A unique process that combines resin transfer molding (RTM) and a collapsible mandrel wasused to create a 3 dimensional hollow airfoil (18 inch cord length) with a monolithic skin / sparstructure made completely of carbon fiber and epoxy. The use of a collapsible silicone mandrelallowed internal features to be created with nearly prepreg fiber and resin consolidation,dimensional conformity and strength without the use of an autoclave or high temperatureprocessing. To close the open airfoil end, RTM carbon fiber and epoxy end caps weremanufactured. These end caps were structurally bonded and riveted in place. Custom titaniuminserts were bonded into the end caps. The resultant carbon fiber components are approximately50% lighter than its metallic counterparts they are slated to replace. The components were testedin shear, bending and as a blade extraction from the parent structure. The components exceededthe design parameters with little failure. The testing program showed the blades were veryrobust and damage tolerant enough for continuous service.
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