Stitched Composite Hollow Core Fan Blade

This innovation relates to the development of a stitched composite hollow core fan blade that would be used in the first stage of a commercial or military turbofan jet engine. It is a novel design concept that incorporates the recent advancements made in stitched composites under NASA Contract NAS1-20546 (Technology Verification of Composite Primary Wing Structures for Commercial Transport Aircraft) and further advances the state-of-the-art by employing a unique fabrication method that results in a hollow core part that is lightweight, damage tolerant, and inexpensive to manufacture. A significant improvement in structural efficiency is made possible by two important features: 1) the superior damage tolerance characteristics of stitched composites, and 2) the ability to produce a lightweight hollow core geometry. The combination of these two features enables the design of a revolutionary fan blade structure that is capable of meeting even the most stringent bird¿strike loading requirements. In addition to the structural benefits, by using a proven low¿cost fabrication approach like Resin Transfer Molding (RTM), this blade concept is capable of creating new markets because its fabrication costs will be even lower than those currently realized for solid titanium fan blade components.