Materials Science in Radiation and Dynamics Extremes (MST-8)
Mean curvature map of a bulge sample
Dynamic and Quasi-Static Loading Theory Simulation and Modeling Team
- Describes the mechanical constitutive response of materials from an atomistic and crystallographic mechanism perspective. Interfaces micro and meso scale models onto macro-scale models for simulating the mechanical response of metallic, geologic, and ceramic aggregates. Accounts for the role that dislocations, twins, grain boundaries, and cavities, play in the mechanical response.
- Derives and validates material parameters for various advanced constitutive models implemented in FEM hydricodes for large-scale simulations used in Weapon and Defense Programs.
- Develops methods for performing in-situ measurements of 2D and 3D deformation, damaging, and cracking, using Digital Image Correlation (DIC) on high explosive materials and other heterogeneous materials and structures.
- Uses atomic-scale modeling with Molecular Dynamics, Molecular Statics, Density Functional Theory and Monte Carlo techniques to reveal the nucleation, growth, interaction and reaction of defects in crystalline materials that are responsible for materials behaviors and properties.
- Developed several Crystal Plasticity codes with available distribution versions: (1) Visco-Plastic Self-Consistent (VPSC) polycrystal code; (2) Elasto-Plastic Self-Consistent (EPSC) polycrystal code; (3) Elasto-Visco-Plastic local deformation code, based on Fast Fourier Transform (EVP-FFT). These codes are used to develop constitutive laws, simulate plastic forming, simulate creep under neutron irradiation, and to interpret neutron and X-ray diffraction experiments. Applications include Zr, Mg, Be, U, stainless steel, geologic materials.
- Performs both 2D- and 3D-DIC tests at various temperatures, strain rates, and loading configurations.
- Computational facilities include various multi-CPU configurations (Skynet, Coyote, Garnet), providing more than 5600 CPU cores. Complete suites of software developed by our team and commercial software (such as VASP) are available for performing atomistic modeling.
Ricardo Lebensohn, Team Leader, Acting
- John Bingert
- Shuh-Rong Chen
- Daniel Koch
- Cheng Liu
- Stephen Niezgoda
- Carlos Tome
- Jian Wang
Damage/cracking in a PBX 9502 high explosive specimen