Multiscale molecular dynamics-FE modeling of polymeric nanocomposites reinforced with carbon nanotubes and graphene

摘要

A multiscale model to investigate the influence of content and morphology on the elastic properties of composites reinforced with carbonic nanofillers is developed. The modeling consists of two consecutive steps of initial molecular dynamics followed by finite element or micro mechanical modeling. The stiffness matrices of Carbon NanoTubes and Graphene NanoPlatelets are fully characterized through molecular dynamics simulations. The results show that exceeding a certain diameter or number of layers, nearly constant values can be considered for the stiffness parameters of nanofillers. Subsequently, realistic morphology based microstructures inspired from conducted electron microscopy studies on the produced composites are analyzed using the finite element method. The results show that simultaneous application of accurate nanofiller properties and realistic composite morphologies can capture the experimental values effectively. In fact, both simulations and experiments show that a fully curved random configuration of the carbon nanotubes leads to decreased rates of enhancement for higher filler content, which proves that the reduction of enhancement rate is not just a collateral influence of agglomerations in the nanocomposite structures. Comparison of computational and Mori-Tanaka modeling with experimental results has also revealed their potential and limitation in predicting the nano and hybrid composites behaviors.