Turbine engines contain disks that rotate at a high-speed and store a significant amount of rotational kinetic energy. In the event of a disk failure, this stored kinetic energy is released, and the result can be catastrophic. In order to ensure optimal reliability, durability, and quality, these disks must undergo rigorous engineering and testing processes. Residual stress is a key characteristic that influences the behavior of engine disks during manufacturing (distortion) and operation (distortion and fatigue). Pre-spin is a mature process that is routinely applied during the machining stage of engine disk manufacturing. The pre-spin process involves rotating (spinning) disk forgings to a specified speed to yield the material. This helps to condition and stabilize the material for subsequent machining and operation (e.g., tip clearance control). The driving mechanism for this manufacturing efficiency improvement is a change in the underlying residual stress in the material (as the material yields during pre-spin the residual stress state is normalized); however, this relationship is not well understood. More importantly, the residual stress state, which is a key result of the pre-spin process, is not currently monitored, controlled, or documented during manufacturing. This leads to uncertainty in the residual stress state, which is managed through conservative assumptions (e.g., assuming the residual stress magnitude is larger than it likely is). This drives uncertainty in overall engine design. This program is aimed at providing a high quality, low risk solution for quality management and Digital Engineering of turbine engine disk pre-spin (a key manufacturing process) by providing a validated, turn-key, solution for residual stress measurement and pre-spin process monitoring to support current and future USAF missions. This program will contribute to Digital Engineering for the USAF Propulsion Enterprise. Most importantly, this program will reduce production (machining) and sustainment (life extension) costs for aircraft engines.
