About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
Presentation Title |
Atomic Mechanism of Near Threshold Fatigue Crack Growth in Vacuum as a Basis for Understanding Environmental Effects |
Author(s) |
Derek H. Warner, Mingjie Zhao, Wenjia Gu |
On-Site Speaker (Planned) |
Derek H. Warner |
Abstract Scope |
In many technologically relevant regimes, the process by which cracks grow remains unknown. A prime example is near-threshold fatigue crack growth in vacuum environments, which constitutes the foundation from which environmental effects can be understood. Here, I will report on atomistic simulations to cycle counts far beyond those analyzed previously by harnessing contemporary computational resources and a parallel implementation of the CADD concurrent multiscale approach. Our simulations show that fatigue crack growth arrests after an initial transient period, reconciling the standing discrepancy between model and experiment. We will then examine hypothesized mechanisms for near threshold fatigue crack growth in vacuum. Finding sustained crack growth to only occur when edge dislocations return to the crack tip on a slip plane behind the one on which they were emitted. This process transfers material away from the crack tip, supporting a long-ago hypothesized necessity for near threshold fatigue crack growth in vacuum. |
Proceedings Inclusion? |
Planned: |
Keywords |
Aluminum, Modeling and Simulation, |