Spanos P.D., Esteva M., Akin J.E.
Rice University, US
Keywords: carbon nanotubes, distributions, entangled fibers, finite elements, modeling, Monte Carlo, nanocomposites
In this paper the impact of entangled and non-straight fibers in the determination of the effective elastic and thermal properties of polymer nanocomposite (PNC) is addressed. Most of the models in recent studies assume nanotubes to be well dispersed straight fibers with fixed size. Nonetheless experiments reveal that nanotube formation become wavy during the manufacturing process, and that nanotubes come in a variety of diameters and lengths. In the paper an attempt to model the behavior of entangled fibers is made in which the distributions regarding the nanotube length and diameter are incorporated. First, an approach to generate random microstructures is developed. Then, using the finite element (FE) method with embedded fibers, the effective properties are computed for each of the random microstructures. This approach requires only a regular grid for the FE mesh, circumventing the requisite computationally costly and human labor intensive mesh refinement of ordinary FE in order to capture the local morphology of the composite material. Finally, a Monte Carlo simulation approach is used to obtain statistics of the computed effective physical properties. The numerical results are found in good agreement with experimental data reported in the open literature.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2009: Life Sciences, Medicine, Diagnostics, Bio Materials and Composites
Published: May 3, 2009
Pages: 527 - 530
Industry sector: Advanced Materials & Manufacturing
Topic: Composite Materials
ISBN: 978-1-4398-1783-4