Hierarchical petascale simulation framework for stress corrosion cracking

We are developing a scalable parallel and distributed computational framework consisting of methods, algorithms, and integrated software tools for multi-terascle-to-petascale simulations of stress corrosion cracking (SCC) with quantum-level accuracy. We have performed multimillion- to billion-atom molecular dynamics (MD) simulations of deformation, flow, and fracture in amorphous silica with interatomic potentials and forces validated by density functional theory (DFT) calculations. Optimized potentials have been developed to study sulfur embrittlement of nickel with multimillion-to-multibillion atom MD simulations based on DFT and temperature dependent model generalized pseudopotential theory. We have also developed a quasi-continuum method embedded with quantum simulations based on DFT to reach macroscopic length scales and an accelerated molecular dynamics scheme to reach macroscopic time scales in simulations of solid-fluid interfaces that are relevant to SCC. A hybrid MD and mesoscale lattice Boltzmann simulation algorithm is being designed to study fluid flow through cracks. © 2008 IOP Publishing Ltd.