Abstract

Current fatigue life modeling with respect to defects is only dependent on the defect size and the applied cyclic stress for a given material. This research augments the process to include defect location into the model analysis for a more precise prediction of the number of cycles to failure and predict where final failure could occur within a component. The focus is a turbine blade structure using nickel-based superalloy 718 subjected to a pure vibration environment. The augmented model predicts component life using a stress map from the frequency analysis of the developed finite element models (FEMs) and measured or predicted defect sizes and locations. Printed test specimens are evaluated to experimentally validate the capabilities of the augmented model to predict fatigue life and crack initiation regions.