About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
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Symposium
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Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
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Presentation Title |
Origin of Long-range Internal Stress with Heterogeneous Dislocation Distributions |
Author(s) |
Yejun Gu, Jaafar El-Awady |
On-Site Speaker (Planned) |
Yejun Gu |
Abstract Scope |
We present a new theory based on three-dimensional discrete dislocation dynamics simulations for the sources of long-range internal stresses (LRIS) associated with heterogeneous dislocation distributions in metals, to develop an understanding of material fatigue. Earlier works (e.g. Mughrabi, Physica Status Solidi (a)104.1, 1987) attribute the LRIS to geometrically necessary dislocations (GNDs) at the interface between “hard” regions having high dislocation density and “soft” regions having low dislocation densities. However, the current theory shows that the ratio between the vacancy loop concentration and interstitial loop concentration predominantly determines the LRIS. When the “hard” region mainly consists of vacancy loops, it is in tension, while the “soft” region is in compression. The opposite is also true. This theory has been successfully applied to the cases of PSBs and dislocation cell structures. |
Proceedings Inclusion? |
Planned: |
Keywords |
Mechanical Properties, Computational Materials Science & Engineering, Modeling and Simulation |