Injection repair of composite fatigue cracks

A wind turbine blade comprising:

• a blade body comprising a pressure side and a suction side joining at a leading edge, and a trailing edge, the blade body longitudinally extending from a root region to a tip region through a transition region extending between the root region and the tip region, and
• the blade body mechanically connected with a rotor hub through a repaired root bushing installed in the root region, the repaired root bushing comprising a multi-layer composite body, the multi-layer composite body comprising a first plurality of fatigue cracks repaired at a first interface between a first layer of the multi-layer composite body and a second layer of the multi-layer composite body;
• a second plurality of fatigue cracks repaired at a second interface between the second layer of the multi-layer composite body and a third layer of the multi-layer composite body,
• wherein the second interface is anchored with the third layer of the multi-layer composite body.

A kit comprising:

• a drill template configured and arranged to go around a multi-layer composite body, the drill template defining drill locations for a plurality of flush holes, weep holes, and fill holes in the multi-layer composite body;
• a quantity of crack-repair fluid suited for repairing cracks in the multi-layer composite body;
• and
• an injector tool configured and arranged to inject the crack-repair fluid through the fill holes.