Thick-Wall Oriented-Fiber TMC Shaft Development

Titanium matrix composite LP shafts have large potential benefits. However, the high torque of current engines requires that oriented fiber TMC shafts have a wall thickness greater than normally considered manufacturable. A Phase I program addressed aninnovative approach for (1) integrating shaft design, tool design and shaft processing, (2) manufacturing a nearer to net shape material arrangement and (3) designing with improved TMC performance-prediction and process models. TMC process developmentwas conducted and specimens produced and tested to assess nearer to net shape fabrication. A Phase II follow-on program is proposed to enhance the manufacturing process, scale up hardware and refine modeling techniques. Phase II objectives are: (1)refine the performance and process modeling, (2) fabricate and test TMC specimens to provide statistical data for model correlation, (3) ruggedize the Phase I near net shape manufacturing process and resolve TMC thick wall issues by fabricating and testingthick wall parts and (4) utilizing the near net shape fabrication process, produce and test a TMC thick wall prototypical shaft barrel to demonstrate payoff. Based on the Phase I preliminary performance prediction model, a oriented fiber shaft barreldesign can provide 28% lower weight, 19% higher stiffness and 22% higher frequency.