Enhanced Life Prediction Technology for Engine Rotor Life Extension (ERLE)

Abstract : The Air Force Research Laboratory (AFRL) conceived of the Engine Rotor Life Extension (ERLE) program as a sound science and technology investment that offers the potential for significant cost avoidance. The strategy for meeting this goal is to extend the life of certain life-limiting components, without increasing risk, by systematically improving, and more effectively integrating, a number of life management technologies -- life prediction, nondestructive inspection, engine health monitoring, maintenance, and repair. The current program has developed physics-based, deterministic and probabilistic, fatigue life prediction models that support the objectives of ERLE, as well as the broader goals of Condition Based Maintenance Plus (CBM+). The new models incorporate small crack effects and enable enhanced fracture mechanics analysis of high stress radients associated with residual contact and thermal stresses. The importance of uncertainty in mission usage is highlighted, and a statistical method to automatically identify mission type from usage data is introduced. Probabilistic simulations incorporating input from an embedded sensor model are used to demonstrate the effectiveness of engine health monitoring. Mature technology from the program has been incorporated into the DARWIN probabilistic life prediction code to facilitate technology transfer to AFRL and the turbine engine community.