About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Material Responses Investigated Through Novel In-Situ Experiments and Modeling
|
| Presentation Title |
Plastic Strain Localization at Twin Boundaries in Nickel Under Cyclic Loading: A Three-Dimensional Discrete Dislocation Dynamics Study |
| Author(s) |
Xiangchen Zhu, Junjie Yang, Satish Rao, Jean-Charles Stinville, Marat Latypov, Jaafar El-Awady |
| On-Site Speaker (Planned) |
Xiangchen Zhu |
| Abstract Scope |
Under cyclic loading, twin boundaries in polycrystalline materials often exhibit early-cycle plastic strain localization, which precedes the initiation of fatigue cracks. Theoretical models suggest that this localization arises from the accumulation of dislocations near twin boundaries. In this study, we use three-dimensional discrete dislocation dynamics (3D DDD) simulations to investigate the mechanisms of strain localization in Ni during early loading cycles. Our model resolves dislocations in adjacent twin-related grains and includes dissociation into partial dislocations at the twin boundary. An experimentally informed, inhomogeneous stress field, extracted from finite element simulations of real specimen geometry, is applied directly to the DDD simulations. Our results capture the experimentally observed strain localization patterns and reveal the mechanisms leading to dislocation accumulation near twin boundaries, providing direct, mechanistic support for dislocation-based models of fatigue crack initiation. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Modeling and Simulation, |