Industrial Multi-scale Modeling of Polymer - CNT Nanocomposites
L. Adam, K. Delaere, J.-S. Gérard, R. Assaker, I. Doghri
e-Xstream engineering, BE
Keywords: nanocomposites, carbon nanotubes, multi-scale, mean-field homogenization, DIGIMAT, electrical conductivity, thermal conductivity, mechanical properties, finite element analysis
Abstract:Mean-field (MF) homogenization describes composite behavior based on average stress/strain tensors on phase and composite level and combines analytical formulae with numerical simulation. In this paper, MF homogenization is applied on polymers reinforced with carbon nanotube. Results are presented and validated by comparison with experimental results and with results from detailed Finite Element models. MF can handle coated inclusions, which is important for nanocomposite modeling because the coating properties can emulate the force between nanoparticles. Also for matrix-particle interaction, the coating can represent a real, new phase, e.g. matrix material with density variations. Two-level homogenization is applied to densely packed clusters of particles and voids. To verify MF predictions, realistic FE models are constructed representing microstructure geometry, including cluster size distribution from image analysis. The MF predicted stiffness, obtained in seconds, are close to the FE predicted stiffness, obtained in hours. In FEA, the coating can represent electron tunneling and percolation, increasing composite conductivity with many orders of magnitude. Results are compared with experimental data from industrial partner.