US Patent 9745956 Spar cap for a wind turbine rotor blade

A rotor blade of a wind turbine having a pultruded spar cap is disclosed. The rotor blade includes a blade root and a blade tip. The blade root includes at least one root insert. The rotor blade also includes at least one spar cap constructed of a plurality of pultruded members grouped together to form one or more layers from the blade tip towards the blade root. Further, the pultruded members separate into one or more pultruded member bundles as the spar cap approaches the blade root. The pultruded member bundles fit within the root insert, along with the blade bolts, such that compression and tension loads of the rotor blade are transferred through the pultruded members.