Pull-Out Testing of SWCNTs Simulated by Molecular Dynamics

Steffen Hartmann,Bernhard Wunderle,O Hölck

doi:10.11159/ijtan.2012.009

Abstract

In this paper we present our results of simulating a pull-out test of single walled carbon nanotubes (SWCNT) out of a single crystal gold lattice by means of molecular dynamics. We compare the obtained force-displacement data of the pullout test to results of simulated uniaxial tensile strain tests of SWCNTs. In doing so, we make a theoretical estimation about the quality of the clamping of SWCNTs in a gold crystal. We investigated the influence of chirality of SWCNTs and of the system temperature. Dependent on SWCNT chirality two different pull-out behaviours can be described. Zigzag nanotubes show stronger pull-out resistance than chiral or armchair nanotubes. Our results indicate a minor influence of embedding length of the SWCNT in the gold matrix on pull-out forces. The system temperature has only little effect on the maximum pull-out forces. The presented results have impact on design criteria of SWCNT-metal interfaces.

Highlights

Since their discovery CNTs (Iijima, 1991) attracted many scientists and engineers
In this paper we present our results of simulating a pull-out test of single walled carbon nanotubes (SWCNT) out of a single crystal gold lattice by means of molecular dynamics
In this work we present our results on atomistic simulations of a pull-out test of a SWCNT embedded in a single crystal gold matrix by means of molecular dynamics

Summary

Introduction

Since their discovery CNTs (Iijima, 1991) attracted many scientists and engineers. Advantageous mechanical and physical properties like modulus of elasticity, tunability of band gap and piezoresistive gauge factor make them favourable to be adopted in several applications or to create even novel ones. Atomistic simulations of a CNT which is embedded in an organic matrix and been exposed to a pull-out loading have been performed by Chandra et al (2004) and in a step these results have been used to feed a continuum cohesive zone model and showed the effect of interface strength on the modulus of elasticity of the composite. Xia and Curtin (2004) investigated friction inside of multi walled CNTs with the result that pullout forces depend strongly on defects in CNTs. To our knowledge there are no further studies on the pull-out behaviour of CNTs embedded in a metal matrix, which would be required especially for reliability estimations of acceleration sensors (Hierold et al, 2007).

Simulation Setups

Results and Discussion

Conclusion