Sarah-Jane V. Frankland*, a, Attila Caglarb, Donald W. Brennera, Michael Griebelb
aDepartment of Materials Science and Engineering, North Carolina State University,
Raleigh, NC 27695-7907 USA bUniversity of Bonn, Department of Applied Mathematics, Division of Scientific Computing and Numerical Simulation Bonn, Germany
Carbon nanotubes have been proposed as fibers to mechanically reinforce polymers. The load transfer mechanism between the polymer and nanotube has been investigated with classical simulation methods in model polyethylene matrices. From molecular dynamics simulation we have estimated that the shear strength of carbon nanotubes in polyethylene is very weak yielding critical lengths (>mm) much longer than is normally physically reasonable for carbon nanotubes. Shear strengths in epoxy matrices are estimated relative to polyethylene. To allow a more direct examination of the mechanical properties, very large-scale simulations of these composite materials (> 1 million atoms) will be reported where the modeled carbon nanotubes approach an experimentally comparable size. These simulations implement a parallel version of the Brenner potential capable of achieving O(N) complexity with good scaling behavior of up to 512 processors at parallel efficiency of 99% on a CRAY-T3E. A new technique is used to apply tensile stress which varies box shape and size. In addition other reinforcement mechanisms will be considered including the effect of bending the nanotube in the polymer and chemically functionalizing the polymer to the nanotube.
Sarah-Jane V. Frankland
Department of Materials Science and Engineering, North Carolina State University
Campus Box 7907
Raleigh, NC 27695-7907 USA