About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
|
Presentation Title |
Atomic Mechanism of Near Threshold Fatigue Crack Growth in Vacuum |
Author(s) |
Mingjie Zhao, Wenjia Gu, Derek H. Warner |
On-Site Speaker (Planned) |
Mingjie Zhao |
Abstract Scope |
Structural failures resulting from prolonged low-amplitude loading are particularly problematic. Over the past century a succession of mechanisms have been hypothesized, as experimental validation has remained out of reach. Thanks to the progression of computational resources and a new implementation of a concurrent multiscale method, we have been able to assess the validity of long-hypothesized material separation mechanisms thought to control near-threshold fatigue crack growth in vacuum, and reconcile reports of crack growth in atomistic simulations at loading amplitudes below experimental crack growth thresholds. We find that sustained fatigue crack growth in vacuum requires emitted dislocations to change slip planes prior to their reabsorption into the crack on the opposite side of the loading cycle. This provides a mechanistic foundation to relate fatigue crack growth tendency to fundamental material properties, e.g. stacking fault energies and elastic moduli, opening the door for improved prognosis and design of novel fatigue resistance alloys. |
Proceedings Inclusion? |
Planned: |
Keywords |
Modeling and Simulation, Mechanical Properties, |