Life Prediction Tools with Engineered Residual Stresses

The Air Force has identified a need for the development of predictive design tools that can be used to accurately determine the fatigue life of components containing both applied and engineered residual stresses and determine the optimal location and processing parameters for residual stress introduction. Impact Technologies, in collaboration with Third Wave Systems, and Fracture Analysis Consultants, propose to develop an integrated analysis tool that will achieve this objective. The technical approach is based on integrating design capabilities for 3D modeling for residual stress prediction, 3D computational fracture mechanics, and life prediction calculations. The approach will also take into consideration statistical variants due to modeling accuracy, loading conditions, and material behavior. This integrated approach will allow for the identification of component high stress/life-limiting regions, determination of engineered residual stress process application regions, computation of damage tolerance effects due to different residual stress inducing processes, and the determination of relative cost benefit per flight hour gained due to each processing method considered.