjacent stacked preform layers; and
solidifying the liquid bonding resin to fix the stacked preform layers to form the structural element.
3. The method of claim 2 , further comprising the step of stacking one or more layers of at least one of a fibrous woven material and a fibrous nonwoven material with the two or more preform layers.
4. The method of claim 2 , wherein the step of causing liquid bonding resin to flow includes the step of employing liquid resin infusion by one of injection and applying a vacuum.
5. The method of claim 2 , wherein, prior to the step of causing liquid bonding resin to flow, the stacked preform layers are placed in a mold of a turbine blade, further comprising the step of drawing a vacuum along the mold, whereby the liquid bonding resin is caused to flow between adjacent strength rods and through the carrier layer to which the strength rods are joined and to the adjacent strength rods and carrier layers within the mold.