9.4 BRIDGE 2: ATOMISTIC SIMULATION TO DISLOCATION DENSITY SIMULATION CONNECTION
Now that the MEAM potential constants were calibrated and validated for the DFT simulations, MEAM MD simulations could then be conducted to study dislocation motion. As shown by Bridge 2 defined in Figure 9.5, the results from the MD simulations were used to provide the drag coefficients for edge and screw dislocations at the next higher length scale. The downscaling requirements for the DD simulations were directly related to these drag coefficients since they affect the dislocation mobility. Figure 9.6 illustrates the downscaling/upscaling bridge between the various length scales for these MD simulations.
Figure 9.5 Schematic of Bridge 2 between the molecular dynamics (MD) scale simulations and associated downscaling requirements and upscaling results to/from the mesoscale dislocation dynamics (DD) simulations.
Figure 9.6 Schematic of atomistic simulations using molecular dynamics (MD) and molecular statics (MS) and the associated upscaling/downscaling with the bridges between the electronic principles simulations using density functional theory (DFT), dislocation dynamics (DD) simulations, and the macroscale internal state variable (ISV) plasticity constitutive model.
The summary of the work ...