Effect of Interface on the Elastic Modulus of CNT Nanocomposites

The paper presents an approach to determine the elastic properties of carbon nanotube (CNT)-reinforced composites, using the principles from molecular mechanics, molecular dynamics, and the finite-element method. Molecular dynamics (MD) simulation is used to determine the elastic properties of matrix, interface energy, and the interfacial gap due to nonbonded van der Waals forces between the matrix and CNT. The value of the interface energy and interfacial gap is used to determine the stiffness of interface between CNT and epoxy. A 3D-RVE (three-dimensional representative volume element) consisting of epoxy matrix, a single-walled carbon nanotube (SWCNT) (8,8), and the interface between them is generated. Finite-element modeling is used to calculate the Young's modulus of the nanocomposites. Parametric studies are carried out to observe the effects of different interface stiffness (soft and hard interface) and thickness for the cases of long (fully embedded) and short CNTs on the Young's modulus of nanocomposites. (C) 2016 American Society of Civil Engineers.