Incorporation of a Probabilistic Monotonic Strain Energy Analysis to a Lifting Method
The proposed work analyzes the possibility of improving the capabilities of an energy-based fatigue life prediction method. The improvement being addressed is regarding the variation of empirical monotonic strain energy density calculations and the effects on the energy-based fatigue life prediction capability. Since the prediction method was developed from the concept that the strain energy accumulated during both monotonic failure and an entire fatigue process are equal, meaning the strain energy accumulated during monotonic failure is a physical damage quantity, it was important to understand the variation of monotonic strain energy density. The process for incorporating this variation into the prediction method explores a probabilistic, Three-Sigma analysis that is applicable for all deterministic methods of measuring experimental monotonic strain energy density. The accuracy of the probabilistic energy-based lifing method was admirably assessed by comparison with experimental fatigue life results, between 103 and 105 cycles, conducted on Titanium 6Al–4V specimens at room temperature.
KeywordsFatigue Lifing Strain-energy Three-Sigma
The authors would like to thank the Air Force Research Laboratories (AFRL), specifically the Turbine Engine Fatigue Facility (TEFF) and the Air Force Office of Scientific Research (AFOSR) for their funding and support.
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