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 ((Formula presented.)), 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 ((Formula presented.)) to Young’s modulus of the polymeric cube ((Formula presented.)) is reported and all findings ((Formula presented.)) are compared to the ESFs-pure CNTs/polymer results as well. It is found that longitudinal Young’s modulus ((Formula presented.)) of nanofillers/polymer RVEs affects remarkably the (Formula presented.) of the ESFs-nanofillers/polymer nanocomposites. The (Formula presented.) decreases by increasing the (Formula presented.) Generally, the reinforcing impact of zigzag nanotubes compared to armchair ones on the (Formula presented.) of polymer RVEs is more considerable. Additionally, FE-based results illustrate that as the volume fraction of ESFs ((Formula presented.)) increases, the (Formula presented.) is enhanced. At a specific (Formula presented.) the reinforcing effect of the ESFs-armchair and zigzag fCNTs is more in favor of polyethylene nanocomposites than that of the polypropylene systems. © 2022 Taylor & Francis Group, LLC.