A Novel Accelerated Fatigue Testing Method for Rapid Additive Manufacturing Qualification

Abstract This work presents a new accelerated fatigue testing method by comparing the experimental results to standard axial fatigue data from a standard database. Motivation for the accelerated testing method comes from advancements in additive manufacturing (AM) processes that enable the development of new materials for future weight and fuel savings in gas turbine engines. To realize these benefits for gas turbine engines sooner, the complexity of AM process parameters needs to be understood and qualified in a rapid fashion, and fatigue uncertainty needs to be proven. The comparison of the accelerated fatigue testing method and standard axial fatigue testing for aluminum 6061-T6 resulted in three key findings. First, an optical strain calculation method that promotes reduced test setup time is validated. Second, the fatigue life results are statistically comparable and within a 99% prediction interval band of each other. Finally, accelerated fatigue required only 5 h of testing time to generate the data in this work versus 100 days for the axial fatigue data. This means that the accelerated fatigue testing method characterized fatigue life of aluminum approximately 500 times faster than the standard test.