Authors: R.E. Rudd
Affilation: Lawrence Livermore National Laboratory, United States
Pages: 524 - 527
Keywords: concurrent multiscale simulation, molecular dynamics, finite element modeling, coarse-grained molecular dynamics
The design of nanoscale mechanical systems poses a novel set of challenges for modeling and simulation. The need for an accurate model of the nanoscale components is clear. This can be of the form of an engineering model, such as a finite element model (FEM), suitably parameterized for the nanoscale, alternatively, nanoscale components may be treated in a bottom-up approach in which the material is modeled at the atomic level. We discuss this latter, atomistic type of modeling. The device is not completely isolated from its environment, however. It is typically bound to a substrate and may interact with fluid surroundings. The relative importance of these interfaces scales like the surface area to volume ratio and becomes more important as the system size is reduced. For system design, it is important to model both the nanoscale components of the device and their surroundings, a problem that is inherently multiscale, and one in which the scales interact strongly. Concurrent multiscale simulation provides a solution to this problem. An atomistic methodology is coupled to a more coarse-grained model, such as FEM, in a single simulation. This provides precision where it is needed, while retaining the efficiency needed to simulate the entire system.