Fatigue Damage Quantification and Life Prediction in Ultra High Cycle Regime
Abstract
Fatigue Damage Quantification and Life Prediction in Ultra High Cycle Regime Interest in ultrasonic fatigue is driven in part by the recent increase in fatigue life requirement for many aerospace components and urgent need to predict lifetimes in aging structures. The fatigue limit or cyclic stress intensity threshold of a material for low stress amplitude cannot be extrapolated from higher stress amplitude experimental data. Time and cost constraints also hinder the use conventional fatigue testing in this range. In complex heterogeneous material systems the microstructural, material and geometric variability at multiple length scales introduces further complexities and increased scatter in fatigue characteristics. To fully characterize the variability in fatigue behavior of materials, it is necessary to develop test procedures which will allow accurate assessment of the fatigue damage and residual life under complex low amplitude stress loading conditions. The proposed system (Shimadzu USF-2000) is well suited to characterize fatigue lives in excess of 1010 cycles under a range of loading conditions (e.g., fully reversed fatigue, superimposed static and cyclic load spectrums, three or four point bending, performed with either axial or torsional ultrasonic excitation). Integration of the ultrasonic fatigue data with advanced material characterization techniques will allow extensive investigations into the relationship between microstructural variability and fatigue life in a wide range of material systems such as complex composites, nanocomposites, aluminum alloys and Nickel-based super alloys, which are relevant to DoD applications. A novel experimental platform will be established to characterize the interaction of nanomaterials with structural composites in a well-controlled manner, leading to a better understanding of their use in fatigue critical applications. The results will directly contribute to the 2013 ONR funded research, “Multiscale Modeling Approach to Predict the Behavior of Nanocomposite Structures. The research outputs will provide a fundamental step forward in understanding and estimating the useful life of many DoD assets.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 08, 2016
- Source ID
- N000141512865
Entities
People
- Aditi Chattopadhyay
Organizations
- Arizona State University
- Office of Naval Research
- United States Navy