Combining FEM and MD to simulate C₆₀/PA-12 nanocomposites

Abstract

Purpose

The purpose of this paper is the computation of the elastic mechanical behaviour of the fullerene C₆₀ reinforced polyamide-12 (PA-12) via a two-stage numerical technique which combines the molecular dynamics (MD) method and the finite element method (FEM).

Design/methodology/approach

At the first stage, the proposed numerical scheme utilizes MD to characterize the pure PA-12 as well as a very small cubic unit cell containing a C₆₀ molecule, centrally positioned and surrounded by PA-12 molecular chains. At the second stage, a classical continuum mechanics (CM) analysis based on the FEM is adopted to approximate the elastic mechanical performance of the nanocomposite with significantly lower C₆₀ mass concentrations. According to the computed elastic properties arisen by the MD simulations, an equivalent solid element with the same size as the unit cell is developed. Then, a CM micromechanical representative volume element (RVE) of the C₆₀ reinforced PA-12 is modelled via FEM. The matrix phase of the RVE is discretized by using solid finite elements which represent the PA-12 mechanical behaviour predicted by MD, while the C₆₀ neighbouring location is meshed with the equivalent solid element.

Findings

Several multiscale simulations are performed to study the effect of the nanofiller mass fraction on the mechanical properties of the C₆₀ reinforced PA-12 composite. Comparisons with other corresponding experimental results are attempted, where possible, to test the performance of the proposed method.

Originality/value

The proposed numerical scheme allows accurate representation of atomistic interfacial effects between C₆₀ and PA-12 and simultaneously offers a significantly lower computational cost compared with the MD-only method.

Citation

Giannopoulos, G.I., Georgantzinos, S.K., Tsiamaki, A. and Anifantis, N. (2019), "Combining FEM and MD to simulate C₆₀/PA-12 nanocomposites", International Journal of Structural Integrity, Vol. 10 No. 3, pp. 380-392. https://doi.org/10.1108/IJSI-10-2018-0071