Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2003

Louisiana State University

LSU Doctoral Dissertations

Simulations

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Parallel Molecular Dynamics Simulations Of Dynamics Of Oxidation And Reactive Wetting In Metal/Ceramic Systems, Gurcan Aral Jan 2003

Parallel Molecular Dynamics Simulations Of Dynamics Of Oxidation And Reactive Wetting In Metal/Ceramic Systems, Gurcan Aral

LSU Doctoral Dissertations

Oxidation of a flat aluminum (111) surface and the reactive wetting of the aluminum (Al) droplet on a flat alumina (α-Al2O3) surface are investigated by using parallel molecular-dynamics simulations with dynamic charge transfer among atoms on a microscopic length scale. The interatomic potential, based on the formalism of Streitz and Mintmire, allows atoms to vary their charges dynamically between anions and cations, when atoms move and their local environment is altered. We investigate the oxidation thickness as a function of time and the oxygen density which is 10-40 times that of the normal state (1 atm …


Massively Parallel Molecular Dynamics Simulations Of Crack-Front Dynamics And Morphology In Amorphous Nanostructured Silica, Cindy Lynn Rountree Jan 2003

Massively Parallel Molecular Dynamics Simulations Of Crack-Front Dynamics And Morphology In Amorphous Nanostructured Silica, Cindy Lynn Rountree

LSU Doctoral Dissertations

Atomistic aspects of dynamic fracture in amorphous and nanostructured silica are herein studied via Molecular dynamics (MD) simulations, ranging from a million to 113 million atom system. The MD simulations were performed on massivelly parallel computers using highly efficient multi-resolution algorithms. Crack propagation in these systems is accompanied by nucleation and growth of nanometer scale cavities up to 20 nm ahead of the crack front. Cavities coalesce and merge with the advancing crack to cause mechanical failure. Recent AFM studies in silica glasses confirm this scenario of fracture [1]. The morphology of the fracture surfaces is studied by calculating the …