Design of an Optimal Overlap Algorithm for Dynamically Coupling Continuum and Noncontinuum Codes in Multiscale Simulation

Different simulation methods are most effective at different length scales, which motivate efforts to simulate overall multi-scale systems by linking multiple simulation codes created by experts at each scale. There are numerous examples where length and time scales are coupled in a serial fashion, where the results from a simulation code are used in another simulation code [1-7]. For example, it is common to use quantum mechanics to compute force fields that are used in a molecular dynamics code. For quasi-static problems, the quasicontinuum method [8,9] couples the atomistic and continuum scales by using a system-wide finite element mesh that is refined to the atomic dimensions where needed. Unlike conventional finite elements, the energy of each cell is computed from the underlying atomistic Hamiltonian. Many other papers propose iterative algorithms to converge codes at multiple length scales to a steady-state or quasi-steady-state solution [10-13].