Title: Multiscale Modeling of the Effects of Nanoscale Load Transfer on the Effective Elastic Properties of Unfunctionalized Carbon Nanotube-Polyethylene Nanocomposites
Yumeng Li,
Dept. of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, (0203) Blacksburg, VA 24061, USA
Gary Don Seidel,
Dept. of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, 228 Randolph Hall (0203) Blacksburg, VA 24061, USA
Modelling and Simulation in Materials Science and Engineering -- 2014 -- Vol 22 pg 25023
Abstract
A multiscale model is proposed to study the macroscale bulk elastic material properties under the
influence of interfacial load transfer at the nanoscale in carbon nanotube(CNT)-polyethylene(PE)
nanocomposites. Molecular dynamic(MD) simulations are performed to characterize the nanoscale
load transfer through the identification of representative nanoscale interface elements which are
studied parametrically in terms of the length of the polymer chains, the number of the polymer
chains and the ”grip” position. Once appropriate scales of these parameters are deemed to yield
suciently converged results, the representative interface elements are subjected to normal and
sliding mode simulations in order to obtain the force-separation responses at 100K and 300K for
unfunctionalized CNT-polyethylene interfaces. Cohesive zone traction-displacement laws are
developed based on the force-separation responses obtained from the MD simulations and are
used in continuum level models to determine the influence of the interface on the eective elastic
material properties of the nanocomposites using analytic and computational micromechanics approaches.
It is found that the inclusion of the nanoscale interface in place of the perfectly bonded
interface results in eective elastic properties which are dependent on the applied strain and temperature
in accordance with the interface sensitivity to those eects, and which are significantly
diminished from those obtained under the perfect interface assumption.
Key words: Multiscale modeling, carbon nanotube nanocomposites, interface, molecular dynamic
simulation, cohesive zone, composite cylinder model, finite element analysis