Effects of carbon nanotubes’ dispersion on effective mechanical properties of nanocomposites: A finite element study

Abstract

Effects of volume fraction and random dispersion of carbon nanotubes on effective mechanical properties of carbon nanotube-reinforced nanocomposites are studied at continuum level using finite element methods. Utilizing a continuum model of tubes with specific pairing of elastic properties and wall thickness for describing carbon nanotubes, representative volume elements with non-uniform distribution of uniaxial nanotubes within a base matrix are generated. Furthermore, a dispersion quantification technique is employed to quantify nanotubes’ dispersion degree. Finite element simulations are carried out in six independent loading conditions, while applying periodic boundary conditions to the models. Homogenizing the models and using the formulations of linear elasticity, equivalent mechanical properties of the models are computed and the effects of the aforementioned influential parameters as well as the modeling volume size are investigated. The results demonstrate that in volume fractions higher than 5%, the effects of carbon nanotubes’ dispersion become more significant and if increasing the volume fraction leads to bigger agglomerations and subsequently worse dispersion, the effective properties of the composite as a whole will decrease. Moreover, the pre- and post-processing procedures implemented are verified by analyzing previously studied models available in the literature and comparing the corresponding results.