A combined molecular dynamics-finite element multiscale modeling to analyze the mechanical properties of randomly dispersed, chemisorbed carbon nanotubes/polymer nanocomposites

Abstract

A two-stage molecular dynamics (MD)-finite element (FE) modeling method is developed based on the concepts of representative volume element (RVE) and equivalent solid fibers (ESFs) containing functionalized carbon nanotubes (ESFs-fCNTs). First, the influences of nanotubes’ chirality, different percent of functionalization (), various functional atoms, and polymers on the tensile and shear properties of the fCNTs inserted into the polymer matrix (fCNTs/polymer) are discovered using MD simulations. Then, using MD information as input data, the effective Young’s modulus of polymeric unit cell strengthened by ESFs-fCNTs (ESFs-fCNTs/polymer) is explored through FE modeling. The ratio of effective Young’s modulus of the unit cell () to Young’s modulus of the polymeric cube () is reported and all findings () are compared to the ESFs-pure CNTs/polymer results as well. It is found that longitudinal Young’s modulus () of nanofillers/polymer RVEs affects remarkably the of the ESFs-nanofillers/polymer nanocomposites. The decreases by increasing the Generally, the reinforcing impact of zigzag nanotubes compared to armchair ones on the of polymer RVEs is more considerable. Additionally, FE-based results illustrate that as the volume fraction of ESFs () increases, the is enhanced. At a specific the reinforcing effect of the ESFs-armchair and zigzag fCNTs is more in favor of polyethylene nanocomposites than that of the polypropylene systems.