About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
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Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
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Presentation Title |
Atomic-scale Examination of the Film Rupture Model for Fatigue Crack Growth |
Author(s) |
Mingjie Zhao, Derek H Warner |
On-Site Speaker (Planned) |
Mingjie Zhao |
Abstract Scope |
The rate of fatigue crack growth in environment can be accelerated by orders of magnitude compared to that in vacuum. However, the fundamental understanding of the crack growth mechanism is lacking, which is largely due to the complexity of coexisting mechanisms. Thanks to the progression of computational resources and a new implementation of a concurrent multiscale method, we have been able to isolate and study the effect of surface film on fatigue crack growth in a ductile material under mode I loading. We find that the crack grows via film rupture mechanism, which requires film thickness and brittleness. Surface film swelling is needed to produce experimentally observed R-effect on ΔK threshold. In order to achieve sustained fatigue crack growth, a critical Kmax is necessary to overcome the compressive stress ahead of the crack tip at the bottom of the loading cycle due to film swelling. |
Proceedings Inclusion? |
Planned: |
Keywords |
Modeling and Simulation, Environmental Effects, Computational Materials Science & Engineering |