Multiscale finite element modeling of graphyne-family reinforced polymer nanocomposites: A topology-controlled comparison

This study presents a unified multiscale finite-element framework for the comparative evaluation of γ-graphyne-family-reinforced polymer nanocomposites. Four planar carbon nanofiller topologies—graphyne, graphdiyne, graphyne-3, and graphyne-4—are represented through an atomistically informed structural-mechanics formulation and embedded within a common three-dimensional representative volume element comprising a continuum polymer matrix and a discrete graded interfacial coupling region. Under identical modeling assumptions, the effective elastic response of the four nanocomposite systems is compared systematically. The results reveal a clear topology-dependent hierarchy in the predicted in-plane stiffness: graphyne provides the highest longitudinal, transverse, and shear reinforcement responses, followed by graphdiyne, graphyne-3, and graphyne-4. This monotonic reduction is consistent with the progressive elongation of the acetylenic linkages and the corresponding decrease in planar lattice compactness. The predicted in-plane elastic properties also increase approximately linearly with reinforcement volume fraction over the investigated range, while thickness-related and direction-labelled out-of-plane shear responses exhibit more component-specific trends. Overall, the results identify γ-graphyne-family topology as a primary structural variable governing the predicted in-plane elastic reinforcement efficiency within the adopted common modelling framework. By applying a single FE/RVE framework to all four reinforcement architectures, the study provides a controlled computational basis for topology-sensitive graphyne-family nanocomposite design