Carnegie Mellon University
Civil and Environmental Engineering
aghaei@cmu.edu
Abstract: I will discuss our use of the method of Objective
Structures to understand the non-equilibrium deformation and failure of carbon
nanotubes at imposed strain rates of 104/s - 108/s. Objective Structures
generalizes the notion of crystallinity to important non-crystalline
nanostructures such as carbon nanotubes. This allows the calculation of
properties of these nanostructures through efficient techniques developed for
crystals. Our simulations with different strain rates,temperatures, chirality
and unit cells show that a variety of failure mechanisms are observed, and
most simulations give a strain at failure of 15-20%. A key finding from this
large set of calculations is the possibility of interpretation in the context
of thermoelasticity. Consequently, this can enable a strategy to calculate
continuum thermodynamic properties from molecular dynamics in settings far
from equilibrium.