About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
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Advanced Characterization Techniques for Quantifying and Modeling Deformation
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Presentation Title |
Reconstructing Dislocation Avalanches via High-frequency Surface Displacement Measurements |
Author(s) |
Junjie Yang, Daniel Magagnosc, Tamer Zaki, Jaafar El-Awady |
On-Site Speaker (Planned) |
Junjie Yang |
Abstract Scope |
Crystal plasticity is governed by intermittent strain bursts induced by dislocation avalanches. Existing in-situ defects characterization techniques (e.g., X-ray diffraction) are limited by their temporal and spatial resolutions and thus cannot quantify the transient behaviors during dislocation avalanches. Here we develop a framework to reconstruct dislocation avalanches at a high temporal/spatial resolution. The framework is based on an ensemble-based variational algorithm. Surrogate high-frequency in-situ surface displacement measurements (acoustic measurements or laser interferometry) from each ensemble are first obtained by three-dimensional discrete dislocation elastodynamic simulations. The dislocation slip localizations over time are then reconstructed by varying the ensemble representations. Our results show that the reconstruction accuracy is dependent on the displacement acquisition rate. We further show that physical regularization of the slip localization can alleviate the strict requirements on acquisition rates and achieve higher spatial-temporal resolutions in reconstructions. |
Proceedings Inclusion? |
Planned: |
Keywords |
Characterization, Modeling and Simulation, Other |