Wind turbine rotor blade components and methods of making same

A structural element for a wind turbine blade (20) comprising: a preform layer (300A - 300H, 400, 400A - 400H) of a composite beam (127) that is configured to extend along at least a portion of a profile of the wind turbine blade (20), the layer preform (300A - 300H, 400, 400A - 400H) that includes multiple elongated resistance bars (202, 402) that are arranged longitudinally to each other in a single layer, each resistance bar (202, 402) is arranged adjacent and spaced of at least one adjacent resistance bar (202, 402); Each resistance bar (202, 402) includes multiple substantially straight, unidirectional collimated structural fibers (306) that are fixed in a solidified matrix resin (308) so that each resistance bar (202, 402) is rigid and defines a finished geometry that includes a selected length and width and a selected profile; the preform layer (300A - 300H, 400, 400A - 400H) including at least one carrier layer (312, 313) to which the multiple resistance bars (202, 402) are attached by an adhesive (316) that is applies to at least one of the carrier layers (312, 313) and the resistance bars (202, 402); wherein the carrier layer (312, 313) locates adjacent resistance bars (202, 402) to allow flow of liquid glue resin (502) between adjacent resistance bars (202, 402); and, wherein the carrier layer (312, 313) of the preform layer (300A-300H, 400, 400A-400H) includes one or more permeable materials suitable to facilitate permeation and penetration to allow glue resin flow liquid (502) through the carrier layer (312, 313), characterized in that the carrier layer (312, 313) of the preform layer (300A - 300H, 400, 400A - 400H) comprises at least one of a non-material woven and a woven material that has one or more of: substantially unidirectional multiple fibers, multiple strands and multiple rovings (315), which are arranged in a substantially transverse orientation relative to the longitudinal axis of the resistance bars (202, 402).