About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
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Algorithm Development in Materials Science and Engineering
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Presentation Title |
Phase Field Dislocation Dynamics (PFDD) Modeling of Non-Schmid Effects in BCC Metals |
Author(s) |
Hyojung Kim, Nithin Mathew, Darby J. Luscher, Abigail Hunter |
On-Site Speaker (Planned) |
Hyojung Kim |
Abstract Scope |
Screw dislocations determine the plastic deformation of body-centered cubic (BCC) metals. The critical resolved shear stress (CRSS) of BCC metals deviates from the Schmid law, indicating that the Peierls barrier is dependent on the stress state. We account for non-Schmid behavior in Phase field dislocation dynamics (PFDD), which describes the total energy of dislocation configuration with elastic strain energy, core energy, and external energy, in two ways. One way is to incorporate non-glide stress components in the external energy. However, this method still produces discrepancies when the maximum resolved shear stress plane is the {110} glide plane, indicating that our understanding of how non-Schmid behavior affects overall material response is not complete. Alternatively, we suggest accounting for the non-Schmid behavior in the core energy by variation of molecular statics (MS)-computed stacking fault energy. The CRSS predicted using PFDD and comparison to MS predictions will be discussed. |
Proceedings Inclusion? |
Planned: |