Evaluating the role of agglomerated carbon nanotubes in the effective properties of polymer nanocomposites: An efficient micromechanics-based finite element framework

Agglomeration of carbon nanotubes (CNTs) refers to their tendency to form clusters, an inevitable phenomenon that markedly influences the performance of composite/nanocomposite materials. Comprehending and managing agglomeration are crucial for tailoring the effective properties of nanocomposites, especially those reinforced with high concentrations of nanofillers. Incorporating this anomaly in numerical simulations can yield significant cost and time savings, while also providing valuable insights into this marvel. This pioneering study explores a promising avenue for a more realistic simulation of CNT-loaded polymer nanocomposites. In the present micromechanics-grounded finite element model, representative volume elements (RVEs) containing CNT agglomerates are ingeniously generated in a three-step stochastic-iterative process. These RVEs are subsequently challenged under commonly encountered engineering scenarios, encompassing elastic, thermoelastic, and viscoelastic aspects. In this case, the precise determination of boundary and loading conditions is accomplished by assessing the constitutive equations associated with each characteristic. Through comparison with available experimental measurements, it has been demonstrated that authoritative prediction of Young's moduli, thermal expansion coefficients, and creep strains necessitates the simulation of building blocks with agglomerated CNTs.