A wind turbine blade includes a plurality of layered sections coupled together end-to-end. Each section includes a side wall that forms a tubular structure and includes at least one bore. When the sections are coupled together, the bores generally align to form a conduit. A strengthening element extends through the conduit and is configured to reinforce the blade under load during use of the wind turbine. A wind turbine includes a tower, a nacelle, and a rotor including a hub and at least one wind turbine blade including a plurality of layered sections extending from the hub. A method of forming a wind turbine blade through an additive manufacturing process is also disclosed.

Compositions and methods for forming epoxy resin systems are provided. In one embodiment, a composition is provided for an epoxy resin system including a liquid epoxy resin component including a liquid epoxy resin and an acrylate monomer, a curing agent component including a compound having an imidazole group and, optionally, a co-curing agent for the compound having an imidazole group comprising a phenolic monomer compound, a branched chain carboxylic acid, and combinations thereof, and a non-aromatic polyol compound. The composition may be used to form composites, such as used in commercial wind turbine blade manufacturing.

A composite beam for a wind turbine blade includes 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 has a rectangular cross section and includes multiple, substantially straight collimated structural fibers fixed in a solidified matrix resin. The preform layer includes at least one carrier layer to which the multiple strength rods are joined by an adhesive. 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.

A rotor blade assembly for a wind turbine includes a pressure side and a suction side extending between a leading edge and a trailing edge. A generally cylindrical blade root section has a flush root end configured to attach the rotor blade assembly to a hub. A plurality of span-wise extending root inserts are disposed around and molded into the cylindrical blade root section, with each root insert having an end face and defining an internally threaded bore configured for receipt of a bolt member for attaching the rotor blade assembly to the hub. A metallic flange is disposed at an end of one of the root inserts. The metallic flange is flush with the end faces of adjacent root inserts such that the metallic flange and end faces of the root inserts lie in a common flush plane of the root end.

The present disclosure is directed to methods for manufacturing wind turbine rotor blades and components thereof. In one embodiment, the method includes forming an outer surface of a rotor blade panel from one or more fiber-reinforced outer skins. The method also includes printing and depositing at least one reinforcement structure onto an inner surface of the one or more fiber-reinforced outer skins to form the rotor blade panel, wherein the reinforcement structure bonds to the one or more fiber-reinforced outer skins as the reinforcement structure is being deposited.

The present disclosure is directed to a method for forming a wind turbine rotor blade. The method includes placing first and second prefabricated skin panels defining a portion of a root section of the wind turbine rotor blade, a pressure side of the wind turbine rotor blade, or a suction side of the wind turbine rotor blade in a mold. The first and second prefabricated skin panels partially overlap to define a connection region. A vacuum bag is placed over the mold. The connection region is infused with a resin.

The invention relates to structural adhesive compositions and more particularly to two-component (2K) structural adhesive compositions. The two components chemically react to bond structural surfaces. N-(3-Aminopropyl)cyclohexylamine (APCHA) has been found to be an improved curing agent for use with epoxy resins in 2K adhesive compositions. APHCA exhibits favorable features including viscosity, pot life and reactivity, and adhesive and thermal performance after curing with epoxy resin. These features and its unique chemistry allow the use of APCHA in curing agent formulations for structural adhesives, in particular wind turbine blade adhesives. APCHA solves issues with viscosity build-up, working time, through-cure, compatibility and adhesive performance that cannot be addressed with the commonly used amine formulations.

A composite beam for a wind turbine blade includes 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 has a rectangular cross section and includes multiple, substantially straight collimated structural fibers fixed in a solidified matrix resin. The preform layer includes at least one carrier layer to which the multiple strength rods are joined by an adhesive. 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.

A method for manufacturing a preform building element used for building a rotor blade of a wind turbine is provided. A plurality of components is arranged at least partly overlappingly in a component stack on a surface of a carrier, wherein the component stack includes a plurality of sections with overlapping components between which a binding agent is arranged, wherein the sections of the stack include at least partly a different thickness and/or different types of components, wherein the component stack is heated using a heating source for activating the binding agent, wherein during the heating, at least one heat input reduction is used to reduce the heat input in the binding agent in at least one of the sections of the component stack for reducing binding agent migration during the activation.

A method for manufacturing a wind turbine blade, comprising the steps of: arranging (S2, S3) a joining portion (8) comprising a fibre lay-up inside adjacent blade sections, covering (S4) the joining portion (8) and the adjacent blade sections at least partially with a vacuum bag, and applying vacuum to a space (54) covered by the vacuum bag (19, 38), infusing at least the fibre lay-up (12, 13, 14, 15, 16, 17) with a resin (43) and curing (S5) the resin (43) to obtain a cured joining portion (44) joining the blade sections (20, 24) inside. A light-weight and at the same time strong blade section joint is provided. In particular, the strength of this laminate joint formed by vacuum infusion is comparable to the strength of the pristine laminate. Compared to a connection using an adhesive, the laminate joint formed by vacuum infusion provides a lighter and stronger blade section joint, in particular, a better weight-to-strength performance.