MD simulation of carbon nanotube pullout behavior and its use in determining mode I delamination toughness

This study presents a multi scale approach of understanding the influence of multi-walled carbon nanotube (MWNT) on delamination toughness. Molecular dynamic (MD) simulation was used to investigate the influence of diameter and length of a MWNT and the boundary and loading conditions on its pullout behavior from polymer matrix. Numerical results reveal that the MWNT experiences non-uniform stretching and necking prior to the movement of its embedded end and pullout, and the force–displacement curve features with four distinct regions. A quadruple-linear model was proposed via a parametric study and validated by comparing with existing experimental result, and then used as a traction law in deriving the formula for determining the enhancement in mode I delamination toughness due to MWNT presence.