| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Structure-Property Relationships in Molecular Crystal Deformation
|
| Presentation Title |
Physical Aspects of Plasticity and Constitutive Modeling of Molecular Crystal HMX |
| Author(s) |
Catalin Picu, Zhaocheng Zhang |
| On-Site Speaker (Planned) |
Catalin Picu |
| Abstract Scope |
While plastic deformation of high symmetry crystals, such as metallic crystals, is well-studied, plasticity in low symmetry molecular crystals received much less attention. We investigate the physical basis of plastic deformation in the energetic molecular crystal HMX. We use atomistic simulations to identify the slip planes and evaluate the critical stresses for dislocation motion and the stress-dislocation velocity relation for various types of dislocations. We observe strong pressure sensitivity and weak temperature sensitivity of both the Peierls stress and dislocation mobility. We also quantify the competition between homogenous plastic deformation and localization. This information is used to calibrate strain rate and pressure-dependent constitutive models for crystal plasticity in this molecular crystal. This allows developing physics-informed continuum models of shock which, in turn, predict the temperature distribution and reaction initiation. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Mechanical Properties, Modeling and Simulation, Other |