Crack Nucleation Prediction through Surface Roughness Measurement

The "fear of failure" mindset which controls the management, deployment, design and usage of military assets is caused by the lack of understanding of a system's health. DARPA has developed the Prognosis program to study ways for improving state awareness and health prediction in order to address this very issue. One way of accomplishing this is by developing methods to predict fatigue. This study will focus on measuring surface roughness of critical aircraft components and correlating it to fatigue crack nucleation. DXE, LLC. will adapt its state-of-the-art surface profilometry technology for use in aircraft inspections by making it portable and easy to use. Phase I of the study, involves looking at different methods of obtaining surface roughness measurements from existing aircraft. DXE’s profilometer will be used to measure surface roughness both on representative and laboratory samples. These samples will be subjected to accelerated cyclic loading until failure occurs with surface roughness monitored throughout the tests. DXE, LLC. will produce data-driven models based on these measurements for use in developing predictive algorithms in Phase II. The algorithms developed in Phase II will be integrated into the Prognosis system to further enhance its prediction accuracy and reduce inspection intervals.