Identifier
etd-1030103-161928
Degree
Doctor of Philosophy (PhD)
Department
Physics and Astronomy
Document Type
Dissertation
Abstract
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 height-height correlation function. The MD simulation finds the first roughness exponent (æ=0.5). Simulations of amorphous nanostructured silica reveal pore nucleation ahead of the crack front, and the crack front meandering around the nanoparticles and merging with those pores.
Date
2003
Document Availability at the Time of Submission
Release the entire work immediately for access worldwide.
Recommended Citation
Rountree, Cindy Lynn, "Massively parallel molecular dynamics simulations of crack-front dynamics and morphology in amorphous nanostructured silica" (2003). LSU Doctoral Dissertations. 3893.
https://repository.lsu.edu/gradschool_dissertations/3893
Committee Chair
Rajiv K Kalia
DOI
10.31390/gradschool_dissertations.3893