Type
Text
Type
Dissertation
Advisor
Jiao, Xiangmin | Samulyak, Roman V, Glimm, James | Simos, Nikolaos.
Date
2012-08-01
Keywords
brittle material, fracture visualization, mesh fracture, numerical algorithms, numerical simulation, parallelization | Applied mathematics
Department
Department of Applied Mathematics and Statistics
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/71454
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
A new mass conservative mesoscale model for the simulation of fracture of solid materials has been developed. Our representation of solids by spring networks contains two degrees of freedom necessary to match real material properties and exhibits a stable Poisson ratio. The algorithm is based on the energy minimization of the network of triangular springs with critical strain and splitting of overstressed bonds and connected to them nodes ensuring the conservation of mass during the crack evolution. An algorithm to resolve the mesh folding and overlapping for the simulation of compressed materials has been developed by introducing special energy penalty terms. The main emphasis of the research is on the study of brittle fracture but elasto-plastic models for springs have also been developed for the simulation of plastic deformations with limited shear bands. Two regimes of the brittle fracture have been onsidered: adiabatically slow deformation and breakup and instantaneously fast deformation and the formation and propagation of cracks in stressed materials. Parallel software for the fracture of brittle materials under strain has been developed with the integration of packages TAO and Global Arrays. A Schwartz-type overlapping domain decomposition and the corresponding acceleration techniques have also been studied. Three different visualization techniques have been developed to capture details of fractured zones in 3D. The software has been applied to the simulation of fracture of solids under slow stretching deformations, the rapid disintegration of highly tempered glasses in the phenomenon called the Prince Rupert Drop, and the fracture of thin brittle discs hit by high velocity projectiles. The bifurcation of the fracture dynamics from the growth of the comminuted zone to the propagation of isolated radial cracks, typical for the fracture of glass sheets and thin ceramic plates hit by projectiles, has been reproduced in our numerical experiments and scaling studies involving the change of material properties and projectile velocity have been performed. The fracture model has also been used in a coupled multiscale simulation of the nuclear fuel rod failure within a study of nuclear reactor safety issues. | 95 pages
Recommended Citation
Wei, Hongren, "Mesoscale Models and Numerical Algorithms for Fracture of Solids" (2012). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 660.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/660